GroupDIY

Project Specific Discussions => Preamplifiers => Topic started by: madriaanse on May 31, 2007, 12:33:26 PM

Title: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on May 31, 2007, 12:33:26 PM
Here are some build progress pics of my 8ch mic pre:

https://s3.amazonaws.com/Neeb/1frontpanel.jpg
https://s3.amazonaws.com/Neeb/1frontpanelzoom.jpg
https://s3.amazonaws.com/Neeb/2inside.jpg
https://s3.amazonaws.com/Neeb/3ez1290.jpg
https://s3.amazonaws.com/Neeb/4backpanel.jpg

It is finished! :-) All channels have been tested, biased and are working as they should individually. I used Carnhill VTB9045 and VTB9049 for I/O. The PCB's you're seeing are the EZ1290 pcb's that feature two pre stages, a driver stage, rotary switch, and all the other decoupling caps, resistors to make a proper 1290/1073 mic preamp.

This project has been a TON of work and in hindsight I probably would have built two 4ch, 2U units. Either way it has given me a lot of respect for the people who build consoles and modules.

Sorry for the grainy pics  ;D

M.

----------------
EDIT:

I wanted to consolidate all the build info for these preamps here, see below:

------
------
IMPORTANT!
For the latest revision - V2.6 - download the latest BOM and assembly instructions here:
https://s3.amazonaws.com/EZ1290/1290BOM26.xls
https://s3.amazonaws.com/EZ1290/assembly6.pdf

For version 2.5 and older use the following BOM:
https://s3.amazonaws.com/EZ1290/1290BOM25.xls

PCB's can be purchased here (most economical and easiest if you order less than 4):
http://www.diyrecordingequipment.com/products/ez1290-preamp-pcb

Gerber file:
https://s3.amazonaws.com/EZ1290/EZ1290V26.zip

Design spec for PCB house:
Board size: 6.5 x 3.75" (165.1 x 95.3mm)
Material: FR4
Min hole size: .3mm
Gold fingers: No
Finished copper: 1oz
Board thickness: 1.6mm (.062")
Solder Mask: Green
Surface finish: HASL with lead
Layers: 2 layers
Min track/spacing: 6/6mil
Silkscreen: White
Via process: Tenting vias

------
------

Front Panel Design for 2U, 2ch (uses Circuit Specialists ET2/35B):
http://s3.amazonaws.com/EZ1290/circuit_specialists_2u_panel.fpd

Front Panel Design for 2U, 4ch (uses Circuit Specialists ET2/35B):
http://s3.amazonaws.com/EZ1290/circuit_specialists_2u_panel4.fpd

Front Panel Design for 3U, 8ch (uses Par Metal 3U case 14-19163x):
http://s3.amazonaws.com/EZ1290/par_metal_3u_panel8.fpd

To open .fpd files, you need Front Panel Designer. Free download from: http://www.frontpanelexpress.com/

----------------
FAQ:
---
How did you get the rear panel drilled?

I laid it out with a ruler and center punch, pre-drilled with 3/8" drill and then punched with a 15/16" Greenlee punch. 15/16 is perfect for Neutrik XLR's. Then put the connector in the hole (use a carpenter's square to align the connectors straight on the case) and mark the small 4-40 flat screw holes. Drill those with a 1/8" drill.
---
Can I use some other transformers besides the Carnhills?

Yes, original St. Ives or Marinair 10468 and LO1166 would be a good start. Other than that it's Carnhill or bust in my humble opinion.
---
BC184C is now obsolete. What should I do?

You should be able to find them on eBay if you're really wanting to use BC184. Another option is to use MPSA18. One important detail about using MPSA18 in place of BC184C is that MPSA18 will need to be mounted backwards (rotated 180 degrees on its vertical axis) on the PCB. Other than that it is a great substitute: http://www.digikey.com/product-detail/en/MPSA18RLRMG/MPSA18RLRMGOSCT-ND
---
Can I use BC184L instead of BC184C?

Don't use the L's. The pinouts are different.
---
How much does it cost to build one channel, complete with case and power supply?

Count on about $200-$300 per channel, not exactly free, but a good deal nonetheless. ☺
---
At higher gain settings, all I get is a very high pitched noise, or screeching, audio drop out??

Ah, the sound of oscillation. This is usually caused by:
not using shielded wire throughout
running mic input wires too close to line output wires (especially unshielded)
having the 10468 (VTB9045) too close to LO1166 (VTB9049)
malfunctioning 2N3055

Also check the resistor values around the gain switch.
---
Is it ok if I use unshielded hook up wire for audio connections such as transformer to XLR, transformer to PCB etc?

In a word, NO! :-) Just use some mic cable (in the BOM) - it has a shield.
---
What cable should I use for the 4pin XLR cable (PSU case to Rack case)?

I recommend some 3 (or 4) conductor 18AWG, stranded, with shield (use the shield to connect both cases together). Most electronics stores will carry this type of cable as it's commonly used for alarm installation. Home improvement stores might also carry it. I have not been able to find it in small quantities online (less than 1000' spools).
---
What type of standoffs (mounting pillars) should be used to mount the EZ1290 boards?

Any nonconductive (nylon) standoffs will work. Don't use metal (conductive)
---
I'm getting 50/ 60Hz hum?

Try moving the power transformer away from audio, preferably outside the rack case.
---
Can I fit it all in a 1U?

Yes, but you have to use the narrow board output transformer: VTB1148 available from: http://www.audiomaintenance.com/ you may also have to mount some of the larger capacitors flat, and bend the fins on the 2N3055 heatsink down a bit.
---
Do I "HAVE TO" bias this preamp? I don't have a scope and/or signal generator.

I would highly recommend getting a scope and generator, but in a pinch you can adjust the 5k trimpot on the EZ1290 board until TR3 collector (the casing of 2N3055) measures 22.66 volts to ground.
---
How do I add Polarity/PAD/DI to this preamp?

I think this is probably the easiest way: http://www.jlmaudio.com/JLMDI.htm
---
I'm having some problems.

Here's a random list of things to check:
check transistor voltages
check resistor values and capacitor orientations.
Reheat all solder joints (including on the transformers, XLR's). 
Did you solder in the jumper (labeled jumper on PCB).
Is 2N3055 bolted to the PCB using conductive (metal) standoffs?
How's the PSU voltage?
Meticulously check the wiring on the input/output transformers.
Are you using shielded cable for audio connections?
---
Any other hints?

Be careful with mains voltages! (120V-220V) It can really hurt (or kill) you! Don't touch anything on the PSU while it is plugged into the wall

Be sure to adjust the PSU for correct voltage **BEFORE** you connect to the EZ1290

Also, be sure to follow the assembly guide, BOM and this FAQ very precisely; read them a few times before you start. Those that have usually end up with a properly functioning, amazing sounding mic pre. ☺

Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: amorris on May 31, 2007, 12:41:28 PM
Words cannot describe my jealousy/ admiration !

sweet!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Ptownkid on May 31, 2007, 01:29:40 PM
:shock:  :shock:  :shock:  :shock:
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: bitman on May 31, 2007, 05:14:46 PM
Not Worthy...

H-H-How do they sound?

 :cry:
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Holger on May 31, 2007, 06:19:27 PM
wonderful build, outstanding documentation...respect :grin:
Title: ...
Post by: shabtek on May 31, 2007, 10:01:28 PM
pronografic



very

very nice build
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Svart on May 31, 2007, 10:24:09 PM
:shock:  :shock:  :shock:  :green:  :green:  very good looking!

where did you get the PCBs?
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: capnspoony on May 31, 2007, 11:51:23 PM
Id love to see the documentation but when I download it its only giving me the transformer diagrams... page two I believe over and over again.  Could you email me at capnspoony (at) gmail (dot) com?  Thanks!

looks terrific! I'm about to embark on a set of four myself.

best

Richie
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: SonsOfThunder on June 01, 2007, 12:31:24 AM
WOw!  Verrry sexy!  Professional implementation all the way!  Congrats!

Charlie
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: asm on June 01, 2007, 01:06:41 AM
that is an AWESOME writeup/pdf. nice job!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: martthie_08 on June 01, 2007, 07:08:14 AM
fantastic job, amazing craftsmanship! :thumb:

I am finishing off an eight channel preamp myself, not a Neve though... will post pictures soon.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Infernal_Death on June 01, 2007, 07:44:29 AM
Wow, very nice build. Looks pretty neat and i guess it was a difficult task to squeeze so much preamp into one case.
Don't want to be an smartass but if you think about it, it's not a 8 channel 1073. It's more like a 1290 since the 1073 is a preamp and eq.

Flo
Title: 1290
Post by: electrochronic on June 02, 2007, 02:36:32 PM
Killer Job !!!!

Like those Knobs. That box must have cost a small fortune in transformers.

great 8 channel preamp, very pro look.


Also, Where is the link to the EZ1290 PCB Layout , can some one post it here ?
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 02, 2007, 05:31:14 PM
Hey thanks for the kind words everyone!! This project's been a long time comin' but all the work, sweat, tears and $$$ are finally paying dividends. The pres sound FANTASTIC!! I absolutely love them on pretty much everything. I blind pick them over my other mic pres 9/10 times and would have no problem tracking an entire album with just these.

I designed the EZ1290 PCB myself;  please email me if you're interested: 1290preamp [at] gmail.com.

Infernal; you're absolutely right about it not being a 1O73, and more like a 129O without a trim fader. But..... I stopped worrying about proper naming the moment Neve issued the 1O73DPA/DPD.  :)

As for the trim fader; I deliberately left it out because I don't have a need for one.

All the best,

Martin
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ioaudio on June 02, 2007, 06:10:05 PM
fantastic drum recording box - stunning work!  congrats  :guinness:  :guinness:  :guinness:
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: SonsOfThunder on June 03, 2007, 12:47:10 AM
Martin,

How about just emailing those files to the GroupDIY gmail account?

Thanks!
Charlie
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 04, 2007, 11:47:09 AM
Hi Charlie,

See first post :)

All the best,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Infernal_Death on June 04, 2007, 12:09:38 PM
Quote from: "madriaanse"

Infernal; you're absolutely right about it not being a 1O73, and more like a 129O without a trim fader. But..... :green: ..... I stopped worrying about proper naming the moment Neve issued the 1O73DPA/DPD.

Martin


Haha yeah you are right. Well you gotta admit 1073 just sounds cooler than 1290  :razz:
Anyway, as i already said, it's very nice build !  :thumb:

Flo
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 08, 2007, 08:01:59 PM
Also, I'm currently revising this PCB so that you don't have to cut any pins on the rotary switch just to make life a little easier. I've ordered 8 test PCB's, but the manufacturing company is jacking around with their pricing and wants to charge me $10 extra per PCB to drill 9 little holes - pfff. We'll see how it goes; I may take my business elsewhere.

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: bluezplaya on June 27, 2007, 03:28:35 PM
:shock:

I would be interested in a couple of boards.

Adam
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: craigmorris74 on June 27, 2007, 05:40:32 PM
ooh, Sta-Level!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 27, 2007, 06:34:30 PM
Hi Adam,

Thanks for your interest in this project! The PCB's are $25 ea. pls email me at 1290preamp [at] gmail.com for shipping details etc.

All the best,

Martin

PS I was able to work out the pricing problem with the manufacturer, and the new V2.0 boards (no need to cut pins on PCB-mount rotary) are scheduled to be here on friday. I am going to be testing them for a while to make sure they're 100% accurate like the V1.0's were.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mhartung on June 27, 2007, 07:00:32 PM
Nice work!

How did you do the white writing on the front panel? Silkscreen??

thanks

Mike
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 28, 2007, 12:39:20 PM
I've had some problems with my email account (spam filter set too aggressively), and just found out a bunch of people's emails never got to me. If you emailed me re: PCB's and I haven't responded, please email me again. Sorry :oops:

The panel is CNC engraved/machined with white in-filling.

All the best,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: cjs2k on June 30, 2007, 01:22:24 AM
Hey Martin, I have a question regarding the phantom power. Your diagram has 6k81 resistors and the schematic has 6k8, can I use 6k8s? Is this configuration usable in any type circuit (312)? Thanks.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 02, 2007, 12:30:45 PM
Hello cjs2k,

The precise value of these resistors is not that important (within reason). What IS important is that they are matched in value as closely as possible. So if you need only four 6K8 resistors, I'd order 20 and use an ohm meter to pick two pairs that have nearly identical values.

This wiring is used for virtually all phantom powering, but some setups need what's called "ramped 48v" - a slow increase in voltage up to 48V when it's turned on. This involves adding a few caps and resistors. 1272/1290/1073 preamps don't require this; see Geoff Tanner's response here: http://www.auroraaudio.net/dcforum/DCForumID1/454.html

Take care,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: cjs2k on July 02, 2007, 06:02:00 PM
Great info, Thanks alot!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 11, 2007, 09:02:08 PM
More V2.0 boards arrived and tested out great! I have a few extras to sell; pls send an email to: 1290preamp [at] gmail.com if you're interested.

Take care,
 
M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: conleycd on August 31, 2007, 02:14:30 PM
If people are looking at doing this project (1 or 2 channels) a simple and cheap way to do the power supply would be to order a JLM Zener splitter and their 48 volt power supply.  It would be under $50 US - well I guess you need shipping on top which is usually pretty cheap from JLM.  That way you could actually have the power supply inside and just have an external 48 volt adapter.

Christopher Conley
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: warpboy on August 31, 2007, 03:22:19 PM
hello,
i had some problems with 48v, the infos you give are really helpfull for diy'ers. the last problem i had was due to the 48v led indicator. Result : transistor oscillations  :evil: .
the response of Rascalseven :
http://www.groupdiy.com/index.php?topic=24132
 :thumb:
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: lofi on August 31, 2007, 04:34:15 PM
may i take the oportunity to drop  my jaw!!!

beutiful!!!!!

Iain
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 04, 2007, 01:21:10 PM
Hi Conleycd,

I like the JLM PSU's a LOT!! They're very clean, easy to build and cheap. I've been using their ACDC to power my Neve's and it's working great. I have noticed that the +24V LM317's get pretty toasty when you power two channels of 1290/1073, so I've since "remote mounted" them to a large 50W TO-3 heatsink.

(this one: http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=HS117-ND)

I know that's probably complete overkill but it keeps them nice and cool. :green:  By "remote mounting" I mean soldering wire leads to the PCB where the LM317's normaly sit and soldering the LM317's to the wires (1/8" heatshrink around the LM317 leads). The +48V LM317 doesn't get as hot, and it seems fine with a much smaller heatsink. I've remote mounted those to a 10W TO-220 heatsink: (this one: http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=HS276-ND)

I also calculate 500mA of current draw per channel for 1290/1073 modules, which again is VERRRRY conservative (read: overkill), but I like building things like a tank - especially when it comes to PSU's.

Warpboy: did you hook up 48V per my instructions at the beginning of this thread? Can you take some pics of your layout and explain how you wired things?

Lofi: Thanks for the kind words!! :thumb:

All the best,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 17, 2007, 12:14:44 PM
Good news, the Carnhill transformers will be **a lot** easier and faster to get at a much lower price from: http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html

I've updated the BOM to reflect this:
http://www.musiciansgig.com/ez1290/1290BOM.xls

Thanks Colin (Slenderchap)!!!!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ipagel on September 17, 2007, 03:08:51 PM
Hi M
what is the difference between Carnhill  vtb9049 or vtb1148?
or is it just size?

thanks mark
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: buschfsu on September 17, 2007, 10:29:12 PM
i got my carnhills from audio maintenance today.  i got the smaller 1u output transformers so my 2 channels will fit in 1u!!!!
ill post when they are up and runnin

thanks again!!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Slenderchap on September 18, 2007, 12:18:14 AM
The only difference between the VTB9049 and VTB1148 is the size of the connector board (VTB1148 being narrower);

http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html

If you click on the photos it will show them in detail... you can see the size difference.

Colin
www.audiomaintenance.com
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ipagel on September 18, 2007, 11:38:09 AM
thanks colin thats what i thought. :thumb:
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 19, 2007, 12:46:36 PM
Our industrious Canadian friend Bluzzi has generously provided us with a consolidated BOM with prices etc. This is very handy if you're just building 2 channels! Pls see:
http://musiciansgig.com/ez1290/Consolidated_1290_BOM.xls

Thank you Bluzzi!!!!!! :thumb:  :thumb:

Buschfsu: sounds like you're getting close to wrapping up your mic pre. I definitely like the 1U idea. I'm looking forward to the build pics!!  

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ffaudio on September 19, 2007, 02:35:11 PM
I wanted to build a 2 channel version in 1u size, but can't pick up the pcb's right now.  Are you going to be selling them for a while?
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: outoftune on September 19, 2007, 08:33:50 PM
just to let everyone know....the fivefish 2448 will work perfectly for this pre. I just ordered one with the torroid powersupply kit since digikey didnt have the amveco in stock...more info here: http://www.fivefish.net/diy/
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: CJ on September 19, 2007, 08:53:09 PM
where's the mix buss?  :grin:
dang nice job.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 20, 2007, 02:38:29 PM
Hehe, Thanks CJ! Funny you mentioned a mix buss. I was actually just thinking of building one of NYD's summing thingies with some nice P&G faders.

outoftune: yes, the PSU-2448 looks like it'll work fine.

ffaudio: I'm almost out of PCB's, but I'll get more made in the future.

Thanks!!

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ffaudio on September 20, 2007, 02:41:41 PM
Quote from: "madriaanse"


ffaudio: I'm almost out of PCB's, but I'll get more made in the future.

Thanks!!

M.

Okay, as long as you'll still be making them I'll be happy.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ChuckD on October 28, 2007, 04:12:58 AM
Hey I trying to design my frontpanel for this 1073DPA clone or whatever you want to call it.

Is this correct?

(http://www.pillarsofnein.com/diy_projects/1073_pre_only/1073_meter.gif)


Thanks!
Just waiting for my swicthes but other then that I think I am almost done.

-ChuckD
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Siegfried Meier on October 28, 2007, 12:25:13 PM
Hey Chuck,

I think if you're using a Grayhill there's only 12 positions and that's it.  No?

Sig
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ChuckD on October 28, 2007, 05:10:05 PM
Yes I am using the standard Grayhill.

From What I thought postion 0 = 0 then it starts at 20 db and goes up 5 db from there hence my meter showing 20-70 with 11 ticks total???

Right?

-ChuckD
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on October 28, 2007, 10:14:48 PM
Hello ChuckD,

Check out this picture for the correct switch layout. There are 12 positions; from 20dB to 75dB in 5 dB increcements. So there's 30 degrees between each switch position, and a "stop" between 75 and 20dB. The stop is there so you don't accidentally switch from 20dB to 75dB - which could lead to musicians hurling headphones and other objects at you in similar fashion to early man attacking a mastodont.

(http://www.musiciansgig.com/ez1290/gain_positions.jpg)

Hope this helps,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on November 01, 2007, 11:54:50 AM
Also, since most people are building 2 channels, I've uploaded a basic 2U, 2ch front panel design for this preamp. It's a Front Panel Express file. (http://www.frontpanelexpress.com/)

This panel will bolt right up to the Circuit Specialists' case specified in the BOM. It should be pretty easy to adapt to a 1U, or a Par-Metal case as well. Pls see:
http://musiciansgig.com/ez1290/circuit_specialists_2u_panel.fpd

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Slenderchap on November 01, 2007, 01:50:40 PM
The following are now available from the on-line store;

VTB9043 - GBP 16.58 each
VTB9044 - GBP 14.88 each
VTB9050 - GBP 14.91 each

Prices exclude feight and VAT [if applicable]

http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html

Colin
www.audiomaintenance.com

P.S. There are only 25 of each in stock .... so expect to be disappointed if you hang about.
P.P.S. VTB9057 & VTB1847 are also in stock and will appear in the store shortly.... VTB1148's are now back in stock.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: guavatone on May 29, 2008, 05:03:01 AM
I missed this M.

Nice one.

or, uh... 8

-Like the neve grey!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: RedNoise on May 31, 2008, 10:52:44 AM
Up!!!Very nice looking 8 Pré!! :thumb:
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: gar381 on June 02, 2008, 02:23:00 PM
Really Nice Build!!! :thumb:  :thumb:  :guinness:  :sam:

I'm going to have to try a build of these one of these days.

Love the knobs.  Reminds me of the ones
maxwall had about 3 years ago.

GARY
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: vertiges on June 02, 2008, 04:44:50 PM
Hi Martin,

 :shock:  :shock:  :shock:  :shock:  :shock:  :shock:  :shock:  :shock: (<--8 of them  :green: )

Congrats !!!  :thumb:

eD

N.B. : I would be interested in buying two EZ1290 PCB. I emailed you.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 09, 2008, 06:49:29 PM
Hey thanks for the kind words guys!! It was a fun project that has taken the sound of the studio to a new level. (was using Millennia Media HV-3 before, always felt like something was missing).

I've actually built 24 channels of EZ1290's since I first posted this thread - two 8ch boxes and four 2ch boxes.

But if I had to do it all over again I would have built six 4ch, 2U boxes; would have been SO much easier.

Take care,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: vertiges on June 09, 2008, 08:48:53 PM
Quote from: "madriaanse"
24 channels of EZ1290's.
 :shock:

You're completely addicted !!!  :wink:

eD)))
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: RedNoise on June 10, 2008, 03:53:20 AM
waow!!!! :thumb:  :thumb:(<--only 2 of them , sorry! :green: )
Did you do the pcbs yourself?? :?:
Title: Hum problem - Need ideas
Post by: Bluzzi on June 18, 2008, 11:46:49 PM
I finally got around to start finishing my 2 1290s. I was getting a loud hum on one and the other was not passing audio.

3nity came down today and he found a few un-soldered points on the board that wasn't passing audio. So that one now is fine although a bit noisy but not unusable. These pups have a hell of a lot of gain!

The other one still has a hum/buzz. We've tried to move the board, and even the input XFR. I haven't tried moving the output and its at 90 degrees offset from the quiet one's XFR. I will try that next but I doubt its that.

I doubt its AC leaking from the Power Supply as then both boards should have the same problem, which they don't.

I'm going to keep trying things like removing the toroidal XFR from the case, moving the output XFR's position. Verifying all parts.

If any of you have any suggestions as to what to try to find the culprit let me know.

I really want to also thank 3nity who came down to my place after a long day at work and spent hours with me on finding solutions. 3nity your the best man!

Thanks to Madrianse, even with some hum I can hear the 1290s are going to be great! I'm hearing a thicker and punchier pre than I'm used to (John Hardy mostly and its fantastic too but another species from these).

So guys please, give me some ideas!

Jim
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 19, 2008, 03:01:53 PM
Hi Jim,

Congrats on one finished pre!! Let's see if we can get the other one to play nice.

To start:
-Is the pre with the hum closest to the PSU transformer?
-Moving the toroid OTB is definitely a good idea
-Pay EXTREMELY close attention to grounding AND shielding. It has to be **exactly** like my assembly guide, or you can run into all sorts of problems.
-Can you post a pic of your layout?
-Any ripple on the DC rails? Can you measure any AC on the DC rails?

Let me know how it goes!!

All the best,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Bluzzi on June 20, 2008, 02:12:05 AM
Hi madriaanse,

Thanks for the encouraging word but I'm not out of the pile of .... yet.

Yes the noisier one is closest to the toroid. By the way the Power Toroid is a big one. I need to drive 2 1290 and 2 MP-2 GR.
Also I must say moving the PCB twice as far from PT than the less noisy one resulted in no perceptible noise loss.

I'll double check the assembly guide again just in case!

I'll post a picture this weekend.

I haven't checked the DC with an oscilloscope yet. 3nity and I were quite tired after 3 hours sitting on the floor with our legs crossed debugging the pres.  It took another 3 hour to get the blood circulating again. :wink:

I have to mention also that on both pres, I have the wiring for the 48v phantom hooked into the XLRs up to the switch but not to the power supply. Maybe its that but again I have to wonder why it would affect one and not the other.

Its 60/120hz hum for sure so I'm sure its grounding.

Thanks again for stepping in. Just replying gets me off my ass to get this finished!

Jim
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 23, 2008, 11:01:56 AM
Hi Bluzzi,

Just wanted to check in and see how it's going with the troubleshooting? A littlebit of white noise at higher gain is normal with these mic pres (Neve haze?), but there should be no hum.

Take care,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on August 16, 2008, 08:19:47 PM
On Behold of Bluzzi i'm glad to let you know that 2 more 1290 are out from the intensive room!

They sound nice and quietly!

Bad toroidal.

Jorge Aristondo.

BTW: 1290CM coming soon.
Title: The Dr. has cured another patient
Post by: Bluzzi on August 17, 2008, 01:55:07 AM
Thanks Dr. Jorge.

Guys I gave my 1290s to Jorge a day ago because we could not figure out what was wrong with my wiring or grouding etc. They passed audio but had small annoying hum.

Now Trinity has figured out that it was the Toroidal XFR that was bad! So I was punishing myself for nothing.

I haven't heard them yet but I trust Dr. Jorge. Apparently he transplanted the bad XFR with a good one and presto! Working Neves!

I just got in and found this out via here and various private messages from him so I will be picking them up soon and listening to them.

This problem had me stop all my DIY including my 1084EQ project so I can't wait to put these pres in my studio.

On to the MP-2 pres now!

Jim
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 17, 2008, 02:09:23 AM
Super cool!! Enjoy the preamps!!  :thumb:

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 25, 2008, 06:19:46 PM
Hi Everyone,

One of our members ran into a situation where the EZ1290's would go into oscillation at higher gain. I asked if he could send me some pictures of his build, and it turned out the input transformer was too close to the output transformer, and no shielded wire was used. After he followed my recommendations of spacing the transformers a bit more and using shielded wire the problem went away and the preamps performed flawlessly. Here are some pics of his layout *before* he fixed it.

Hope this helps.

M.

(http://lh5.ggpht.com/moadriaanse/SNwLS7S1xiI/AAAAAAAAABk/_Gp48XIFg_M/s512/IMG_0008.JPG)

(http://lh5.ggpht.com/moadriaanse/SNwLTCN8ZvI/AAAAAAAAABw/YP2Dm88w8L4/s512/IMG_0009.JPG)
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mfdu on September 26, 2008, 11:50:07 PM
i just need to check in about input and output transormers.

i've got two ez1290's and two jlm baby animals in a box, with the 48v jlm psu and his 24v zener to supply to the ez1290's.

what are the specs of the carnhill input and output transformers?  or what does the board expect to see?
i hope i have some strange old units to suit.
 
chunky 10ohm:15ohm outputs and 7.3ohm:63ohm inputs (below - not the green cans Astors)

but i just can't seem to find the actual resistance readings or whatever it is i need to know so i can unmask the hidden secrets of the transformer world and

oops.  sorry.

here's a construction photo, but i'm lazy and haven't got an internal case shot.  but i'm using a 3RU case with chunky handles - it looks the biz.

(http://members.optusnet.com.au/~mfdu/images/diy_trannies.jpg)
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mfdu on September 26, 2008, 11:58:58 PM
OMFG

i just read a revised build PDF which details cutting particular pins from the middle row of the greyhill switch

oh no!!!  that wasn't in my older build manual (page 5 http://musiciansgig.com/ez1290/assembly2.pdf )

i haven't trimmed off the specified pins.  neither have they been soldered in - there were no pads to solder to!

is this going to be an issue???  i've been dragging my feet to final hookup, and then come up with concerns around the transformers.
now this.

chris.mfdu
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 27, 2008, 02:56:41 AM
Hello Chris,

Use this assembly guide:
http://musiciansgig.com/ez1290/assembly.pdf

The version you referred to is for an earlier, prototype version of the EZ1290's.

Thanks,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mfdu on September 27, 2008, 07:10:10 PM
cool.  so the one you referred me to doesn't specify trimming off the un-soldered pins on the greyhill switch.

just as b%@@dy well.

but mate - there is still no info on the actual readings of the input and output trannies.

not even whether the input is a 1:6.5 or 1:1, and whether the output is 4:1 or 1:33.
can you give me some kind of idea of whether my trannies are even close to the requirements?

chris.mfdu
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: bobschwenkler on September 28, 2008, 12:47:38 AM
Quote from: "madriaanse"
One of our members ran into a situation where the EZ1290's would go into oscillation at higher gain. I asked if he could send me some pictures of his build, and it turned out the input transformer was too close to the output transformer, and no shielded wire was used. After he followed my recommendations of spacing the transformers a bit more and using shielded wire the problem went away and the preamps performed flawlessly. Here are some pics of his layout *before* he fixed it.


I'm curious if this was feedback due to inductive coupling between the input and output transformers?
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on September 28, 2008, 09:57:51 PM
Chris,

Check this link: http://www.technicalaudio.com/reading/neve_xfmrs/neve_edo7113.html

As a note, if you want a Neve 1073, it's Carnhill or bust IMO. Sowter may also be good but I've never tried those personally.

bobschwenkler,

When I did some experimentation with transformer placement for my 8ch unit, I could get the mic pre to oscillate at max gain by holding the mic input transformer next to the line output transformer. And this was WITH shielded cable. So I think inductive coupling is definitely something to pay attention to. Also, the mic pre's will easily oscillate if you hold an unshielded mic in wire next to an unshielded line out. Best to follow the Neve spec and use shielded cable as well as space the transformers a bit.

Best Regards,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on October 02, 2008, 04:18:42 PM
Channel one of my pair is sounding nice but i haear a small hum...but hum goes away when i touc the front panel?

what could be wrong here?

Thanks.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mfdu on October 02, 2008, 06:19:32 PM
sounds like a grounding issue.  do you have ground from pcb to case to power earth inlet and XLR input ground? (ie. full star-grounding)?


yeah yeah - i know it won't be a 1073 without carnhills.  but it isn't anyway, is it?  i'm gagging to use these old trannies i've got, and if they sound sweet then thats all i'm concerned about.

hopefully i'll do final hookup this weekend and report back.

chris.mfdu
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on October 02, 2008, 06:50:53 PM
What i did was XLR in # 1 to Go beetween ground.....
And since i didnt use Carnhill i went ground directly from Shield to XLR out #1.

But no #1 to star ground.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on October 03, 2008, 12:24:54 PM
Chris,

Quote
yeah yeah - i know it won't be a 1073 without carnhills. but it isn't anyway, is it?


It is; pay attention to parts and there's no discernible difference. However, experimentation's a lot of fun, and I am curious about your transformer findings.

3Nity,

Try leaving pin 1 on the output XLR disconnected.

All the best,

M.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on October 03, 2008, 01:39:26 PM
thanks gonna try!
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mfdu on October 03, 2008, 06:52:00 PM
madriaanse - no offense meant.  it's just the whole DIY thing, you know?

i mean, i'm looking forward to seeing how the trannies sound.  but i have nothing to compare the sound to.  not being the proud owner of any n*ve gear.

hopefully i'll knock them up today.

chris.
Title: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on October 04, 2008, 06:29:51 PM
Quote from: "mfdu"
madriaanse - no offense meant.  it's just the whole DIY thing, you know?


Hi Chris,

None taken! I just wanted to clarify and probably should've stuck a smiley somewhere :thumb: .

Let us know what you learn about those transformers!!

Cheers,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 21, 2008, 12:17:27 AM
;)

Amazing Stuff.

I would like to buy 2 boards for this project if you still have some. Sent you a pm.

thanks

TS
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 29, 2008, 12:20:53 AM
Love it, I'm setting up to build a sweeeeet 4 channel unit in a 2U or 3U depending on what's actually going to fit them all. Sneak peek below of some ideas I'm working on, I think I like #2 & #3 the best with no borders. I think building in the 3U might be easier too.

Any feedback on these panels?

I'll be using the JLM Go Between to add pad and phase to Martin's design as well as the JLM Power Station V2 to run all 4 units easily. Pricing this out so far including all the best stuff including Marconi knobs, a 4 channel unit is only looking like it's around $1500...

(http://aermotorstudio.com/neve-mockup.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 29, 2008, 07:16:31 AM
They look lovely. great work.

I also prefer the 2nd and 3rd.

How did you design them?

Will you use front panel express to make them?


Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: jackies on November 29, 2008, 09:41:58 AM
I, too, was wandering what transformers I can use here except Carnhills. I happen to have JLM 1:4 mic input so I was thinking that should be good for the input. Not so sure about output though. Will 600:600 work here? Does it have to be gapped? Are Carnhill outputs gapped?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: RedNoise on November 29, 2008, 11:25:01 AM
 ;D
Great looking front panels...I prefer 1st and second... :P
T.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 29, 2008, 01:24:54 PM
carhill all the way!!!!!!!!!!


Carhill/St Ives and Neve are two really good Lovers.

Made for each other
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on November 29, 2008, 01:37:14 PM
It's Carnhill or bust IMHO!! They really sound great. Buy from Audiomaintenance; they also have the switches.

I like panel 1!!

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 29, 2008, 02:46:44 PM
Updated a few of them, yea I'm really liking the #2 in the 2U, made some tweaks to fonts etc, if everything can actually go together like that I'll be very pleased, it's gonna be a freaking tight squeeze though.

(http://aermotorstudio.com/neve-mockup-2.jpg)

I'm trying to decide what would be the best way to make these:

1) FPE
2) Laser Engrave
3) Silk Screen

I think I'm leaning towards silk screen for a nice authentic look, anyone know how that compares to FPE?

Just thinking about this more and more, I think I'm going to try and add the Trim Pot to this as well. That's gonna mess with my space! Maybe I do need the 3U  ::) Anyone know where the get the grey small Neve knobs?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 29, 2008, 10:35:07 PM
to be honest you really dont need the trim pot.

I've been using the Neve 1073 DPA and Vintech 73 for a while and never had to touch the trim/output knob.

you are recording at 24 bits, its not that important to be as close to 0dbs as was in the 16bits era. 5dbs steps is quite enough.

like madriaanse said in a lot of posts, why do you want to put something in the signal way that can degrade the sound if your really don't need it?

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 29, 2008, 11:50:04 PM
That is a good point... The idea is more so that you can drive the transformers hard and get some nice saturation and grit out of them. I'll still have to decide, but might just do without it for the sake of ease in the build, it's already going to be enough adding the Go Between.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 30, 2008, 12:15:37 AM
Another update, I think these work better with the knobs on the top and the switches on the bottom. Gonna have to have some really tall risers for the PCBs. I'm ordering a Go Between soon so I'll be able to check all these things out. I'm not sure if they reflected switches will work on the right while they are upside down, we'll see.

(http://aermotorstudio.com/neve-mockup-2u.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: RedNoise on November 30, 2008, 05:06:14 AM
just a question : don't you slightly modify the N*eve logo??(the N in the circle seem to be bent/roundish a bit , no??)
BTW knob on top and logo centered on top  is beautiful!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 30, 2008, 05:21:01 AM
That is a good point... The idea is more so that you can drive the transformers hard and get some nice saturation and grit out of them. I'll still have to decide, but might just do without it for the sake of ease in the build, it's already going to be enough adding the Go Between.

ohh, oki. Now I get it. It's quite usefull if you need saturation out of the preamp, so that you distort the preamp and use the trim so that you don't clip the AD, is that right?

need to try that at the studio actually, when I want to distort preamps I always go for the SSL desk pres (E series) , just because I'm used to it and I really like the way they distort. Don't even now why I never tried to saturate the Neve or Vintech just to see what happens.
thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 30, 2008, 05:57:15 AM
RedNoise: I redrew it quickly because I didn't have it in vector yes. There are a few different versions of it throughout the years too.

Whoops: Yea that's why I was thinking of doing that, not that you use it all the time, but if you're paying that kind of money for that coveted iron, you might as well get the most out of it that you can. The problem though is finding a place for the pots and knobs, it doesn't really work well in the 2U. I'm still undecided.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 30, 2008, 10:10:25 AM
Could we have a switch so that we could the trim pot out of the signal path when not in use?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: buschfsu on November 30, 2008, 10:40:47 AM
anyone have luck getting those red knobs?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mushy on November 30, 2008, 02:36:38 PM
I'm working on a 1U 4 channel FPE layout for Martin's 1290s.  I'll post it when I get it done.  Obviously, the JLM Go Between board won't fit so I'm scrapping the pad and putting in the phase and +48 switches manually.  I'm debating a JLM DI.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 30, 2008, 07:06:59 PM
Whoops: I'm sure you can do something like that. You can probably get it to bypass the pot but you'll be adding a little something extra to the circuit.

buschfsu: You can order them from Brent Averill, just sent them an email asking for pricing. Make sure you specify 1/4" shaft.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on November 30, 2008, 09:40:09 PM

buschfsu: You can order them from Brent Averill, just sent them an email asking for pricing. Make sure you specify 1/4" shaft.

What about diysurplus like is mentioned in the BOM aren't they supplying the Knobs anymore?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on November 30, 2008, 10:01:39 PM
I'm not sure if those are the actual Marconi knobs or the red ones like in Martin's finished case...

Mushy: Sounds cool, hopefully it's not too tight in the 1U.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on December 01, 2008, 08:49:36 PM
I'm closer to deciding on a final design for mine. I think I'm going to ditch the Go Between and save the cost/hassle of it, and just try and wire in a little phase switch since I probably don't need the pad. All of the boards are correctly spaced now and everything seems positioned nicely.

If I can I'm going to ditch the thumb screws and attach the panel another way.

(http://aermotorstudio.com/neve-mockup-final.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on December 01, 2008, 09:08:49 PM
just a newbie question,

I've seen a lot of people using companies logos in ther DIY stuff, Like the SSL logo and Neve logo.

Can you really do that? aren't the Neve and the SSL logo's registered since they are trademarks?
Shouldn't we avoid to do that?

sorry if it's a dumb question
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on December 02, 2008, 12:54:31 AM
I would say you can do whatever you want for your own personal use, as long as you're not selling things commercially for money and not trying to pass it off as the real thing.

Here are some questions Martin has answered for me for anyone else who might need them.

DPDT for Phase: Mouser #108-0010-EVX
Bigger Power Transformer for 4 channels: Digikey: Amveco TE62085-ND
PCB/Part Dimensions: 3.75" wide 1.25" tall
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on December 06, 2008, 04:17:23 AM
Working on my 4 boards now, man there's a lot of soldering. I've got 2 boards all the way done and 2 about half way.

I noticed there's a few blank solder holes on in your photos you've soldering them in, I suppose we're to do the same?

For the psu, I already built my JLM Power Station, am I going to use the negative rail at all? Am I just supposed to split 4 different wires off of the +24? I understand most all the wiring on this project except how the power supply works.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: wolfgang on December 06, 2008, 05:03:32 AM
>>>>Is this what I need to do to power my 4 units?

Yes! You dont need a negative rail for your neve!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on December 06, 2008, 05:45:06 PM
Yea that's what I figured. I'm still unclear as to how I get the +24 for all of them. The Power Station only has 1 +24v on it, do I just wire up 4 different pairs off the xlr 4 pin power that go to each pcb?

Would it be easy to add the Carnhill VTB9046 (Line Input) by simply wiring it the same as the Mic Input and attaching both to the PCB in the same place, or would it have to be done differently? Just thinking if in the future I would want to add line ins if it would be that simple or much more work than that.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on December 06, 2008, 06:35:38 PM
A quick question.. I'm am buying a couple of these boards from another member, and just started getting the BOM together... Couple quick questions... The caps listed as polystyrene are actually ceramic, I know either will do, but is there any authenticity factor in going with styrene?

Also, the infamous grayhill... Is there any other (cheaper) alternative?  Could any 3P12T shorting switch be wired in?

I guess that's it for now... til I get my boards, then I'll have a ton more questions!

Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on December 06, 2008, 07:01:33 PM
The best thing to do is stick strictly to the BOM and use the part numbers that are provided. Not sure on the caps, it would seem as they are done that way to stay true to the original. On the switch, there's been a lot of talk between this thread and the Neve 1290 thread, look around and see. I know the consensus was always just go for the Grayhill, you'll be thanking yourself later.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on December 06, 2008, 09:55:36 PM
Yeah, I'm planning on it.. I'm ordering from TAW instead of Digikey, so I had to look up the Cap part numbers to see what values they actually were, and that's how it came to my attention... Anyway, I am going to get both ceramic and styrene, but in the meantime I did some searching for pics of old Neve boards and it looks like they had styrene in them, which I guess is  why Martin labeled them as such.

And I just saw that the board sale included the grayhills! so no issue there anymore.. :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on December 06, 2008, 11:20:50 PM
can you please tell me were can I find that info on the caps?

where have you seen them labelled or listed?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on December 07, 2008, 02:59:09 AM
And I just saw that the board sale included the grayhills! so no issue there anymore.. :)

Is Martin now selling the boards with the grayhill switches?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on December 07, 2008, 08:59:09 PM
The caps listed as polystyrene are actually ceramic, I know either will do, but is there any authenticity factor in going with styrene?

Thanks!

I would like to ask the same question.
What capacitor type are you using for the non-polarized ones?

Would Styrene be the best option?

how about Panasonic Polypropylene? or Panasonic Stacked Metal Film?

thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Gachet on January 04, 2009, 07:38:10 PM
Hi everybody

Where can i find boards or pdf to make pcb for this project?

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on January 04, 2009, 09:45:28 PM
Gachet

it's as simple as going to the first page, first post of this thread.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Gachet on January 07, 2009, 07:35:00 AM
Hi there

Thanks whoops and madriaanse

Payment sent for 4 boards

Best regards
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nikonet on January 09, 2009, 07:11:46 AM
hello !!!

two EZ1290 finished but i have some questions:

what's "jumper" on the PCB ?

thanks a lot for your responses
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: digichild on January 09, 2009, 12:26:45 PM
hello !!!

two EZ1290 finished but i have some questions:

what's "jumper" on the PCB ?

thanks a lot for your responses

thats an resistor with zero ohms  ;)
no seriously: its just a piece of wire
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on January 09, 2009, 09:20:42 PM
hello !!!

two EZ1290 finished but i have some questions:

what's "jumper" on the PCB ?

thanks a lot for your responses

thats an resistor with zero ohms  ;)
no seriously: its just a piece of wire

You can use the legs that you cut from resistors or capacitors and solder it there.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 11, 2009, 05:51:56 AM
Getting closer to finishing up my 4 channel version. Drilled out all the XLRs tonight with a stepped bit and a drill press, man what a ***** that can be  :o

At the last minute I decided to go with the Go Betweens, pretty glad I did as well, makes a lot of things easier. The only thing is that I don't want the switches so close together so I'm wiring them off board. It's pretty nuts thought because there's 6 wires per switch, 3 switches per board, and 4 boards to do, yikes. Should be worth it in the end.

Quick question: Can I add a 24V lamp on the front panel just by tapping off of the 24V going to a channel? Also, I'd like to make the power cable able to unhook from the psu box, is it a problem to use another xlr there instead of wiring it right into the psu?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nikonet on January 11, 2009, 12:36:47 PM
ok, thanks a lot !!!!

and excuse me for my stupid question...........
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on January 11, 2009, 04:42:34 PM
Getting closer to finishing up my 4 channel version. Drilled out all the XLRs tonight with a stepped bit and a drill press, man what a ***** that can be  :o

Quick question: Can I add a 24V lamp on the front panel just by tapping off of the 24V going to a channel? Also, I'd like to make the power cable able to unhook from the psu box, is it a problem to use another xlr there instead of wiring it right into the psu?

Oh Yeah, Drilling can be painful even with a stepped drill. I don't have a Drill Press, so it was a terrible experience.
But anyway i got it done.

You can use an XLR on the PSU Box, just make sure it's a Female XLR nad not a Male. You don't want the voltage exposed in the male pins.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 11, 2009, 05:41:16 PM
Wow yea I can image with a hand drill that wasn't good. I've had better luck with a hole saw bit actually, might have been better.

Yea good point that makes sense thanks.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nikonet on January 15, 2009, 07:14:31 AM
hello, 2 préamp finished..............

but a little noise at -70dB when switch turn at full clockwise (gain full)

so i'v got a question: r7 need to be a 47ohm/1w resistor on the pcb, and on the bom it's 47H-ND which is 47ohm / 1/2w.........is it important?

an other one: pin1 on XLR need to be connected to the box (ground) ?

excuse for my bad language, i'm french.............

thanks a lot !!!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 15, 2009, 04:01:56 PM
Either wattage is fine I believe, I think someone else asked the same thing recently, or similar. No ground to box from pin 1.

These will have a little sound at 70db, here's what Martin has to say about it which seems fine.

Quote
Like all 1073/1290's, these preamps have some hiss ("Neve haze"). They are not dead quiet, but the hiss shouldn't be distracting unless you're recording quiet sources with ribbon mics. The noise floor specs can be improved somewhat by hand-picking BC184C's for highest HFE (especially the first one in the darlington config), but I never bother.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 16, 2009, 02:16:14 AM
1/2 W or 1W are both fine for the 47R.

making XLR holes: By far the easiest/cleanest way to go is to use a 15/16" Greenlee punch (predrill w. 3/8"): http://tinyurl.com/825fqg
Then I put the XLR connector in the hole, use a square to align the XLR with the chassis, mark the holes for the 4-40 screws, centerpunch and drill. Even better is to befriend a guy w/ a CNC lasercutter!!

I don't sell the Grayhill switches. You have to get those from Audiomaintenance.

All the best,

M.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 16, 2009, 05:31:03 AM
How does that punch work manually, just predrill, put the bolt through, finger tighten and it grabs the metal enough for you to use a ratchet you bring it all the way through? I thought you had to have a hydraulics for those, that's pretty cool if you can do it otherwise.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 16, 2009, 11:58:59 AM
Hi Zach,

exactly. That's how it works if you use a ratchet. It works even better (and very fast) with an automotive impact wrench. You can punch a hole in seconds.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 16, 2009, 02:11:50 PM
Cripes I should have bought one of those instead of my $60 stepped Greenlee bit! Oh well, great tip thanks.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on January 17, 2009, 11:12:00 PM
Hi, has anyone built this using metal film resistors? Just wondering since I have tons of them around, or is the 5% carbon thing part of the sound? Is it to stay true to the original specs? thanks!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on January 18, 2009, 03:44:26 PM
Metal Film 1% all the way!!!!!!!!!!!!!!!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on January 18, 2009, 04:23:38 PM
OK, was just wondering because the parts list seems to call for 5% and people here say to stick to it as closely as possible for the most "neve-like" sound.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: trancedental on January 18, 2009, 10:25:57 PM
Many Guitar Tube Amp builders, for example,  prefer to use carbon film resistors in most places. Metal film is good for higher values, like 470k or even slightly lower and & of couse above that value, to keep down the hiss. So I'm assuming that the pres would have more of "retro" sound with carbon films although the transformers themselves would have more influence on how the output signal sounded.

Maybe Madriaanse & other experts on here can give us some advice?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Gachet on January 19, 2009, 10:26:10 AM
Hi there

Is it possible to wire the input transformer primary in parallel for line level operation?
Or is there another trick?

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 19, 2009, 10:50:08 AM
The reason I chose carbon resistors was twofold: 1. The original module I used as a clone source used carbon; it was a stellar sounding module. 2. carbon's cheap. I know Neve also used metal film later in their production, so you can use either and still be "authentic". Like trancedental mentioned, the transformers (and tantalum caps) probably have the greatest single effect on the sound.

All the best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 19, 2009, 11:27:00 AM
Is it possible to wire the input transformer primary in parallel for line level operation?
Or is there another trick?

How about a Go-Between from JLM: http://www.jlmaudio.com/JLMDI.htm

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Gachet on January 19, 2009, 12:10:38 PM
Hi,

Thanks for answer.
I will use the pad idea with 470R but what is the 120R parrallel resistor for?
What is the parrallel wiring of the transformer  for? Z=300ohms instead of 1K2
Maybe for ribbon or other low Z mike ?

Thanks

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 19, 2009, 06:22:34 PM
I will use the pad idea with 470R but what is the 120R parrallel resistor for?

Together with the 470R's it makes a U-Pad, see: http://www.uneeda-audio.com/pads/

Quote
What is the parrallel wiring of the transformer  for? Z=300ohms instead of 1K2
Maybe for ribbon or other low Z mike ?

That is correct. Supposedly it works well for ribbons; however I just leave mine at 1200. I have an AEA R88 on the way from Mercenary and I'm going to try 300 ohms with that.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on January 19, 2009, 07:46:31 PM
Is it possible to wire the input transformer primary in parallel for line level operation?
Or is there another trick?

How about a Go-Between from JLM: http://www.jlmaudio.com/JLMDI.htm

M.

Martin , with the JLM DI you would have a DI input and not a Line in.

In the Neve 1073DPA they are doing the Mic in and Line in with only one input transformer, so it would be nice to see how did they wire it up.


It would be nice to be able to change the inpedance of the pre-amp, it's cool for ribbon mics and also to play around with dynamic mics.
Anyone knows how to do that?




Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on January 19, 2009, 08:19:09 PM
You just swap your input trafo primaries from serial to parallel. Putting them in series you get more turns on your primaries which gives you a lower turns ratio (and higher impedance primary). Putting them in parallel gives you half the turns on the primary side, so it doubles your turn ratio, and makes your primary impedance four times lower.

In practice, you get the 1K2 impedance by tying the + of one primary to the - of the other and using the other + and - as the primary connections. In parallel you tie your +'s together and your -'s together and are left with the equivalent of one winding.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 19, 2009, 10:38:50 PM
Martin , with the JLM DI you would have a DI input and not a Line in.

Oops, sorry you're right. For some reason I thought JLM had a line-in plugin for their Go Between.

Quote
In the Neve 1073DPA they are doing the Mic in and Line in with only one input transformer, so it would be nice to see how did they wire it up.

From what I've heard (don't quote me on this), AMS bypasses the input transformer alltogether on the line-in and uses an IC line receiver to go directly into the pre-stage. I personally wouldn't go this route and prefer the traditional 31267 setup.

Quote
It would be nice to be able to change the inpedance of the pre-amp, it's cool for ribbon mics and also to play around with dynamic mics.
Anyone knows how to do that?

Yes - it takes one DPDT. Check out S1 on: http://www.technicalaudio.net/neve/neve_pdf/1073-EH10023.pdf

Cheers,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Gachet on January 19, 2009, 10:40:28 PM
I will use the pad idea with 470R but what is the 120R parrallel resistor for?

Together with the 470R's it makes a U-Pad, see: http://www.uneeda-audio.com/pads/

Thanks for the documentation...very useful ;)
To achieve line to mic attenuation and impedance the two series resistors should be 7500R and the parallel one 150R.
Maybe I can build the preamp with both 20db and 40 db pad selectable.

Quote
What is the parrallel wiring of the transformer  for? Z=300ohms instead of 1K2
Maybe for ribbon or other low Z mike ?
Quote
That is correct. Supposedly it works well for ribbons; however I just leave mine at 1200. I have an AEA R88 on the way from Mercenary and I'm going to try 300 ohms with that.

M.
I think I'll put this as an option on the front panel.With a toggle switch it may be craky with audio out on so i'll try relay switching and 1n4148 diodes as long as i have a spare psu rail.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 20, 2009, 01:18:31 AM
Quick question: Can I add a 24V lamp on the front panel just by tapping off of the 24V going to a channel?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Gachet on January 20, 2009, 08:24:34 AM
Quick question: Can I add a 24V lamp on the front panel just by tapping off of the 24V going to a channel?

Yes you can ;)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nikonet on January 20, 2009, 02:59:25 PM
thanks zachs, so.......there no solution.........about this noise at 70db :'( :'( :'( :'(
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 20, 2009, 03:10:42 PM
Perhaps you're having more noise than usual, I'm not sure... best for Martin to chime in.

What are you recording at 70db gain that's quiet enough to hear it? What mic as well?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on January 20, 2009, 03:14:47 PM
thats is normal...if you got the gain at last position of switch....and i doubt that in practice you need that much gain.
And yeah theres some hiss but nothing to worry about when recording.
Do you have your toroidal on an external case or in the same case?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 20, 2009, 03:46:29 PM
Hi Nikonet,

Just to make sure your noise floor is normal, can you record something with this preamp, and with another preamp you have; maybe upload the clips?

Thanks,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: YLab on January 20, 2009, 06:48:54 PM
''the transformers (and tantalum caps) probably have the greatest single effect on the sound''

Hey Martin, are you thinking about a particular brand of tantalum caps other than the kemets on the BOM.

Thanks
Hubert
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 20, 2009, 07:01:55 PM
Alllllllmost done with mine... had a freaking cap blow in the Power Station last night on the first hook up, scared the blimey out of me my god, my ears were ringing for 20 minutes. Not sure what caused it, I've been going back and forth with Joe from JLM. He thinks backwards cap, but I'm 99% sure it wasn't. I've got the center pin jumped to Doubler.

I removed the rest of the blown cap, powered again and it's ok. Looks like I now need to replace the cap, resistor and regulator. Ugh. Double check your work I suppose. Perhaps it should be quadruple.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 21, 2009, 01:25:24 PM
Quote
Hey Martin, are you thinking about a particular brand of tantalum caps other than the kemets on the BOM.

Hi Hubert,

The Kemets sound lovely! :-)

Zach: that's some SERIOUS phantom power you're getting there.... what are you seeing on the secondary of your power transformer (AC voltage between green and blue)? What's the DC voltage after the rectifier, before the regulator? Check with a fine-toothed comb for incorrectly placed components and solder bridges.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 21, 2009, 02:33:50 PM
I think we got it figured out, turns out the phantom is about 66.8 – so looks like the reg is just gone. I think I was originally measuring AC and not DC for the +48. Voltage from 0V to both AC ins was 25.5.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Bluzzi on January 21, 2009, 05:28:56 PM
Don't feel too bad. I blew my JLM by connecting my 0v to the center terminal! I didn't look at the schematic that one time and I presumed 0v would logically be in the center. WRONG! Blew 2 resistors and 1 regulator. All back to normal now. Oh yes also I hadn't soldered the jumper so I was getting erratic measurements.

Jim
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on January 22, 2009, 08:35:16 AM
JLM stuff is awesome!

But i managed the V+ regulator to not regulate enough....it was putting 24V, when loaded with a 1290 it fall down to 19V....not good sounding.
then i set the 48V to +24 and the sound great.....what happens??

See i left out the V- parts...but putting them in the pcb fix the problem.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 23, 2009, 03:56:43 PM
Martin: I'm using a lighted rocker switch from Mouser

http://www.mouser.com/Search/ProductDetail.aspx?R=YRM32F2BBRLNvirtualkey54010000virtualkey540-YRM32F2BBRLN

I'ts switching on the power but not lighting up, I think I need to do something with the prongs on the other side but not sure. It looks like:

| |
| |

And I've got my wiring hooked up to the left side, 1 & 2.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 24, 2009, 03:58:33 PM
Hi Zach,

Neutral goes to either 4 or 5. Verify that you measure resistance between 2 and 5 before connecting anything to power.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: YLab on January 28, 2009, 01:24:05 PM
He!

I'm looking at the schematic of a compagny that make a popular neve clone and i can notice somme differences with the org. schematic. Here are some questions that i have if someone is willing to anwser them. :)

1- 100p instead of 180p accross the input transfo.
Is that to extend the top end??  This clone utilize the same input transfo than the ez1290.

2- 22uf tant instead of 10uf tant in front of the first bc184 of the input and output section.
Is that to extend the low end??

3- They suggest to put a loading resistor (620R) on the output.  If im going directly into my soundcard that have a 24k input impedence when balanced, should i care about putting a loading resistor??
I'm asking this because i've just notice that inside my api 3124, there's a place to put an ''optional 1k loading resistor''!!

Hubert
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 28, 2009, 02:26:54 PM
Whatever the specs are in Martin's 1290 design I think are all true to the original design. Not sure what other clone you are referring to.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: YLab on January 28, 2009, 02:40:29 PM
Whatever the specs are in Martin's 1290 design I think are all true to the original design. Not sure what other clone you are referring to.

Yes,, i know that Martin's 1290 is true to the original, i'm just trying to understand what those value changes can do to the sound of the preamp. You know, i'm far from being a electrical engineer  ;D
The compagny i'm refering to is s c a.

Hub
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 29, 2009, 06:55:43 PM
Anyone have quick tips for measuring the TR3 Collector voltage? I'm not really sure I'm doing it right.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on January 29, 2009, 07:54:48 PM
All DC voltages  are taken from 0V to the desired spot!
http://www.musiciansgig.com/ez1290/transistor_voltages.pdf (http://www.musiciansgig.com/ez1290/transistor_voltages.pdf)

Usually put the positive lead over the screw...
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 29, 2009, 08:26:07 PM
Err maybe because I didn't have my output trannies hooked up to the board?

Hopefully the last thing, on the trim pots, pot #3 goes to the front 10k space, pot #2 goes to the L Jumper; does pot #1 go to the other 10k space, then you jump the 10k space to the P Jumper hole? I'm looking at the drawing now, just not sure how you connect those two together.

(http://aermotorstudio.com/trim.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: wolfgang on January 30, 2009, 06:19:12 AM
This wiring for the trim-pot should be ok !

I also want to know how a 600R Termination on the OT would affect the sound.
Read somewhere that on the old consoles the modules were loaded with 600R and now we are running the modules in 10K gear.
Could somebody explain pro and cons for terminating with 600R? Is it necessary?

best regards,
Wolfgang
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on January 30, 2009, 03:06:49 PM
My question was mainly about how to wire to the 10K spot, do I just go to the front 10k and the jumper or does something go to the back 10k as well?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on January 30, 2009, 04:13:05 PM
This wiring for the trim-pot should be ok !

I also want to know how a 600R Termination on the OT would affect the sound.
Read somewhere that on the old consoles the modules were loaded with 600R and now we are running the modules in 10K gear.
Could somebody explain pro and cons for terminating with 600R? Is it necessary?

best regards,
Wolfgang

this is actually interesting...
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on January 30, 2009, 06:36:54 PM
'Quick' search at Geoff Tanners site:

http://www.auroraaudio.net/dcforum/DCForumID1/506.html
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: wolfgang on January 31, 2009, 05:34:56 AM
Just wire the pot and leave the 10k resistor offboard. if you look at the pcb you will see that point "P" is connected with the backside of the 10k resitor.

regards,
Wolfgang


Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on January 31, 2009, 11:14:49 PM
Quote
1- 100p instead of 180p accross the input transfo.
Is that to extend the top end??  This clone utilize the same input transfo than the ez1290.

Yes, it would increase bandwidth - at the possible expense of increased ringing.

Quote
2- 22uf tant instead of 10uf tant in front of the first bc184 of the input and output section.
Is that to extend the low end??

Hmm, I'm not so sure. It could possibly increase stability; this could mean lower THD at expense of bandwidth. Or perhaps it was done to be more resistive to DC offset. I would be interested to hear SCA's reasoning for this, or perhaps ask Geoff T.

Quote
3- They suggest to put a loading resistor (620R) on the output.  If im going directly into my soundcard that have a 24k input impedence when balanced, should i care about putting a loading resistor??
I'm asking this because i've just notice that inside my api 3124, there's a place to put an ''optional 1k loading resistor''!!

As always, Geoff Tanner's info is GOLDEN (thanks Desol for posting):
>Hi Geoff,
>
>I have got a Neve 32074 with the BA283 and LO1166.
>Should LO1166 always be terminated with 600ohm?

No, not "always"... if your set up is relatively small and you don't have long cable runs on the output, you won't need termination on the output.

The terminations come into play when the cable on the output presents a sufficiently high capacitive content to the load of the transformer that will resonate with the leakage inductance in the transformer to produce a high frequency peak and would be seen as ringing on a square wave or sibilance on a voice or music signal.

Then a 600 ohm load would damp that effect though you might experiment with a scope and a square wave to find the optimum load... which might be higher, like two or three Kohms.

-----------
That said, I'm not sure "improving" these preamps is at all necessary, but that's a personal choice and a bit of experimenting is always good.

Zach, did you get that trimmer worked out?

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: YLab on February 01, 2009, 08:19:26 AM
Thanks for your anwser Martin, really appreciated!

By the way. i've just received my pc boards, and they look fantastic!!

Thanks again.
Hubert
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: basementmedia on February 04, 2009, 04:34:41 PM
Hey madriaanse,

are you still selling PCB's?
I'd want to built a 8 channel Version like yours...

Would be great to get this sound into my DIY collection which seems to be never completed AARGH ;-)

Greetings

Daniel
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on February 09, 2009, 10:40:16 AM
Hi Daniel,

Sorry I missed your post, I do have more PCB's available. Please email me at: 1290preamp [at] gmail.com.

Best Regards,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nikonet on February 09, 2009, 11:36:07 AM
 ;D
Hello !
i found my noise problem: i move the transformer outside the case

the PSU didn't make good job:
20v instead of 24v, so i use the 48v regulated to 24v .
I dont need 48v for this préamp, but i would like to know if it's possible to correct this problem: i would like to use it for other préamp.......

and a last question, how many préamps can i use with one PSU (PSU-2448 from fivefish)

thanks a lot every one , i think i'm going to be totaly addict!!!!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on February 09, 2009, 11:58:12 AM
From the looks of your powersupply, i'm thinking 2 channels.

30va / 24v =1.25A

If i remember correctly, Martin recommends 500ma per channel.

D.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on February 09, 2009, 07:43:56 PM
I'm putting a trim pot in my 1290's.

I would like to have a rotary fader , with a center detent for 0dbs.

What brands and models would you advise?


I've searched for Penny and Giles RF11 but it costs 120€.

I can Buy PEC from Banzai, but couldn't find any rotary fader there, just normal pots. the same for CTS

Vishay Spectrol can't find an easy European store.


Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on February 09, 2009, 09:37:15 PM
What are the differences with a rotary fader instead of of a pot?

I still need some high quality pots for my 4x 1290s...
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on February 10, 2009, 04:45:56 AM

center detent for 0dbs.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on February 10, 2009, 11:36:29 AM
Rotary fader(r11) is the way to go...but ya gotta pay the price.

One could always rig up a fader pack with used faders....they're pretty affordable on the market...but take up rack space. Then's there's the way that everything gets wired into the faders. I have two seperate preamp packs...6 in ea...both these types would connect to the fader differently. Still thinking about how to wire this up properly.





Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on February 10, 2009, 12:15:42 PM
unfortunately  I can't afford to pay  240€ for two R11.

Is there any other rotary fader alternative?

I would like to have 0dbs at the 12'oclock position, do I need a rotary fader to do that or any Pot would do the job?

I was seeing a 5K Log PEC, it costs 15€, much more affordable. It just feels strange for me not having a centre detent (if that's the correct name)

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on February 10, 2009, 06:07:43 PM
I would like to have 0dbs at the 12'oclock position, do I need a rotary fader to do that or any Pot would do the job?

I was seeing a 5K Log PEC, it costs 15€, much more affordable. It just feels strange for me not having a centre detent (if that's the correct name)

I think you might have the wrong idea. The trimpot is an attenuator only, and so all the way clockwise would be 0dB, and it's down from there - all the way to -Inf.

P&G or bust baby!! :-)

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on February 11, 2009, 07:54:24 PM
I think you might have the wrong idea. The trimpot is an attenuator only, and so all the way clockwise would be 0dB, and it's down from there - all the way to -Inf.

maybe I'm getting confused.

I attached a picture showing what I would like,

in number 1 the pot has a centre ident at 12oclock position where it says 0dbs.

number 2 it's exactly the case you described all the way it's 0dbs.


is it possible to have a pot that acts like the example in picture 1?


I searched for alternatives to the P&G 120€ pot,
what do you think of these ones?

http://www.banzaieffects.com/PEC-MIL-MO-LOG-5k-pr-26690.html

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on February 12, 2009, 03:24:44 AM
That Vishay looks nice...
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: R3 on February 12, 2009, 01:21:34 PM
madriaanse if your not too busy PM me when you get the chance, I've been trying to get ahold of you for 2 or 3 weeks but your box is full.
-Richard
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on February 12, 2009, 03:00:33 PM
I PMed you his email.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nikonet on February 21, 2009, 06:23:54 PM
hello Martin, i received 4 pcb 3 days ago

thanks; thanks; thanks!!!!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: skal1 on February 22, 2009, 07:13:36 AM
Hi madriaanse


This might be a stupid ? , is this pre amp the same used in the neve mic pre 1272 .

regards

skal1
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: junkmaster on February 22, 2009, 11:58:43 AM
so beautiful.... :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on February 22, 2009, 12:14:18 PM
Sorry for the delayed responses guys - been busy:

Quote
in number 1 the pot has a centre ident at 12oclock position where it says 0dbs.

number 2 it's exactly the case you described all the way it's 0dbs.


is it possible to have a pot that acts like the example in picture 1?

Hi Whoops
You can print anything you want on the front panel. :-) The pot is an attenuator only (gain comes from the gain switch) and cannot be made to add gain without significant departure from the original design.

Quote
I searched for alternatives to the P&G 120€ pot,
what do you think of these ones?

http://www.banzaieffects.com/PEC-MIL-MO-LOG-5k-pr-26690.html

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

If you really don't want to use P&G, I would start by searching for some "decent" conductive plastic potentiometers and trying them to see how they sound and feel. My resentment for cheap pots comes from their poor operation over time, the way they degrade sound/add grain, and how rough they feel. If you come to find out that none of the pots work out you can always switch back to "faderless" by putting the resistor back in - shouldn't take more than a minute.

Quote
if your not too busy PM me when you get the chance, I've been trying to get ahold of you for 2 or 3 weeks but your box is full.

Hi Richard, please email me at: 1290preamp [at] gmail.com

Quote
hello Martin, i received 4 pcb 3 days ago

thanks; thanks; thanks!!!!

Hi Nikonet, you're very welcome and enjoy, enjoy, enjoy!!!! :-)

Quote
is this pre amp the same used in the neve mic pre 1272 .

Hi Skal1, up to 50dB a (correctly wired) 1272, a 1290 and a 1073 (w. eq disengaged) should sound absolutely identical because their inards (BA183, 10468, LO1166) are absolutely identical WITH THE EXCEPTION OF: an additional pre-stage (BA183NV) in the 1290 and 1073. (the 1073 also has EQ of course) A 1272 was designed as a bus amplifier, and was never meant to have more than 50dB of gain. To get more than 50dB of gain without adding significant distortion, the 1290 and 1073 switch in this extra pre stage. Any 1272 with more than 50dB has been "hacked/cranked" and should not be taken serious past 50dB. (IMHO)

Quote
so beautiful....

Thanks!! :-) They are great fun to record with and get used all the time!!

Hope this helps!! :-)

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: skal1 on February 22, 2009, 04:58:48 PM
Thanks for response, have you got a self etch pdf ,or do i have to buy the boards from you .


regards

skla1
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on February 23, 2009, 11:52:03 AM
Hi Skal1,

See first post :)

All the best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: okgb on February 23, 2009, 11:57:15 AM
it's so worth it , just to have someone offering boards
the EZ version really is so
thanks Martin
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Neil on February 23, 2009, 12:18:38 PM
This is on my list of get-to projects. Thanks for offering this Martin!!

Is it possible to build a 2-ch version into a 1 RU case? All of the ones I've seen are 2 RU high, but would like to start with just 2 channels and conserve rack space. Is using a 1 RU case not advisable because of the proximity of the transformers to each other, or can it be done fairly easily? Ideally I'd like to have the PSU in the same case, but I realize that may not be good. Has anyone done such a thing? I will probably be using an ACDC for power.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on February 23, 2009, 02:27:39 PM
Thanks for the kind words Greg and Neil!!

You can certainly fit everything in a 1U. With a bit of creativity you can even fit 4ch into a 1U (deep case, w. external PSU). Check out the most recent finished EZ1290 build: http://www.groupdiy.com/index.php?topic=32196.0 You'll want to order the Narrow Board output transformers from Audiomaintenance: http://www.audiomaintenance.com/acatalog/CA-18-VTB1148_extended_info.html
Also, use a low profile heatsink on 2N3055, and you may have to mount the 470u caps on their sides.

I am not a fan of having the PSU inside the case, but it should be ok if you have audio and PSU components on far opposite sides inside the case.

Best Regards,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on February 24, 2009, 07:18:00 PM
ALl that's left for mine is to get my FP made and then put it on! I fired it up today for the first time and audio was all messed up, then I realized I forgot the jumper  :-\ Once I put those in, sonic glory. I don't currently have the pots wired but will probably add them, not sure yet. Pretty stoked it worked first time up. Completed unit pictures coming soon.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on February 24, 2009, 08:06:06 PM
thanks for explaining Martin,
I will try the Vishay conductive plastic pots,
they seem to be the best option in terms of quality / price !!

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on February 24, 2009, 09:26:15 PM
Along the pot lines I asked Mark at Brent Averill today what he uses for the 1272's and he said he uses 5k Panasonic Plastic Conductive.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on February 25, 2009, 08:03:27 AM
Cool.

I know that Phoenix Audio use 10K Vishay plastic conductive also.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: zachs on March 01, 2009, 02:36:48 PM
Do you have a part # for the pots you're using Whoops?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on March 01, 2009, 03:36:45 PM
I think Whoops is talking about the Vishay-Sfernice pots.. Very nice, yet a bit expensive... If you can get your hands on some OMEG ECO pots in the resistance/taper you need, you'd save yourself some serious $$. They too are conductive plastic and nice quality so should last a bit longer than run-of-the-mill carbon pots.. Can't comment on the quality difference between the vishay and omegs though. I would assume the vishay-sf are more rugged.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on March 01, 2009, 05:34:18 PM
Do you have a part # for the pots you're using Whoops?

I will use this ones:

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

They are Vishay, and are quite affordable.
I would not go with anything cheaper than this.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: kml23956 on March 12, 2009, 05:32:48 PM
Martin,

Do you have any boards left?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on March 12, 2009, 06:56:26 PM
I have more coming in soon; shoot me an email at 1290preamp [at] gmail.com

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: stitch-o on March 12, 2009, 08:30:37 PM
Do you have a part # for the pots you're using Whoops?

I will use this ones:

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

They are Vishay, and are quite affordable.
I would not go with anything cheaper than this.


in the US, I found this for trim:
http://www.mouser.com/Search/ProductDetail.aspx?R=6187R5KL1.0virtualkey57700000virtualkey858-6187R5K
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 4toes on March 18, 2009, 06:23:02 PM
does anyone know how you would wire a phase and pad for this build?
is there a kit somewhere, or is it easy enough to do it myself?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: trancedental on March 19, 2009, 12:38:33 AM
does anyone know how you would wire a phase and pad for this build?
is there a kit somewhere, or is it easy enough to do it myself?

Igor has a preamplifier universal input board kit available here with Pad / DI & 48V http://www.groupdiy.com/index.php?topic=29771.0

I've ordered one of those myself, looks easy enough ;D

Just waiting for a few parts on my EZ1290 to finish off, missed the post today. Still at least I've managed to build & test my JLM AC/DC power supply without mishaps!  :o
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on March 19, 2009, 11:01:20 AM
OK, finally getting around to sourcing these parts. A bit of confusion for me... The trim pot next to the 2N3055 (output bias, right?) is marked LOG on the board. But the digikey part on the BOM does not say anything about being LOG... Nor does the datasheet, unless I missed it.  Is there a reason you want a log trimpot for this? Or is this a misprint? Or did I miss something?

Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on March 19, 2009, 01:50:00 PM
does anyone know how you would wire a phase and pad for this build?
is there a kit somewhere, or is it easy enough to do it myself?

JLM Go Between Kit

Or

Igor preamp input board Kit

those are the best options in my opinion.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on March 19, 2009, 05:08:40 PM
Hi Mitsos,

Just follow the BOM; all the parts on there are tested to work fine.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: kml23956 on March 19, 2009, 06:10:50 PM
Martin,

I received the boards today.  That was fast, thanks.

Did you do the metal work for the board mounting?

Kevin
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on March 19, 2009, 07:32:07 PM
Hey Martin, thanks for the reply.. Can you confirm if it's an ordinary linear Tpot or, in fact, LOG? I don't live in the states so won't be ordering from Digikey... I found all the resistor values and caps, and (I think) this is the last thing missing..

ALSO, I saw that my board is v2.0 (got it from a member here, he must have had it for a while)... does this make any difference besides with the output fader? The instructions on how to connect one look a bit different (looks like I'd have to cut a trace to add the fader?? )

thanks!

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: YLab on March 19, 2009, 10:50:33 PM
The trim pot next to the 2N3055 (output bias, right?) is marked LOG on the board. But the digikey part on the BOM does not say anything about being LOG...

Hi Mitsos.

Its a 25 turn 5k regular trim pot (multiturn). The BOURN on the BOM is the right one. Dosent really mather for a trim pot if its log or linear.

Hubert
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nflame13 on March 20, 2009, 08:30:25 AM
Hello i am looking into making the 1073 as my first project, but as i am a student i wanted to know how much the total would be for a 2CH 1073/1290, before ordering the PCB's. Pice would be in £'s preferably.

Thanks :)

Regards
Sam
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on March 20, 2009, 10:37:22 AM
Hello i am looking into making the 1073 as my first project, but as i am a student i wanted to know how much the total would be for a 2CH 1073/1290, before ordering the PCB's. Pice would be in £'s preferably.

Thanks :)

Regards
Sam

Hi Sam welcome to the forum.

The best thing for you should be download the different BOM's (Bill of Materials list), and do a rough check on the different parts, and prices in Europe and the UK.
you can get the 12Pos Switch, input and Output transformers from Audio Maintenance.
The rest of the Parts get them from Farnell.

As this is your first post and you are new to the forum, I advise you to read the full thread from the beginning to end,
like myself and everyone else did.

hope I could help you

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Bluzzi on March 20, 2009, 11:09:43 AM
Sam,  welcome to the forum. If you want to build pro quality audio gear this is the place. Not knowing your level of experience I will assume that by "first project" you mean first project ever and therefore a beginner? If so I advise against a 1073. That is first an expensive project and second not many here have done a finished 1073 so you have almost no one to fall back on for questions.

However the EZ1290 (preamp of the 1073 without EQ) is much cheaper and I believe could be done by a beginner but....I would start with something simpler and cheaper. One 1290 would set you back about 250 BPDs. Something like the Green pre would cost around 50 BPDs.

Please don't get offended if I am implying beginner and you are not as its only a guess. People here are very helpful for the most part and will recommend projects so that you succeed and have a great experience in DIY. That is what gives you the push to go on to other projects.

Again welcome and enjoy.

Jim

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: danjpiscina on March 21, 2009, 03:05:03 PM
Hey. quick silly question semi-regarding the 1290's. Doe's anyone know where to get those sticky cable tie things that you can attach to the side of a chassis? Like, they're really useful for organizing cables, but I can't find anything when I search "sticky cable tie thing" in Mouser! haha.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nflame13 on March 21, 2009, 04:36:25 PM
Hi thanks bluzzi and whoops for answering my question, As for the project being to hard i should be ok. I am skilled at soldering, surface mount rework and very fine pitch components. And pratically there has been nothing yet i havnt be able to do. This is because i used to build ultrasonic thickness gauges for a company called cygnus instruments here in the uk. This was where i learnt 90% of my skills but unfortunatley i was just soldering and assembling, with some fault finding and repairs. So my theory of electronics has much to be desired and this is something i want to improve on, as i was only using work instructions to build products, which is simple enough, but i didint know the exact going ons in side the circuits! ;D I am studying Audio engineering at SAE london and want to put my practical skills to good use and develop them for later on in my carrer in studios! I hope this project goes well for me it looks fantastic i cant wait to get started!

Are farnell the best suppliers here? I know of RS CPC Farnell and Rapid, but im not sure who is the cheapest? Is digi-key any good?

I have just ordered 2 boards does any one have the most recent and up to date Components list and assembly guide? i see there have been a few versions and wanted to get the most up to date??

Sorry that my question arnt to project specific!

Any help will be really appreciated!

Regards
Sam
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on March 21, 2009, 05:23:30 PM
Is digi-key any good?

I have just ordered 2 boards does any one have the most recent and up to date Components list and assembly guide? i see there have been a few versions and wanted to get the most up to date??



Digikey is excellent. I've had great service from them.

There aren't very many changes between old and new revisions. New has 470 35v cap's on rails...instead of 470 25v(this includes lead spacing differences)....and greyhill switch doesn't need to be cut...that's about all i can see?

Got 4 old and 4 new here.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on March 22, 2009, 12:32:30 AM
Hey. quick silly question semi-regarding the 1290's. Doe's anyone know where to get those sticky cable tie things that you can attach to the side of a chassis? Like, they're really useful for organizing cables, but I can't find anything when I search "sticky cable tie thing" in Mouser! haha.

Are these the ones you are asking for?

http://www.banzaieffects.com/KC-04J-Cable-Clip-pr-26200.html

http://www.banzaieffects.com/KC-06J-Cable-Clip-pr-26201.html

(this shop is in Germany)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on March 22, 2009, 12:36:44 AM
hem for later on in my carrer in studios! I hope this project goes well for me it looks fantastic i cant wait to get started!

Are farnell the best suppliers here? I know of RS CPC Farnell and Rapid, but im not sure who is the cheapest? Is digi-key any good?

I have just ordered 2 boards does any one have the most recent and up to date Components list and assembly guide? i see there have been a few versions and wanted to get the most up to date??

Sam,
all the documents you need are in the first post of this thread by Madriaanse.
To complement that you should read the full thread, that will help you a lot understanding the project.
It helped me a lot.

In the UK you can also try Maplin, they are everywhere and have most of the basic stuff also.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: danjpiscina on March 22, 2009, 05:35:06 PM
Hey. quick silly question semi-regarding the 1290's. Doe's anyone know where to get those sticky cable tie things that you can attach to the side of a chassis? Like, they're really useful for organizing cables, but I can't find anything when I search "sticky cable tie thing" in Mouser! haha.

Are these the ones you are asking for?

http://www.banzaieffects.com/KC-04J-Cable-Clip-pr-26200.html

http://www.banzaieffects.com/KC-06J-Cable-Clip-pr-26201.html

(this shop is in Germany)

YES!!!! thanks. it's funny how such simple, useful things can be so hard to find. cheers!

Dan.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: trancedental on March 23, 2009, 04:29:48 PM
Just powered up one channel & tried it out with a few different mics, this pre sounds fantastic , even tried it with a cheapo T Bone Ribbon mic which cost £50 ;D Doesn't even need much gain, plenty on tap here. It also likes my knackered old Sennheiser MD441D as well! What a great larger than life sound especially on bass frequencies :o Thanks to Madriaanse for all his hard work for making this possible ;D

Just got to install Igors DI 48V Pad & do the other channel, although the crap Maplin 1U case I got has the inside dimensions probably too small for the VTB1148 narrow version of the output transformer ??? Might need to get another case? :'(

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: skal1 on March 26, 2009, 01:32:37 PM
Hi everyone just need to clarify some thing about this 1290 .I have no need for a mic pre  but i was wondering could i just connect  the vtb 9046 instead of the one been use for the input .

Would this be a straight swap ,or do i have to change some componets

regards

skal1
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: sgenevay on March 28, 2009, 07:31:11 PM
hey madriaanse 

i'm new here...   just wanted to say i'm really impress by your work ...   i wanna try to make one preamp to see if i'm abble to make it work...   i sent u a mail to know if it's possible for you to sell me a PCB (if u still have some of course) or send me via mail the draw of the board....  i can of course send you the price you asked via paypal .. just give me the informations..
my mail is:       sgenevay (at) free (dot)  fr
I can't wait to start this interesting work :)))))

thhhxxxxxxxxxxxxxxxx
regards

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nflame13 on April 14, 2009, 05:49:37 PM
I received 2 boards about 2 weeks ago now im back from holiday i cant wait to get started the boards look spotless and are of a fantastic quality!
Thanks Martin!

A quick question on Digi key how much more will they charge for the components to the uk?? do you have to pay VAT or any extra?

Regards
Sam
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Slenderchap on April 15, 2009, 02:02:16 AM
If you go to the digikey UK website;

http://dkc1.digikey.com/uk/digihome.html

and order from there.... the prices are in pounds and include all your VAT and import duties (and freight if you order enough).....

The stuff comes by UPS about 3-4 days later....

It is just as though you had ordered it from a UK based company.... really easy (that is my experience of Digikey anyway)

Colin
www.audiomaintenance.com
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on April 15, 2009, 12:52:04 PM
Ah, great reply Colin!! Digikey UK also has the BC184C's and 2N3055's btw, so you can one-stop shop. :-)

Skal1, if you just need a LINE-IN module only, I'd do the following:
1) buy: CA-18-VTB9046 from www.audiomaintenance.com
2) buy: 71BD30-01-1-AJN (but preferably -AJS if in stock) from Digikey
3) leave the second pre-stage empty on the EZ1290 (closest to switch), and leave off the onboard rotary switch and surrounding resistors
4) point to point wire according to "Neve EH10023" - that's R1, R7, R9, R24, R25, R26, R27, R28, T2, C6 on www.technicalaudio.com/neve/neve_pdf/1073-fullpak.pdf (page 2). You'd connect to "U" of the first pre-stage, which on the PCB is to the right of the horizontal 18K resistor near the bottom.
The switch should be very simple to wire up because there's only one deck/pole and 7 positions; you'll also want to "stop-pin" it after the 7th position.

As I've said before, if there's enough demand it would be easy for me to do a line-in version of the EZ1290, but so far almost everyone wants a mic pre. The point to point work described above is really so pedestrian it's hardly worth sticking the rotary on the PCB. Different story for the mic-pre however. :-)

Enjoy the preamps Sam!!! :-)

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on April 15, 2009, 02:21:52 PM
Martin,
Does leaving out the one pre stage make it like a 1272 then?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on April 15, 2009, 02:55:37 PM
Hi Mitsos,

Sort of. If you wire like above, you'd basically have a 1272 with line-input (31267) only. A true 1272 has the 10468 transformer to match the impedance of a passive summing bus (like NYD's design) and provide about 40dB of makeup gain. If you built an EZ1290 per my instructions, but omitted the 2nd pre stage, stopped the PCB mount rotary after 50dB you'd essentially have a 1272 - with adjustable gain from 20-50dB.

HTH,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on April 22, 2009, 05:37:37 PM
Just powered up one channel & tried it out with a few different mics, this pre sounds fantastic , even tried it with a cheapo T Bone Ribbon mic which cost £50 ;D Doesn't even need much gain, plenty on tap here. It also likes my knackered old Sennheiser MD441D as well! What a great larger than life sound especially on bass frequencies :o Thanks to Madriaanse for all his hard work for making this possible ;D

Hi trancedental, sorry I missed you post!! Congrats on the successful build!! Happy tracking!

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: hotbaby on April 23, 2009, 12:58:14 PM
where did you buy the 10pin power plug with the blue inside?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on April 23, 2009, 02:30:56 PM
I ordered those from Allied Electronics. I believe they were Amphenol Series 97 (w. solder cups).

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: hotbaby on April 23, 2009, 04:42:23 PM
must have these for my extern psu, thanks :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: tskguy on April 28, 2009, 12:27:36 PM
Whats up!

Is anyone still producing the ez1290 boards? If so I may be interested in four or so.

Thanks,

Eric
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on April 28, 2009, 05:51:41 PM
Hi Eric,

Email me at 1290preamp [at] gmail.com

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on April 28, 2009, 07:45:33 PM
BC184L instead of BC184C?
They are out of stock at Digikey.
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on April 28, 2009, 07:56:16 PM
Hi 3Nity,

Don't use the L's; pinouts are different. I'd just order from Mouser.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on April 29, 2009, 08:25:05 AM
Thanks Martin.
I did ordered from Newark.
Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: luis on May 03, 2009, 08:12:58 AM
Hi Zachs,

Did you ever did a FPD file from your design? Would you share it?
I would like to build a 4 channel, and I think you design is awesome!

Thanks,
Luis

Updated a few of them, yea I'm really liking the #2 in the 2U, made some tweaks to fonts etc, if everything can actually go together like that I'll be very pleased, it's gonna be a freaking tight squeeze though.

(http://aermotorstudio.com/neve-mockup-2.jpg)

I'm trying to decide what would be the best way to make these:

1) FPE
2) Laser Engrave
3) Silk Screen

I think I'm leaning towards silk screen for a nice authentic look, anyone know how that compares to FPE?

Just thinking about this more and more, I think I'm going to try and add the Trim Pot to this as well. That's gonna mess with my space! Maybe I do need the 3U  ::) Anyone know where the get the grey small Neve knobs?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: echotodd on May 03, 2009, 11:48:23 PM
Hey Martin,

I'm in the process of putting my two 1290s together.  Just waiting on some transistors and transformers.  After stuffing the boards tonight I've got to say I'm really impressed with how you laid the circuit out.  It's nice to see each gain stage separated and spaced out.  No issues yet, I just wanted to give a thumbs up!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: guidoz on May 08, 2009, 08:00:58 PM
I still havent started building it, but was wondering if it was possibile to have both configuration (LINE IN as explained by Martin above) and original MIC IN in the same unit.

ciao..
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: rmccam on May 11, 2009, 10:17:57 AM
Okay, I finally have everything ready to go with my 4-channel EZ1290 but I'm second guessing how I populated the PSU after seeing this...

(http://jlmaudio.com/JLMACDCneve.jpg)

I used a JLM Powerstation - which I realize isn't what's being shown there - which I just fully populated and added heat sinks to the transistors. However, looking at that picture, should I have not fully populated it? Do I have to remove those caps and add those extra jumpers? Am I still using the jumper for the voltage doubler (not the tripler)?

I have +V1 heading to channels 1 & 2 of the EZ1290, and +V2 heading to channels 3 & 4, so I'm not using the negative rails. Even though I still populated them. I'm itching to fire this up.

Thanks!!!


Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on May 11, 2009, 02:50:11 PM
Okay, I finally have everything ready to go with my 4-channel EZ1290 but I'm second guessing how I populated the PSU after seeing this... Do I have to remove those caps and add those extra jumpers? Am I still using the jumper for the voltage doubler (not the tripler)?


How is your secondary set up on the transformer? Series or parallel? If your using a series connection(12x0x12v) to get your 24 volts, the answer is no to the above question. If your secondary is in parallel(24v-0v) then you would want to make the necessary changes for full wave rectification and tie the two diode legs as Joe suggested for the 48v rail as well.

( I think i sort of know what i'm saying... :) I'm learning too. Someone correct me if i'm wrong)

How you populate and which voltage multiplier u use...depends on how you connect and what your secondary winding is. Double check the JLM website for instru. Voltage multiplier is where our 48v comes from, simply input voltage doubled or tripled.

Make sure to use the largest heatsinks you can or install rectifiers 'underneath' the pcb, bend backwards and attach to to bottom of the case with insulation. You could attach the rectifiers off-board with wires as well, instead of bending the legs. Make sure to test all voltages in and out of powerstation before hooking anything up...and be sure to attach a fuse to the secondary of the transformer before powering up, just in case something smokes. Always have a fuse hooked up...and spare fuses to boot.

Maybe Joe will chime in here. Again, I think i know how this works, but be sure and double check with Joe.

D.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on May 21, 2009, 11:39:26 AM
Well, thus far, i've completed populating 8 cards(nearly passing out a few times)...and managed to get one hooked up.

.....Punchy as 'hell'....with just vocals, full sound, lots of gain...sounds really good.
Everything is pretty much on hold until i get frontpanel done. $220...youch...


(http://img132.imageshack.us/img132/6625/dsc02020b.th.jpg) (http://img132.imageshack.us/my.php?image=dsc02020b.jpg)


(http://img200.imageshack.us/img200/1245/dsc02018.th.jpg) (http://img200.imageshack.us/my.php?image=dsc02018.jpg)


Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on May 21, 2009, 11:48:23 AM
220$ i get the front panel engraved for 15$ locally...
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on May 21, 2009, 11:52:58 AM
220$ i get the front panel engraved for 15$ locally...


I used frontpanel express...this was the pricing in the software quote...not sure if it's actual pricing.

Wondering if there's any way i can swing this somewhere else, with frontpanel express..cheaper?
Or maybe import into other software, for local engraver? hmm

I need to contact them, to find out what the deal is on pricing. Maybe that prices includes panel, etc.
Or maybe just have another look at the pricing list in the software...

Edit: nOPE. Just looked at price list. That's the price for just engraving and infill. actually $204...darn pricey as suggested.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on May 21, 2009, 06:18:14 PM
As 3nity pointed out, look for an engraver locally. They do CNC, sometimes laser and can usually work with Corel files.  Get a piece of anodized aluminum, let's say black, then put some kind of clear sticker on the engrave side (ask the engraver what would work with their machine, you don't want the laser to melt the whole thing) so that they engrave through the sticker. When you get it back, take some white paint to the sticker-covered faceplate, let it dry, then peel off the sticker. What you should have left is an engraved panel with inlaid paint. Since the paint is in the grooves, it shouldn't rub off with use and should be a heck of a lot cheaper than FPE. Haven't tried it but I think someone did this with Chae's service (white market). Now that I think of it, depending where you live, Chae may be able to do this cheaper.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on May 21, 2009, 06:20:52 PM
Thanks for the advice. I gotta find some other solution for this cause yes, it's just way too expensive.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on May 21, 2009, 06:40:05 PM
Yeah FPE is pretty $$$. I would also recommend Chae Ham's services here on Prodigy Pro. I checked with him a while ago; he is very reasonably priced, and his work looks great: http://www.groupdiy.com/index.php?topic=27917.0

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on May 21, 2009, 07:31:59 PM
Thanks Martin(and Mitso)...I'll contact Chae. I also like the idea about the sticker.

I fired up a channel the other day and was blown away. My API's are great too...punchy lows, etc.
They both have that top end shimmer...but it's hard to believe the the N*ve bottom end...it's bigger and more complex or something. Hard to describe. Bigger overall. Awesome sound.

Definately different than the API. Both great...

D.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on May 22, 2009, 07:47:09 PM
Hi Desol,

That's really cool to hear; I am glad you like!! IMHO, they seem to be a very good pairing for digital recording. The 1290's really help smooth over and "fill out" the sharp, vacuous sound resulting from A/D conversion. Another project that I think does the same thing (and then some) is Drip's LA-2A w/ original iron - just stunning on bass and vocs.

Best!!

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on May 22, 2009, 08:07:45 PM
Martin, i wanted to point this out too regarding our frontpanel discussions above.

http://www.groupdiy.com/index.php?topic=33694.0

Cheers,

Darrick
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: djn111 on May 25, 2009, 11:34:45 AM
If possible I am interested in two PCB's
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: kambo on May 25, 2009, 03:58:42 PM
if you do line in only version, i take 8 :)

if more people interested....  may be open a new thread for this.

kam




Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: kambo on June 07, 2009, 08:05:27 AM
Ah, great reply Colin!! Digikey UK also has the BC184C's and 2N3055's btw, so you can one-stop shop. :-)

Skal1, if you just need a LINE-IN module only, I'd do the following:
1) buy: CA-18-VTB9046 from www.audiomaintenance.com
2) buy: 71BD30-01-1-AJN (but preferably -AJS if in stock) from Digikey
3) leave the second pre-stage empty on the EZ1290 (closest to switch), and leave off the onboard rotary switch and surrounding resistors
4) point to point wire according to "Neve EH10023" - that's R1, R7, R9, R24, R25, R26, R27, R28, T2, C6 on www.technicalaudio.com/neve/neve_pdf/1073-fullpak.pdf (page 2). You'd connect to "U" of the first pre-stage, which on the PCB is to the right of the horizontal 18K resistor near the bottom.
The switch should be very simple to wire up because there's only one deck/pole and 7 positions; you'll also want to "stop-pin" it after the 7th position.

As I've said before, if there's enough demand it would be easy for me to do a line-in version of the EZ1290, but so far almost everyone wants a mic pre. The point to point work described above is really so pedestrian it's hardly worth sticking the rotary on the PCB. Different story for the mic-pre however. :-)

Enjoy the preamps Sam!!! :-)

M.

thank you for this tip.

is this correct...not sure about the 0V connection!

(http://i852.photobucket.com/albums/ab85/kambokambo/neveconnection.png)

typo EDIT :  meant shielded cable on diagram :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: echotodd on June 08, 2009, 10:32:59 AM
Martin,

Just wanted to thank you again for the PCBs.  Two more completed 1290s entered the world over the weekend.  I let them burn in for a bit, biased them, plugged a mic in and smiled.  Very nice indeed!

Todd
 
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 08, 2009, 12:19:01 PM
Thank you Todd!! Great job, and enjoy!! :-)

Kambo, your diagram is correct. However, if you can wait a week or two; I am awaiting a shipment of 1073 line-in PCB's, and should have them shortly. Once I test them and all works out well, I'll make them available to the board. I made these boards because I needed a good front end for a 16ch. line mixer I'm building.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: wolfgang on June 08, 2009, 01:10:31 PM
Quote
I am awaiting a shipment of 1073 line-in PCB's, and should have them shortly. Once I test them and all works out well, I'll make them available to the board. I made these boards because I needed a good front end for a 16ch. line mixer I'm building.

Thats great news!!!!!

Will this be line-in only or switchable line/mic?

greetings and good luck for this project!!!
Wolfgang
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: kambo on June 08, 2009, 01:13:42 PM
:)
i am a very happy man.

if only line input i take 8 :)

thank you
kam


Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 08, 2009, 01:25:07 PM
Thanks Guys! They will be line-in only. I'll start a new thread once everything's been thoroughly tested and checks out perfect.

Best,

m.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: guidoz on June 11, 2009, 09:19:50 AM
Thanks Guys! They will be line-in only. I'll start a new thread once everything's been thoroughly tested and checks out perfect.

Best,

m.


Great..!.sounds veery interesting..:)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: solderspongebob on June 13, 2009, 06:22:39 AM
Hi madriaanse,

Wonder if you could have a quick look at the figures below please - these are the transistor voltages on an EZ1290 I'm trying to get working:

TR       C          B          E       
12.2520.9420.378
223.442.2331.678
323.441.6781.117
4a3.7552.3701.821
4b3.7692.3761.823
5a12.253.7553.153
5b12.293.7673.169
6a20.6412.2511.64
6b20.6612.2911.67

(where 4/5/6 a are in the 1st gain stage, and 4/5/6 b are in the 2nd gain stage - transistor numbering and voltages refer to this document: http://www.musiciansgig.com/ez1290/transistor_voltages.pdf (http://www.musiciansgig.com/ez1290/transistor_voltages.pdf))

I'm a little concerned about the figures shown in red as they are a bit off from the measurements in your document, although the above figures are taken with the input and output transformers connected, but no signal present; oh and supply rail at +24.05V.

Problem is I'm getting barely any output - very low level and distorted. If I turn up full gain with a microphone connected then it starts to smoke a little around the output stage  :o (couldn't locate what was smoking and nothing looked charred!).

I have two sets of transformers and two boards built up - both exhibit the same behaviour. I've checked PSU and all is good; phantom power to mic is ~49V, so OK there too. I've also swapped transformers between boards with no difference. Would disconnecting the transformers and ohming the coils prove they are working? (I'm not sure what measurement to expect as I'd be measuring resistance and not impedance - advice welcome).

Any ideas? I think something simple is wrong here and I'm going to publicly end up wearing the dunce hat for a week afterwards  :D

Any help appreciated.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on June 14, 2009, 12:34:06 PM
Just wondering if anyone has built these with the conductive plastic pots mentioned earlier and what their experience has been?

Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 17, 2009, 03:42:10 AM
Hi Soldersponge,

Sorry for the delayed response. Take a real close look at R3 (68K), R6 (18k), R7 (47R) - are they the right values? You're probably smoking R7. Also, see if you can adjust the trimpot so that you see about 22V on the TR3 collector.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: solderspongebob on June 17, 2009, 04:31:49 AM
Hi madriaanse,

Thanks for the suggestions - I will double check those values those later today and also get the oscilloscope out and trim the bias.

The good news is that I got the preamp working last night after re-writing my connections to the transformers; I couldn't see anything wrong with the wiring before, but re-did it anyway and now it works!

Also, the output transistor barely got warm and there was no smoking this time!!!  :D

I did initially think I had a problem with a buzzing noise, but after a couple of minutes I found the cause - it was my temperature controlled soldering iron!!!  :o  Once I switched it off, there was no more buzzing - I guess it just uses a similar circuit to a dimmer switch and was after all right next to the circuit I was testing. Just goes to show...

Now to wire up and check out the 2nd preamp.

Many thanks madriaanse!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 17, 2009, 12:41:06 PM
Great!! It sounds like you may have had a cold solder joint. Also, make sure the 12R and 270R are the correct values.

Speaking of cold solder joints, the new EZ1290 V2.2 boards will have bigger .080" solder pads, and are even more "EZ" to solder. (my apologies for the lame pun)

Best,

m.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on June 17, 2009, 01:12:57 PM
Hi madriaanse

for the 47ohm resistor, the board says 1w, but the part number in your BOM is a 1/2w resistor.

Is the part in your BOM (and in my possession) OK to use, or shall I get a 1w version?

Thanks a lot, boards are great quality... a pleasure to work with!

Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 17, 2009, 01:30:19 PM
Hi Jake,

1/2W from the BOM works just fine.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on June 17, 2009, 02:57:50 PM
Sorry if this maybe has been asked, but what PSU is everyone using to power 8 channels?? I don't mean the trafo, I mean the board/regulators. For example, if you use a LM7824, it's good for 1 amp, right? This would give you .125 Amps per channel, which is over the original neve spec, but way below what most people are calculating their trafos for.  So, I guess I am wondering if we are potentially bottlenecking these things if we calculate our trafos to put out 0.5 Amps per channel yet use a PSU that is capable of much less? Is there a 3-4A version of the 7824?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on June 17, 2009, 07:17:16 PM
I asked Joe at JLM. He told me the 1290 uses about 120ma ea...but have a large surge on power up.
Not sure how much it'll use when pushing low impedances.

I'm gonna use 2 x ACDC to power my eight....giving 375ma per channel. Should be good i figure, unless someone here suggests otherwise.
Cheers.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: danjpiscina on June 17, 2009, 10:51:09 PM
So to power 2 channels you use one ACDC, and that's tried and true. It's probably best to use 4 of them to power an 8 channel unit (Like Martin did)! At high gain (if you're tracking drums, for example) they're going to use more power and the pre's might not get enough. if they don't, they crap out and distort. That's one reason why it's best to "over-build" your power supply.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on June 18, 2009, 11:18:03 AM
So to power 2 channels you use one ACDC, and that's tried and true. It's probably best to use 4 of them to power an 8 channel unit (Like Martin did)! At high gain (if you're tracking drums, for example) they're going to use more power and the pre's might not get enough. if they don't, they crap out and distort. That's one reason why it's best to "over-build" your power supply.
That's what I thought.. I was hoping there was a higher current regulator available. I googled a bit after I posted and found this among other links:
http://ourworld.compuserve.com/homepages/Bill_Bowden/page12.htm

The second schemo uses a pnp transistor with an LM317 to do a 12V, 4.3A supply. Is it just a matter of swapping out the voltage setting resistors to get 24V (as well as using an appropriate trafo)??

ALSO, I just saw that the switches I got from someone here are non-shorting  ::)  .... Will this pose a serious problem or will wiring a resistor from each pole to ground take care of the pops? If so, how do I figure out the value?

thanks!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: danjpiscina on June 18, 2009, 12:51:55 PM

The second schemo uses a pnp transistor with an LM317 to do a 12V, 4.3A supply. Is it just a matter of swapping out the voltage setting resistors to get 24V (as well as using an appropriate trafo)??

ALSO, I just saw that the switches I got from someone here are non-shorting  ::)  .... Will this pose a serious problem or will wiring a resistor from each pole to ground take care of the pops? If so, how do I figure out the value?

thanks!

Good questions. Martin? Help!  :-\

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on June 19, 2009, 01:15:34 AM
maybe I'm confused on the switch, cuz the part number matches the bom. I had always just assumed it was shorting. Good thing I got these as a package deal, otherwise I would have bought the wrong switches.....  doh!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: dave_3283 on June 19, 2009, 02:50:15 PM
Does anyone know of any substitutes for the toroidal transformer?  Digi-key has it on *cough* 20 week back order.  All help is appreciated.

Thanks-
dave
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mitsos on June 19, 2009, 06:06:02 PM
call John at Antek for toroids. They also sell on Ebay but it's a couple bucks cheaper direct.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: guidoz on June 22, 2009, 05:49:05 AM
Hello everyone,

i am very happy to say that i finished building 2 channels 1290 and it sounds absolutely fantastic!! Thanks martin! :)

i just have one issue on 1 channel:
when i get to high gain (it should be around 50dB and more) i have no sound. when i tried it first it was going on and off, but now i have no sound at all. at lower gain it sounds fine and great.
I even havent set the bias yet.

any help is much appreciated!

thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Bluzzi on June 22, 2009, 11:17:58 AM
guidoz: Check for cold solder joint on the last switch terminal.

Jim
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: solderspongebob on June 22, 2009, 11:27:16 AM
Check the resistor values around the gain switch setting that produces no sound - if the resistance value is too large, it will also block out all the gain settings after the one you mention as they run in a chain.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: guidoz on June 22, 2009, 11:44:12 AM
thanks!
will check both options.

how can i check the resistance value? between which points on the PCB?

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on June 22, 2009, 11:59:29 AM
Read resistor values on circuit its almost impossible.
you said you have 2 channels? check 1 vs the other...
If it worked before maybe as Bluzzi said cold joint!

 ;)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Bluzzi on June 22, 2009, 12:21:19 PM
The resistors are connected to switch. So just make sure you are not in the position of the resistor you want to measure and it will be out of the circuit. If you can read the color code then look up value that way. But wait, you said you had 2 channels. So 1 channel works 100% right? Then compare color codes to make sure values are same, then measure (with switch in position 1 lets say) and compare.

If above does not yield any answer check for cold joint by either de-soldering and then re-soldering. Also make sure you do not have any solder jumping to an adjacent point. The gaps in between the Grayhill are quite tight and its more possible to solder badly there than anywhere else on the board.

Jim
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nflame13 on June 30, 2009, 10:14:08 AM
Hi All,

I am very nearly done with my 2 channel 1073/1290, i do have a few small issues that i would love some help with!

Firstly the ACDC PSU from JLM.
How do i populate the board for 230v/240v UK power, and how do i connect the Toroidal transformer from Digi key??
Also what voltages do i need to measure from the output of it?

Secondly i have designed a front panel using front panel express which i am happy with but i'm not sure how to design the rear panel and rack chassis to integrate with the front?? I spoke to the guys at FPE, they told me to design the rear just like the front, which im ok with i can do that just about. But how am i to know what rack chassis to buy to fit the front and rear panels from FPE???

The last thing is in the assembly guide it says to use 6/32 bolts to attach the heat sink and transistor to the board, what is 6/32 in mm is that and m4 bolt/nut etc?? Will these also fit the 4 holes for the main pcb to fix to the chassis??

Would appreciate any input,
Regards
Sam
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: wolfgang on June 30, 2009, 10:33:40 AM
Hello!

for the AC/DC: look at the JLM-Website. As you need only +24V and +48V you can leave the -V rail parts out!

And you should adjust it like said before to+24 and +48 for phantom.

I dont knw the digikey transformer. Is the primary 2x115 or 1x 230? doy you have dual secondaries?


FPE: I think you shhould buy a rack before you order at FPE. You can measure every hole to be sure your panels will fit in the end!


Heatsink screws are 4mm i think and the PCB mounting screws are 3mm.

In this minutes i am finishing my third 1290! Measured all voltages and they are fine!!!!!:)
Now i only need an osci to bias this great pre!!!

Many thanks to madrianse for this great sounding and so well documentet project!!!!!!!!!!

all the best,
Wolfgang
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on June 30, 2009, 11:38:51 AM
Firstly the ACDC PSU from JLM.
How do i populate the board for 230v/240v UK power, and how do i connect the Toroidal transformer from Digi key??
Also what voltages do i need to measure from the output of it?

Please see: http://musiciansgig.com/ez1290/220V_ACDC.pdf
Be sure to adjust for correct voltage **before** you connect to the EZ1290

Quote
Secondly i have designed a front panel using front panel express which i am happy with but i'm not sure how to design the rear panel and rack chassis to integrate with the front?? I spoke to the guys at FPE, they told me to design the rear just like the front, which im ok with i can do that just about. But how am i to know what rack chassis to buy to fit the front and rear panels from FPE???

You're putting the cart before the horse :-) - you'll want to buy the case first. Then design a panel for it and print a cardboard, 1:1 scale mockup to see how it all fits before ordering your panel.

Quote
The last thing is in the assembly guide it says to use 6/32 bolts to attach the heat sink and transistor to the board, what is 6/32 in mm is that and m4 bolt/nut etc?? Will these also fit the 4 holes for the main pcb to fix to the chassis??

6/32 has a 3.5mm major diameter.
M3 will definitely fit, M4 may or may not.

Hope this helps.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: nflame13 on June 30, 2009, 11:52:30 AM
ahh ok thanks guys that helps alot! ;D

Just one question for the acdc 220 v wiring diagram, what pins are yellow and violet connected to on the IEC connector. Basically which colour corresponds to live, neutral, earth etc?

Regards
sam
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 09, 2009, 12:15:35 PM
Hi madrianse,

My 2 channel project is close to finishing now... just need to wire up the xlrs to the transformers / boards / switches etc. Thanks so much for great boards and great documentation.

One thing im not 100% on is the input section on the board. As per your photos and the assembly guide, there are 2 connections from the input transformer to the board. However, on the 2.1 boards, there is an additional hole, between the power and input sections. Does this need to be wired up?

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: wolfgang on July 09, 2009, 12:44:10 PM
Hello!

I think this is just a 0V Test point for measuring!

wolfgang
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 09, 2009, 02:34:12 PM
I think this is just a 0V Test point for measuring!

Correct! :-)

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mmmyesm on July 14, 2009, 04:48:18 AM
Just paid for four 1290 pcbs... figured I'd drop a line here too.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 21, 2009, 01:49:21 PM
Hi Man... need a little more help ;)

Ive got one channel working fine, but one channel makes no noise. A quick visual check looks likes everythings right. Ive got power to the board...just no sound!

ive knocked up a diy signal tester but not 100% sure how to use it. Ive got 1 leg in ground and another making the circuit. When I touch pins 8 or 7 on the output transformer i get a signal, but when i touch pins 1 or 3 i dont. However, this is the same on the working channel. I cant seem to get a noise prodding away anywhere on either channel. The only difference I can find on the output transformer is that on the dead channel I get a signal if I touch the jumper between pins 2 & 4. The noise is a higher pitch than the test tone. One the working channel, I get no noise touching this jumper.

Any ideas ???

Thanks again (the working channel sounds nice!!) ;D
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 21, 2009, 03:13:17 PM
Hello,

How are your voltages?
http://www.musiciansgig.com/ez1290/transistor_voltages.pdf

so on LO1166 you have 2/4 and  6/7 jumpered, right? pin 1 goes to the pad marked 1 on the board, pin 3 goes to the pad marked 3 on the board? Shield's only connected to the board and nowhere else?

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 21, 2009, 03:58:03 PM
ive got the jumpers in, and the transistor going to the correct the pads on the board.

Just took some rough voltages. They are in the right ballpark, but a little off. Power at the board is only measuring 23.5v at the moment though.

Do I need to get these a bit more accurate?

Thanks a lot dude! 

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 21, 2009, 04:39:22 PM
Say, you don't happen to have an oscilloscope laying around do you? (That way you can trace the signal through the mic pre and figure out where the fault lies). Also, try reheating some of your solder joints.

m.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 21, 2009, 04:56:30 PM
Thanks man... no I dont have a scope unfortunately. Only the signal tester for now  :'(
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 21, 2009, 06:16:04 PM
I would highly recommend trying to score a cheap one (sometimes under $50) on ebay, craigslist etc. A good scope and signal gen. are indispensable.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 23, 2009, 05:49:07 AM
Thanks dude... I will try and pick up a scope when I see one for a good price.

I have done some more tests (seems I was using the signal gen incorrectly).

I can trace the signal up through the board to the area with the 4700p cap. The signal reaches one leg of that cap ok, but doesnt come out the other leg very strong. There is no singal at all on the 82u's.

Knowing this was the problem area, I tested the transistor voltages again and they are way off.

4, 5 & 6 are all fine. I couldnt easily measure 3 so i havent got that result now. 1 & 2 are as follows:

1)
C - 1.2
B - 0.0
E - 0.0

2)
C - 0.5
B - 1.2
E - 0.5

Does this make any sense to you?

Thanks for your help!
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 23, 2009, 05:38:07 PM
Im trying to figure this out on my own in the absence of assistance from the almighty creator ;)

Does anyone know where 'm' on the schematic comes from?

It seems to form the part of the circuit im having issues with. the 68k resistor is fine, which makes me think there is an error in the part of the circuit leading to the 68k... but I cant figure out what it is from the schematic.

All help very much appreciated!!

Cheers
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 23, 2009, 06:33:18 PM
Ah, m is +24 right?

Just a little development.... my working channel is no longer working, dont seem to get a signal on the output of the input tranformer anymore!!!!

Look forward to hearing from you genius's!!  :-*

Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 23, 2009, 06:41:18 PM
Hi
Im trying to figure this out on my own in the absence of assistance from the almighty creator ;)

Haha, I'm flattered, but "almighty duplicator" is probably more appropriate. ;-)

Anyways, can you measure the DC voltage on pin 1, 2, 3, 4 of LO1166 and report your findings? Did you try reheating all solder joints on the output section, and the 12R/1W (near the +24 connection)?

Best,

m.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 23, 2009, 06:45:09 PM
Ah, m is +24 right?

Just a little development.... my working channel is no longer working, dont seem to get a signal on the output of the input tranformer anymore!!!!

Look forward to hearing from you genius's!!  :-*

Jake

Hmm, try different gain settings and see if it only does that on certain settings. Also, how's the PSU doing? Still putting out +24?

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 23, 2009, 07:38:55 PM
Hi - thanks for getting back to me.

forget the issue on my working channel... the carnhill has died!!! Bizarre, but when i swapped it with the other one it works fine. I'll see if AML will do me any favors on a new one.

When i realized m was +24, I measured the 12r resistance. on the working channel i got approx -160, but on the broken channel i got approx 12. This made me think it was isolated form the circuit so I dropped a new resistor in, but no joy :'(

I will take the measurements of TR3 and get back to you.

(p.s - the 68k isnt fine..this was a mistake from me... its late here in the uk! ::) )

Thanks again!!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 25, 2009, 11:36:51 AM
Hi snipsnip, any luck sorting out the problem?

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Barish on July 25, 2009, 08:33:55 PM
Hi Martin,

Great boards, many thanks for the effort. Three questions:

1) Is there a preference for a particular make of 2N3005? Motorola or ST or On or something else?
2) Is there a preferable Hfe range for BC184Cs and 2N3055?
3) Does the Grayhill switch chosen for this project -that AudioMaintenance sells- have an adjustable stop to prevent it from going around the clock?

Also some of the Digi-Key codes in the BOM seem to lead to an irrelevand part number, so it would be good to check them just to make sure.

Thanks.

B.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Nele on July 26, 2009, 09:32:26 AM
Hi Barish,
Some quick answers about my almost finished 2-channel build:

1) Is there a preference for a particular make of 2N3005? Motorola or ST or On or something else?
2) Is there a preferable Hfe range for BC184Cs and 2N3055?
3) Does the Grayhill switch chosen for this project -that AudioMaintenance sells- have an adjustable stop to prevent it from going around the clock?

1. I used ST's
2. Don't think so. I just grabbed what I had lying around. Just be sure you use BC184C's, not BC184L's (different pinpout).
3. Yes. It comes with stop-adjust pins which you can insert yourself. It even comes with a sticker so the pin won't fall out.

adios,
Corneel
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Barish on July 26, 2009, 09:48:53 AM
Thanks for the replies Nele, vey much appreciated mate.

Regards,

B.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: ElectricApe on July 26, 2009, 01:45:30 PM
Here are some build progress pics of my 8ch mic pre:

http://www.musiciansgig.com/neeb/

It is almost finished; I just need to hook up the power supply. All channels have been tested, biased and are working as they should individually. Carnhill VTB9045, 9049 for I/O. The PCB's you're seeing are the EZ1290 pcb's that feature two pre stages, a driver stage, rotary switch, and all the other decoupling caps, resistors to make a 1290/1073.

This project has been a TON of work and in hindsight I probably would have built two 4ch, 2U units. Either way it has given me a lot of respect for the people who build consoles and modules.

Sorry for the grainy pics :green:

M.

----------------
EDIT:

I wanted to consolidate all the build info for these preamps here, see below:

Here is a complete BOM:
http://www.musiciansgig.com/ez1290/1290BOM.xls

Assembly guide:
http://www.musiciansgig.com/ez1290/assembly.pdf

Transistor voltages for troubleshooting:
http://www.musiciansgig.com/ez1290/transistor_voltages.pdf

To connect a trimmer to these boards, see:
http://www.musiciansgig.com/ez1290/trimmer_v2.1.pdf

Front Panel Design for 2U, 2ch:
http://www.musiciansgig.com/ez1290/circuit_specialists_2u_panel.fpd
(to open this file, you need Front Panel Designer. Free download from: http://www.frontpanelexpress.com/)



I´m new to this forum - hello everyone. I hava a question, does anybody know how much much cash this BOM takes ?

Glad for any hints, thank you.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: mmmyesm on July 26, 2009, 02:16:16 PM
pg 2, reply #37.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 26, 2009, 02:45:18 PM
Hi snipsnip, any luck sorting out the problem?

M.

Hi mate,

no luck yet. To complicate matters, I blew up my PSU when I first built it because I shorted the lm317 tab to the case. The board itself was quite damaged from the heat. I managed to frankenstein something together, but it seems the power is oscillating occasionally (damaged voltage reg?)... this means I cant really take readings from the TR3 for you at the moment.

I need to fix the PSU issue before following up on the other issue. Will try and hit you up for more advice soon though!!  ;D

Thanks for your help so far.
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Whoops on July 26, 2009, 08:34:00 PM
Hi snipsnip, any luck sorting out the problem?

M.

Hi mate,

no luck yet. To complicate matters, I blew up my PSU when I first built it because I shorted the lm317 tab to the case. The board itself was quite damaged from the heat. I managed to frankenstein something together, but it seems the power is oscillating occasionally (damaged voltage reg?)... this means I cant really take readings from the TR3 for you at the moment.

I need to fix the PSU issue before following up on the other issue. Will try and hit you up for more advice soon though!!  ;D

Thanks for your help so far.
Jake

Maybe Doing a new PSU that you can tottally rely on???

;)

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 27, 2009, 01:17:09 PM
1) Is there a preference for a particular make of 2N3005? Motorola or ST or On or something else?

Some people say they prefer the Motorola's. I haven't done any comparisons, but I will state the preamp sounds stunning with the ST Micro version.

Quote
2) Is there a preferable Hfe range for BC184Cs and 2N3055?

Yes, there is. I think Neve spec'd to use BC184's with HFE of 600 or higher, this would be especially for TR2. I haven't bothered with it. Noise hasn't been a problem with these and if I'm recording really quiet source I use GML.

Quote
3) Does the Grayhill switch chosen for this project -that AudioMaintenance sells- have an adjustable stop to prevent it from going around the clock?

Yes, if you insert the stop pin at 12 o'clock it will not allow you to switch from 70 to 20 dB or vice versa - a very good feature indeed! :-)

Quote
Also some of the Digi-Key codes in the BOM seem to lead to an irrelevand part number, so it would be good to check them just to make sure.

Thanks for the heads up. Which part #'s?

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on July 27, 2009, 01:52:20 PM
Hi mate,

no luck yet. To complicate matters, I blew up my PSU when I first built it because I shorted the lm317 tab to the case. The board itself was quite damaged from the heat. I managed to frankenstein something together, but it seems the power is oscillating occasionally (damaged voltage reg?)... this means I cant really take readings from the TR3 for you at the moment.

I need to fix the PSU issue before following up on the other issue. Will try and hit you up for more advice soon though!!  ;D

What PSU are you using? It's strange the LM317's "blow" like that - I've done that myself. I thought they were supposed to crowbar during shorts? You'll probably want to replace the 10R, the diodes and LM317.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on July 27, 2009, 06:06:00 PM
Hi mate,

no luck yet. To complicate matters, I blew up my PSU when I first built it because I shorted the lm317 tab to the case. The board itself was quite damaged from the heat. I managed to frankenstein something together, but it seems the power is oscillating occasionally (damaged voltage reg?)... this means I cant really take readings from the TR3 for you at the moment.

I need to fix the PSU issue before following up on the other issue. Will try and hit you up for more advice soon though!!  ;D

What PSU are you using? It's strange the LM317's "blow" like that - I've done that myself. I thought they were supposed to crowbar during shorts? You'll probably want to replace the 10R, the diodes and LM317.

M.

Hi, Im using the JLM Audio ACDC v2

The voltage reg didnt 'blow', but i replaced it anyway. The 10u caps nearest the 48v LM317 blew up and the 10r and 47r completely burned out.

I replaced the 317 as a precaution. So you think I should change the diodes too? Board is falling to bits so i think I better get a new one (sigh) thinking long term.

As soon as I get a stable PSU I'll give you the DC reading from TR3, and LO1166.

Ive also just ordered a scope, so this should maybe help?

Cheers!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: vitopower on July 30, 2009, 02:50:32 PM
PCB arrived right away, looks great!  Warming up the iron.  Thanks, Martin!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 02, 2009, 10:59:27 AM
Hi Martin,

Im building a new PSU, but I swapped out a voltage reg as a temp fix and managed to get it outputting a solid 23.5v for some tests.

Do these results mean anything to you?


TR3

C: 0.5
C: 0.5
B: 0.5
E: 0.0

The readings on LO1166 are
1: 0.5
2: 0.5
3: 23.5
4: 0.5

Just as a recap, my TR4, 5 & 6’s are all measuring OK, but my TR1 & 2’s measure as follows:

1)
C - 1.2
B - 0.0
E - 0.0

2)
C - 0.5
B - 1.2
E - 0.5

My scope has arrived, but its at my friends house. But I can get it at any point next week if you need me to do any further diagnostics.
Thanks a lot!
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: SIXTYNINER on August 03, 2009, 12:58:54 PM


HI madriaanse
interested about this project you made....
please , is possible add a DI input for gtr & bass
to this preamp?
thanks in advance
cheers
6t9r

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 04, 2009, 11:16:26 PM
Do these results mean anything to you?

TR3
C: 0.5
B: 0.5
E: 0.0

The readings on LO1166 are
1: 0.5
2: 0.5
3: 23.5
4: 0.5

Hello,

It seems something's not right with your LO1166. 23.5V on pin 3 is correct, but pin 4 and 2 should be about .3 volts lower than pin 3, and again, pin 1 should be about .3 volts lower than pin 2 and 4.

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: SaMpLeGoD on August 04, 2009, 11:48:17 PM
Hello Martin, how are you?! I tried to PM you, but your mailbox is full...  :-\
I'm writing you to ask if you have some EZ1290 boards available, and how much can it coast with the shipping to Portugal!
Thanks a lot for this awesome project!!

Cheers,

Eddie :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 05, 2009, 07:21:20 AM
Do these results mean anything to you?

TR3
C: 0.5
B: 0.5
E: 0.0

The readings on LO1166 are
1: 0.5
2: 0.5
3: 23.5
4: 0.5

Hello,

It seems something's not right with your LO1166. 23.5V on pin 3 is correct, but pin 4 and 2 should be about .3 volts lower than pin 3, and again, pin 1 should be about .3 volts lower than pin 2 and 4.

M.

Thanks for your thoughts martin.

I think you are correct! If I put the non working channel to the working lo1166, the voltages all come up correctly.

If I put the working channel to the bum transformer then the voltages drop to the reading previously displayed on the broken channel. I think we can safely say there is an issue with the transformer. I checked for continuity between all the wring & jumpers and its set up correctly, so I will send it back for testing.

However, even with the correct voltages, im getting no sound!

I'll try and trace the audio with the scope and see where its dissapearing.

Cheers!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 05, 2009, 11:22:01 AM
Well, i traced the audio with the scope all the way up to the transformer, then i remembered I had changed my routing last night!!!

We have sound. The answer was a bum lo1166. The last thing i expected!!

Thanks for all your help martin! you're a legend!  ;D

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 05, 2009, 11:38:24 AM
Congrats and good work!! I hope you get to enjoy them for many session to come! :-)

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 06, 2009, 02:19:29 PM
Hi Martin,

Really sorry to bother you again.....


Ive got a new problem.. when I turn the gain up to 50 and beyond, all I get is a very high pitched irregular hissing noise. No audio at all.

Do you have any idea what may cause this?

Thanks a lot!
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Carlos Lima on August 07, 2009, 12:51:50 AM
Sorry to interrupt the topic.  :-[

There is still PCB's available?

Thanks.

Carlos
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 07, 2009, 01:52:31 PM
Ive got a new problem.. when I turn the gain up to 50 and beyond, all I get is a very high pitched irregular hissing noise. No audio at all.

Do you have any idea what may cause this?

Hi Snipsnip, yes that sounds like oscillation. This is usually caused by:
A. not using shielded wire
B. running mic input wires too close to line output wires
C. having the 10468 (VTB9045) too close to LO1166 (VTB9049)
D. malfunctioning 2N3055

Also, double, triple, quadruple check the resistors values around the gain switch.

Hope this helps,

M.

PS. (for Carlos Lima) email me if you're interested in PCB's: martin_adriaanse (at) yahoo (dot) com
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 07, 2009, 03:11:14 PM
Martin, Thanks so much for this, I  will look into all these things and update you. I might upload a pic of my layout to show you how close my ins and outs are.. I thought they would be OK as there is a bit more of a gap than in your 8 channel monster!  ;)

BTW - the noise is coming from the transformer, as when i have no source plugged in and no output hooked up, I can hear the same noise coming from the LO1166 itself if I crank the gain.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 1954U1 on August 07, 2009, 10:20:37 PM
Hi Martin,
received the EZ1290 PCBs, great stuff, thanks for doing that  :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 08, 2009, 10:59:05 AM
Hi Martin,

I have used shielded wire, but I didnt connect the shield to the pad on the output, Instead I just connected a separate wire from pin 1 on the XLR to that pad. After reading a bit more about how shielding works, I realize this is not an appropriate solution and Im thinking this may be the cause of my oscillation.

Have you connected the shield to pin 1 at all, or is it ok to terminate at the LO1166?

Thanks again!
Jake

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: SaMpLeGoD on August 08, 2009, 01:19:56 PM
Hello all! is there anyone here that can post some schematic drawing for a vocal's hipass filter (around 100hz) that can be used in this project or in another preamp wiring?
Where shoul I wire that? on the input on the output of the preamp?
Thanks a lot!!!!
Keep on with the great work martin ;) i'll order more boards soon :)
Cheers!!

Eddie :)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Neil on August 08, 2009, 02:49:16 PM
Received my boards today, Martin, thanks- they look great!

Cheers,
Neil
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: danjpiscina on August 08, 2009, 03:29:18 PM
Hi Martin,

I have used shielded wire, but I didnt connect the shield to the pad on the output, Instead I just connected a separate wire from pin 1 on the XLR to that pad. After reading a bit more about how shielding works, I realize this is not an appropriate solution and Im thinking this may be the cause of my oscillation.

Have you connected the shield to pin 1 at all, or is it ok to terminate at the LO1166?

Thanks again!
Jake



Hey Jake. Just read your posts. IMO I'd say just follow Martin's build guide for the i/p o/p xformers. I did that and I got 4 pairs up and running! There's no ground on the o/p XLR. Also, maybe post some pics when you get a chance. You can see pics of my first pair here:

http://www.groupdiy.com/index.php?topic=20152.320 (http://www.groupdiy.com/index.php?topic=20152.320)

These worked fine so you can get an idea. I used Canare quad cable (a twisted pair for hot and cold) but I just did this because I had a bunch of it. I'm sure it's overkill. Any high quality standard mic cable (mogami, canare, gotham, etc.) is fine. Hope this helps!

Dan.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 09, 2009, 09:21:22 AM
Cheers Dan,

Yeah I was just a bit confused by the assembly guide as there it says only use pin 1 for shield, but nobody seems to have connected this in their pics.

I guess you just leave this disconnected.

Yours looks nice BTW!

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 09, 2009, 01:57:22 PM
As requested, here are some pics of my progress so far.

Only the right channel hooked up as my other transformers have had to go back for testing as they didnt work.

I redid the output with shield connected, but still get some oscillation.

Martin - Im looking at resistors around the gain switch again. I notice a couple of them are marked '12k0' etc. Is this different from 12k? I assume is just means 12k, but notice it is a different naming convention from the rest of the board.

(http://i96.photobucket.com/albums/l163/irisone/IMG_3068.jpg)
(http://i96.photobucket.com/albums/l163/irisone/IMG_3065.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: danjpiscina on August 09, 2009, 04:08:24 PM
hmmmm.... i'm not sure i follow how you have the right channel working. where's the i/p xformer?
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 09, 2009, 04:34:45 PM
right there between the right input XLR and right PCB  ;)
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: tazwolf on August 16, 2009, 07:05:32 AM
Hi
I was just wondering what kind of standoffs to use for the pcb metal or plastic?
The mounting hole near the 5k trimmer is part of the circuit ground so should it
make contact with the case?

 
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 16, 2009, 12:12:03 PM
the standoffs in the BOM are plastic, and great if you're mounting the thing in a 2u case as it puts the switch at the perfect height.

Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 16, 2009, 12:21:39 PM

Hi Snipsnip, yes that sounds like oscillation. This is usually caused by:
A. not using shielded wire
B. running mic input wires too close to line output wires
C. having the 10468 (VTB9045) too close to LO1166 (VTB9049)
D. malfunctioning 2N3055

Also, double, triple, quadruple check the resistors values around the gain switch.

Hope this helps,

M.


Hi Martin, (or any kind soul)

Ive got all both channels working, but face the oscillation issue on both.

my input and output transformers arent very close (as per photos), and the wires arent close at all.

I have used shielded wire (however I havent taken the shield to pin 1 on the XLR - do I need to do this?)

Im guessing both TR3's being faulty i highly unlikely?

Ive also checked all the resistors where I still have spares and have matched the colours. They all seem OK. Again, Im not sure if the 18KO and 12KO are different to a normal 12/18k resistor?

As I mentioned before, even with no input signal, and no speakers turned on, you can hear the noise coming from the transformer itself with high enough gain setting.

Really appreciate ideas from anybody!

Thanks a lot
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: Bluzzi on August 16, 2009, 02:11:14 PM
Hi Jake, since no one answered you on the 12K0 etc. yes its same as 12K. I had the same exact same oscillation on my 2 EZ1290s when I first hooked them up. I could actually hear a tone about 1KHZ.

I don't remember exactly what I did to make it go away. Have you set your trimmer as per Martin's instructions? I think that's what it was.

My XLR's pin 1 are all connected together and then to a star ground point. Power Supply ground also goes there. When you are testing I would recommend totally removing the second unit from any common connections (in case you have some ground loops). Just isolate and work on one board at a time.

If you have an oscilloscope verify you don't have any AC ripple in the DC.

Jim
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 16, 2009, 02:24:18 PM
Hey Jim,

Thanks a lot for the response, really appreciate it.

Ive had a random twiddle of the 5k trimpot to no avail, but I havent had a proper look with the scope.

I'll also check for ripple in the power whilst Ive got it set up.

I'll let you know how I get on. Thanks again!
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: 3nity on August 16, 2009, 05:35:09 PM
What psu are you using? IF theres a small ripple on the psu you'd be able to hear it on the preamp!
Hey its that a LEADER scope? i have the same!
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 17, 2009, 02:08:21 AM
snipsnip,

Sorry for the delayed response. Work's got me so tied up it's not even funny. I don't see the drain (shield) wire connected on the shielded cable going from PCB to your input transformer?

M.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: snipsnip on August 17, 2009, 05:07:06 AM
Hi martin,

No worries on the delayed response, Im greatfull for any help and am more than happy to wait a few days!  ;D

You know what, you are absolutely right, I think I used a 3rd wire on the canare rather than the shield (as per one of my earlier posts I didnt really understand shielding until recently) and I had totally forgotten thats how you spec'd the input wiring in the guide!

I'll give this a go when I get home, as well as looking for ripple. (BTW 3nity - Im using a JLM ACDC, and my scope is an old hitachi one.. cheapest I could find!!)

Thanks a lot guys,
I'll let you know how I get on.
Jake
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: madriaanse on August 17, 2009, 11:48:05 AM
no problem, you might also try mounting the input transformer closer to the PCB - use a longer wire on the balanced side and a shorter wire on the unbalanced connection to the PCB.

m.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: SaMpLeGoD on August 17, 2009, 01:28:59 PM
Hey Martin! the boards arrived today!
Thanks a lot for your great work!!!
Cheers,

Eddie :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on August 19, 2009, 11:16:38 AM
You're welcome Eddie!! Enjoy!!

Snipsnip, how are you doing?

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ricothetroll on August 19, 2009, 11:55:43 AM
Hi Madriaanse,

Congratulation for that great work !

I have a small question : where did you get the metal plates where each PCB is mounted on ? I need some for my 8 Green and I did an estimation at FPE, but 10€ for a piece of blank metal is quite expensive ! Besides I don't need it to be aluminium, steel would be just fine for that use.

Thanx in advance.

Best regards.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 19, 2009, 12:16:51 PM


Snipsnip, how are you doing?

Best,

M.

Like you, im under the cosh at work at the moment so not much progress. I did wire up the inputs using shield, but now im getting a really quiet signal on one channel. Im sure I just need to spend a bit of time on it.

I think using the shield has reduced the oscillation, but not removed it entirely. If this proves to be the case once both channels are running I'll try moving the transformer closer  to the PCB.

Thanks for following up.
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zachs on August 19, 2009, 05:40:13 PM
Had my power supply working a while ago, just finished up the rest of my stuff today, turned it on, and now my fuse in the PS is blowing... any ideas why that might be now?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on August 19, 2009, 06:04:20 PM
I'm about to finish my 2ch Ez1290.
2 boards stuffed,  tranformers to be wired... waiting for the case so I won't make my usual messy wiring

I'll use siik screen for the painel. 2ch and JLM go between (pad, phase, phantom toggles..)

Can someone share a Panel design in JPG or .psd for 2U rack? I could change some things...

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: SIXTYNINER on August 19, 2009, 08:14:46 PM
Can someone share a Panel design in JPG or .psd for 2U rack? I could change some things...
HI
check here:

http://www.musiciansgig.com/neeb/
Front Panel Design for 2U, 2ch:
http://www.musiciansgig.com/ez1290/circuit_specialists_2u_panel.fpd
(to open this file, you need Front Panel Designer. Free download from: http://www.frontpanelexpress.com/)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on August 19, 2009, 09:22:03 PM

Front Panel Design for 2U, 2ch:
http://www.musiciansgig.com/ez1290/circuit_specialists_2u_panel.fpd
(to open this file, you need Front Panel Designer. Free download from: http://www.frontpanelexpress.com/)

I know, but this software does not allow me to Export a JPG or any image format, nor print...
 :-\
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: diyfanatic on August 20, 2009, 04:03:31 AM
you can use this software, it's free.

http://www.inkscape.org/

you can export as jpeg but also as HPGL if you finally want to go the FPE way.

and this will ease up your life for the scale!

http://stiftsbogtrykkeriet.dk/~mcs/Scale.html
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: SIXTYNINER on August 20, 2009, 06:32:47 PM
nice project
there is way to add a meterled ?

 8)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 22, 2009, 02:16:55 PM
Hi Martin -

Im back with more problems ::) Sorry dude

My biggest issue is that im getting a really low signal on my right channel. Its the PCB that I previously had up and running, which makes me think it wont be anything on the board. Ive also swapped the input & output transformers over to see if thats where the problem was, but Im getting the same results. Ive adjusted the 5k trimpot and all my voltages are within .1v accuracy and ive reheated all the joints for the input and output wires. Is there anything you can suggest?

Also on the agenda, but not so urgent is the oscillation issue.  I have rewired everything using shield as intended, but am still getting the oscillation above 55db gain. I have also moved the input transformers close to the board so only very short unbalanced connection now, but no joy there.

Here is a pic of the new layout in case that helps.

Thanks a lot
Jake

(http://i96.photobucket.com/albums/l163/irisone/newlayout.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Carlos Lima on August 22, 2009, 07:02:09 PM
Hi Martin,

Received the boards today. Let's the fun begin...

Thanks

Carlos Lima
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Nele on August 22, 2009, 08:35:53 PM
@snipsnip: are your pcb's grounded? Although I didn't use plastic standoffs my pcb-ground wasn't connected to the case. I also had oscillation an humm. As soon as I connected pcb-ground to case, using one of the standoffs and a wire (instead of the prescribed 10 Ohm resistor) everything was solved..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 23, 2009, 05:12:40 AM
Hi Nele - Thanks for the tip! 

I just did a quick bodge test on my working channel with a bit of wire to case and it did seem to resolve the oscillation issue! :-*

Thanks so much... its great to only have 1 problem on the go at any one time!  ;D

Now, just to figure out why the right channel is so quiet..........

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 23, 2009, 07:51:26 AM
Hi Guys,

I think Ive been really stupid  ;D

I was testing by running a line level sine wave into the pres using a line level to mic level pad.

It seems the pad is faulty, and my boards are fine!

I just didnt even consider the pad as the measurements with the scope all looked fine at the input XLRs, after the pad. I think maybe the hot & cold is wired up backwards in the pad.

Thanks so much for all your help.... I think a new pad should resolve everything.

Thanks again
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Gachet on August 24, 2009, 08:36:22 AM
Hi there,

Just finished one unit and it sounds great ;D no oscillation no hum...
3 more channels and i'm done
The calibration didn't look like the assembly guide.Impossible to get the same distortion on both side of the signal.
But it 's not critical to me.Maybe it should?

I don't have enough 5K trimmers...Can i use 10K or 470R to do the job?(It's what I have in stock...)

By the way a great thanks to madriansee.This must be the best preamp I have ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 24, 2009, 08:44:21 AM

Just finished one unit and it sounds great ;D no oscillation no hum...



Show off  ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Gachet on August 24, 2009, 09:46:58 AM
(http://i146.photobucket.com/albums/r254/timcyrius/neve.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 24, 2009, 06:49:24 PM

Just finished one unit and it sounds great ;D no oscillation no hum...



Show off  ;)

Ha. I did eight, and they all worked first go!!   ;D

(fingers crossed)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: danjpiscina on August 24, 2009, 08:18:28 PM

Just finished one unit and it sounds great ;D no oscillation no hum...



Show off  ;)


Ha. I did eight, and they all worked first go!!   ;D

(fingers crossed)

Same here! 4 pairs. No problems. These pre's are the best, and for ≈$350/channel with Carnhill iron, you really can't beat it. Once again, Martin you ROCK!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 25, 2009, 01:11:53 PM
Well, I had a proper play with these for a couple of hours and they are seriously classy!

Thanks for all your help martin (and others).. this is a great project! 

As everyone else seems to be posting pics of their 1290's... here mine. (my grounding of PCB to case is brutally ugly, but I wanted to get these racked!)

Thanks again!

(http://i96.photobucket.com/albums/l163/irisone/IMG_3166.jpg)
(http://i96.photobucket.com/albums/l163/irisone/IMG_3173.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on August 25, 2009, 04:50:38 PM
Hey guys, just read through this post today and I have to try this. I've done a couple small DIY projects but was looking for a pre to sink my teeth into. I think I'd like to try a 2 ch. My question is what has been the experience with the PSU inside the enclosure vs outside?

I noticed Martin prefers outside. Has anyone installed it inside? Pros/Cons?

Also what about 2U vs 1U regarding a 2ch?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on August 25, 2009, 05:30:38 PM
Hey guys, just read through this post today and I have to try this. I've done a couple small DIY projects but was looking for a pre to sink my teeth into. I think I'd like to try a 2 ch. My question is what has been the experience with the PSU inside the enclosure vs outside?

I noticed Martin prefers outside. Has anyone installed it inside? Pros/Cons?

Also what about 2U vs 1U regarding a 2ch?



I don't know about other people but I built two 1290 into a 1Unit rack case, with the Toroidal and PSU inside.
I didn't notice any noise.

You should put the toroidal inside the rack as far away from the boards as possible, I put it on the far corner.
Also you can rotate the toroid while listening the mic pres, and choose the position where you feel there's less noise. if there's any noise at all in the first place.

Anyway I totally respect Martin opinions, and I should let you know that having the PSU outside the box is always preferable if you can do so.
I just can't have that many external PSU's in my studio floor.

Neve 1073 DPA PSU and toroid is also inside the rack case.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: danjpiscina on August 25, 2009, 08:58:53 PM
Hey guys, just read through this post today and I have to try this. I've done a couple small DIY projects but was looking for a pre to sink my teeth into. I think I'd like to try a 2 ch. My question is what has been the experience with the PSU inside the enclosure vs outside?

I noticed Martin prefers outside. Has anyone installed it inside? Pros/Cons?

Also what about 2U vs 1U regarding a 2ch?



for what is costs to make an external PSU, it's worth it. it's like an extra $20-25 for the case/XLR's/cable etc. It's more reliable and simpler to build. Plus you can build a pair in a 1RU enclosure this way. Martin designed the boards and does it this way so I'd take his word for it. I recommend a separate PSU.

This is a great project!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on August 26, 2009, 04:12:14 PM
thanks guys. so you didn't need to bend any parts to fit in a 1U? Did you mount anything funny? Is it possible to see pictures of your work? Thanks for the help.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: danjpiscina on August 26, 2009, 05:58:59 PM
thanks guys. so you didn't need to bend any parts to fit in a 1U? Did you mount anything funny? Is it possible to see pictures of your work? Thanks for the help.

Here are some picture of the first pair I built.
http://www.groupdiy.com/index.php?topic=20152.msg419581#msg419581 (http://www.groupdiy.com/index.php?topic=20152.msg419581#msg419581)

I didn't have to bend anything except for the heatsinks. This was really easy to do and I'm sure if you look around and take some measurements you could find some that fit without bending. You also have to get the "narrow board version" o/p transformer:
http://www.audiomaintenance.com/acatalog/CA-18-VTB1148_extended_info.html (http://www.audiomaintenance.com/acatalog/CA-18-VTB1148_extended_info.html)

Also, make sure you get a decent case.

Dan P.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on August 26, 2009, 06:19:34 PM
thanks guys. so you didn't need to bend any parts to fit in a 1U? Did you mount anything funny? Is it possible to see pictures of your work? Thanks for the help.

Like Dan said, maybe you have to slightly bend the 2N3055 heatsinks, nothing special.

And you have to get the narrow board version of the Carnhill output transformer.

I can't find any pictures now, but i will search for them tomorrow
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on August 27, 2009, 02:40:07 PM
I already know the answer to this I'm sure but is there a place in the states to order the carnhill transformers from? Looking to save on shipping. I'm sure it would have already been posted but before I order I'll try my luck.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on August 28, 2009, 04:39:18 PM
thanks guys. so you didn't need to bend any parts to fit in a 1U? Did you mount anything funny? Is it possible to see pictures of your work? Thanks for the help.

here is he way I mounted everything in a 1unit rack case,
I still need to redo some stuff in the wiring and tidy up a bit, but the placement of parts will be the same.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: danjpiscina on August 28, 2009, 05:15:14 PM
I already know the answer to this I'm sure but is there a place in the states to order the carnhill transformers from? Looking to save on shipping. I'm sure it would have already been posted but before I order I'll try my luck.

I haven't found a reasonably price US dealer. I got mine from Audio Maintenance (in England) and considering they're English transformers I doubt you can get them cheaper in the US. Shipping from AML was pretty reasonable.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Neil on August 31, 2009, 03:26:33 PM
I'm trying to finish up the power supply for a 2-ch version, but Digikey is backordered on the TE62085-ND toroid until November!  :'(

Can I sub the TE62075-ND since I'm only running 2 ch? It's only 35 VA, and 22 @ 1.590 parallel, 44 @ .795 series instead of 50 VA, 22 @ 2.272 parallel and  44 @ 1.136 CT series.

If that won't work does anyone have a good substitute? I've already got the ACDC and everything else on the power supply built per Martin's excellent assembly guide.

Thanks!
Neil
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on September 01, 2009, 12:57:50 AM
To be honest I don't really know which capacitors are in Martin's BOM.

Are you refering to the Styroflex (Polysterene) capacitors? 
(white and transparent ones)


As far as I know those are the type of capacitors used in the original Neve modules,
you only find them in pf Values.
They are much expensive than Ceramic capacitors.

Don't know the sound differences because I never compared it to any other module.
I can just tell you that my 2 channels sound really good.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: SIXTYNINER on September 01, 2009, 03:43:19 AM
To be honest I don't really know which capacitors are in Martin's BOM.
Are you refering to the Styroflex (Polysterene) capacitors? 
(white and transparent ones)

yes whoops
the white and transparent ones
martin bom have ceramic
cheers...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on September 01, 2009, 04:04:00 AM
whoops, I see you used an SSL9k board for the PSU, which I am planing to to as well.
Did you just replace the 7818 with a 7824? and the transformer with 2*24 Volts?

BTW, I accidentally ordered WIMA's for all the PF and NF capacitors, which involved a lot of bending into shape but does work. Is this going to sound different to Styroflexes? I guess the tolerances are higher for starters...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on September 01, 2009, 09:57:47 AM
as far as I know these wima are inductive, styroflex and ceramic-multilayer are non-inductive design

on the smaller values 100pf and 220pf I even used silver mica
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on September 01, 2009, 05:36:38 PM
whoops, I see you used an SSL9k board for the PSU, which I am planing to to as well.
Did you just replace the 7818 with a 7824? and the transformer with 2*24 Volts?

BTW, I accidentally ordered WIMA's for all the PF and NF capacitors, which involved a lot of bending into shape but does work. Is this going to sound different to Styroflexes? I guess the tolerances are higher for starters...

Yes I used the SSL9K PSU. You're right I just replaced the 7818 with a 7824, it's as simple as that.
2 x 24V transf. Left the negative side empty since you only need the positive rail.

I'm sure the Caps will sound different than the Styroflex ones, don't know in what way.
People seem to describe Styroflex as more "hi-fi" sounding, but I don't really Know.
Maybe someone can help here.

As I said I just used them because those were the type used by Neve.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zachs on September 02, 2009, 02:47:26 PM
Thanks so much for this awesome project madriaanse!

You can see my 4 channel version here: http://www.groupdiy.com/index.php?topic=35124.0
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: promixe on September 07, 2009, 08:36:00 AM
Hi All,

Just ran into an issue with my 4-channel 2U rack. I use a single 50VA 2x22V toroid to power all four boards through two separate PSUs (FiveFish PSU-2448 for Phantom and two EZ1290 & Igor's 33609 PSU for the remaining two EZ1290s). It worked fine for a while until today I powered it up and started calibrating the bias. The toroid started buzzing after 5 minutes of being powered on, then it started overheating, so I had to power everything down. Beside powering 4x EZ1290s there are 7 total LEDs in the unit (4 of them were off at the time of toroid saturation).

Any suggestions as to how to troubleshoot this issue?

Basically, I run the secondaries with the center tap to the FiveFish PSU as suggested in its manual. Then I also run one of the secondary 22V (the black wire) and the center tap into Igor's single 24V PSU to derive 24V for the additional two channels. Both PSUs spit out correct +24V (+/- 0.10V). FiveFish also gets me exact 48V.

Could it be a defective toroid? Or am I maxing it out with 4x channels? 50VA @110VAC should be enough for peak 500mA per channel x4, right?

Thanks for the input!

UPD: After waiting awhile to cool down the trafo I powered the unit again and the toroid is buzzing immediately from the start now, so it seems to be permanently damaged. =( Everything still powers up though, I'm just not able to run it past 10 seconds due to overheating again. Thoughts?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on September 07, 2009, 07:42:45 PM
is your transformer an Antek AN-0525?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: promixe on September 08, 2009, 12:28:40 AM
is your transformer an Antek AN-0525?


No, it's Avel Lindberg Y236205 - http://avellindberg.com/transformers/y23_range_specs.htm . It's 1.14A per 22V winding.

After thinking a bit more about the issue I realized that I might have overloaded the first secondary winding. Correct me if I'm wrong but wouldn't it work if I fed the yellow wire into Igor's PSU (a single +24V PSU) instead of the black one? That would load the 2nd trafo winding with Igor's PSU and the 1st winding with the FiveFish PSU, since I'm not using the negative rail on it? Does that make sense at all? Or do I still have to pretty much double the VA rating of the toroid for this scenario?

THanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on September 09, 2009, 01:38:52 PM
Didn't want to start a new thread with my humble little EZ1290 build, so here goes:
(http://img.photobucket.com/albums/v426/brio/briomusicEZ.jpg)

I decided against the go-between for two reasons:
1. I don't think I need a pad with the level switching (none of the commercial 1073 clones seem to have one)
2. I wanted to put the phase swap on the output (instead of the input) to avoid the popping sounds you get when switching phase with phantom power engaged.

I accidentally ordered wima caps for all the polys, but so far it sounds ok to me (only tried speech sofar). If anything a little brighter than the Ch*ndler LTD-1 I used to compare.

I am using the Ch*ndler PSU for the time being but plan to stick a transformer in there eventually. If I use the outer windings of a 2*12 will this work as a 24v psu? can the SSL PSU still derive 48 Volt phantom or are modifications needed?

Thanks to the group and especially madriaanse for the PCB.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on September 10, 2009, 08:30:10 AM
is your transformer an Antek AN-0525?


No, it's Avel Lindberg Y236205 - http://avellindberg.com/transformers/y23_range_specs.htm . It's 1.14A per 22V winding.

After thinking a bit more about the issue I realized that I might have overloaded the first secondary winding. Correct me if I'm wrong but wouldn't it work if I fed the yellow wire into Igor's PSU (a single +24V PSU) instead of the black one? That would load the 2nd trafo winding with Igor's PSU and the 1st winding with the FiveFish PSU, since I'm not using the negative rail on it? Does that make sense at all? Or do I still have to pretty much double the VA rating of the toroid for this scenario?

THanks

Pedro, have you had problems with the Antek? I'm using a couple with no issues...

Promixe:  I don't know either of those PSUs (can't find anything on Igor's) but I would have connected both secondaries to both PSUs.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on September 10, 2009, 11:47:08 AM
No, I've bought an antek 50VA for 4 channels, just wondering if it could handle...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on September 10, 2009, 02:11:18 PM
It should, since it puts out 2A (in parallel).  Martin recommends 500mA per channel (this is with lots of headroom, Neve's original spec was around 120mA per channel). Anyway, 500mA x 4 = 2A, so you should be fine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: promixe on September 10, 2009, 03:42:37 PM
Quote
I don't know either of those PSUs (can't find anything on Igor's) but I would have connected both secondaries to both PSUs.

Right, but Igor's PSU design I think calls for a single 22-25 secondary rail connection. You either hook up a center-tapped 12-0-12 trafo, or single secondary 22-25 (which is what I did). FiveFish PSU however calls for 22-0-22 with centertap and both secondaries connected because of the 48V rail (it uses CT as ground and each of the 22VAC secondaries as + and - and then also uses the "-" secondary as the ground for the 48V rail). So if I used my 22-0-22 trafo and connected both secondaries to Igor's PSU, it'd shoot about 55-60VAC into the LM317 which at 1A I don't think it can handle thermally etc.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on September 10, 2009, 04:04:19 PM
I'm starting to get confused. You will not put out 50-60 volts unless you put the secondaries in series, or leave the "center tap" disconnected and use one of the other wires as 0 and the other as 24V. then you will have double the voltage. What I am saying, and I would verify this with Igor, is to connect the five fish as you have it. Then take the "center tap" and connect it to Igor's 0V or ground. Finally take the other 2 wires, join them and connect them to the + or whatever it's called on his PSU.

My only doubt is if this type of connection would create problems of it's own between the PSUs (like with the voltage doubler) and that's why I say ask Igor.

Or (don't know why I didn't think of this before) you could build the five fish supply with the 78s24 regulator which is capable of 2A. Or, if Owel uses adjustable regs take a look at the LM150 (3A regulator). Should be pin compatible, but double check. And also check with Owel if the board can handle the current. Then you could get rid of the second supply. (btw, have you tried running all 4 channels of the five fish supply as is?)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: promixe on September 10, 2009, 04:27:19 PM
This is how I had it hooked up before the toroid kicked the bucket:

(http://dev.ax-design.com/electronics/DSC04701a.JPG)

The output voltages were all correct. I haven't tried running 4 channels on a single FiveFish, but I ran 2 channels in my previous design and the +24V reg gets extremely hot in a short time, that's why I decided to take a load off of it by using the second PSU (Igor's one, which I had sitting around all assembled already).
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on September 10, 2009, 06:11:19 PM
After reading your first post about this, it's likely the trafo is done. Does it work with just one PSU connected? In the 10 seconds before it overheats, can you check your voltages? You may have a short in one of the PSUs and that could be causing the trafo to overheat.

If not, get a new one and connect it the way I told you. The way you had it set up you are running all 4 channels of of one secondary (each secondary can only handle 1A, hence your troubles). 

You should connect both PSUs in parallel to the trafo. To do that you connect the fivefish the way you had it, take the CT to the 0V on Igor's PSU and then join AC1 and AC2 and take them to the other pad on Igor's PSU.  I THINK that would work, but if your trafo is done, then nothing will help. 

Sorry I'm bad at explaining things. That's why I did not become a teacher.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: promixe on September 10, 2009, 06:19:06 PM
Mitsos, thanks for the suggestions! I'm getting new trafos tomorrow and I will test the way you described.

In the mean time, any other suggestions are welcome. Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: owel on September 12, 2009, 11:34:11 PM
The secondary CT of the transformer becomes my GND connection.  

You said:
(http://dev.ax-design.com/electronics/DSC04701a.JPG)

The way you wired it above, (connecting another PSU which treats one of the 22vac line as the GND, is you're creating a short in the secondaries of the transformer. Thus, the transformer gets hot after a few seconds. (and you may even fried it).

Use the Avel transformer for my PSU, and buy another transformer to connect to Igor's PSU. i.e. you need to have (2) toroid transformers. Then tie my PSU GND with Igor's PSU GND.

i.e. don't connect the transformer secondaries to both my PSU and Igor's PSU.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: promixe on September 13, 2009, 12:30:48 AM
Owel, thank you for the clarification! I'll do a dual toroid setup as you are suggesting.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on September 14, 2009, 11:58:33 PM
I've just finished my 2ch easy 1290.
Everything is ok, no hum, no noise and nice sound.

I didn't take it to the studio yet because I couldn't calibrate the bias.

I don't have a scope and don't know anyone who could have one...

Does anybody have calibrated it with virtual oscilloscope softwares on PC or MAC?
I tried but the soundcard clipped before the preamp.
Then I used this HOSA atenuator ( http://www.directproaudio.com/product.cfm?directid=60155 ) on the preamp outputs. After using this attenuators, I could see irregular clipping but the trimpots don't seem to have any effect...

my question is:
Is it possible to calibrate it without a "real" oscilloscope? any tips on that?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on September 15, 2009, 02:22:10 AM
hi pedroplanet,
one thing I did find out when doing the bias (albeit with a real oscilloscope) is that it's best to clip the signal just a little, to the point where you just start seeing the flat bit at the top and/or bottom of the sign wave. you get a more precise result that way. I also found that while clipping it very hard, it was difficult to see the effect of the trimpot, so this might be what's happening on your end.
FWIW, I thought the EZ1290 sounded great even before doing the bias, but it turned out that I didn't have to change the trimpot that much.
hope this helps,
briomusic
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Barish on September 15, 2009, 03:31:27 AM
I've just finished my 2ch easy 1290.
Everything is ok, no hum, no noise and nice sound.

I didn't take it to the studio yet because I couldn't calibrate the bias.

I don't have a scope and don't know anyone who could have one...

my question is:
Is it possible to calibrate it without a "real" oscilloscope? any tips on that?

Take it to the studio, feed it a sine wave signal from Pro Tools, adjust the gain until you get the appropriate signal level, start recording the output, maximize the track view, and monitor the waveform on the screen in chase mode while adjusting the trimpot.

Never as precise as a scope sure enough, but if push came to shove, it does the job.

B.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on September 16, 2009, 12:49:00 AM
one thing I did find out when doing the bias (albeit with a real oscilloscope) is that it's best to clip the signal just a little, to the point where you just start seeing the flat bit at the top and/or bottom of the sign wave. you get a more precise result that way. I also found that while clipping it very hard, it was difficult to see the effect of the trimpot, so this might be what's happening on your end.
Thank you Barish!

I could make it using "SignalScope PRO" for mac and a HOSA attenuator(pad) after the preamp outputs
It seems ok now but I haven't tested it on a real recording session

I'm trying a different approach on the front pannel, It's acrylic over a transparency layer and backlights.

My goal would be making a luminous pannel, but the backlight stuff is not ready yet, here are some pics:
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on September 16, 2009, 12:51:29 AM
and inside
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: gerardmanvuca on October 20, 2009, 12:20:49 PM
Well, thus far, i've completed populating 8 cards(nearly passing out a few times)...and managed to get one hooked up.

.....Punchy as 'hell'....with just vocals, full sound, lots of gain...sounds really good.
Everything is pretty much on hold until i get frontpanel done. $220...youch...


(http://img132.imageshack.us/img132/6625/dsc02020b.th.jpg) (http://img132.imageshack.us/my.php?image=dsc02020b.jpg)


(http://img200.imageshack.us/img200/1245/dsc02018.th.jpg) (http://img200.imageshack.us/my.php?image=dsc02018.jpg)




Yo Desol! nice lookin boards.. was wondering wat caps those are? they are different from the BOM ones and look more like the type used by chandler and old neves ive seen with open hoods. do they sound better than the BOM ones?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 20, 2009, 11:19:02 PM
Not sure how they sound in comparison. The blue cap's are the well known BC type, vishay axial tantalums, pansonic carbon films(1/2 watt and 1/4 watt), motorola 3055's and styroflex poly's. The tantalums and bc's were pricey, but whatever. The carbon film's countered it a bit.

Close to getting the frontpanel etch'd, so till then cards are sitting. Shielding plates being made up...etc.
She's slowly gettin done.


EDIT: Also thought to add, I got the frontpanel price down to around $110. I had some things messed up in the software. So, not too bad a price considering.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tazwolf on October 23, 2009, 03:19:16 PM
Hi !
Just built two EZ1290's in one 1U rack with a seperate box for a JLM AC/DC. so far so good - they work fine. From the AC/DC i have +24 and +48 with a common ground as it shows in the build pdf. problem is when I try to connect a Igors DI - I've started by connecting up just one of the 1290s with the DI, however the way i have done it the R56 12ohm resistor starts to smoke on the EZ1290 board.

I don't know if i should ask here or in the Igor DI thread, so i hope its ok that I ask here.

The igor Di PSU connection has 24v, 0, 0, 48 so I have shorted the two 0v on the Di board with the one ov I have coming from the AC/DC.

Has anybody used this combination of ACDC, EZ1290 and Igor DI and can tell me what I am doing wrong? The other pre in the same box without the DI connected (yet) works fine and no 12R (R56) resistor burn.

Thanks

(/Taz
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: trancedental on October 24, 2009, 03:29:42 PM
AC/DC grounding scheme, the 0V on the JLM AC/DC is for audio ground
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tazwolf on October 25, 2009, 07:32:16 AM
Transcendental - Thanks! That helped a lot!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrtrev on November 19, 2009, 06:19:36 PM
Hi everyone, I'm new to the forum! Just ordered 4 boards from Martin & I can't wait to get my build going :D Loved seeing all your pics about your builds, awesome stuff you've all inspired me to give it a go! ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kambo on November 19, 2009, 06:48:11 PM
you will be so glad  ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 19, 2009, 07:30:41 PM
Hi everyone, I'm new to the forum! Just ordered 4 boards from Martin & I can't wait to get my build going :D Loved seeing all your pics about your builds, awesome stuff you've all inspired me to give it a go! ;)

Good for you man. Cheers and welcome!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrtrev on November 20, 2009, 10:54:11 AM
Thanks for the welcome guys ;D I just hope I can do a half decent job of it, I'm good with a soldering iron but not so good at metalwork. I can even screw up drilling a pilot hole lol :o I must thank Martin too, very quick response to my email inquiry.

I'm looking forward to receiving the boards and getting started. I'm looking at building a 2U unit with 2 boards and an internal PSU, with PPM meters (would a tap from point B be good for this?). This box will hopefully go into my voice over studio, as that's what I do for a living. The other 2 units will be going into a Ham Radio transceiver set-up! Don't laugh lol :D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: stitch-o on November 20, 2009, 10:57:14 AM
Any chance someone has a quick solution for US source of 2A PT to power 4 modules?
Can I still use the ACDC with the increased draw for 4 channels?

Cheers!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on November 20, 2009, 11:13:42 AM
Check Antek for a toroid..

http://www.antekinc.com/details.php?p=33   
2x25, 50VA

Most people do it 1 psu for every 2 channels. You could, I suppose, get the 5 rail JLM, and use one positive rail for each 2 channels.  they are running in parallel off the bridge, so it's like 2 positive PSUs.  Would need to get different rectifier diodes that can handle the amperage as well, I think 1N400x are 1A max or thereabouts, but mouser/digikey are full of stuff that'll work.


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: YLab on November 20, 2009, 12:56:04 PM
I have open a v*i*n*t*e*c*h  power supply recently because i plan to power my 1290s with it,, and what i find inside was this http://ca.mouser.com/ProductDetail/International-Power/IHB24-12/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6Mz7QmyNtuSw%3d (http://ca.mouser.com/ProductDetail/International-Power/IHB24-12/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6Mz7QmyNtuSw%3d) and this http://ca.mouser.com/ProductDetail/International-Power/IHB48-05/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6zs1mSMsOndg%3d (http://ca.mouser.com/ProductDetail/International-Power/IHB48-05/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6zs1mSMsOndg%3d)  i dont know if they add some additional filtration in their preamp but in their psu, there was nothing more than those two unit. Seems like a very affordable solution to me. And they say on their website that it can power up to four x73 (1073) so it should be enough for four 1290 maybe more. i could post some pics of the inside if you guys want some.

Hubert


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Deyo on November 20, 2009, 06:23:57 PM
I am toying with making knobs . Have you found a place to get the ones you want ? Best   D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: stitch-o on November 20, 2009, 08:12:55 PM
I have open a v*i*n*t*e*c*h  power supply recently because i plan to power my 1290s with it,, and what i find inside was this http://ca.mouser.com/ProductDetail/International-Power/IHB24-12/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6Mz7QmyNtuSw%3d (http://ca.mouser.com/ProductDetail/International-Power/IHB24-12/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6Mz7QmyNtuSw%3d) and this http://ca.mouser.com/ProductDetail/International-Power/IHB48-05/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6zs1mSMsOndg%3d (http://ca.mouser.com/ProductDetail/International-Power/IHB48-05/?qs=sGAEpiMZZMu0oxGuRuNKH8MNxSrv1EW6zs1mSMsOndg%3d)  i dont know if they add some additional filtration in their preamp but in their psu, there was nothing more than those two unit. Seems like a very affordable solution to me. And they say on their website that it can power up to four x73 (1073) so it should be enough for four 1290 maybe more. i could post some pics of the inside if you guys want some.

Hubert




Pretty standard setup Id imagine too just 110AC in 24V/0VDC out.
Martin suggests 5mA per channel (I like the overbuild philosophy) so maybe:
http://ca.mouser.com/ProductDetail/International-Power/IHC24-24/?qs=0xCm9DOQnC6ncDRyEaAHUw%3d%3d
for 4 channels?

Def pics would be great!

Looks like maybe a good solution? Def wind up a bit more beefy than the JLM supplies.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: YLab on November 20, 2009, 08:25:19 PM
Yes,, good idea for only 60$..

Image from the inside of the psu...pretty straightforward. left 48v, right 24v

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on November 21, 2009, 12:27:53 AM
You do realize that Rupert Neve (and now AMS-neve) spec the 1073, etc at 110mA per channel? That is a preamp and EQ which could, potentially, require more current. Can't really go wrong with an overdone PSU, but isn't 500mA (4x required current) per channel a bit wasteful? 

Maybe I'm reading specs wrong here but it seems, AMS-neve's 5U racks are rated at 0.8A, a bit less than a single JLM psu, and that's for 8 channels... How'd we go from 110mA to 500mA?

http://www.ams-neve.com/Sites/8/Files/Documents/Outboard/1073_1084_User_Manual_Issue5.pdf
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: stitch-o on November 21, 2009, 07:19:15 AM
You do realize that Rupert Neve (and now AMS-neve) spec the 1073, etc at 110mA per channel? That is a preamp and EQ which could, potentially, require more current. Can't really go wrong with an overdone PSU, but isn't 500mA (4x required current) per channel a bit wasteful? 

Maybe I'm reading specs wrong here but it seems, AMS-neve's 5U racks are rated at 0.8A, a bit less than a single JLM psu, and that's for 8 channels... How'd we go from 110mA to 500mA?

http://www.ams-neve.com/Sites/8/Files/Documents/Outboard/1073_1084_User_Manual_Issue5.pdf

Very good point.
I'm just going with Martin's philosophy and suggestion as I seem to recall reading somewhere that he suggests 500ma a channel
for the rugid overbuild.
Now that you lay it out, it does seem somewhat excessive...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 21, 2009, 09:20:06 AM
When the 1073/1290 channel powers on, it draws a big chunk of current, then stabablizes down to 80-100mA. The rating is spec'd to properly handle this power on 'draw' i believe.
Title: Re: 8 Channel, 3U NEVE 1073 nearing completion
Post by: desol on November 21, 2009, 10:09:51 AM

Speaking of the trim fader; I deliberately left it out because I really don't like what a trimpot does to the sound??? Sounds grainy/"slightly distorted" or something. Anyone else notice this on their Neves?


Maybe it was the brand of trimmer you used Martin? What trimmer did you try? I've put drill holes on my frontpanel for the P&G RF11 if they ever need to be added.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on November 21, 2009, 07:15:40 PM
I'm just going with Martin's philosophy and suggestion as I seem to recall reading somewhere that he suggests 500ma a channel
for the rugid overbuild.
Now that you lay it out, it does seem somewhat excessive...
I don't like to go against anyone's beliefs or philosophies, there is some validity to the idea of not running your PSU at maximum all the time. Taking into consideration that some toroids and other components may not be true to spec (meaning they are over rated), and maybe that's why some people decide to overbuild stuff. But if you use decent quality components I can't see it being a problem. Then again, I could be wrong.

When the 1073/1290 channel powers on, it draws a big chunk of current, then stabablizes down to 80-100mA. The rating is spec'd to properly handle this power on 'draw' i believe.
I saw that written somewhere as well... Wouldn~t this imply that the AMS 8 channel rack would not be able to handle this inrush of current at startup if it's only 0.8A?  Also, there would be a problem for anyone building a 10 or 11 space GDIY rack full of neve pres (51X style, whenever they become available, I'm sure people are already designing the PCBs), since the PSU is using 3A regulators, no?   

kinda thinking out loud I guess...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 21, 2009, 08:08:27 PM
Well, Peter Purpose has already designed his EQ's to power on delay, so they wait for
the power supply to stabilize. So...either over-spec the power supply for this in-rush or
design the modules to delay on a bit. I'm guessing.. Excess current i think would be also needed
if the pre's are driving something after and for headroom.

The AMS thingy may have something else going on entirely. Don't know.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on November 22, 2009, 09:40:07 AM
I think the delay in Peter purpose's EQ (haven't checked that thread these days, but I think it's Dan Kennedy's circuit) is not for the 24V rail, but for the DC-to-DC converter on the 16V rails (it will be compatible with either the 51X or regular 16V racks). It's the converter that sucks a lot of juice at startup. 

I've been trying to find an answer to this for weeks, because there are those (like bae, vintageking, and others who rack and/or remake neve stuff) who use the terms "overspec'ed PSU for higher quality audio," while at the same time there are quite as many big mfgs who don't do this.  I found a couple of interesting threads here and there, but nothing concrete, and seeing that Vintech uses 1.2 Amps for 4 channels and AMS themselves use a smaller one for 8 channels (a bit unbelievable, this one, but it's written in the manual), doesn't it make you wonder how it's possible that perhaps these guys (who are paying big $$ for engineering) are using so much less?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: stitch-o on November 22, 2009, 10:34:21 AM
I saw that written somewhere as well... Wouldn~t this imply that the AMS 8 channel rack would not be able to handle this inrush of current at startup if it's only 0.8A?

Hence the 500ma per channel? What might the current spike be on powerup?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on November 22, 2009, 07:51:46 PM
I don't know the answer. I've tried posting in this thread 10 times and this computer keeps erasin my posts.... so maybe it's a sign. I just think it's curious that there are so many mfgs making this circuit, and some use large PSUs while others use smaller ones, and the ones who use the large ones overtly advertise it as something that makes the audio of their product better.

There is the argument of running your PSU at less than capacity in the hope that it will last longer, but I don't think that is the case here, otherwise BAE (and others) wouldn't mention it. So.. anyone?

Current inrush, I guess could be measured with an Ammeter. I'll do it when I get a chance. Not sure if it's true or not, since class A is supposed to be constant currrent, no? So unless you have tons of capacitance in the circuit this shouldn't happen, I think.

But anyway, this is getting a bit academic.  I do plan to continue searching this out, but you mentioned you were making these for some studio I think, so sorry to get your attention off that.. get whatever works and be done with it. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrtrev on November 23, 2009, 02:53:07 AM
This may be completely irrelevant (if so ignore lol) but how about a bit of conditioning on the mains input? Perhaps something like this http://www.spezial.com/commercio/dateien/produktbeitraege/FN_9263.pdf IEC inlet with filtering and current inrush protection.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leafcutter on November 23, 2009, 06:53:25 PM
Just wanted to say I just wired up 2 of 4 channels of the EZ 1290 and after a brief problem with a shorting power cable they are sounding absolutely wonderful! Big warm and round, my guitar has never sounded so good. I'm so happy!!

This was my first build, and I'd be happy to post some pics and sound samples if people want to see and hear.

Thanks Martin and thanks to all the people who post here.

Take care everyone,

John.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on November 24, 2009, 04:47:11 AM
Pictures are always fun!

Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrtrev on November 24, 2009, 01:29:27 PM
Indeed! Hi Jake, speaking of which your pics are really cool, love that red front and where did you get those knobs from they rock! I would try and get some neve-a-like reds but I think I'd have more luck trying to find some Unicorn cr*p lol ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on November 25, 2009, 05:13:41 AM
Cheers mate!

I cant remember, but I think the knobs are just brushed aluminium ones from farnell or similar.

I couldnt get any decent neve style ones so I thought I would just go for a 'non-authentic' look.
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leafcutter on November 25, 2009, 07:25:02 PM
Here are a few snaps of my first pre-amp. I'm not into trying to make it look anything like a Neve so I went for a minimal look. The knobs I got from ebay, they are supposed to be from the 50's - not sure if that's true but I like the look of them.

(http://farm3.static.flickr.com/2734/4134138665_f52ed7170e_o.jpg)
Just need to get busy with the letraset  :)

(http://farm3.static.flickr.com/2746/4134901230_e107fe8e69_o.jpg)
The (blurry) guts. Any tips for neater wiring?

(http://farm3.static.flickr.com/2729/4134900810_38a4212974_o.jpg)

(http://farm3.static.flickr.com/2657/4134138885_b9b0608e18.jpg)

(http://farm3.static.flickr.com/2511/4134138561_68f97a984d_o.jpg)
The second unit in slate blue rather than brushed aluminum because I scratched the face quite badly and ended up sanding smooth and spray painting. This one will have white letters.

This is my first build so Let me know what you think, good or bad. Sonically these sound amazing and worked without any major tweaking.

Cheers,

John.


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on November 25, 2009, 07:49:27 PM
Nice Work!

I really like to see some tidy wiring, and yours looks great!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on November 26, 2009, 12:34:09 AM
Way to go John!!! Hope you get some great sounds from them!! Don't worry about your wiring; it's fine! Your input wiring is far away from output wiring and that's really all that matters.  ;)

Wanted to chime in re: my 500mA/ch. Yes, it is way over the top. I remember (I think...) inrush current being about 300mA, so I piled some extra on top of that and arrived at 500mA/ch. I also stick monster heatsinks on the LM317's. In the grand scheme of things, overbuilding a PSU isn't really all that much more expensive, and so I happily spend the few extra dollars for a PSU that will probably last me a decade or two. In three years of intense use I've never had a PSU failure, and the pre's (all 32 of them - 16 PSU's) sound lovely.

All the best,

Martin
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on November 26, 2009, 08:45:04 AM
Hey Martin,  thanks for chiming in.  Do you remember seeing that inrush current anywhere? Or anywhere that explains where it comes from?  Is it the caps charging?  For sure a beefy PSU won't hurt (except your electrical bill maybe), but I am wondering how AMS-Neve seemingly "get away with" such small PSUs for their 8-channel racks. Searched high and wide and didn't find much...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on November 26, 2009, 02:39:11 PM
Hi Mitsos,

I measured the inrush myself. I don't think a bigger PSU draws more current than a smaller one except for when it has to source more current - it is able to do so. I'm not sure why anyone uses small, under-spec'd PSU's to be honest.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrtrev on November 27, 2009, 10:46:41 AM
Hi Martin, my boards arrived today ;D Brilliant, I can't wait to make a start! Better get ordering parts ;)

I managed to get some 2N3055's cheap from eBay, although they're advertised as Motorola's I've never seen a K replace an M, take a look at the link http://bit.ly/4Vo8ON Have I been had?

Trev
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: GeertSamuel on January 04, 2010, 09:08:34 AM
Ordered some days ago 2 PCB's. I'm now ordering all the other parts....
Can't wait to start this build, I'll keep you guys up-to-date... (building 2 preamps in a 2U)..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on January 11, 2010, 11:00:12 PM
Guys i need some help here...
I'm measuring some volts in my 1290 and i'm getting like 3.0 volts at the collector of TR6 and 0V at Collector of TR1..
I have the right values for resistors and i see only 3V after the 270R resistor..
Please any help is appreciated
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 14, 2010, 01:13:08 PM
HI 3Nity,

Is everything else measuring low too? PSU going bad/out of adjustment perhaps? What's the voltage at the +24 power input on the board?

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on January 14, 2010, 01:25:04 PM
fixed!!!
Emitter was shorting to ground by something else!

Sorry for all!!

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 14, 2010, 02:06:05 PM
Glad to hear you got it worked out! What was shorting it?

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: stevez82 on January 20, 2010, 03:47:46 PM
Can I order some PCB's from you?  I want to do a 4-channel version for my mobile Pro Tools Rig.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on January 25, 2010, 05:47:22 AM
Hi Guys,

Ive unpacked my kit after moving to a new house and think Im seeing a problem with my 1290's .

The output seems to be clipping way before the input of my interface (SSL Alphalink).

Im pretty sure the input of the 1290 has to be OK as Im padding the mic, and the source just aint that loud.

However, when I go to over 55 db gain, the signal is getting clipped. I Havent taken any real meausrements but there is plenty of headroom on my interface. I would assume the neves would have the headroom here?

Anyone clever have any ideas?

Thanks a lot
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 25, 2010, 04:58:41 PM
hi snipsnip,

Are both channels doing that? It sounds like the transistors voltages on the 2nd pre stage (closest to switch) might be off. carefully check resistor values there.

Your A/D should be clipping long before the EZ1290.

HTH,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on January 26, 2010, 06:44:04 AM
Thanks martin,

I probably wont get a chance to open this up until the weekend, but I do remember my voltages being fine before.

If the resitors were wrong, the voltages at the pins would differ from your chart right?

Thanks again!
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: redmojosteve on January 27, 2010, 01:24:56 PM
Hi Martin
The PCB's arrived today and they are superb! Thank you very much!
I need to save up some money for the transformers now and search the thread for details of appropriate power supply information which will enable me to supply 4 boards and will be mounted externally. Or at least that is my current thinking.
Steve
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on January 27, 2010, 08:21:09 PM
I received my PCB's the other day as well, very well made!

This should be what your looking for: http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=11
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: baadc0de on January 28, 2010, 01:21:42 AM
Hi madriaanse - I'm putting this question into this thread, because you inbox is full;

I've been talking to Jim about his 1084EQ project and he tells me that you will be providing the microphone preamp boards for his project. Do you have a time frame on when these would be available? As a rough estimate, how much do you think these would cost and do you feel they could fit inside Dan's case or what can be seen of it in Jim's thread?

Thanks,
B.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on January 28, 2010, 09:38:36 AM
Hi Martin,

In answering someone elses question, I just reminded myself that I hadnt grounded through 10r... I think this might be the cause of the problem.

I thought I had done everything as per the instructions, but then I remembered this! I'll update the results as soon as I can. Sorry to be a plumb!

Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on January 29, 2010, 09:16:08 PM
Hi Martin
The PCB's arrived today and they are superb! Thank you very much!
I need to save up some money for the transformers now and search the thread for details of appropriate power supply information which will enable me to supply 4 boards and will be mounted externally. Or at least that is my current thinking.
Steve

I think you could use the SSL9K PSU board.
you can buy it from gustav in the white market
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: GorillaToast on February 03, 2010, 11:58:26 AM
Concerning c9 in BA 283AV, does anyone know if Digi-Key part # 490-3676-ND is a suitable substitute for #P4925 which is no longer stocked?

It is a 100pf 50V ceramic mono capacitor.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 03, 2010, 03:51:23 PM
C9 is a polystyrene cap...not ceramic. You can find some of these in the specialty capacitor area at Mouser.

EDIT: Pretty much ALL of those pf cap's are styrene's. 'cept the termination cap for the input transformer and obviously the tantalums/electro's.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: GorillaToast on February 03, 2010, 06:21:24 PM
Then is the BOM incorrect?

Here is the part# listed in the BOM (from Digi-Key catalog)

http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=P4925-ND&x=16&y=15
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 03, 2010, 06:57:14 PM
Hi Guys, Sorry for the confusion; please be sure to use the latest, updated BOM, available for download at the first post of this thread:

http://www.groupdiy.com/index.php?topic=22828

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: GorillaToast on February 04, 2010, 10:59:29 PM
Received 2 EZ1290 boards today. They look very nice. I will order parts tomorrow, now that the confusion over the BOM is settled, and hope to have 2 working preamps in a few weeks.

Thanks Martin.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 08, 2010, 01:47:18 PM
Hi Everyone,

I've just updated a bunch of stuff in my first post on this thread (page 1). Please be sure to download the latest assembly instructions and BOM as a bunch of parts have become obsolete. I also recommend reading the FAQ at the bottom of my first post.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on February 08, 2010, 07:43:10 PM
Hi Everyone,

I've just updated a bunch of stuff in my first post on this thread (page 1). Please be sure to download the latest assembly instructions and BOM as a bunch of parts have become obsolete. I also recommend reading the FAQ at the bottom of my first post.

Best,

M.

Hi Martin,
great updates, The FAQ is something that is really useful and will prevent the same questions to appear over and over again.

I would like to ask you just one thing, is it possible that you could modify you Trim fader pdf, so that a newbie can clearly know where to connect the shield of the cable (from pcb to fader).

thanks a lot for all your dedication to this project
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 09, 2010, 12:00:44 PM
Thanks Whoops, will this work?  ;)

http://s3.amazonaws.com/EZ1290/trimmer_v2.3.pdf

(also updated on first post)

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on February 09, 2010, 05:38:30 PM
Thanks Whoops, will this work?  ;)

http://s3.amazonaws.com/EZ1290/trimmer_v2.3.pdf

(also updated on first post)

M.

Hi Martin,
thats great really

thanks a lot , you're the Man
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on February 12, 2010, 03:21:05 PM
Hi Martin,

I've almost finished my unit using the 1st BOM, with carbon film resistors but without polystyrene, but I still have to buy C9, C10 and the one on the transfo. Should I take ceramic mono caps like the 1st BOM, or should I get polystyrene.
Is there a big sound difference with the polystyrenes ? Should I change all my mono ceramics ?

Thanks,

Ben.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 13, 2010, 02:27:03 PM
Hi Ben,

You'll be totally fine with Ceramic. I have updated the original (and added a metal film BOM) due to continued prodding to be even more authentic and the fact that some parts went obsolete. You basically can't go wrong either way IMHO.  :)

Take care,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on February 14, 2010, 09:40:27 AM
Thanks a lot Martin !
Just to know for futur project : is there a big difference of sound with the polystyrene caps ?
Best,

Ben.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 14, 2010, 05:15:11 PM
I don't think so, but I have not done any stringent testing. My mic pres (with ceramic) definitely hold their ground next to a well maintained set of originals. Using Polystyrene definitely will not hurt though.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on February 15, 2010, 07:22:32 AM
Ok, thanks again Martin.
Now I just need to do some shopping for finishing my 1290, can't wait !
Best,

Ben.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gerardmanvuca on February 18, 2010, 09:31:04 PM
so ive been usin the ez1290 for a few weeks now and it sounds great.
................but it only works properly if i run my soundcards inputs (m-audio delta 1010) at +4dB. if i run them at -10dB i have to turn the input gain up about 3/4 and it sounds extremly distorted...   its fine for when im recording at my studio at +4db but wen i took it to my mates studio it was reacting the same way it was at -10dB ...he has the m-audio delta 44 and its slightly difrent in that u select the +4dB/-10dB on the software control panel (on the 1010 its a switch on the 1u rack).........but changing it to +4 didnt help......i still had to turn the input up 3/4ish to register any sound on the soundcard ins, and by then it sounds extremly tinny and very distorted and i could evan hear the audio from the rack itself! im guessing because im clipping the crap out ofthe neve..........is there a way i can get this rack to work at -10dB and run smoothly on other souncards?

any help wud be awsome, cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: YLab on February 18, 2010, 10:14:30 PM
My guess is that you have a problem with your interconect. (xlr to 1/4?)
The ez1290 have so much gain that you should clip your soundcard  way before the preamp. +4 on the 1010 should be the same as +4 on the delta44.
 
Hub

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 19, 2010, 12:59:13 PM
yes, what YLab said. It could also be a gain staging problem. How's the mic pre perform with units that have line level XLR inputs?

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: herrmann on February 21, 2010, 04:00:21 AM
Hi
I'm about to finish a pair of 1290, I will put them in a 2U rack.
Am I going into problems if I put some 312 boards in the same rack, sharing the same psu? I've build a powerstation with the 6A bridge.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 21, 2010, 12:18:24 PM
Hmm. If you run a powerstation @ 2x25v, full rectification...you should be able to run the api's on one rail and the Neve's on the other. 1.5 amps per side. Transformer will be pricey for this setup though..i think. Also, you have to consider your heatsink setup for all 5 regulators.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: herrmann on February 22, 2010, 06:30:00 AM
Ok, I have a 50VA 2x24 transformer, I think it should be enough for 2x1290 and 2x312. The 312 run on +/-24 and +12 for the relays. Maybe I could power the relays with a inverted -12V ?
+48
+24 -> 1290
+24 -> 312
-24 -> 312
-12 -> 312 relays
 ???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on February 22, 2010, 09:17:46 AM
Make sure the opamps you use in the 312 can handle +/- 24V. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 22, 2010, 06:43:01 PM
Yeah I don't know about putting +24V on 312's. Don't those usually get +/-18V?

m.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on February 22, 2010, 07:23:40 PM
I have hooked everything in my dual channel 1290. I am not getting any signal out of my pres. Only a sizzling sound. I resoldered most of the joints, went through all my wiring. Checked my voltages. Any everything should be working, but it is not. Is there any else I should try or look for? I am now considering buying new PCBS and doing it all over again. :(.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 22, 2010, 07:31:27 PM
Hi Funkymonksf,

How are your voltages? http://s3.amazonaws.com/EZ1290/transistor_voltages.pdf

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on February 22, 2010, 08:05:11 PM
They are reading within the limits I believe. If they are off what do you believe is the cause?

Thanks again for such a speedy reply!

Brice
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gerardmanvuca on February 23, 2010, 12:30:38 AM
yes, what YLab said. It could also be a gain staging problem. How's the mic pre perform with units that have line level XLR inputs?

M.

i did some tests with diferent xlr leads and the problem is defo not the xlr leads. i should mention that i built a stereo pre and the level problem is identical in both channels. I also have 2 jlm fet di modules installed in both channels (i haven't taken them out and tested the pres, maybe i should?).  i also havent tested the pre on line level xlr AD inputs but will do as soon as i can get into my mates studio.   So is it the case that the ez1290 should clip the soundcard evan at line level/-10dB, before the pre itself clips?   cus mine is clipping way before the soundcard(at -10dB).

heres a pic if it mite help in any way
http://i282.photobucket.com/albums/kk280/iamproof/IMG_0657.jpg (http://i282.photobucket.com/albums/kk280/iamproof/IMG_0657.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on February 23, 2010, 05:37:53 AM
Did you ground the PCB to the chassis with 10ohm resistor.

Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: YLab on February 23, 2010, 08:07:52 AM
i did some tests with diferent xlr leads and the problem is defo not the xlr leads. i should mention that i built a stereo pre and the level problem is identical in both channels. I also have 2 jlm fet di modules installed in both channels (i haven't taken them out and tested the pres, maybe i should?).  i also havent tested the pre on line level xlr AD inputs but will do as soon as i can get into my mates studio.   So is it the case that the ez1290 should clip the soundcard evan at line level/-10dB, before the pre itself clips?   cus mine is clipping way before the soundcard(at -10dB).

I would do a quick test without the jlm just to be sure. Should be pretty easy with those screw terminals. And dont forget that your sound card is more sensible at -10dbv than +4dbu (can take more input at +4) And even at +4,, the preamp should not clip before the soundcard!
Hub
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 23, 2010, 08:55:09 PM
yes, what YLab said. It could also be a gain staging problem. How's the mic pre perform with units that have line level XLR inputs?

M.

i did some tests with diferent xlr leads and the problem is defo not the xlr leads. i should mention that i built a stereo pre and the level problem is identical in both channels. I also have 2 jlm fet di modules installed in both channels (i haven't taken them out and tested the pres, maybe i should?).  i also havent tested the pre on line level xlr AD inputs but will do as soon as i can get into my mates studio.   So is it the case that the ez1290 should clip the soundcard evan at line level/-10dB, before the pre itself clips?   cus mine is clipping way before the soundcard(at -10dB).

heres a pic if it mite help in any way
http://i282.photobucket.com/albums/kk280/iamproof/IMG_0657.jpg (http://i282.photobucket.com/albums/kk280/iamproof/IMG_0657.jpg)

Definitely give it a try without the DI's. The soundcards should clip waaay before the EZ1290 at either +4 or -10. Do you have your output transformer(s) wired backwards (out of phase) by any chance? Also have a look at the FAQ at the beginning of this thread. Voltages ok? Did you bias the mic pre?

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 23, 2010, 08:56:03 PM
They are reading within the limits I believe. If they are off what do you believe is the cause?

Thanks again for such a speedy reply!

Brice

Hi Brice,

It could be a number of things, but usually is caused by cold solders or wrong resistor values.

HTH,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on February 24, 2010, 12:32:56 PM
AHHH!!!! So it turns out that the problem was a grounding issue. I had an inkling  as much, but just could figure where it was or what was missing. I decided to solder hookup wire from the hole between input trans and power holes and connect it to the case. SUCCESS! These things sound great! I still need to Bias them and switch the48v switches around! Thanks Martin, you are a bad ass!


-Brice
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on February 24, 2010, 11:04:45 PM
team,

i can't read the BOM on my computer! Has anyone got the new BOM as a PDF or something that my MAC can read. It will not read xls.

Thanks for any help. This is my first post for this project

Regards

Michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Carlos Lima on February 24, 2010, 11:23:35 PM
Download Neooffice from www.neooffice.org

Free (!), both PowerPC/Intel versions and reads and writes .xls, .doc, etc...

Carlos Lima
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 24, 2010, 11:27:50 PM
Download Neooffice from www.neooffice.org

Free (!), both PowerPC/Intel versions and reads and writes .xls, .doc, etc...

Carlos Lima

Yep, there's also http://www.openoffice.org/ (and really no longer any reason to buy any microsoft office products :-)

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 25, 2010, 11:49:11 AM
AHHH!!!! So it turns out that the problem was a grounding issue. I had an inkling  as much, but just could figure where it was or what was missing. I decided to solder hookup wire from the hole between input trans and power holes and connect it to the case. SUCCESS! These things sound great! I still need to Bias them and switch the48v switches around! Thanks Martin, you are a bad ass!


-Brice

Nice work Brice. So let me get this straight, you hooked 0V to case and that made it work? That doesn't sound quite right, maybe I'm misunderstanding...

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on February 25, 2010, 12:06:50 PM
Martin,

On the latest PCB there's a hole between the power holes and input trans holes. It's not labeled. I randomly decided to ground the PCB using it and attaching to the case. It seemed to do the trick. It now works with little noise. Now I am trying to figure out how I am going to Bias this thing without an Oscilloscope. Any recommendations?

-Brice
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 25, 2010, 12:48:42 PM
Hi Brice,

That's interesting. There's supposed to be 10hm resistance between case and 0V (they're not supposed to be connected). I wonder why doing this made yours work. Is your PSU connected correctly (pls see updated assembly guide: http://s3.amazonaws.com/EZ1290/assembly3.pdf).

You can (kinda) get away with not biasing using a scope by adjusting the 5k trimpot on the EZ1290 board until TR3 collector (the casing of 2N3055) measures 22.6 volts to ground/0V. This is assuming you have the ACDC rail adjusted to a nearly perfect +24.0V

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adrian on February 28, 2010, 06:22:11 AM
hello!
i'm finishing my 4 1290 unit, i'm very exited to test it!
i know Madriaanse doesn't like so much the idea to put a trimmer but i'd like to  test it, do you think this pot would be good enough?

http://radiospares-fr.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=169398&x=0&y=0

thanks!

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 28, 2010, 01:49:59 PM
Hmm. Not sure if you want to use Cermet for rotary fader.

I'm thinkin these: http://ca.mouser.com/ProductDetail/Vishay-Sfernice/PA16NP502KAB15/?qs=sGAEpiMZZMtxdMMi52izyloICbkjSMPkjj%252byCuROyso%3d


More bread tho. ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on March 04, 2010, 08:43:35 AM
hey Martin and Team EZ1290,

my boards have arrived in super quick time and they look fab.

My first question with this project involves the two identical sections on the PCB. When I was ordering parts I thought there was a typo involved with the repeated list of parts. Do I need to fill in both sections if I am just building the mic amp stage?

I'm gonna look through the thread armed with my new knowledge and find out.

Thanks in advance

Michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 04, 2010, 12:18:10 PM
Hi Michael,

You will need to fill both sections; the BOM is correct.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on March 10, 2010, 08:36:43 PM
Hey there,

can I connect the drain wire via the 10r resistor to the audio output jack?
Can I do this for each channel or will this effect the resistance ie:

10r on channel one to audio output earth

10r on channel two to audio output earth

I am using metal 1/4" jacks. Will this cause a problem considering the earth is connecting to the chassis?

Michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on March 11, 2010, 04:08:50 AM
Hi everyone !

I've finished my 1st unit, it works well but don't know where and how should I connect the 10r/1W resistor.
Any advice ? Thanks.

Ben A.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on March 11, 2010, 06:17:25 AM
hey,

got mine going too! had a nightmare with a few loose bit of copper wire floating in the case causing shorts. Now all is good.

MAKE SURE YOUR 1U/2U CASE IS CLEAR OF DEBRIS AND THAT THE PCBS DO NOT TOUCH THE EARTH EXCEPT THROUGH THE DRAIN.

I have attached the earth  drain from the top right of the PCB ( itself is connected to the earth of the PCB ) to the earth on my XLR/JACK AUDIO OUTPUT via the 10r/1W resistor. Hope that helps!!!IS that right? Works for me!!!


XOX

GO TEAM 1290
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 11, 2010, 12:10:27 PM
Hey there,

can I connect the drain wire via the 10r resistor to the audio output jack?
Can I do this for each channel or will this effect the resistance ie:

10r on channel one to audio output earth

10r on channel two to audio output earth

I am using metal 1/4" jacks. Will this cause a problem considering the earth is connecting to the chassis?

Michael

Hi Michael and Ben,

Don't connect the 10R anywhere. Leave pin 1 entirely disconnected on the output XLRs; any properly designed AD converter or tape machine will have its own ground reference from its own power supply. Connecting the EZ1290 0V to XLR pin 1 will only give you an increased chance of ground loops. The 10R (R98 on BOM) is actually on the JLM ACDC, and when you connect the ACDC to the PSU case (& AC earth), the proper connection is made. I left R98 on the BOM just in case people use a PSU other than the ACDC. The PSU case is connected to the EZ1290 rack case through the shield (drain wire) of the 3 (or 4) conductor 18 gauge power cable that connects to the 4 pin XLR connector.

HTH,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on March 11, 2010, 02:43:12 PM
That's what I thought ! Thanks Martin for clarifying that point. And BTW, I've already told you but again : that's an amyzing project, thank you very much ! Mine worked like a charm at the 1st time.

Ben A.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 13, 2010, 01:21:38 PM
You're welcome Ben!

So here's something funny that happened. I've built around 32+ channels of these and never really had one that didn't fire up right away. The last one I built worked but had a problem with the second pre stage, and the voltages around TR5, TR6 were off. Went through my usual checklist and didn't find anything else out of whack. Serious head scratching followed, and nothing was solved. Came back later (frustrated) and noticed I had soldered in TR5 backwards. D'OH!!! The channel worked perfectly after I flipped it.

Humbled,  ;D

Martin

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: frederikkofoed on March 13, 2010, 04:31:10 PM
Usual Checklist??  :)

Is it possible you maybe would like to share that.. :)

I would love to see it.. in case my doesn't work the first time...

- Frederik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 14, 2010, 03:12:01 PM
Hi Frederik,

I pretty much listed my "usual checklist" at the beginning of this thread. I start with transistor voltages, visually check components and their values against the schematic. In this case checking the transistor voltages revealed there was a problem in the TR5/TR6 area. I just didn't "see" I had mounted TR5 backwards. Which brings up another good point. If you can't figure it out, take a break, do something else, read Prodigy Pro, and then come back to it. A lot of times you'll notice or think of something you didn't before. This works for mixing as well. :-)

HTH.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on March 19, 2010, 08:59:42 AM
Martin,

I'm not using the ACDC so I have to fit the 10R somewhere right?

I am using the MNATS and the 0V is the common connector on the Mnats PSU. This PSU is in the 1U rack case along with the Ez1290s/

Do I connect this common (0V) to the case via a 10R resistor?

I am using 1/4 metal jack sockets for the output and they automatically connect the earth of the jack socket to the earth of the rack case.

I used to have the 10r going from the the 0V on the EZ1290 to the jack socket earth or rack earth. i used to have a little 40-50hz hum on the output.

I have removed this, and now I'm getting full on buzz.

What shall I do?

Do any drain wires come off the EZ1290?

Thanks

Michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on March 19, 2010, 09:58:06 AM
Ok,

what I have now done is connected a 10r resistor between the MNATS common / 0V and the rack case! The MNATS PSU and the toroidal transformer are both in the 1U case along with the preamps.

Ov to earth reads 10ohms much as before when I had the resistor connected between the EZ1290 0V and the jack output.

Maybe that's cus the jack is connected to the rack case.

Is this right? Am I getting warmer?

XOX

The mic amps sound great. really rich sounding
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on March 19, 2010, 03:28:06 PM
Hey,

does anyone find that there is a slight low end hum on their EZ1290 when cranked to full by comparison to the Focusrite ISA 428 or any other premium grade pre?

Is this what they do or could it be the MNATS PSU?

XOX
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wolfgang on March 19, 2010, 04:24:10 PM
does anyone find that there is a slight low end hum on their EZ1290 when cranked to full

Do you have your Mains Transformer inside the chassis with the preamps?
If yes, try turning the transformer around while you listen to the hum. I some positions hum will get louder or quieter. then fix it at the most silent position.

Or the best solution will be to make an external psu!

Hope that helps!

regards,
Wolfgang
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuce42 on March 20, 2010, 09:43:16 PM
Like wolfgang said - is your psu external?

Rotating the power toroid can help as well but external mounting psu should be for more beneficial.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 21, 2010, 02:30:00 AM
External PSU is always a good idea. Ask GML.

10ohm between 0V and earth is perfect, but it doesn't sound like you have the output (XLR pin 1, 1/4" TRS sleeve) disconnected, so your hum problem could also be a ground loop. 0V should not connect to the output - anywhere. Older TT patchbays used to do this automatically for you anyways. On my units there is no noticeable hum - it is below the noisefloor... that is as long as I use good mic cables and keep away from AC.

M.
Title: Almost done! With channel 1.... Need some wiring advice.
Post by: statzern on March 31, 2010, 01:24:55 PM
Hey guys, I am about to finish the first channel of my dual channel box. Unfortunately, my planning was not so great in my placement of the trannys. I am afraid that my setup may cause some issues. The input and output lines have to cross as I have it set up (see attached file - red is "pre-preamp" and green is "post-preamp"). Does anyone forsee this being a real problem?

Thanks in advance!

Nick  ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on March 31, 2010, 02:38:36 PM
I would change the Transformer placements this way:

(pic attached)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 31, 2010, 03:02:16 PM
Yes, Whoops nailed it! You probably want the total cable length between VTB9045 and EZ1290 PCB to be about 9-10".

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: DIYnoob! on April 03, 2010, 03:12:57 AM
Hey just wondering what transformers 3nity used for his build? I know they were cinemags...anyone know which exact ones?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on April 03, 2010, 09:57:00 PM
Hello,

I didn't see anything on Cinemag's (or Jensen's) website that really fits the bill.

You can use:
Carnhill VTB9049
Carnhill VTB1148
Carnhill VTB1847
Sowter 8751
Sowter 9160
Lundahl LL2734 (I think, not confirmed)

HTH,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on April 04, 2010, 11:16:44 AM
Hey Team,

thanks for the help with the pSU. I have ordered a new PSU so I can have 48v.

Guys, has anyone built the Great River MP-2 aswell?? Does the EZ1290 have less top end than the Mp-2? What are people finding?

Thanks

XOX

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on April 04, 2010, 05:49:19 PM
Hey just wondering what transformers 3nity used for his build? I know they were cinemags...anyone know which exact ones?

using the "Search" function I got this:

Cinemag CMMI-2C and CMOQ-2SG
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on April 04, 2010, 06:56:21 PM
Quote

using the "Search" function I got this:

Cinemag CMMI-2C and CMOQ-2SG
I've talked to Cinemag about these.  You'd most likely want the CMOQ-1SG.

The CMOQ-2 is a 625EI core, (API 2503 size), while the CMOQ-1 is a larger core, (same size as the Carnhill?) which should give you better bass (or less distortion at the same levels).  FWIW, all the CMOQ are quadfilar wound, meaning 4 equal windings, so not exactly what Neve originally used, but they will work.  When I spoke to Cinemag, they mentioned the Carnhills had some phase distortion which Cinemag got rid of in theirs. Marketing speak?  Don't know since I have not used them, but some people say they are cleaner.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on April 05, 2010, 02:15:55 PM
Hi Mitsos,

I'm not sure what turns ratio the CMOQ-1SG has, but if it's like the other CMOQ-1's that are on their website it's not an exact match for LO1166. LO1166, as wired in a 1073, is a 200 : 600 (1 : 1.73). You definitely want gapped (unless you go the LO2567 / T1310 coil route but that's a whole different story).

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on April 05, 2010, 02:47:59 PM
Hi Martin,

It's not an exact match to the St Ives/Marinair/Carnhills, but it is a good transformer for the circuit, if GAPPED (that's what the G suffix means, the S means steel core).  As far as I understand, all the CMOQ are quadfilar, meaning 4 equal windings. It works like the API 2503, you can run 1:2 or 1:3 (or 1:1, I suppose).  I guess the closest would be running 1:2 which will give you a bit more gain, but I wonder if that .27 is discernible... Anyway, it's good this info is out there since these are easier to get on the west side of the pond.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on April 05, 2010, 04:44:33 PM
Interesting. Do you know what Cinemag recommends for the RC network on the output? I'd like to hear an AB of original vs CMOQ-1SG. I might order a few to do so.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on April 05, 2010, 06:24:24 PM
We didn't get that far into the discussion. happened to get tom r on the phone and started talking all kinds of stuff. I know that for the APIs there is no RC network on the output, I can't be 100% sure it's the same here. 
Title: Only two wires to go...
Post by: statzern on April 07, 2010, 03:54:10 PM
My pre is almost done. I have been having a hell of a time fighting with this braided shielding. Most of my work has always been with guitar amps - not a lot of shielded anything going on in there.

Things are getting awfully crowded on the front panel. Perhaps too many bells and whistles. I am having a tough time getting things into the terminal blocks on the JLM GoBetween - they're too full.

Testing the main board and (hopefully) biasing tonite. At least the power is ok - the lights come on. Woo.  ::)
Title: NOOOOOOO!!!!
Post by: statzern on April 07, 2010, 08:17:39 PM
Hey guys, so testing has started... annnnnd.... problems. When I input a 1kHz sine wave, it comes out looking something like this: (http://i43.tinypic.com/vi086r.jpg)

Looks OK, but not exactly right. Maybe I am doing something wrong? I connected the signal generator to the shield and one of the wires that go to the input transformer. At very low levels, the output looks like a perfect sine wave. As I increase the amplitude, it turns into the picture above. Though turning the bias pot does seem to change things, it never really gets symmetrical. Notice that the tops and bottoms are not flat. Wonder why?? The wave is not necessarily the same shape at all frequencies, either. Any ideas?

OK, so here's some really effed up stuff - If you continue to increase the amplitude of the sine wave further, the power to the whole preamp will start to pulse. Could this be some sort of thermal shutdown? I don't know exactly how "big" the wave is, but it's likely bigger than anything that would be coming from a microphone in terms of amplitude.

If any more info would be helpful, let me know and I will try to get it to you asap! Thanks guys.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on April 08, 2010, 02:40:22 AM
Hmm, how's your scope hooked up? (Probe to 5, ground clip to 8 - on LO1166).

Voltages ok? http://s3.amazonaws.com/EZ1290/transistor_voltages.pdf

This pre should swing some +26dBu before going splat. Pretty crazy stuff.

Make sure the 2N3055 screws are very tight.

LM317's on the PSU have big heatsinks on them, right?

Got any (very detailed) build pics to share?

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on April 08, 2010, 10:10:37 AM
Hey Martin, thanks for the response. I am going to get some bigger heatsinks for the PSU. I checked and it is delivering 140mA on the 24V line, and the regulator is getting kinda hot, even at such a low current. Also, I checked voltages on the transistors and some are perfect (all the transistors in the output section are dead on), and some are not. I will have to recheck them once the power supply has been taken care of, because things start out OK, then if the power supply starts struggling it all goes haywire. If that doesn't take care of it, what does the transistor voltages being off suggest? Is it that the transistors are no good? Possibly overheated while installing?

To answer your other questions, the scope is hooked up correctly, and I will post some build pics when I get home.

Thanks everyone,
Nick
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 08, 2010, 01:36:17 PM
Has the probe been calibrated with a square wave? ie: on the front of the scope?
Title: Probe
Post by: statzern on April 08, 2010, 02:47:27 PM
Hm, no it hasn't. Thanks desol, I will make sure to do that.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on April 09, 2010, 02:33:12 PM
I didnt use any R load on my outputs..
Off course i planned to try them but never did!
I have less gain on my pres than the regular Bluzzi Carnhill units...
But come on i have more than enough though..!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: New Soul Rebel on April 10, 2010, 09:58:09 AM
Jeesssusss! the mind boggles!!!

Wow, Adria that is just unbelievably nice build mate. What does it sound like! Incredible i bet! Very inspiring to see what is possible! :P 8)

Matt
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on April 10, 2010, 10:33:56 PM
Hey guys - all is well with the pre! It just turned out to be a PSU issue. I mounted the regulators to the chassis and everything is operational!

Waves are nice and even now, frequency response is very flat all the way from about 32 Hz out to about 65-70 kHz. Wow! The only things that I am still having an issue with are the VU meters (needle is not moving??) and I have these lights for the +48 indicators... they're not working either. They are not the LEDs included in the package. I need to go back and study the JLM GoBetween schematic, I guess.

Anyway, the pre sounds great so far! Really clear and very quiet. Will do more testing soon!
 ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on April 11, 2010, 10:21:23 AM
I didnt use any R load on my outputs..
I have less gain on my pres than the regular Carnhill units...
Hi 3nity, your output is wired 1:1?   You should have a little less than 5dB (4.6dB) less gain then?  Did you use 2 windings in series for primary and 2 for secondary?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 14, 2010, 06:06:15 AM
Hey Guys,

Looking at build pics, it seems some people have filled the PCB trace 'jumpers' and some have not.

Should these be filled or left open?

Thanks
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: YLab on April 14, 2010, 08:10:39 AM
You need a jumper if you dont use the trimpot/fader option. You can find this information on the first post of this thread in the pdf : trimmer_v2.3.pdf

Hub
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on April 14, 2010, 08:34:43 AM
On older versions of the boards there was a trace where the jumper is now, so you had to cut it to use the fader. In the newer ones, Martin replaced the trace with a jumper, so no more cutting traces, but you have to use a jumper.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 14, 2010, 11:48:19 AM
thanks for the responses.

Im not talking about that jumper though, sorry for not being clear.

Im talking about the unlabled traces that terminate at both ends with a through hole and solder pad.

I assume these are some kind of jumper? If there are 2 examples on the trimmer pdf YLab mentioned.

Thanks
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on April 14, 2010, 03:10:09 PM
A picture is worth a thousand words  :D

Are you asking about filling vias? (the little holes with no component in them connecting a trace on the top layer with a trace on the bottom).  If so, it's not necessary to add solder here as the inside is plated during mfg and thus already connected, but some people might feel it's playing it safe (mabe in case of mfg problems, the plating might have problems and may give an intermittent connection or something.

good luck!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 15, 2010, 04:55:02 AM
Thanks Mitsos!

Thats really helpfull, and I learned the proper name!

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on April 21, 2010, 05:02:43 PM
Help! This is my first big DIY.

I'm having trouble with the PSU. when i take a reading from 0v and +48v i can adjust to get 24v. But when i take a reading from 0v and and +V I get 37v and doesn't matter how much I adjust the trimmers it stays put.

shouldn't I be able to get that to read 48v?

I have the jumper on the center pad and right pad.

Not sure what to do...

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on April 21, 2010, 05:23:09 PM
just realized I have LM317 and LM337 in backwards...ARRRRRGGGG.

Now i have the happy task of getting them out in one piece to switch them.

Any tips?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 21, 2010, 05:24:45 PM
have you def got the right voltage reg in?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 21, 2010, 05:25:58 PM
oh - i see you spotted you havent!

have you got some solder wick? should be easy enough to get in and out with some.

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on April 21, 2010, 05:30:39 PM
Yeah I used the wick but with three terminals right next to each other it's getting annoying.

just called the local parts shop. They have the regulators. I may just break them off at the terminals, pull out the legs and replace them. $4 for the parts. probably worth it.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 22, 2010, 04:30:26 AM
yeah, these regs are cheap as chips.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: adam1176 on April 22, 2010, 01:50:50 PM
Should I adjust my psu to output +24.05v or just 24? When I look at the transistor voltages pdf all the numbers are based off +24.05. It's such a small difference I'm wondering if it has any effect on the outcome or perfomance?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: djn111 on April 23, 2010, 11:20:52 AM
Hi,

0.05 volt difference, how big is the percentage compared to the 24V ? Check your part deviation (10 to 20% on capacitors alone) and you now the answer. So it has no influence at all on the performance. And the measurement are also a guidance not like exact mathematics, if all are within 10% you are good to go.

Kind regards DJN
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on April 24, 2010, 09:21:20 AM
hello
anyone has ever tried to use other input and output transformers?
How could play with the OEP?
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gandhalf3 on April 25, 2010, 11:47:05 AM
Hello everybody,

I'v just finished building my unit. it works well, but i'v got a problem with the Trimmer.


I'v put this one : http://uk.farnell.com/bi-technologies-tt-electronics/6187r5kl1-0/potentiometer-7-8-st-5k-1w/dp/1520667

and it doesnt work. 

which good trimmer should i use ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on April 26, 2010, 07:03:10 AM
hello
anyone has Mouser code of the toroidal transformers?
this might work? http://it.mouser.com/ProductDetail/Pulse/DP241-4-24A15/?qs=sGAEpiMZZMv4oUrzpPKU3NRXAOIguu8XvmVg6jn%252bIO0%3d
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 26, 2010, 07:37:36 AM
I cant see an amp rating on that link.

Also, please dont post duplicate questions in multiple threads. Its pretty annoying :-)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on April 30, 2010, 01:02:43 PM
Hey,

I'm wondering if anyone can tell me if this is the correct way to hook up the transformer.

(http://img714.imageshack.us/img714/776/psut.th.jpg) (http://img714.imageshack.us/i/psut.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: djn111 on May 01, 2010, 01:02:02 PM
Hi,

I would prefer a double contact switch so both mains connections are switched on/off, and I presume you are in a 110/120V region.

DJN
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on May 01, 2010, 05:13:14 PM
Yes, I'm from a 110/120V region.

The switch I'm going to be using is: http://parts.digikey.com/1/parts/971015-switch-power-rocker-spst-20a-cre22f4fbbne.html

If Ii wired it like shown in the picture would everything be fine?
Title: HUM! NOOOO!
Post by: statzern on May 04, 2010, 07:23:41 PM
Hey guys. Problems. I just finished my second channel and I am getting 60 Hz hum and also a very diminished low end response. A sine wave severely falls off below about 200 Hz.

I used shielded cable throughout. Transformer placement is not the problem (I moved them). I am running out of ideas!

Any suggestions?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on May 04, 2010, 07:25:37 PM
I should add - the grounding schemes are the same in both channels, and they are in the same box. Power supply is in a separate box. First channel is silent, no hum, and even frequency response over a very wide range.

Cannot figure why they would be different. The wiring is even better on the second channel...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on May 04, 2010, 08:24:34 PM
I checked the transistor voltages, and there are some huge differences. Power supply is adjusted to 23.9 V.

Transistor Voltages:
        Correct     Mine
TR1
C       3.8        6.4
B       0.9         1.3
E       0.4        .2

TR2
C     22.6      49.4 
B     3.6       6.4
E     3.1       5.2

TR3
C     22.6     49.4
B     3.1       Not measured
E     2.5       Not measured

TR4
C     3.8       7.5
B     2.4       1.1
E     1.8       3.2     - Base is not more positive than emitter

TR5
C     12.4       26.1
B     3.8       7.5
E     3.2       6.2

TR6
C     20.6       44.5
B     12.4      26.2
E     11.8       24.9


So as you can see, a lot of the voltages are essentially double their normal values.
Hope someone (help, Martin!!!!) can help me out here.

Thanks again.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on May 05, 2010, 04:31:17 AM
is the voltage when it first reaches the board correct?

have you triple check the orientation of all your transistors are correct?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gemini on May 05, 2010, 06:52:47 AM
Really interested with this project. is there alternate way to contact other than email to get the PCB? Tried email him but no response...perhaps my email went into Spam folder?


or anybody has the file so I can self etch it?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on May 05, 2010, 10:24:47 AM
is the voltage when it first reaches the board correct?

have you triple check the orientation of all your transistors are correct?

The DC at the board is just under 24 V, right at 23.9....

Checked the transistors, all are in the correct orientation.

My plan at this point is to:
1. recheck all resistor values
2. remove all connections from both boards
3. connect inputs/outputs/power from "good" side into the "bad" board

That way I will know whether the problem is on the board or outside the board.

Thanks, snip.

Will post soon.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on May 05, 2010, 07:29:37 PM
Hi Statzern,

You have some pretty far out voltages. Can you post some very zoomed in/hi res pictures of the top of your PCB and i/o transformer wiring? I would highly recommend not connecting the bad channel at this time to prevent damage. How does the good channel measure? Any solder bridges anywhere?

gemini:strange I'm not getting your email; sorry about that. did you send to martin_adriaanse (at sign) yahoo (period) com?

Best,

m.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on May 05, 2010, 07:45:01 PM
Wow, I am really dumb.  :'(

Forget those voltages... my voltages were fine.

I disconnected both boards and connected the crap board to the trannys that the good board was connected to. Everything seems to be operating normally.

So, either I have a bad transformer (let's hope not $$$$$!) or I have bad cable.

Will post soon.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gemini on May 06, 2010, 02:15:06 AM
Hi M

I will send email again. I am sure I have the correct address.

Regards
G
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on May 19, 2010, 06:01:08 AM
1290 Gang,

can more people get back with reports on how their units sound? Alot of people are posting pictures of they're builds but little on how the units are working in a mix.

I have finished my first track using a dual EZ1290 for everything except the inside/close micing  of the drum shells. So the vocal, guitars bass et al went through the EZ1290 into my ISA428 a/d convertors.

I found the pres to be kinda slow and lacking in any top end. Was really concerned. Felt that the acoustic guitar needed no compression, that's how slow I thought they were.

Anyway, came down to mixing OTB with my Phoenix N16 Niceriser and whilst hittting the vocals and bass guitar with 1176 action and EQ, the rest was without EQ..........and holy moly the track sounds great ( for me ). I thought half way through that I was in a world of mush but gotta say, my recording actually sounds like a good old record.

These pres work well but by gosh are they slow. They make my tracks sound as though they have been hit by a tape machine. Is that right?

Michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on May 19, 2010, 01:15:17 PM
Hi Michael,

Your findings certainly reflect mine. I'll chime in with my own biased observation; these things sound more tube-like than most tube pre's. :-) They're a welcome, warm cup of analog chocolate milk on a cold day in the digital ice age IMHO. Whenever I hear darker sounding albums like Norah Jones' Come away with me, or any of Ray LaMontagne's albums I'm instantly reminded of this tone (and ribbon mics). It's not for everyone (like chocolate milk for the highly lactose intolerant), or every style of music, but when it works.....

Take care,

m.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on May 19, 2010, 02:16:04 PM
I noticed mine were way less bright than my modern pre's - and bright tends to sound more immediatly pleasing, but I chuck everything through them now and dial that high back in on a pultec clone where its needed. I put my pair on the 2bus for tranformer compression effect. very nice.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 19, 2010, 02:58:40 PM
"Treble is overrated" - Terry Manning.

 ;D

Kinda seems like were just rediscovering the past.

My vintage API's are like this too. They have this kind of softness to them, that's really nice. Could have something to do with 2622. There are a couple samples of them at my link below. A couple quick tunes i did (first two) are with the API. Kinda messed the vocals due to my wonderful, shoddy old digi audiomedia 3 card with those wonderful RCA connectors. Very easy to distort with balanced equipment....even with levels wayy down.

I'm lazy, i need a new recording interface.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 21, 2010, 07:07:54 PM
Hey Martin,

Just wondering, what is the purpose of connecting the one mounting hole in the driver stage to 0v?
Is the shielding plate on the back supposed to connect to this mounting hole? I guess it would even if using plastic standoffs, as the screw and nut still make contact? I was thinking the shielding plates should go to ground? Hmm..

Thanks!

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tomfrost on May 21, 2010, 10:00:42 PM
Hello everyone!
First post ever!

I ordered all of the materials on the BOM metal list and there's 2 items backordered from mouser for 2 months.
Is there alternatives for these 2 items? (without affecting the sound of the preamp):
> Bipolar Transistor 2N3055    http://ca.mouser.com/ProductDetail/STMicroelectronics/2N3055/?qs=ljbEvF4DwOOO8oAO03E4Jw%3d%3d
> Capacitor 23PS118  http://ca.mouser.com/ProductDetail/Xicon/23PS118/?qs=VbcEA1k3avMBB6CatG1TDA%3d%3d

Thanks!

Update: Found parts elsewhere on the net thank you!
And Thanks deuc224 for the link
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuc224 on May 22, 2010, 02:02:36 AM
Martin told me to get this one:

 http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=497-2612-5-ND

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Chrome Heart on May 22, 2010, 11:35:25 AM
Heres a question. I see a 100p cap on the silkscreen but not on the BOM. Am I missing something? Is there a misprint?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: penguin on May 22, 2010, 01:25:26 PM
hi all,
i am trying to solve a noise issue ;

i am using stereo 1073 as summing amp makeup gain. i have -83db noise  ???
surely, cant heat it unless blast my amp... but is this normal ?

to be able to get unity gain from summing mixer, i am using 5 clicks of gain (45db)...
(summing amp is passive;  the one is available here)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Chrome Heart on May 23, 2010, 02:19:52 PM
So the photo below shows the stop pin on the Grayhill in the 5:00 position, but the assembly instructions say to install at 12:00. Can someone clarify?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on May 23, 2010, 08:58:21 PM
Hi Chrome heart,

Not sure why you don't see a 100p in the BOM; it's part C9, item # 23PS110 from mouser.

If you insert the stop pin at 12 o'clock per the instructions, it will be stopped after 75dB which is what you want.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Chrome Heart on May 24, 2010, 07:25:22 AM
Thanks Martin for the part number. Maybe I have an out of date BOM, C9 shows on the BOM Digikey PN. P4922ND which looks to be a 10000pf ceramic.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tomfrost on June 11, 2010, 12:57:52 AM
Ok so updates on mine!

Finished the board and the go between. I Have to do the 2 transformers and do my rack. All went well on this side.
Also finished the power supply, but after putting it in the case and screw everything, i power it on (after i already tested it without the case and fixed the voltages at 24 and 48) and smoke and flames was coming out of it!

I found out that there was a short between the case and the board because the 10r burned out as the 47r 1w. So what I did is use plastic screws to fix the LMs to the case to be on the safe side and it worked (as someone told me to do so). So a suggestion, either use plastic screws or heatsinks for your LMs. Now i replaced the two resistors and it works perfectly  ;D

Anyways hoping to finish it this week and to try it! (have to record vocals and acoustic guitar wednesday). Everything seems fine now. I ordered two but will start with only one as I'm short on free time right now.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on June 24, 2010, 09:23:02 PM
Here's a picture of my second completed build!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on June 27, 2010, 01:56:02 PM

Sounds amazing, thanks to madriaanse for all the help!




(http://img824.imageshack.us/img824/42/neverack11.jpg) (http://img824.imageshack.us/i/neverack11.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

(http://img443.imageshack.us/img443/9918/neverackclose10.jpg) (http://img443.imageshack.us/i/neverackclose10.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

(http://img404.imageshack.us/img404/1995/neveback28.jpg) (http://img404.imageshack.us/i/neveback28.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

(http://img88.imageshack.us/img88/3388/nevetop6.jpg) (http://img88.imageshack.us/i/nevetop6.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on June 27, 2010, 04:41:41 PM
Joelv, great look man, I like the racked PSU. Where'd you get those knobs if I may ask?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on June 27, 2010, 07:35:44 PM
Thanks!

e-mail [email protected] and ask for the "Red Neve Knobs"


-Joel
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on June 28, 2010, 06:14:27 PM
nice work joelv

Whats that think blue wire youve got that appears to be attached to pin 1?

Thanks
jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on June 29, 2010, 05:24:35 PM
The blue wire goes to the LO1166 shield on the PCB.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on June 29, 2010, 05:49:32 PM
Ahh, OK - so you attached the transformer end of the shield to pin 1..... anyone else doing this? I gathered Pin 1 could be left disconnected.

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mattyblue on June 29, 2010, 07:47:26 PM
If you don't mind me asking, how much did the whole project run you?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Joelv on June 29, 2010, 08:05:09 PM
@ snipsip - correct, you could also leave Pin 1 disconnected.
@ mattyblue - around $1600 CAD (I have a lot of left overs though)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 29, 2010, 09:38:24 PM
Ahh, OK - so you attached the transformer end of the shield to pin 1..... anyone else doing this? I gathered Pin 1 could be left disconnected.

Cheers

I'm running the full shield on the output. You don't have to but...
Just be careful with the ground loops i'm guessing...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: beatnik on July 01, 2010, 06:46:22 AM
beautiful job!

can you post pics of the psu too?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 02, 2010, 05:46:39 AM
Ive had my pair in bits for a few weeks as I coundnt resolve my darned crackle.

I built it into a new case with a couple of tiny changes:

1) I used an M4 bolt to connect the audio ground to the case, avoiding any extra / messy wiring.

2) I used the fivefish PCB's for input transformer, with molex headers. I was personally convinced this was the cause of the crackle, as the thick mic cable would be under some degree of tension, and the little pins never seemed like a solid connection to me. (BTW I wanted to use screw terminals, but had already soldered the molex to the pcb, and the PCB to the transformer.... once that PCB is on it doesnt seem to want to come off, and those transformers are prone to failure if you overheat the pins... so decide on your connector of choice before soldering anything! )

3) I added an extra pair of input XLR's which were not hooked up to phantom power. I use this unit for a pair of mics and my mix bus (after a pad that takes it down to mic level). Now I can have both hooked up and I dont risk blowing my Alphalink up by accidentally sending +48 to it.

I missed having these around... they sound amazing!


Thanks again martin
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 03, 2010, 10:07:55 AM
DAMN - after poweing up properly to use in a session, I have crackle in my left channel again.

Did anyone every make any proper headway with resolving theirs?

I have my LM317 heatsinked to the PSU case. All wiring looks good. Crackle is intermittent on the left channel, with or without phantom turned on.

Appreciate your thoughts - really want to start using these properly but its unusable at the moment

Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on July 04, 2010, 02:42:54 PM
Hi Jake,

One forum member resolved the crackle by *really* tightening the screws that hold 2N3055. These need to be very, very tight. (you are using metal screws right?) Also, reheating the solder joints for the rotary switch may do the trick.

Let me know how it goes!

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 04, 2010, 04:01:29 PM
Cheers martin - I'll give them both a go!  :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 07, 2010, 01:22:54 PM
Hey martin,

I think tightening those screws has worked. I'll give it a bit more time, but so far so good.

I have a slightly odder problem after my rebuild that i cant quite figure out.

I used 4 input XLR's and only connected phantom power to one pair. both wired to the input tranformer making use of all 4 conductors in my mic cable.

The other 2 connecters are used for my mix bus, which has already been padded to mic level.

Both pairs of XLR's work as I can get a level when i patch my mix bus in using either pair, but the odd thing is I cant get get a mic signal to register. I have measured correct phantom power is getting to the mic.. so im totally bemused.

Me and a friend share a scope, so I will get that back and do a few more investigations of my own, but an ideas at all what this could be? Im totally stumped.

Thanks a lot
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on July 07, 2010, 01:51:54 PM
Hi Jake,

Can you confirm that: +48V from PSU is split and connects to:
A: 6K8 resistor -> XLR Pin 2
B: 6K8 resistor -> XLR Pin 3

So you should measure +48V between pin 1 and 2, pin 1 and 3, and 0V between Pin 2 and 3. Sometimes people (read: I :-) mistakenly swap pin 1 and 2 because they are mirrored depending on whether it's an input or output.

Also, trying this mic/mic cable combo with another preamp just to be sure might be a good idea.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 07, 2010, 05:01:33 PM
hey martin,

I had checked the mic and cable with another pre and all was good.

What you said made me reexamine my switch wiring though (which I was trying to make as tidy as possible), and I think I may have managed to parallel the 3k9 along with the phantom feed.

I had measured 4.8v at the mic, but thought in my haste that was 48v. Im off to bed now, but im pretty confident I can get it working now.

Thanks for your help (again) dude... always appreciated!  :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on July 08, 2010, 05:45:23 PM
Cool; you're very welcome!  ;)

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 10, 2010, 06:35:36 AM
Hey guys,

Im a little confused about what the voltages im getting at the input XLR.

I measure around 33v at pins 1 & 2.

Whats the purpose of the 6k81's? We have 48v at the toggle switch, so why are the resistors required?

Im also a bit spun out as the 3k9 take the 48v line down to 5v for the LED, so wouldnt the 6k81's theorectically do more than this?

Im sure Im missing something very simple here 

Any ideas?

Thanks a lot
jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: johnR on July 10, 2010, 07:42:42 AM
I measure around 33v at pins 1 & 2.
Is that with a mic plugged in? The voltage will drop when loaded by a mic.
Quote
Whats the purpose of the 6k81's? We have 48v at the toggle switch, so why are the resistors required?
Without them the 48V supply would short out the ac mic output signal. With them in circuit, they give a 13k6 (2 x 6k8 in series) load in parallel with the input transformer primary, which most mics will be OK with.
Quote
Im also a bit spun out as the 3k9 take the 48v line down to 5v for the LED, so wouldnt the 6k81's theorectically do more than this?
Yes, if the mic draws more current than the LED. The resistors limit how much current can be supplied to the mic. Most phantom powered mics draw a low enough current not to cause a problem.

http://en.wikipedia.org/wiki/Phantom_power
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 10, 2010, 08:34:21 AM
Thanks John.

Thanks for the info. What you said made me look at voltages with different loads. Seems its actually the line to mic level pad I had hooked to my second set of input XLR's that was doing funny things.

So in case anyone else was thinking of doing this (4 conductor mic cable> 1 pair to XLR with +48, 1 pair to XLR with no +48)... dont!  :)

Well having the input split over 2 XLR's doesnt do anything, but having the pad in the second set of XLR's creates some kind of load... maybe the resistor network? Its all a bit over my head really.

Thanks for the tip john.


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 10, 2010, 01:53:11 PM
Right - seems most of my problems are gone.

No crackle, no oscillation, working with and without phantom.

Perfect except one small thing.

The pre's sound distorted when turned up highis (45db+), but not clipping according to any digital metering. Could this be the result of not biasing properly?

I have attempted to bias but had issues getting a clear result on my scope.

Thanks a lot
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 12, 2010, 07:49:34 AM
Sorry to bump this.

Any ideas regarding how possible incorrect BIAS will effect the sound?

Thanks again
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on July 12, 2010, 09:49:45 AM
I have attempted to bias but had issues getting a clear result on my scope.
What do you mean? Are you unable to see both sides of the wave simultaneously?  If so, are you feeding a steady signal and then turning up the gain on the 1290 until it clips? Try keeping the gain on the low side and then turning up the signal you are feeding it.  Play with both until you can see both sides of the wave on your scope and the uneven clipping.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 12, 2010, 10:12:08 AM
As far as i understood it, your supposed to turn your pre to full, then input a 1k sine until you see clipping, then adjust for even clipping on both sides with the trimmer. Martin was correct in that, 22.6vdc was about right; i think i fine adjusted to 22.65 or something. Still working on them..

Why your getting distortion +50 could be a number of reasons. These pre's will distort something after it pretty easily? What are going out-into? Are you sure the thing your going into isn't distorting?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 12, 2010, 11:41:16 AM
thanks for the tips guys. I know this shouldnt be so hard, but im a bit of a novice with a scope so please bear that in mind.

Delsol.. where are you measuring your 22.5v? At the power terminal on the board?

Maybe mines running a bit hot @ 24v? Although I thought that was standard requirement for neve?

Im going straight from my mic (or SSL alphlink converters depending on source for test) and straight back to converters, so no chance of distortion coming from anywhere else.

The SSL has nominal operation level of +4dBu.




Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on July 12, 2010, 11:50:51 AM
As far as i understood it, your supposed to turn your pre to full, then input a 1k sine until you see clipping,
yes, that is on martin's pdf, I tried it and it did not work for me. I could not get both sides of the wave on my scope. Maybe my sig gen gain is jumpy, I don't know.  I was a bit lost until someone told me to try turning the preamp gain down, which turned out to work just fine.

where are you measuring your 22.5v?
Check the first post of the thread. Take your measurement from the case of the 2n3055 w/respect to ground.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 12, 2010, 12:13:20 PM
Weird? I'm assuming you tried all the vert divisions...hmph.

My sig gen rig isn't great either...lol. Using the output of a computer soundcard half hazardly into the input...with a small resistor network inline.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on July 12, 2010, 01:12:19 PM
yeah, I did play with the scope quite a bit.  I think the sig gen level knob is jumpy. I should check that out I guess, but it works for most things.  Anyway, this was a long time ago and my memory cells are not what they used to be... but as far as I remember, I lowered the preamp gain a few notches, fiddled with the signal generator level a bit and then could finally get both sides of the wave on the scope at a decent enough resolution where I could see what was going on when adjusting the trimmer. weird for sure.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 12, 2010, 02:45:20 PM
I just wanted to post these shots for anyone interested. This is my new JLM powerstation with the mod's done for full rectification, + rails only (neg's disabled/parts left off ) with 1.5 amps going to each positive rail. This will do up to eight channels, 375 mA per channel.


(http://img651.imageshack.us/img651/5778/dsc02810g.th.jpg) (http://img651.imageshack.us/i/dsc02810g.jpg/)

(http://img14.imageshack.us/img14/4966/dsc02817m.th.jpg) (http://img14.imageshack.us/i/dsc02817m.jpg/)

(http://img249.imageshack.us/img249/381/dsc02814v.th.jpg) (http://img249.imageshack.us/i/dsc02814v.jpg/)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 28, 2010, 12:35:38 PM
Neve gurus... sorry to constantly pester you with my troublesome build... but Im still straching my head over this distortion Im hearing.

If I run a line signal into the pre (using a fearne lp-1 to make it mic level) this thing sounds awsome. Really big and controls the bottom end into a lovely tight bundle.

When I run mic signals into it, either condensor or dynamic, the pre sounds pretty distorted and closed. Someone has suggested input transformer saturation. But how come it saturate from mics only? It sound like it clips way before I reach FSD on my SSL alphalink converters.

The biasing may not be 100% accurate but its definitely close.

Can anyone help me? The fact it happens on both channels if making me think its human erro somewhere, rather than a faulty part.

Are any parts I should swap out just incase they got damaged or are prone to failure?

Thanks so much... been working on these babies for a long time now ;)

Cheers
jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 29, 2010, 05:46:17 PM
in fact, any of you UK builders want to take a look at it for some money?

I just want to use them now. Have to let go of my pride :(
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 31, 2010, 09:05:05 AM
Do you have some up close shots of the board? You should be able to use a scope along the way to see where the clipping is occuring, 1st stage, 2nd stage, etc..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 31, 2010, 10:19:59 AM
thats a really good idea..... but I cant hear the clipping when im feeding a tone into the pre, which might make this difficult huh? Or do you think I'll still maybe see something?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Biasrocks on July 31, 2010, 11:37:37 AM
thats a really good idea..... but I cant hear the clipping when im feeding a tone into the pre, which might make this difficult huh? Or do you think I'll still maybe see something?

Depending on how much gain you're applying (very little with a line input) there's two extra gain stages that kick in, three in total for a 1073. I suspect that either the second or third gain stage is the culprit.

Mark
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on July 31, 2010, 06:13:53 PM
good thinking. although Im actually padding my line signals to mic level with a fearne LP1 and applying similar gain. I will try tomorrow without the pad.

Thanks for all your input so far.

jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dazazone on August 08, 2010, 01:46:10 PM
Hey Martin,
Just wondering if you or anyone else has tried out the EA-1166 on an EZ1290 yet?  They are a lot cheaper than the Carnhills and I suspect a lot better. 
Also I have a funny story about my calibration procedure.  I hooked up my nord lead into EZ1290 into Lynx Aurora into PTHD.  I could see the waveform in Pro tools and stuck down a pure sine wave note on the nord, turning it up to the clipping point.  I had my speakers off and thought I was going crazy but the Carnhill output transformer was audible. Like a mosquito, but I could definitely hear it.  I even played a song on the Nord and the output transformer was singing along in tune! Quite amazing.
A side story to my calibration procedure, I accidently dropped my screw driver whilst calibrating channel 1.  It landed on Carnhill output transformer of channel 2 and joined a couple of the terminals for a couple of seconds, then there was a burning electronics kind of smell, oh no!  Anyway that channel still works totally fine, I'm hoping I haven't damaged anything but there is one problem in the sound and I'm not sure if it was there before calibration or not.  With a mic I get the same output and tone as channel one but there is a 50Hz hum going on very quietly, I could prob hpf it out but I know it's not right.  I haven't done any more testing since then and it is in my rack.  I'm suspecting either I rooted the output tx with the screw driver short circuit or another machine in my rack is too close with its toroidial power tx. My JLM ACDC PS for the EZ1290 is external.  I'll test more and report.  One thing I noticed is when a 57 is plugged into it the 50Hz is actually a bit louder than a bald mic lead.
Hmmmmmm.......

  :o
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dazazone on August 11, 2010, 03:55:33 AM
ok it seems one of my 3055 legs was touching the heatsink! The heatsink measured 23.5V, nasty.  Fixed and now the 50Hz hum is gone! woo!  :-*
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuc224 on August 12, 2010, 04:46:35 PM
I wanna know about the EA-1166 trannys in the 1290 also.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 12, 2010, 07:24:20 PM
It's probably fine...the Carnhill is fine too.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dazazone on August 13, 2010, 02:24:29 AM
J0e [email protected] was telling me that the original 1166 is different in the way it is wound which affects the capacitance, and that is where the Carnhills fall short.  I cant remember exactly but one of the windings requires flipping the transformer and winding the opposite direction.  Tom M won't let this design happen anymore apparently.  Hey Tom I did yr coarse 10 years ago and it sucked!   :-X
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 13, 2010, 04:16:42 PM
Well, there's been alot of talk concerning this subject. It's been going on forever.
As far as i know, no one has succeeded in cloning the original.
CJ would know a hell of alot more on this subject than I. I speculate when I disuss this matter...
as there's always someone out there that knows more, or has seen something else.
I'm assuming Carnhill has a transformer that does match the Neve spec. Whether it's the
same transformer people buy or not, i do not know. Nor do i care really..

I don't know very much about Ed's transformer...or Telefunken's attempt.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dazazone on August 15, 2010, 04:48:28 AM
Yo Ed, are you gettin about?  :o
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Jazzboms on August 21, 2010, 11:39:27 AM
Hi

Just put together 2 ez1290, and I got the same problem on both.

With both transformers connected I get nothing. Removing input transformer, and put signal right into the pcb, sound flowing through the preamp, but checking the signal with my probe at pin 5 on output transformer, the sound is not nice. Checking the sound at pin 1, the sound is good.  So with transformers = no sound. Only output = bad sound. No transformers = sound ok.
Edit: After some more checking i found it kind of passes signal with transformers, only it is very distorted and low. More like sound variations in the noise(Ground issues???)

Im hoping to also use the transformers in the amp :-)

My transistor measurings are:
TR.1: C 3.66 / B 0.91 / E 0.34
TR.2: C 22.4 / B 3.65 / E 3.09
TR.3: c 22.4 / B 3.1 / E 2.5
TR.4: C 3.76 / B 2.37 / E 1.81
TR.5: C 12.23 / B 3.76 / E 3.14
TR.6: C 20.4 / B 12.24/ E 11.61
Seems to be inside.

Also measured the transformers
Output
Pin 1: 22.4
Pin 2/3: 22.8
Pin 4: 23.1
Rest 0

Input:
all 0V

Double checked resistor value, and caps direction.

Im using a SSL9K psu, with 23,9V measuring. Transformer is a toroidal 25V/60VA.

Hope that anybody can direct me towards ending this beautiful preamps.

Thanks for reading and helping.

Best

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Jazzboms on August 22, 2010, 06:17:38 AM
Hi again

Done some more checks, and now the output transformer is ok when bypassing the input transformer. It is actually very nice without input trans.
But I really dont know what is wrong with the input. I have tried with some of the other input trannies i ordered(4 of them), with the same result.
Shouldnt it be signal on pin 7 on the input transformer?

Thanks

LAST UPDATE: Finally got it working right. Puh. I rewired the input tranny, and it worked. So now Im putting together 2 more, and make a 4 unit box!
Thanks for making this great project.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 22, 2010, 09:20:13 AM
Everything is listed on Martin's assembly guide.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Slenderchap on August 22, 2010, 02:27:06 PM
This is what your problem sounds like to me....

In this application the transformer output is fully floating and has no groung reference..... so if you try to probe the output (pin 5) you will get nothing (or something poor) unless the ground of the probe is attached to the other side of the transformer winding (pin 8)....

.... in other words you must "listen" across the transformer winding..... probing either pin 5 or pin 8 will yield no signal because the other end of the winding will just "flap about in the wind"...

Alternatively just attach the transformer output to the input of a piece of balanced gear (pin 5 to hot, pin 8 to cold.... no ground required) and see what you get.

Colin
www.audiomaintenance.com
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: scottlangendyk on August 25, 2010, 09:19:22 PM
Awesome project, are PCB's still available?

EDIT: E-Mailed Martin and was informed that they are available  :)

Had a few questions though for fellow builders.

With regards to the power supply, is there any reason to use the transformer listed in the BOM, or will any transformer work as long as it's outputting 24 volts? I'm not quite sure how the 0 volts would be wired up that way though. I read somewhere that toroidal transformers  are better for line noise in audio applications, but does it really make a difference especially when the power supply is in a separate enclosure all together? Also Any particular reason why 4 pin XLR was chosen for connecting the power supply?

How specific are the capacitor selections in the BOM? I noticed that some of them are axial mounted as opposed to radial mounted, and I'm wondering if that was a design thing specific to the PCB, or just a random selection at the time?

Thanks guys.

Scott
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: scottlangendyk on August 27, 2010, 08:34:25 AM
Bump
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 27, 2010, 09:23:26 AM
Awesome project, are PCB's still available?

EDIT: E-Mailed Martin and was informed that they are available  :)

Had a few questions though for fellow builders.

With regards to the power supply, is there any reason to use the transformer listed in the BOM, or will any transformer work as long as it's outputting 24 volts?


It depends on how many channels you are building...how many amps you need. Two channels can use a smaller transformer than 8 channels. It also depends on which power supply your using. If your using the JLM stuff, you'll need 24vac.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: scottlangendyk on August 27, 2010, 09:48:32 AM
It depends on how many channels you are building...how many amps you need. Two channels can use a smaller transformer than 8 channels. It also depends on which power supply your using. If your using the JLM stuff, you'll need 24vac.

Only looking at building 2 channels at the moment, depending how that goes might look at building two more in the future, but would want to run those off the same PSU.

I'm looking in to using the JLM stuff, as it's well praised around here (unless I can find a 24 and 48 volt power supplies). However assuming I go the JLM route, the power transformer is where I'm a little stumped. I have a 24V 12VA transformer from somewhere (same as http://www.plccenter.com/buy/ATC-FROST/CA1225), for which I'm wondering if I can just use this over spending 60 bucks on a toroidal transformer. I'm concerned the 12VA may not be enough, as I was reading somewhere that each channel can use upwards of 500mA, but I've also got two 24 V wall transformers rated for 20VA and 40VA respectively.

Thanks again.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 27, 2010, 11:45:54 AM
Well, you can only fit 2 channels in a 1u rack, so unless your planning to put them vertically into a 3u, you may as well just focus on doing a two channel. If your planning on doing 2-1u racks...2 channels each...you would want to pre-plan your powersupply(amperage/wiring) for 2-1u racks.

For a single 1u rack with two channels, i'd probably go with Y236102 from Avel Lindberg transformers(30VA/24v)...and the JLM acdc. For the 4 channel powersupply, i'd step up to the 50VA toroid with the acdc. Either way, the acdc needs to be assembled to provide full rectification to just the + rail. Simple mod..

Welcome to the forum BTW.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: scottlangendyk on August 27, 2010, 02:00:35 PM
Most likely the second pair would be in a separate enclosure all together, so don't even worry about that, I just want to plan ahead as best as I can. For now I'm just focusing on the two channels in a single 1U or 2U case. I'm still in the stage of doing as much research as I can before I actually set my foot down and start purchasing all the parts.

That avel transformer is dual 12vac, and the amveco from the BOM is dual 22vac. The diagram in the assembly shows the dual 22vac being wired up in series, which from my understanding would double the output to 44 vac? Which one should I be looking for?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 27, 2010, 06:47:51 PM
I don't know why Martin spec'd the 44vac transformer. If your using the ACDC, it runs off of 24vac input.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on August 27, 2010, 09:24:49 PM
No, desol - the one you want is a 22-0-22 transformer.

If you get the 24 VAC one, you will not be able to get your +48 up to 48. And probably will have issues with your +24 too. I had this issue, and I am 100% sure that you NEED to have more than 24 vac.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on August 27, 2010, 11:20:04 PM
JLM specifically states that their PSUs will generate 3-5 rails (depending on model) off of one or two 24-30 VAC windings. So you could get one 24VAC or 24-0-24 or 24-0,24-0, and each can be made to work. You generally don't want to use a lower AC voltage winding than the DC you need in your circuit, although in many cases it will work just fine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 28, 2010, 01:12:40 PM
No, desol - the one you want is a 22-0-22 transformer.

If you get the 24 VAC one, you will not be able to get your +48 up to 48. And probably will have issues with your +24 too. I had this issue, and I am 100% sure that you NEED to have more than 24 vac.

Have a look at JLM's site. All you need is one 24vac winding ( 12+12 in series)...
You don't need a larger transformer than the 30VA 12+12...for two channels.
Plus, your only using the + rail, so the powersupply needs to be modded for full rectification
using both windings on the the transformer (12+12 series) at 1.25 amps single rail only(negative rail disabled; parts left off). Then the pump charge is set to tripler to get the 48v rail. Your not using the negative rail...so, no sense in powering it with half of a larger transformer. Consult Joe at JLM. Have a look at my post on page 30 here...

I wish someone would make a definitive post about this at JLM's forum. It confused me too for a while until Joe helped me with the basic idea. It began when i realized i didn't want to use a larger transformer than necessary and/or the neg rail.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on August 28, 2010, 01:20:36 PM
you will not be able to get your +48 up to 48. And probably will have issues with your +24 too.

I dont think this is true. The AC/DC has a voltage doubler, no?

Perhaps you had a problem with the amp rating of your transformer?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on September 05, 2010, 04:13:41 PM
I finished up my first channel today and tried it out, I'm getting sounds but also getting crazy hum. I haven't mounted anything to my chassis yet but I think the hum may be coming from my power supply. I don't have an oscilloscope but I used my DVM to measure the +24 rail and I had it check for Hz on that rail and it reads 60Hz. I'm using a left over SSL 9k PSU board. I tried upping the caps to 2200uf but that didn't help, I feel I may not be getting full wave rectification, any help guys?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on September 05, 2010, 06:20:56 PM
When i had mine outside of case etc...i had to put ground wires running all over the place, but it was quiet.

(http://a.imageshack.us/img200/1245/dsc02018.th.jpg) (http://img200.imageshack.us/i/dsc02018.jpg/)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on September 10, 2010, 09:21:08 AM
Hey guys, let me explain what I am trying to say:

In Martin's Assembly Guide, he suggests the Amveco TE62085 power transformer. This transformer will give you 22 VAC if you wire it in PARALLEL, but Martin's guide is set up to be wired in SERIES which will give you a total of 44 VAC. If you look at the datasheet (http://www.amveco.com/pdf/Amveco_Catalog.pdf#page=25) you will see that wiring the output AC across the GREEN and BLUE wires is putting the secondary windings in series.

Anyway, it definitely wasn't a problem with the current capacity of my transformer - it was like 100VA for only 2 channels!

Hope everyone's enjoying their preamps, I definitely am! Unfortunately, medical school has gotten in the way for now.. so the recording has significantly slowed... I wonder if I'll ever have free time again??
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: JPK on September 15, 2010, 12:27:25 PM
Hi Martin,
I really love the way the schematic diagram looks in your "EZ1290 Assembly Guide".
Which software did you use ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on September 15, 2010, 01:40:55 PM
I actually liked the way yours (Sound Skulptor) looks like!!
Dont change it!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: JPK on September 15, 2010, 03:33:22 PM
There is something that I really like in Martin's drawing, maybe in the components proportions.
But looking closer, it seems it has been done manually with a simple draw program.
All the merit goes to the artist.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Lowfreq on September 16, 2010, 05:38:20 PM
I have a question that I think has been touched on a bit in this thread, but I can't figure out a definitive answer.

One of the standoff (mounting holes) connects with 0v on the pcb. Now if I use a metal standoff wouldn't that connect 0v and chassis ground together?? Which is a no no when it comes to grounding?? Am I meant to use a plastic standoff? Am i meant to connect to chassis ground here also via another 10r resistor as well as the one in the PSU?
Now I understand the 10r in the PSU, and even though I'm not using the JLM acdc board, I know how to implement it into my own PSU, but it's more the use of this standoff thats confusing me. If we're meant to use plastic standoffs then why is 0v even connected to the mounting hole?

desol asked a similar question earlier in the thread, but I'm not sure if there was an answer. If there was I missed it somehow, but that can happen when reading through long threads.............. just try the G1176 one ha ha
Quote from: desol
Hey Martin,

Just wondering, what is the purpose of connecting the one mounting hole in the driver stage to 0v?
Is the shielding plate on the back supposed to connect to this mounting hole? I guess it would even if using plastic standoffs, as the screw and nut still make contact? I was thinking the shielding plates should go to ground? Hmm..

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on September 17, 2010, 04:28:28 AM
I have heard people say dont use metal standoff's.... but in my build I DID have to connect that PCB ground to chassis.

When I rebuilt mine to tidy wring and fix a few other probs, I decided to use a metal M4 bolt to ground to chassis and it works well, and means you dont have a messy wire.

I went for a bolt ratrher than standoff, because I glue my standoffs, and then there would be no continuity between ground and case. Metal standoff and little screw through bottom should work though.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on October 13, 2010, 10:29:22 AM
hi guys...

i was just using my 1290s for the first time in a while. all seemed good, then suddenly the 47r near the 2n3055 started to smoke.

i only used a 1/2 watt here, but thats as per the bom and should be ok according to martin.

any idea what might cause this resistor to burn?

thanks a lot]
jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on October 13, 2010, 10:45:38 AM
....also, the phantom power led indicator was flickering. I find this weird as surely that is unrelated to the pcb? only thing they share is the 0v.

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on October 13, 2010, 02:41:03 PM
Hi Jake,

Burning the 47R is most likely due to improper biasing. Do you get 22.66 volts on TR3 casing? What are you using for PSU? The excessive current drain on the +24 rail could make the +48 flicker depending on what PSU you use.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on October 13, 2010, 03:15:31 PM
cheers martin,

I was getting 22.8, but have now adjusted to 22.6... the smokey channel still seems to work fine, but I will swap out the resistor when I get a chance.

The unit seems to be stable on its own, but when im using a pad to use line signals and patching it around. I cant understand whats happening but its something weird. I think im going to take it out of my patchbay and just route the outs manually.

Thanks for your advice, its really appreciated as always  :)

BTW - im using the JLM AD/DC - there was some debate on wether or not the toroid should be wired in series or parallel... can you advise?

Cheers!
jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Basso Ostinato on October 21, 2010, 11:23:56 PM
Hi everyone, Hi Madriaanse. Just amazing work, congrats.

I'm a completely newbie and I was searching a nice 2 channel pres project to start my lab when I found this. Looks like the holy grial for me since I love Neve sound. But, after following about 10 pages of discussion I get dizzied with many versions of assembly instructions, BOMs, ideas, etc. . . and there was about 22 more pages to go.

So here I need some orientation.
Is this a recommended project for a DIY'er with only DC circuits experience and just AC basic understanding but no practice?
If so, can anybody point the latest versions of the documentation (or more suitable) for a 2 channel version?
What's the best power supply option? (I will connect it on 110V)
What is the approximated total cost for a 2 channel version? . . .and for a 4 channel?

But if not, what project would you suggest to start over? (I desperately need some new pres).

Thanks!
 


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on October 22, 2010, 03:35:07 AM
I'm a newbie too and made this pre as 1st project : it is very easy to built, worked at the 1st time ! For the PSU I took a JLM Audio (very good and easy too) but the FiveFish Audio look awesome too !
I suggest you to patiently read the entire threads (the 2 of madiaanse) and wrote somewhere everything that might be important, the different issues of the builders and how they fixed them... That's what I did for all the projects I've done, this way when I begin to solder I know exactly what I do and how to avoid issues. Be patient, take your time and everything will be ok. Plus, everyone would help you here if you need.

Best,
Ben.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on October 22, 2010, 04:17:04 AM
a lot of your questions are answered in the FAQ's at the begining of this thread. as evil cat says, read them, then read the entire discussion.

This is theoretically an easyish build, but there is perhaps a little more offboard wiring than some other projects, as transformers  are not pcb mounted.

This isnt difficult, but is a little fiddly, and consideration needs to be given to transformer placing in the early stages (as per martins suggestions).

I had quite a lot of issues with my build, but some was down to bad luck (faulty open circuit carnhills), some was due to to stupidity and some were just the normal kind of faults you have to troubleshoot an anything like this.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on November 01, 2010, 07:39:41 PM
Hi guys
does anyone know a code (mouser, Farnell, Digikey, rs) for the trim fader?
thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on November 04, 2010, 05:12:21 AM
I am getting some weird behaviour from one of my EZ1290 channels. some of the resistors that make up the voltage dividers on the input switch appear to have changed their values  ???
I started getting weird level steps for positions 3-6 of the grayhill switch and when I measured R3, R4 and R13-16, all the values were off. This is with the input switch set to 75db so none of these resistors should be connected to anything (apart from R13-16 which have one side connected to ground). How is this possible? Faulty Grayhill switch?
(http://img.photobucket.com/albums/v426/brio/inputswitch.gif)
ETA: solved...solderbridges on the grayhill switch :-[
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: offramp on November 06, 2010, 01:57:07 PM
I haven't had the moment to go through all 32 pages... is there a PDF version of the BOM available? I can't open XLS on the Mac.

Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on November 06, 2010, 05:58:54 PM
you can, with http://www.openoffice.org/ or even google docs
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Jazzboms on November 07, 2010, 06:42:17 AM
Hi
Just finished 4 ez1290 and put them in the same case. They all sound great, and with proper cabels and grounding, they are very quiet.
I have one issue though, and I think its something with the power transformer. With high gain on more than one unit at the same time, I get dropouts, like a steady pulse, with more and more intensity with higher gain on all units. The power transformer I had laying around, was a toroidal 25-0-25 30VA. I assume the 30VA is to low, and going to order a bigger one. How big do the power transformer need to be to run 4 preamps?

Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on November 07, 2010, 07:53:59 PM
Hey Jazzboms,

You check your regulators. Sounds like they are going into thermal shutdown. They will cycle on and off as the temperature fluctuates. Consider heatsinking them to the chassis, not just little heatsinks. Depending on other things you may have in your unit (lights, etc) you may be trying to dissipate too much heat. I had this problem with my first set.

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Alistair on November 16, 2010, 06:15:03 PM
Hi guys,

Working on a 4x EZ1290 to go into a 2ru.  Nice and straightforward project so far, I'm looking forward to getting them finished.  Thanks Martin!

Just a quick question- I've got the v2.4 boards, and on the BOM C13 is listed as a 150uF 16v cap (Electro), however on the board they are listed as 150uf 6.3v.  I ordered the 16v off the BOM before I received the boards, I assume as these are over spec that's a totally fine substitution in that part of the circuit and I can just use the 16volters?

Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on November 16, 2010, 06:18:51 PM
they will be fine.

jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Alistair on November 17, 2010, 12:25:48 AM
Thanks Jake.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 06, 2010, 04:34:26 PM
So im trying to get all the parts together for a pair of pre's... (a few are out of stock until feb or march i think at all online retailers)

I was thinking of creating a little extra board to act as a switchable trim pot. 

I would connect the 3  wires that would normally go to the trim pot on the main EZ board to a little board with a switch on the front panel that would switch from the trim fader to the jumper/resistor creating an on/off.  Any thoughts on this?  If anyone has built one with/without the trim that HASNT noticed a tonal difference, perhaps this isn't needed. ???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dutu on December 10, 2010, 05:26:03 PM
Hi guys!

My name is Ovidiu Turcu, I'm from Bucharest, Romania. I am working on a dual 1073 by Martin's design. (no eq)

First, I'd like to say that I'm very happy that I found this forum thread! I searched for weeks for a diy Neve 1073 preamp without EQ schematic and here I found all that I needed!

I got the 2 PCBs from Martin the other day and I really wanted to say that they are absolutely great!!! Incredibly well crafted, easy to solder, etc. I think they are made using an automated machine. Thanks, Martin!!! And the price is also very good! It would have taken me 4 to 5 days at least to design and make a PCB after the schematic, and wouldn't have come out nearly as good as these boards are!! (with green laquer and everything). 40$ is a very small price to pay for this quality!!! I think these boards will live at least 100 years from now on! :))

What I can contribute with to this diy thread is the power supply. I managed to find the schematic of the power supply that Martin sugested to use for the preamps, got rid of the negative rail, and made up a PCB design. The thing is not tested, so I'll wait until then to post here the PCB layout (and the schematic) and BOM for the power supply. It seems really simple. I got it from the pictures at JLM audio's site and deduced it from their PCB. Here it costs me less than 10$ to make it. I don't know how much those LM317s are.. but they can't be that much!

If you want the design until then so you can study it, you can e-mail me at ovi_turcu at yahoo dot com

Wish me luck!

Ovi (dutu)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 13, 2010, 10:46:21 AM
Would anyone be able to give a suggestion on how i can take the 24v coming in and step it down to 12v.  I ordered the regular ACDC and probably should have gotten the powerstation (would have been able to just send a 3rd rail in) but this was an afterthought for an aesthetic addition to the case.  Thanks  ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on December 13, 2010, 11:05:51 AM
Im not sure I understand.

What do you need 12v for? The ACDC is a good PSU for this project, which runs on 24v.

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 14, 2010, 10:01:07 AM
My apologies, im a real novice when it comes to this stuff.
I have the 24v for the project (and the 48 for phantom)...
I have a VU meter i wanted to throw in the case which according to spec operates at 6-12v.  (not even sure I'm going to keep it in there until they're all done)  just wanted to see if i could fit it in there as a visual reference (and they look really cool)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on December 14, 2010, 10:16:13 AM
Im no expert when it comes to powering VU's on projects that dont have dedicated supplies, but you should be able to drop the 24v down with a resistor (probably need 2watt for a drop that big).

Also research VU buffers, so it doesnt effect your output.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 14, 2010, 10:28:19 AM
was thinking of kind of side chaining it so the output goes straight out and the meter is just leeched off of it and not in the signal path directly.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on December 14, 2010, 11:25:27 AM
Without fully understanding your plans, I think you will still need a buffer.

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 15, 2010, 03:48:36 PM
I see your point.  JLM has a nice buffer kit that will work fine with the 24V coming in from the PS.  (as you stated, just gotta add an extra resistor for proper functionality) ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MikeFFG on December 19, 2010, 01:48:04 AM
I finished my build and it sort of works...It seems to be fine up until about 50db...55+cause either lots of oscillation or noise or even sometimes a clicking sound.  In reading the schematic, being semi-new to this, am i right in assuming the problem must be in the BA183NV section?  It looks to me like only 55db plus is sent to that section.  Also, when checking my transistor voltages, they all seem a few volts high compared to what they should be... I think it's 6 (no longer in front of it) was like 29 v compared to the 20.6 it should be.  Thanks for any help!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 20, 2010, 11:04:42 AM
May be a dumb question, but what are people that are using an external PS using for the cable between the PS and the Pres?  Should i be using shielded cable/ unshielded?  And the wire listed in the BOM seems REALLY thin for power.  Any thoughts?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on December 21, 2010, 09:41:04 AM
i've had good luck with non shielded cable as its just DC travelling from PSU to case.
Its up to you...as a matter of taste.
Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on December 21, 2010, 10:22:12 AM
I used standard 3 conductor mains cable you can get from any hardware store.

Cheers
Jake
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MikeFFG on December 22, 2010, 09:45:31 PM
So, I posted a few posts back about some problems with mine above 50db.  I checked the transistor voltages, and they are all fine except #3, the 2N3055.  For that I'm getting a C/B/E voltages of 23.5/1.64/1.01.  So my Collector is higher than it should be and the other two are lower...could this be the culprit?  I think my next step is to resolder the Grayhill switch because I feel like that's the most likely place to have made a mistake.  Any thoughts?  Thanks guys!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Jazzboms on December 23, 2010, 03:25:07 AM
So, I posted a few posts back about some problems with mine above 50db.  I checked the transistor voltages, and they are all fine except #3, the 2N3055.  For that I'm getting a C/B/E voltages of 23.5/1.64/1.01.  So my Collector is higher than it should be and the other two are lower...could this be the culprit?  I think my next step is to resolder the Grayhill switch because I feel like that's the most likely place to have made a mistake.  Any thoughts?  Thanks guys!

Mike
I had the same problem on 1 of my 4 pres. It turned out that I had connected the wires from the PCB to output transformer wrong. Another problem I had was that the input/output transformer was to close, causing oscillation from 55db and up. Moved them a little apart and then everything was fine.
Hope this helps.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MikeFFG on December 23, 2010, 03:43:26 PM
cool thanks I'll check that out!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on December 24, 2010, 05:03:18 PM
What can I use as Trim Faders?
Mouser code?
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on December 28, 2010, 04:27:51 PM
Jumping in on the 1290 wagon!    ;D

Any chance someone has done a 'digikey (or mouser/etc..) quick-checkout' with the current BOM??  (I know I'm lazy)

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on December 28, 2010, 07:11:21 PM
sorry if its been explained befor and i confess now i've only read up to page 13 of the thread.
i have 2 boards i bought from a board member. they are marked  version 2.2.  i see that i should use the older assembly instructions (for anything older than 2.4)
but im wondering  what the difference is between 2.0 version i see referenced in the thread and the 2.2 version that i have. thanks
 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8)
Title: NEVE 1073 power supply
Post by: dutu on December 29, 2010, 06:30:00 AM
Hi!

I am still working on the power supply.. that's why i didn't post its layout, schematic and bom yet.

I worked it after the jlm audio power supply schematic (the one Martin reccomends). I made the layout (no mistake in the connections, checked 100 times).

I purchased a transformer that is rated 2 x 24V, at 2 X 0,68A. If I plug it in the outlet alone and measure it (without being connected to the power supply), I get 25,8V (side to center) and 54,3V (side to side - or end to end of the coil).

Then, after rectifying, i get about 40V and 110V..

I connected the center tap and a side to the 24V circuit, and it works fine.
I connected the sides to the 48V circuit and the LM317, protection diode across input-output pins and the 5k trim pot burned out (sparks and flames). The trim pot melted!!

I did this again and got the same results. Then, I replaced (the 3rd time) theese components and conected the center tap and a side of the transformer (instead of the sides-ends of the coil) and worked perfectly (was able to make another 24V circuit).

If I'll connect the 2 ends of the coil again, I'm sure it will burn out again.

But here's what I don't understand. I worked exactly by the schematic and that's how they do it. This means that the problem should be in my transformer?.. Is it too hot? If I take out turns from the secondary, would it then be able to power 2 preamps?

I'm waiting for sugestions.

The original JLM Audio schematic is here:

http://www.jlmaudio.com/JLM%20PowerStation%20Ver%202%20Schematic.pdf

Ovi
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 01, 2011, 11:21:05 AM
Received 8x EZ1290 pcbs yesterday!! 

Thanks Martin for the speedy turn around!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 10, 2011, 10:56:46 AM
So this is my plan for the layout of my build... any suggestions or warnings before i commit?
(http://www.silent-fate.com/images/project.jpg)
EDIT:  I was thinking of stacking the input/output jacks on top of one another not side by side...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on January 10, 2011, 11:13:26 AM
should be ok. alternatively you could have the input iron inbetween the pcbs, to get more distance from the output transformers.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 10, 2011, 11:49:36 AM
There wont be a problem with proximity having the input TX close to the boards?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on January 10, 2011, 02:13:07 PM
There wont be a problem with proximity having the input TX close to the boards?

No, that's not really a problem. I would say as far away from the power trafo followed by as far away from each other.
Title: Power supply problem
Post by: dutu on January 11, 2011, 12:12:36 PM
Hi! Please help!! :))

It's about the 48V rail of the power supply... how come theese power supplies work if the LM317 can handle MAX 40V (out-in)? My LM317 from the 48V rail is always burning... tried a lot of times. I did exactly the JLM Audio's power supply. My transformer measures 26V - 0 - 26V AC and it's rated 24-0-24. The 24V rail is working perfectly.

I plugged the 48V rail into a 24V coil of the input transformer, and I have another perfectly working 24V rail. But if I input 48V (actually 56VAC), the LM317 burns out.

Thanks!

Ovi
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Ptownkid on January 11, 2011, 12:29:03 PM
40V is the max input output DIFFERENTIAL. They can handle hundreds of volts as long as the difference between the in and out is 37V or less.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dutu on January 11, 2011, 04:21:12 PM
Thanks!

Yea...You're right. But still, I think here lies the problem.. on the input I've got about 110VDC... Have no idea why. After rectifying, I have like 80VDC.. (the transformer outputs 52VAC)

All measurements are without a load, i.e. without a preamp plugged into..

What transformers do you guys have?

Ovi
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 13, 2011, 11:57:23 AM
Hi Guys, just wanted to let you all know I will be volunteering in Haiti from 1/15/11 to 2/15/11. While I'm there I will have very limited or perhaps no access to email, and I will not be able to mail PCB's during that time period. All current orders have been shipped.

All the best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 13, 2011, 12:04:20 PM
Wow man, that is awesome.  Best of luck, stay safe and healthy!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gevermil on January 13, 2011, 07:46:06 PM
 would this switch work for this project or the new 1073


71BF30-03-1-11N  , it dose not have the adjustable stop but ?
I have a chance to score a bunch cheap

http://www.alliedelec.com/search/searchresults.aspx?N=0&Ntt=71BF30-03-1-11N&Ntk=Primary&i=0&sw=n

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 19, 2011, 03:40:02 PM
So i got all the parts together and hooked up a channel last night.  All voltages look correct on everything. (no smoke or fires...phew)

I am using the JLM powersupply, maybe someone can give me some advice on this.  there is a -24V rail that is not being used on the PS.  If i change the regulator to be + (just put in another 317) and roll the pot down to 12v would there be an issue with doing this?  (does there HAVE to be a negative rail on the PS...) my theory is for **poop** and im not sure changing this would mess something up.

(in the end id like a +48v, +24v, and a +12v rail off this thing)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kambo on January 19, 2011, 03:51:48 PM
check with schematic, you need to reverse the polarity of elec caps etc....
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dutu on January 23, 2011, 03:59:58 PM
Hi guys!

As I promised, this is the finished power supply PCB and BOM. I exactly cloned the JLM Audio power supply, and did no changes anymore. ;D

I could only make a JPEG file, but, in order to have the exact scale, you should know it's 600dpi resolution. I already mirrored the pcb, you just have to print it.

I've made it, tested it, and works perfectly. Be very carefull not to make solder bridges between pads. I burned a couple of sets of diodes because of this. Check with a magnifier!!  ;D

http://www.legacy.ro/neve_power_supply_final_600dpi.jpg (http://www.legacy.ro/neve_power_supply_final_600dpi.jpg)

Make sure not to forget the 3 jumpers (thick lines on the top mask), and there is a wire going from D10 (there is a hole) going to the 48v output terminal (there is another hole)

Martin, it would be great if you could make some boards for the people here. I'm sure they'd wanna buy some. I worked mine manually and took me half a day :))

Ovi
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 24, 2011, 10:20:36 AM
So, im still waiting on a couple of insignificant parts (trim pot and face plate)for my project... i decided to hook up the parts I have (with great success!!!)
I do have some questions as far as hooking all the added bells and whistles ive added to the project though.

I have a VU meter and the JLM go between (48V phase and pad).  I was unable to get the VU to function properly BEFORE the output tranny.  (if i send a lead off the output tx the meter works really well and is pretty damn accurate... still needs calibration).  What i would like more (and would be more useful, since i can see the output levels going into the DAW.... ok well, i guess its just an asthetic thing either way lol but I'd like it to work proper) is to have the VU respond to the INPUT signal rather than the output.  And im not sure if i should put a lead stemming off the INPUT TX or from somewhere on the actual EZboard.

And do i have this set up correctly? 

I have pin 2 and 3 going into the go between (input) the 48v and the 0v also goes in from the powersupply. I then have the + - out of the go between going to the INPUT TX (is that right?) and pin 1, goes from the XLR input right to the input TX (should I have the shield(pin1) go to the 0v of the go between?)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on January 24, 2011, 07:14:22 PM
Best would be to tap the VU meter from the L-P connection (this is either a jumper or a out-level pot on the EZ1290 board). I don't know if a buffer amp is required. I guess you could connect BEFORE the trim pot, to see how hard you are driving the pre-amp, before you are attenuating the level with the trim.
AFTER the trim pot would once again be the same signal that the DAW sees.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 25, 2011, 09:48:24 AM
Yes i have a VU buffer build and in there.  And Ill have to try that... I completely forgot about that! Thanks :)

On a side note: As Im getting closer to finishing this thing, ive noticed a couple of odd things.  First, the grayhill rotary switch for the input gain is positioned really strange.  Any knob i use puts the lowest setting at around 10 or 11 o'clock on the front panel.  The set screw for the knob would have to be in line (on the same side) with the indicator.  Is there a way to reset this or did i mess up putting that stop pin in.  I believe i put it in a 12:00 if you're looking at the board with all components facing up (laying flat on a table).  I found possibly the most disgusting knobs ever created for this thing which i think i may have to put a set screw in anyway so, might not be a huge deal, but if those knobs dont work it might be a little awkward.

second is what im going to do with looming the wires with all the crap i added to this thing, but thats more of a personal battle for now.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 26, 2011, 08:16:31 PM
Sir:  You have brought a tear to my eye.  I just finished the 2 pre's and I cannot believe the sound.  My crappiest dynamic sounded pretty good... my crappiest condenser sounds like GOLD... unreal man!  Thank you so much!  Ill post some pics after i get the real front panel done.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: herrmann on January 30, 2011, 05:23:05 AM
Hi all,
Just finished my dual pre. All is working fine and sound good, but in the last 2 positions (70 and 75) I have no sound... Voltages are all good. I've this issue on both channels.
Are the grayhill non-shorting ? Because I've a pop sound when switching.
Have some ground problem too, some hum when I touch the case. As I read in the assembly guide, 0V should not be connected to the ground/case. Will work on this.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on January 30, 2011, 08:25:10 AM
Hi all,
Just finished my dual pre. All is working fine and sound good, but in the last 2 positions (70 and 75) I have no sound... Voltages are all good. I've this issue on both channels.
Are the grayhill non-shorting ? Because I've a pop sound when switching.
Have some ground problem too, some hum when I touch the case. As I read in the assembly guide, 0V should not be connected to the ground/case. Will work on this.


Have a look at R20 (3k9), does it have the right value and is soldered in properly?
Have another close look around the rotary switch for any solderbridges etc.
I think you are meant to connect 0V to the case via a 10 Ohm resistor if I remember correctly.
Did you connect pin1 of the XLRs to the case?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: herrmann on January 30, 2011, 09:57:17 AM
Ok, problems gone since I've connected case. Thanks for the tip !
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on February 01, 2011, 12:30:04 PM
apologize for the stupid question ....
is possible for a rock voice to saturate the input stage of the  EZ1290?
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on February 01, 2011, 06:00:17 PM
apologize for the stupid question ....
is possible for a rock voice to saturate the input stage of the  EZ1290?
Thanks

I would say this is exactly what's been happening on a daily basis since the 70s  ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on February 01, 2011, 06:03:33 PM
but if you do not want to saturate the input stage?
pad?
thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on February 01, 2011, 06:17:52 PM
yes, i find that sometimes even the lowest gain-setting is too hot.
this obviously depends largely on the signal and mic, but does happen to me a lot with a snare drum through an SM57, so conceivably also with rock voice.
I have a jlm go-between on one of my Dual-EZ1290s which includes a pad (-20db i think).
the other one doesn't have a pad, so I am using an XLR-pad-adapter like this one:
http://www.karmamics.com/shop/Karma-In-Line-XLR-Microphone-Pad.html (http://www.karmamics.com/shop/Karma-In-Line-XLR-Microphone-Pad.html)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on February 08, 2011, 06:25:49 PM
 :-[  nearly had a heart attack

http://www.mouser.com/Search/ProductDetail.aspx?R=225P10394XD3virtualkey61320000virtualkey75-225P400V0.01 (http://www.mouser.com/Search/ProductDetail.aspx?R=225P10394XD3virtualkey61320000virtualkey75-225P400V0.01)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on February 08, 2011, 07:12:04 PM
:-[  nearly had a heart attack

http://www.mouser.com/Search/ProductDetail.aspx?R=225P10394XD3virtualkey61320000virtualkey75-225P400V0.01 (http://www.mouser.com/Search/ProductDetail.aspx?R=225P10394XD3virtualkey61320000virtualkey75-225P400V0.01)

That's a fair price if you only getting one of them ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Chrome Heart on February 11, 2011, 06:23:48 PM
Just finished the front panel. Now on to number 2
Thanks Martin
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 12, 2011, 06:07:59 PM
Congrats! Nice build!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on February 13, 2011, 04:34:20 PM
Here's a question..

What transformer are Vintech now since they've gone away from the Carnhills and why? 

Whose transformers are they using, I suspect they cost less than the Carnhill?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dutu on February 14, 2011, 03:24:39 PM
Hi!

Martin, what are the gain positions that are switched by the red gain switch?

Starting ___ dB (first position),  Ending ___dB (12th position)

On your faceplate you didn't specify. Either goes until 75dB and starts from 20, either starts from 15 and ends with 70dB... which one? Or is it different?

Thanks!

Ovi
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: SimonB on February 15, 2011, 12:45:29 AM
Hi!

Martin, what are the gain positions that are switched by the red gain switch?

Starting ___ dB (first position),  Ending ___dB (12th position)

On your faceplate you didn't specify. Either goes until 75dB and starts from 20, either starts from 15 and ends with 70dB... which one? Or is it different?

Thanks!

Ovi

The FPE file shows the gain positions. Starts at 20 and goes to 75.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dutu on February 16, 2011, 03:48:35 PM
Thanks, Simon!

My problem was with the position in between 20 and 70. Didn't know if it was a 15 or a 75. Thanks for clearing this for me!

I have another question.. Souldn't we use a fuse for the preamp unit? Or more?

Sould we put 2 fuses? One right after the mains plug and one in the 24 circuit? Should we also use one for the phantom circuit? Or it's not that necessarry to use so many?

What fuse values shall I use for a 2 channel preamp? I'm using the JLM Audio clone power supply (cloned by me - I posted the pcb & bom earlier). It's identical to the JLM Audio one but costs about 10$ :) to make.

The transformer is a 2x24VAC 40W one. I'm also using 220V mains power.

Thanks!

Ovi
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: NannerPuddin on February 20, 2011, 02:58:50 PM
I have been lurking here for a couple of months.  I think I am ready to build one of these.  Time to order the boards.  Thanks in advance for so much good information that will help......

Thanks,

Doug
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuce42 on February 26, 2011, 12:11:51 AM
Ok I am stumped with my build. Connected a switchmode 24vdc power supply to the board, (just for testing it - I intend to use a JLM once the boards is up and runnin), and my output carnhill makes a terrible hissing sound from its bobbin !!!! - Cant be good.

I am measuring my transistor voltages and am getting something like 24v across their legs when the chart indicates most of them around the 3-6v range. Clearly I am way off here. But I have cross checked all my components and have correct value resistors and caps, and the caps polarities are the right way round.

I am totally stumped. Anyone offer any ideas? A squeeling output transformer cannot be a good sign:)  Funny how more straighforward circuits like this can humble ones abilities:)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 01, 2011, 01:05:34 PM
Is the gain set at its lowest?  And which transformer (input or output).  And i was getting really off voltages also until I hooked EVERYTHING up, (input and output TX's)  Once everything was in there I was good.  If the TXs are too close and you have the gain maxed you may be getting some oss.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 01, 2011, 02:09:26 PM
On another note... My front panel finally got here!  (woo hoo!)
(http://www.meirecords.com/images/210731.jpg)

(http://www.meirecords.com/images/210732.jpg)
(http://www.meirecords.com/images/210733.jpg)

If ya wanna se pics from the whole build
http://www.facebook.com/anthony.paganini#!/album.php?id=1326207212&aid=104345 (http://www.facebook.com/anthony.paganini#!/album.php?id=1326207212&aid=104345)

And when martin is back from his humanitarian work, I hope hes got some more boards in stock! This was fun!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on March 02, 2011, 10:10:10 PM
Great work sr1200 - congratulations!!!!
two questions:
how did you connected the VU meter?
what you used as trim fader?
Thanks and congratulations again
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 03, 2011, 09:57:18 AM
Thanks :) was my first real build.
The VU meter is connected to the trim pot.  In martins instructions, there is a diagram to connect the trim pot.  I basically just tapped off the center and ground.  (right now the VU is showing POST trim fader levels.  I had it set to PRE-trim levels and was a little confusing.  My racks are under my desk and when setting the level, i cant see both the DAW display and the pre at once so i figured if i get the right setting on there i should be close going to the daw)

As far as a buffer goes I used the JLM VU buffer.  It can run off a 24V line and JLM has pretty decent instructions on how to set it up on their site.  (took a bit of calibrating since they're so small but its just a few (read: many) turns of the trim pot on the VU buffer. (meters i got on Ebay and look exactly like the JLM versions - amber lamp not LED)

Trim fader I used
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=51AAD-B28-D15L-ND&x=15&y=15 (http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=51AAD-B28-D15L-ND&x=15&y=15)
A little pricey in my opinion, but i used a cheaper pot before i got this, and it really was crappy.  (felt bad and kinda sounded weird. no other way to describe it)  You get what you pay for.  This thing sounds AWESOME! Its dead silent and just has this really nice flavor.
Its hooked up to the apogee rosetta 200 to convert into the daw.  Perfect match.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on March 03, 2011, 11:18:28 AM
thanks sr1200!!!
Great info!!! ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on March 03, 2011, 11:36:26 AM
sr1200,

Had a chance to manipulate the gain/trim color/clarity?  Betting all around it sounds great, but have you noticed  'sonic differences' if any, while playing with the two knobs?

I've yet to purchase transformers as I'm not sure which direction I want to go there....   thanks for the lead on the trim pot.

Love the front panel and your work is nothing less than pro!

 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 03, 2011, 11:50:27 AM
I will say that there was a HUGE difference in using a carbon pot to the conductive plastic pot.  I bought a cheap $.70 10K carbon (which Martin states NOT to use lol) but i figured for $.70 what the heck.  It felt like garbage, you could hear the tabs inside scraping against the disc and it made the unit sound like it was (and im using the totally wrong word here) scratchy, gritty, lo-fi almost.  As soon as i put the good pot in it was ultra clean.  I usually leave the pot maxed unless one of the steps is just a little too much (it also helped in calibrating the meters)  I brought the input gain up quite a bit and gradually rolled the trim up until i got unity on my signal generator, my 1073 and the apogee. 

It is nice to be able to drive the hell out of the input tx and roll the trim down to get a little grit, which is why I decided to ADD the trim pot. 

Even with my ribbon mic, i can barely get this thing over the 50 mark on the gain stage without clipping the DAW.  With an SM57 I got up to about 55/60 on an "acceptable" level sound source.  Condenser mics.... rarely going above the 25 mark. 

From all the research I did before ordering parts (i was looking at different tx's)  the carnhills always came out on top.  Well worth the investment.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on March 03, 2011, 11:59:05 AM

It is nice to be able to drive the hell out of the input tx and roll the trim down to get a little grit, which is why I decided to ADD the trim pot. 


Yes this is what I was curious about, was thinking it would benefit from having the trim for some coloring options as well as being more versatile.

For $7/pot, that's a pretty good investment (value) added IMO.

I've been leaning Carnhill, but I'm very easily mislead and have been reading some regarding the Vintech models moving away from Carnhill (or at least in appearances are different)  wasn't quite sure the reasoning.  If this is not correct I'm open for clairification  ;)

again great build sr1200

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 03, 2011, 12:06:51 PM
Thanks again, my thoughts would be that Vintech has either started to do their own, or found someone else to make them cheaper.  Its all about the $$$ for the commercial product which is why there is so much crap on the market.  You cant go wrong with the Carnhills.  And im sure anyone else thats built this unit can attest to.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on March 03, 2011, 01:33:46 PM
Ed Anderson has made a copy of the original:

http://hairballaudio.com/shop/product_info.php?cPath=24&products_id=76

and

http://hairballaudio.com/shop/product_info.php?cPath=24&products_id=63

cost less ...
someone has tried them?
thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gavthirdphase on March 06, 2011, 04:21:48 PM
Hi,

I have bought one of these boards and I was wondering if there would be any issues with me initially supplying the 24volts to the board but not the 48v. Other than not being able to use a condensor mic would the pre amp function ok? I will probably get a jbl acdc but in the meantime i Just wanted to see if I could get the thing working. Also could I get it to work without out the transformers as I am a little tight for cash and wanted to make sure I could get it working before I buy nice transformers.

Thanks

Gav
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on March 06, 2011, 04:38:53 PM
Yeah it's fine, 48v is for the mic only.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 06, 2011, 07:39:15 PM
You can do without the 48v but not wuthout the transformers.  Thats where not only the timbre of the pre comes from but the input unbalances and the output rebalances amongst other things.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on March 07, 2011, 02:35:01 AM
Yes, completely missed the bit about transformers for some reason.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: skal1 on March 07, 2011, 05:41:15 AM
Hi madriaanse

you back yet, need some boards

skal1
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 07, 2011, 10:28:09 PM
So i built these a while back and i have to say i love them!
putting 10 of these into a 3u rack wasnt much fun, but all my drum duties can be in one 3up rack!
oh the pain!
haha
Govinda
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 07, 2011, 10:29:32 PM
more pics..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 07, 2011, 10:30:19 PM
and more... it was a tight squeeze!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on March 07, 2011, 11:11:23 PM
Awesome! What are you using to power that beast?

Best,
jb
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 07, 2011, 11:25:20 PM
i'm using for now a switch mode power supply.....
i'm about to build a discrete power supply, there is a difference without the discrete... switch mode is my temporary solution!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on March 07, 2011, 11:38:08 PM
Cool. I'm planning out a 6 RU 16 channel 1272 box with faders, and pots instead of gain switches.  I'd be interested in what you do for your discrete supply.

Looks like you stacked your output 1066's on the backplanes. Inputs back there too?

Any thought of reversing the IP for a line in? Maybe with a switch or relay's?

Looks great!
Best,
J
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 07, 2011, 11:52:27 PM
I was going to get a custom power supply made by my tech friend, 2amps is whats needed with not much headroom for 10!
the input trannies are bolted near the input jacks and the output trannies are bolted to the metal chassis that separates the modules from the transformers, it was a very tight squeeze and no oscillating as the input transformer spacing to the output was just enough!
G
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on March 08, 2011, 08:03:05 AM
That is impressive Govinda Doyle to even think of squeezing them so close, and in a 3RU !?!?!   ;)

My hat is off to you.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 09, 2011, 12:43:07 AM
aluminium sheet separating the modules and connecting each other to the grounding was the key!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 09, 2011, 12:45:51 AM
thanks MicDaddy!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on March 09, 2011, 06:48:04 PM
2amps is whats needed with not much headroom for 10!

Make it 5amps! These little guys just sound better with a hefty supply pushing them - can't explain why. Can't believe you fit 10 - nice work!!!

Skal1; I'm back! :-)

Later,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Govinda Doyle on March 09, 2011, 11:53:55 PM
Thanks for the tip Martin!!!
Im gonna try a few different caps instead of ceramics next!
hehe... endless!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:03:24 PM
So ... here is mine...

Before everything.... i have to say thanks and send all my respects to Martin, who helped me a lot in this project, and i know that i have been a f....ng annoying guy during all the time i was building it...

in fact yes... i think specially for an 8 tracks rack, you have to think very well to every details before doing anything... cause you can't easily come back on a hole badly placed...
And then you have to solve a lot of problematics to make everything entering the case.

By my side,  the rack case is longer than martin's one, but i had to face the fact to add 8 "go between" to add Pad, Phase and 48v and every channel. i maybe worked like 3 weeks on the front panel just to be sure everything would feet perfectly inside the box...  and as martin said about his rack, i had seriously the feeling to play Tetris  for the panel to look nice, but with no problem beside.

you can see that i sent the front AND rear panel for drilling and engraving...   

i decided to put extra power switch in the rack with condenser on all 48v and 24v circuits.
for the ACDC , after wiring boards i measured 280 mA needed for 4 boards, with a 2sec peak at 1,2 Amp at startup. as new ACDC boards can be boost to 1,5 Amp, i used only 2 boards for the full pack. which seem to be enough up to now.

i had 3 problems to solve (with one still in standby for now)
- i had wrong transistor voltage on a board, which was easily solved when i saw i mixed 2 legs of a transistor.
- i have burn a 47R on a second board... but after having replace a lot of component around it's still burning...  i have 14v in 47R entrance, same as tr3 collector, and turning the 5k pot doesn't change anything. the 18k res seems to act weird also.... so if someone had same problem.. i would be curious to know how to solve it...
anyway... as i planed to make a second rack, i had 8 extra boards ready... for now i simply replaced the board..   but i will have to find a solution anyway.

the last pb i met was a very low signal on track #1 compared to 7 others...   at first i was testing only hiss at higher gain and i was so happy to have really less noise on track #1... up to the moment i plugged a mike to compare all track... i had something like a 40 dB difference in signal level...
after checking voltage, bypassing the "go between",  and replacing the lo1166.... i finally found out that the input transformer was defective.... simply had to replace it.

i added a fan on rear panel too...   but i noticed it's making a light buzz at higher gain ... for now i just unplugged it.. but....   after tests in studios... i see now i will NEVER use higher gains...    so maybe i will plug it back cause my rack is not as martin's one and i have no ventilation. 

Yeah... the sound...  it's simply ... woooow
i'm sound engineer and composer in studios for several years now...  and as soon as u use those boards in your session... u see how good they are compared to the hardware u usually use.  i have compare them to a lot of preamps now, and they sounds far better than a lot of "good" preamp...   and compared to original Neve preamp.. well....   it's a Neve !!!
never thought i could built a so good preamp by myself one day !!!!

BUT... for me the pad is "must have" when u use those boards. as when u record a drum... u nearly peak on lowest gain position...   and u will easily peak depending of your drummer or your mics....

Anyway, hope that will help someone...

i will soon start my second rack....

and again Martin...   thanks... a lot :)

Sylvain.


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:04:57 PM
rear panel
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:05:56 PM
powered
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:06:51 PM
...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:07:57 PM
inside 1
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:08:47 PM
inside 2
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:09:36 PM
inside 3
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 26, 2011, 08:10:13 PM
inside 4
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: ilfungo on March 26, 2011, 09:13:30 PM
GREAT SGENEVAY!!!!
can you post some PSU pics (inside)?
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 27, 2011, 12:10:29 AM
Good stuff...

 8)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: college101 on March 27, 2011, 12:57:08 AM
All I can say is WOW!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 27, 2011, 04:07:47 AM
Thx :)

mmmmmmm the PSU case....    the problem box...
That was maybe the most difficult part for me with the front panel designing..
As the challenge was to fit everything in the original box reference...
but i wonder now if the box is not too small for heat. and i'm close to change it
I would like to know what u think about it... bigger case ? if yes ... does someone know a good reference of a nice and bigger aluminum case... (maybe even bigger to place a second PSU for my second preamp) pls let me know :)
I have boost the boards to 1,5 Amp with 4 extra 4007 (as explained on JLM website) and i used metal standoffs as the ver 4 of ACDC board allows it...  

Best,

Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 27, 2011, 04:08:31 AM
Psu... outside
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 27, 2011, 09:42:59 AM
Are those two acdc's? Looks like it.

I ended up using a single powerstation at 1.5 amps per rail.
Martin recommended 500ma per...needing 4amps.

At 3amps this gives 375 ma per...which i figured was good nuff.
Can always upgrade if need be. I decided on 1u for power stuff.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on March 27, 2011, 10:38:17 AM
sgenevay   :o     WOW!!   it's builds like these that are both so inspiring and also will humble a fellow real quick.  Very nice build!!

desol  You're getting away with just 1 powerstation for 8x channels?  Have you had a chance to push all your pres hard, simultaneously, say in a drum session or other demanding scenario? 

All you guys rock!!  My boards have been sitting for a few months now but I think I just felt a spark under my butt.   ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 27, 2011, 10:52:28 AM
The powerstation with the 6amp rectifier is good for a full 3 amps...1.5amps per +24v rail.
Also disabled the negative rails as they were uneeded and strapped for full rectification, which allowed for a cheaper/smaller toroid.
Single 24vac winding. (don't need 2x24 winding for neg rail-why waste money)

http://www.groupdiy.com/index.php?topic=22828.580

This is my build:
http://img835.imageshack.us/i/dsc02837.jpg/
http://img839.imageshack.us/i/dsc02842z.jpg/
http://img31.imageshack.us/i/dsc03059mf.jpg/

It was explained to me, that once the pre's are done ramping at the beginning(which is alot), they don't use more power(single or together) and run at about 130ma ea. I figured 375ma per outta be enough. Sgenevay seems to be running pretty much the same config.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 27, 2011, 12:16:26 PM
thx MicDaddy !!  really loved to build it...

for ACDC...Look .. i made measurements on a single board... then on a 4 boards pack....

-The single 1290 board needed about 280 mA during first 2 sec....   then stabilized to about 80 mA

and the 4 boards pack used about 1,2 Amp at startup (as i said) and stabilized to about 280 mA
the ver4 of ACDC is now at 1,5 A ... but the only problem is that Joe (from JLM) told me  that his ACDC board provides 1 amp for V+/V- rail
Which means 500 mA for V+ and 500 for V-... and told me that u normally can't have 1 full Amp on V+ even if u have no use of V-...

but anyway.. i'm feeding 4 boards with a single 1,5 Amp ACDC board...   in worse case i have 750 mA for V+ and it's enough to face the 280/300 mA needed for the 4 Boards (the startup didn't provide any problem up to now...)
and in better case... i have 1,5 Amp which, i think is enough even for startup...

I was close to take the powerstation but i was unable to know what transformer to use to feed it (i'm a kinda lost in power and transformer stuffs....)


Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 27, 2011, 01:14:42 PM
but anyway.. i'm feeding 4 boards with a single 1,5 Amp ACDC board...   in worse case i have 750 mA for V+ and it's enough to face the 280/300 mA needed for the 4 Boards (the startup didn't provide any problem up to now...)
and in better case... i have 1,5 Amp which, i think is enough even for startup...

I was close to take the powerstation but i was unable to know what transformer to use to feed it (i'm a kinda lost in power and transformer stuffs....)

I was too. :) Still am a little...

Transformer i got from Avel lindberg --- 12x12 @ 6.66 amps or single 24vac at 3.33 amps. 80va. $30.
Primary in parallel. Sec in series.

What transformer do you have? Do you have link to specs?
 
Connection for neve is here(both single or dual winding-with explanation): http://www.groupdiy.com/index.php?topic=16184.0
 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 27, 2011, 01:38:37 PM
I'm in 220v and u se the reference That Martin gave in his 220v pdf...   TE62085-ND in digikey.
a 50 VA transformer. Joe from JLM told me it was enough...
As i told you i'm really lost with transformers... i don't even know if i have enough power at startup .. but all i know is that i'm far over the boards need when they are stabilized...
And for now it's working well...  At least i used the preamp 3 full working days (like 10/ 11 hours/day) and it's still here...
But  yes if someone can tell me more about it... that would be good to learn...   ;)

Sylvain.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 27, 2011, 02:48:00 PM
Hmm.

The way Martin has the ACDC configured is for 750ma at half-wav rectification on the + rail...centre tapped connection(0v connected on transformer secondary(red/brown) - this splits the amps 750ma + 750ma -). Probably an ok configuration for one or two channels.

4 boards with this, would then be getting 187ma ea, connected to the postive rail.

You have the capability to get more with what you have, so i would probably do it...but you would have to remove a few things from the acdc's (neg parts) and hook up the transformer secondary to the acdc differently and add strap to bottom right capacitor.

The way i would hook it, is to removed the negative parts off the acdc's(as per joe's diagram), then hook only the 24vac connections to the two 24vac in's...hook nothing to the zero volt (centre tap) connection on the ACDC. Just shrink tube that connection. Leave primary as is.

This would give you full wav @ 1.5a to only the + rail....yielding 375 ma to ea channel....per acdc.
Not much work for a better supply to the Neve's.

I think this is correct. If Martin or anyone would chime in to confirm, that would be great.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on March 27, 2011, 02:54:02 PM
So if i understand well what u mean....  as i already removed the negative voltage regulator... i only have to remove the link to 0v from the transformer to the board ?
sounds weird... where does the 0 come from then ? :-s
Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 27, 2011, 03:19:29 PM
Check joe's diagram for parts removed. (above link)

There is no zero volt reference as acdc is no longer bipolar, +/-/0v. (trying to be sure i have this right:)
0v to boards is simply other side of 24vac input...neutral.

So negative parts off board and 24 vac secondary to 24 vac in's(nothing to zero volt), and also....jumper across bottom right capacitor.

Half way down:
http://www.groupdiy.com/index.php?topic=22828.580

If you change, make sure to disconnect boards and have 500ma fuse connected in case short or something.
...and double check all this with Joe, just to be sure.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on April 05, 2011, 05:43:53 AM
is "jumper" a good place for inserting passive eq?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: letterbeacon on April 06, 2011, 11:48:35 AM
I know it's possible in theory to fit two 1073 pre amps in a 1U case, but has anyone actually done it in practice?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on April 06, 2011, 01:09:26 PM
yes, loads of people have done it. there are examples in this thread and others in the other 1290 build thread.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on April 06, 2011, 04:52:56 PM
Hi everybody...

I dunno if someone already gave those datas but i think it could be very useful, as this is the first thing i thought about when my preamps were finished...

what should be the "hiss" level at higher gain ?

Here are 2 audio files recorded from an original Neve 1073DPA channel directly in protools HD interface: aif  - 96kHz/24Bits - Mono.

-On the first one, the 1073DPA gain switch was set on higher gain, and the trim pot set to 0:
http://sgenevay.o2switch.net/Invite/Higher%20Gain%20-%20trim%200.aif

-On the second one, the 1073DPA gain switch was set on higher gain, and the trim pot set to 10 (its max level):
http://sgenevay.o2switch.net/Invite/Higher%20Gain%20-%20Trim%2010.aif

U can then easily import those files in your DAW application and compare Hiss level with your ez1290 Preamps....
At least it can give an idea about a correct level.

Hope that will help :)

Best.

Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on April 06, 2011, 11:14:42 PM
I have almost NO hiss even at max gain on mine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 07, 2011, 12:05:36 AM
Sylvain, did you do anything with your powersupply or leave it as is?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on April 07, 2011, 02:36:46 AM
I'm finally building a new one in a serie-20 box of par-metal.com... More space... And vent holes...
I will put 2 power supply in the same box to feed my 2 8-channel racks.
With separate switches, a led per channel and voltage rail... and same design as the preamp.
Didn't try what u said yet but I'm working on it and will ask Joe about it.
Just didn't have a lot of time yet cause so much work in studios lately. But the preamp is still working well this way...
 So it could take several weeks to recieve and mount everything... Will tell u more :-)

best,

Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on April 07, 2011, 07:28:30 PM
Hit a snag, as I'm populating cards I don't see anyone else using axials for C4, C6, and C7  Electrolytic 100uF 25V.

I purchased MAL213836101E3  which is an axial package and I see all the builds on here using radials....  where did I go wrong?  I've double/triple checked BOM against digikey/mouser/allied and they tell me axial package....    are the VishayBC axials I have ok to use for these 3 designators?  See attached photo...

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on April 07, 2011, 07:41:55 PM
Those are 105C caps. Should be fine as long as they are oriented correctly. Won't cause it to not work. Original had 80uF in those positions according to the schematic but I believe that Martin explained why he went with 100uF previously in this thread.

Cheers,
jonathan
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 07, 2011, 08:07:50 PM
80uf isn't available any longer. Those will be fine..
Radial or axial doesn't matter. I used axial bc caps on mine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on April 08, 2011, 12:33:46 PM
@MicDaddy
Mine was like that too, they work fine, however, you might need a little bit of wiggle room for when you get the heat sink on there.  I had to bend those caps slightly away from the heatsink so they didnt touch.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on April 08, 2011, 01:20:12 PM
Quote
@MicDaddy
Mine was like that too, they work fine, however, you might need a little bit of wiggle room for when you get the heat sink on there.  I had to bend those caps slightly away from the heatsink so they didnt touch.

 ;D   I already installed with that in mind, heat sinks will be here today so we'll see how well I did judging the foot print

edit: They fit just fine with heat-sink 532-501503B00
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: beatnik on April 11, 2011, 07:29:28 AM
Hi there,

I have almost finished building two channel of this pre. However, I have some questions about the output transformer.

I am using Ed Anderson EA-1166. Since they already come with unshielded wiring, how to proceed? Cut the wires and solder shielded wire directly to the transformer, or can I use the unshielded wiring without noise problems?

And about the 0.01uF cap and 1K5 resistor on the secondary. I have to put them or they are specific for Carnhill transformer?

Thanks in advance
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 11, 2011, 09:33:45 AM
Keep the transformer close to the pcb and wire to the board...then run shielded from x-former to xlr.
Keeping things neat and plenty of space from input wiring.

Yes, i would think you still need the termination.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on May 05, 2011, 01:11:33 AM
Hit a snag, as I'm populating cards I don't see anyone else using axials for C4, C6, and C7  Electrolytic 100uF 25V.

I purchased MAL213836101E3  which is an axial package and I see all the builds on here using radials....  where did I go wrong?  I've double/triple checked BOM against digikey/mouser/allied and they tell me axial package....    are the VishayBC axials I have ok to use for these 3 designators?  See attached photo...



Hey Micdaddy, you may have to mount the bottom axial cap upright to clear the heatsink. Basically stand the Axial on end on the bottom through hole.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: letterbeacon on May 05, 2011, 10:25:22 AM
I've also noticed that the BOM is calling for axial caps, but in the photos there appears to be radials.  Does the PCB call for radial or axial?

Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on May 05, 2011, 10:43:52 AM
Quote
I've also noticed that the BOM is calling for axial caps, but in the photos there appears to be radials.  Does the PCB call for radial or axial?

You can use either, I used what the 1290BOM24 called for MAL213836101E3 (axial) and was able to fit them fine.  
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on May 05, 2011, 10:57:21 AM
..another angle.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: letterbeacon on May 05, 2011, 02:47:28 PM
Great, thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on May 05, 2011, 07:06:30 PM
Nice! what heatsink/standoffs are you using for 2n3055?

Later,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on May 05, 2011, 07:51:26 PM
Nice! what heatsink/standoffs are you using for 2n3055?

Later,

M.

Heat-sink 532-501503B00  from Aavid Thermalloy (via Mouser), I did notice the footprint looks a tad smaller than what I've seen on others' boards (look smaller overall).  Hopefully the 2N3055 will stay cool.

For the standoffs I cheated and used a pair of 6-32 zinc plated nuts, stacked, using 1" 6-32 machine screw to secure, with a 6-32 locking nut on the bottom of the pcb.  I checked for good continuity prior to soldering, and was sure to put a nice bit of elbow grease on the locking nuts.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on May 06, 2011, 06:42:28 AM
btw Desol !! 
I finally changed my ACDC wiring..
as joe has validate this way to plug with the TE62085 Transformer for 220v Countries..
with that i removed all V- parts of the board, have set it to tripler, and shortcut the C8... then add 4x 4007 under the board on the specified places...
i'm building my new power supply like this to power 16 Channels with 4 ACDC....   seems to be fine.
But as Joe said.. The first wiring that Martin gave was enough too for 4 boards normally...

In other way....

i can't choice the correct finish for my new preamps racks ...    i'm between anodized and powder coated...    and i can't understand which is the better looking one... the stronger one...
if someone can tell more about this... Thx a lot.

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 06, 2011, 11:19:43 AM
btw Desol !!  
I finally changed my ACDC wiring..
as joe has validate this way to plug with the TE62085 Transformer for 220v Countries..
with that i removed all V- parts of the board, have set it to tripler, and shortcut the C8... then add 4x 4007 under the board on the specified places...
i'm building my new power supply like this to power 16 Channels with 4 ACDC....   seems to be fine.

Great sgenevay! At first i thought it was strange too...but i took the time to suss it out with Joe and i'm glad i did. It's the better way to run jlm power for this application. I'm sure there are better supplies period...but this setup is fine...and Joe's a good guy.

I think i personally would like the anodized finishes better, but that's just me. :)

This is how i did mine: (still trying to find knobs)  ::)


(http://img835.imageshack.us/img835/6180/dsc02837.th.jpg) (http://img835.imageshack.us/i/dsc02837.jpg/)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 17, 2011, 04:14:39 AM
I've just finished a 2 ch version, with JLM PSU and Go-between kits. I had tested the PSU and adjusted it to output 24V/0/48V as it should and connected everything, but when i turned on the phantom on the second channel: BAM! a puf of smoke and the 47R 1W resistor (right next to the JLM logo on the PCB) on the PSU fried, as in completely black! Im not sure if it was a coincidence, but im pretty sure it was when i turned on phantom on both channels at the same time..  I not that great at electronics, but could someone give me a pointer on what to look for when debugging?

thx

Michael
Denmark
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 17, 2011, 04:16:07 AM
.. also a pic of the (almost) finished unit :)
Thx for a great project by the way!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on May 17, 2011, 05:36:20 AM
If I remember correctly, the 47R 1W is a protection resistor for the phantom cicuit. Mine burned too when I accidently did a shortcut between +48V and another rail or ground, I don't remember...
Anyway, check your solderings, shortcuts in the phantom area. Hope it'll help. Good luck.

Ben
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on May 17, 2011, 02:24:45 PM
I've done something similar (twice... didnt learn my lesson the first time).  Make sure the JLM power supply is not using metal standoffs.  For some reason you can hook up the ground wire fine to it without problem but as soon as you try to use metal standoffs... bam.  (just my experience, using both the old style of JLM PS's and the new)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on May 17, 2011, 05:38:41 PM
Strange.... i'm using metal standoffs on all versions of board... as said on Jlm website... that let use less wiring in the box... and i never had any problem on 1W res cause of that...  ???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on May 18, 2011, 08:40:34 AM
Strange.... i'm using metal standoffs on all versions of board... as said on Jlm website... that let use less wiring in the box... and i never had any problem on 1W res cause of that...  ???


Yep ! Same thing here ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 21, 2011, 01:55:24 PM
Thx guys. I got it sorted out.. There was a short on the go-between kits phantom switch on ch 1. Its up and running now, just need to adjust it... I stuck with the metal standoffs, and it seems fine. :) will post hi-res pics as soon as it's 100% done ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 21, 2011, 04:44:13 PM
OK, trying to do the BIAS adjustment: add a 1 KHZ tone to input untill clipping.. My Ch 2 is lower in volume that Ch 1 for some reason, and the waveforms look very different:

Ch1:
(http://cybercraft.dk/osc1.png)

Ch2:
(http://cybercraft.dk/osc2.png)

Could someone point me in a direction on what to look for?

M
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 21, 2011, 05:02:20 PM
Do you have a scope? Follow the sine wave along from first to second stage to output, to see where it goes wrong.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on May 21, 2011, 05:08:38 PM
I had output problem on a Channel...level was lower... It seems that there could be several reasons... But my problem was defective input transformer.
Maybe compare resistance between transformers pins. And see if u have same values.
Martin told me to check if 2n3055 either was not defective.
Hope that will help....

Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 21, 2011, 05:09:04 PM
I only have a software scope so im stuck with only reading waveforms from the final output.. But what could be wrong when the output signal is lower and the waveform looks uneven like it does on Ch2? I should mention I'm not very advanced when it comes to electronics :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 21, 2011, 05:10:31 PM
Thx Sylvain.. I'll look into that. :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on May 21, 2011, 07:56:44 PM
Hi all newbie here. I'm doing an EZ1290 for my 1st DIY project. I'm using everything exactly as listed in the BOM.

Here's my problem:
I tested the JLM ACDC PS outside of the case with the transformer and Qualtek piece specified in the BOM. Everything worked perfectly and I adjusted all the voltages correctly.

BUT, now I have put the powersupply in the case and everytime I turn it on the fuse blows.

I would really appreciate some advice!

UPDATE: Okay I just took the ACDC and Transformer out of the case and put them on a rubber mat. Everything is working out of the case, but the fuse still blows when its drilled into the case. Any thoughts?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: signalflow on May 21, 2011, 11:15:25 PM
How about a pic or description of how it's mounted in the case?

-Casey
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on May 22, 2011, 05:48:22 AM
somethings clearly shorting to the case. your voltage regs maybe?

Pic will help.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 23, 2011, 03:58:33 AM
OK, trying to do the BIAS adjustment: add a 1 KHZ tone to input untill clipping.. My Ch 2 is lower in volume that Ch 1 for some reason, and the waveforms look very different:

Ch1:
(http://cybercraft.dk/osc1.png)

Ch2:
(http://cybercraft.dk/osc2.png)

Could someone point me in a direction on what to look for?

M

Hmmm.. made a test yesterday with some simple vocals, and the two channels sounds very much the same, also in volume, when turned up equally high.. I have no idea why the two waveforms are so different..?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on May 23, 2011, 11:31:19 AM
Had the same issue using metal standoffs with the case... (others say this didnt happen to them, but 3 out of 3 JLM powersupplys i had would blow if metal stand-offs were used...) perhaps the standoffs i was using were too wide and contacting a trace on the board... who knows... as soon as i used nylon s/o's everything worked perfectly.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 23, 2011, 11:45:29 AM
Hmmm.. made a test yesterday with some simple vocals, and the two channels sounds very much the same, also in volume, when turned up equally high.. I have no idea why the two waveforms are so different..?

Well, you wanna be sure it's not something stupid before you start desoldering. ie: connectors, cabling, etc...

Time to invest in a scope. Tek 2215 or something...you can get em for next to nothing these days. Must have.

Either way, the top waveform is not adjusted symetrically and the bottom waveform could be an incorrectly installed, valued or damaged component.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 25, 2011, 03:48:10 PM
Well I got the waveforms sorted out.. they look the same now, and like they shoud.. But.. I have a humming problem. When I either touch the Gain knob or put my hand in the case close to the wire between the input trafo pin 7 to PCB 7, it hums louder and louder the closer i get. Its the same on both boards. What did I forget to do? (Im using metal standoffs all round if that might be an issue?)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 25, 2011, 04:17:33 PM
Something isn't grounded...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on May 25, 2011, 05:04:35 PM
May want to check that your mic cables are wired correctly. I had two instances pop up not long ago where the cable shield was carrying signal and GND was on one of the conductors. Both situations were pinned out slightly different but symptoms were very similar to yours.

I know it sounds sorta obvious but those mistakes apparently do happen. Even with buildings full of engineers. Ahem.

Cheers,
jb
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 26, 2011, 01:40:42 AM
Something isn't grounded...

How should it be grounded? I'm using the Jlm psu, and metal standoffs to the case. I havn't done any specific grounding yet..?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 26, 2011, 01:58:25 AM
Is your case ground ok? Do you have continuity from frontpanel to ground? Scrape some paint off if you need to. Make sure that you use star washers that cut through the paint and touch the metal underneath. You should have continuity from the switch spindle to ground...

Input transformer and xlr cabling needs to be completely shielded.

Experiment, but don't touch ground to any power...obviously.  :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 26, 2011, 09:48:59 AM
Sorry but i have no idea how to start.. My electronic skills are limited to say the least. Everything is wired ok, shielded where it should be (and my voltages and sound is ok, so im pretty sure its the ground thing ;)), but how do I "start" ground? Where should i draw it from? I have tried removing the PSU from the case so it doesnt touch the case, but still humming.. When I touch the case or a shield somewhere the humming stops..
Could someone maybe explain it as simple as possible.. Im really trying to learn here :)



M
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on May 26, 2011, 02:29:54 PM
Well there are some details above. Scrape the paint off the case where the screws are. Check and double check your wiring. Also try grounding the pcb to the case from the standoff hole near the 5k trim pot.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 26, 2011, 03:15:46 PM
Also try grounding the pcb to the case from the standoff hole near the 5k trim pot.

Actually, you don't want to do this. There should be 10ohms between 0v and ground. The resistor is actually on the JLM.
You don't want to hook 0v to ground directly.

The case, switches, metalwork, etc....should be straight to ground. There should be a nylon standoff used on that hole(i glued mine to the pcb).
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on May 26, 2011, 05:55:16 PM
Agreed in theory :D

However, linking the audio ground to chassis has resolved problems from hum to oscillation in more than one build (including mine).

I dont know why.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 26, 2011, 07:23:01 PM
Look here: http://www.groupdiy.com/index.php?topic=13710.0

I have 10 ohms and mine's pretty quiet. Oscillation and hum would probably be due to placement of components/proximity to pwr trans, sheilding, etc... Also, bad case grounding.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on May 26, 2011, 08:26:05 PM
As one of those who magically had his oscillation problems resolved by grounding the board to the case through the mounting hole, I have to say that I later got oscillations again. It's been ages and I don't remember any more what it was from, but I just looked at it now and in it's current state (still frankensteined, waiting for a facelift) it's grounded through a 10R to PSU ground which is tied to the case. I don't think this will let me use phantom as is, so I'll have to eventually change it (when I build the 2nd channel and it gets a facelift).

I agree on the paint removal, your problems sound like interference (your hand coming close to the gain knob) from improper/incomplete shielding. Grab your multimeter and check for continuity between all case panels.

It is hard for someone to tell you how to ground your equipment without a clear understanding of how it's set up (how many channels, what PSU, etc.. a good hi-res picture is sometimes better than words). Grounding is not so much a "star" as it is a  "tree"with branches. Grounds go down to earth(ground pin of your IEC connector), which would be the trunk of the tree. Each channel or PCB is a branch and its ground goes back to the trunk. It can either walk along the branch and get to the big tree trunk and safely climb down or it can try to jump from branch to branch and maybe hurt itself. When you have two branches connected together and to the trunk, it doesn't know which way to go and that's a ground loop. 

For this build, you want your 0V going to PSU ground and PSU ground going to case (the infamous "star" ground) THROUGH a 10R resistor.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 26, 2011, 08:51:56 PM
I don't think this will let me use phantom as is, so I'll have to eventually change it (when I build the 2nd channel and it gets a facelift).

I have phantom running fine here w/JLM Go Between's and ACDC/Powerstation. Inputs and 48v are all tied to the same 0v connection.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on May 26, 2011, 08:59:30 PM
Hmm, I just looked at it again and you're right. My pin 1 is connected through the trafo to the PCB so phantom will get it's 0V from there.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 26, 2011, 09:23:38 PM
The way i had it hooked at first was so wrong. :) I had all kinds of problems. Once Joe explained a couple things about the proper wiring layout...it all came together.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on May 27, 2011, 10:56:17 AM
I dont know if this would help but i have a bunch of pics of my build using the JLM gobetweens and the JLM PS.  (also used the JLM VU drivers)
http://www.facebook.com/media/set/?set=a.1817484879991.104345.1326207212&l=f66b9d117c (http://www.facebook.com/media/set/?set=a.1817484879991.104345.1326207212&l=f66b9d117c)
Its a public album on facebook, you dont need a FB account to view.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 28, 2011, 02:44:45 AM
Thanks a bunch for all your help..
Im going to try to use plastic standoffs for all my PCB's incl the JLM PSU today, as some of you recommends and see what happens.

Heres a picture (the psu is not mounted in the case here)
(http://cybercraft.dk/neve.jpg)

Heres a hi-res image of my build:
http://cybercraft.dk/neve-hires.jpg (http://cybercraft.dk/neve-hires.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on May 28, 2011, 12:07:34 PM
Curious. What do you have the tripler/doubler hooked up to on the JLM ACDC? Normally there's just a jumper in there.

It doesn't look like you have ground hooked to anything? The two yellows on the tranformer primary are hooked to power, but there should be a third wire that goes from your case to that plug that is ground!

You don't have to use plastic standoffs everywhere(although they are cheaper) just the one hole that is connected to 0v on the acdc pcb. That should be plastic...and glued on(or any other non-conductive method). The hole by the trimmer pot.

Once you have your ground hooked to the case and your acdc screwed down to the case...you should be able to measure 10ohms between any shield or 0v connection to the case.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: earl on May 30, 2011, 08:29:28 PM
any more boards left to order? Would like to order 4
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on May 31, 2011, 10:28:29 AM
Quote
Curious. What do you have the tripler/doubler hooked up to on the JLM ACDC? Normally there's just a jumper in there.
I wanna know the same thing... looks like that part of the board is hooked up to an input???

I think the wiring here is all sorts of not right.  What re the inputs on the board wired to its not the input transformer...

Off the top of my head... The input jack hits the JLM go between, the go between outs to the Input Trafo, the input trafo outs to the board, the board outputs to the output trafo and that outs to the output jack.

The JLM PS takes the 3 wires from the IEC, the 0v and 48v go to the go between, a 0 and 24v go to the boards (i didnt daisy chain any of mine)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mica on May 31, 2011, 04:08:24 PM
The PSU is not hooked up to any input. Its looks weird i admit, buts its just a home-made jumper. I made it so i could easily test the jumper settings on the PSU board because i had no idea what to do with it.. I can see it looks weird on the picture..
The inputs XLRs are hooked up to the go-between kits, and from the go-between kits to the input transformer, and from the input transformer to the main PCB. The output from the PCB goes to the output transformer,and from there to the output XLRs.
The PSU outputs 0V, 24V and 48V and its not daisy chained to the two PCBs but drawn separately from the same points on the PSU.

Im pretty sure my problem is that i have no ground from the power input (I told you im bad at this ;) ). I will try it out this week. One thing though: There's two mounting holes on the JLM PSU board thats is marked "case" Should they both touch ground then?

Thank you for your help so far.. I really appreciate it!

Michael

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on May 31, 2011, 06:57:29 PM
Just use either of the ground points on the psu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 02, 2011, 07:39:51 AM
Hi...
Just finished my definitive PSU2 box....    to power two 8-channels racks...  so 16 Channels.
with optional fan on back panel (depend if i need it to be totally quiet or no)
using conductive standoffs.... no problem.
Desol, i finally used the wiring that Joe gave me...

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 02, 2011, 07:40:27 AM
front power Off
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 02, 2011, 07:40:56 AM
front power On
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 02, 2011, 07:41:35 AM
Back Fan/power Off
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 02, 2011, 07:42:11 AM
And Back Fan/Power On
Title: Gain mismatch?
Post by: statzern on June 07, 2011, 10:48:03 PM
Hey all,

I just realized that the gain between channels 1 and 2 in one of my 1272's is almost exactly 10 dB different. In other words, when one is set to 50 dB, the other has to be set to 40 dB to output the same level - but it's like exactly the same when they are set that way (as seen on a scope).

Any idea what might be the most likely culprit for this?

It's this way all the way up the scale, so it's not just one resistor in the gain-switching network... I used all 1% resistors and everything all through the build. I was thinking maybe a bad transistor? Should I start yanking them out and replacing with better matched ones?

Thanks in advance!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on June 08, 2011, 12:29:52 AM
Hey Statzern, to narrow down the problem can you measure the level at the L-P junction of each pre-amp?
This is the point where a trimmer would be inserted if used and would allow you to see if the different level is due to the second or third amplification stage. I don't think the first amp stage is at fault as this only kicks in for the higher gain settings and you are observing the difference across the whole scale. Cheers, Briomusic
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 08, 2011, 04:35:00 AM
Already posted in the other 1290 thread, but no reply, so retry here:

Hi all

Iam soldering the parts on my EZ1290 at this moment finished soldering the parts on my EZ1290s but I have run into a two little problems:
1. I did not recieve R56 (resistor 12 Ohm 1W). But I got two extra R98 (resistor 10 Ohm 1W).
Can I use the 12 Ohm in place of the 10 Ohm?
I have bought in a local shop two 12Ohm 1W resistors, but they are twice the size (see pic) ...will fit though, but Iam wondering.. are they a different kind of resistor?

2. I have an empty space on both boards labelled 3k3. I do have two 33Kohms resistors, but they are not the ones right? Or can I use these anyway?

Input highly appriciated!
Thank you in advance...
Erik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuce42 on June 08, 2011, 02:17:59 PM
I have a question about noise - how much noise is normal for these units?

I mean I understand there is this phenomena known as "Neve Haze", and I am also aware that finding a good HFE level with the choice of transistors will affect the noise, but I get this white noise /ssshhhhhh sound on the last three steps of the grayhill.  As I have no experience with a real Neve module, I cant determine whether this is just normal Neve Haze or whether I have an issue with my build. Some people seem to report "no noise" on the builds however.

I dont hear any hums or sound reminiscent of ground loops, and I solved the osciallation problem (high pitched squeels) by grounding the 1290 pcb to the rack case, but there is still that soft sssshhhhhhhh sound at the last three highest volumes.

Can anyone enlighten me?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 08, 2011, 02:35:40 PM
Hi Deuce42

Look at my April 06 Post (page 38)
i recorded a 1073 DPA.... to compare...
u have links there...

Hope this will help you


Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 08, 2011, 02:43:31 PM
What people call the phenomenon of Neve 'haze', doesn't have anything to do with noise. It's the overall buildup of low - mid frequency in a mix. I don't think there's ever been a consensus on whether such a thing actually exists. The grounds are supposed to be seperate with 10ohms between them, which means the pcb Ov should not be connected to case ground. Other problems such as placement of components, etc are causing oscillation.

As to what the problem is on the switch you'd probably have to trace the audio signal with a scope to see where/what is happening throughout the stages.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on June 11, 2011, 08:35:04 PM
Can I skate by with this power trafo?  I plan to use with 1x JLM powerstation for 8x preamps.

http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT24-2080/?qs=wkKrz7WmEgMMEIeVWR4gGA%3d%3d

24VAC ct @ 2.08A   not enough??

Anybody recommend anything else?  I think Desol sent me the part# for the toroidal used but I can't find them anymore.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on June 11, 2011, 11:45:46 PM
Gonna need a bigger boat....

I believe the JLM is good to power a pair of boards. (probably can do 3 but its gonna get toasty!!)  Gonna need 4 of them JLMs for that task im thinkin...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 12, 2011, 02:04:36 AM
I have eight 1290's running off a single powerstation with the larger rectifier upgrade. Although it has been modified further to disable the neg power rails as well as provide full wav rec. I posted about it earlier on in this thread. The onboard 317's are bolted to the case and are barely warm to the touch. The toroid i used was the avel lindberg  3.33 amp 80va unit. I have thought of putting in a bigger supply but this seems to be working fine.

I did a quick amp test tonight with my AC meter. On start, they pulled around 2.71 amps, then settled at 740mA idle(with phantoms engaged). DC did about the same...with idle a little lower at ~610mA.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 12, 2011, 08:06:54 AM
Hi All

I have designed a front panel for my 2 channel 1290 (based on MatthewF's kindly supplied design - tnx!). I have attached a picture for you to take a look at. If anyone has any comments / tips /things I have overlooked, your input is highly appriciated. I would also like to know how to add another font type in front panel express, so I can match the font to my other builds. I have the font on my pc, but it is not showing up in front panel express...
 
Als I would like to take the opportunity to repost my previous question, since you guys might have overlooked it, and Iam stuck with my built without answers (no preassure though):

Iam finished soldering the parts on my EZ1290s but I have run into two little problems:
1. I did not recieve R56 (resistor 12 Ohm 1W). But I got two extra R98 (resistor 10 Ohm 1W).
Can I use the 12 Ohm in place of the 10 Ohm?
I have bought in a local shop two 12Ohm 1W resistors, but they are twice the size ...will fit though, but Iam wondering.. are they a different kind of resistor?

2. I have an empty space on both boards labelled 3k3. I do have two 33Kohms resistors, but they are not the ones right? Or can I use these anyway?

Thanks a lot


Erik

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on June 12, 2011, 10:26:57 AM
hey desol, would you take a peek at the model number of your toroidal?

The largest 12+12 I found was only 30VA for an Avel.

Thanks again!!

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 12, 2011, 12:36:55 PM
Micdaddy: have a look at the y23 range 80VA. 12+12 @ 3.33A.

Erik: Use the resistors specified. A larger 1 watt doesn't matter. 33k is not 3.3k.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 12, 2011, 12:56:03 PM
Desol: thank you!

I have spotted an error in my front panel design! The DI was much too close to the gain, those boards (DI & 1290) would be completely in each other's way! Attached the new version, for this the DI board has to be mounted upside down, but otherwise the DI is much too far from the gain...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on June 12, 2011, 01:02:34 PM
Hey thanks, who sells them?    

Avel Lindberg Y236351


edit:  Avel Lindberg of course  ;D
Awesome, thanks!!

For future reference,

Avel Lindberg Sales 

800-979-1022, x 1, or fax 860-354-8597
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 12, 2011, 04:00:12 PM
You order direct from them..
Title: Output signal level difference
Post by: statzern on June 13, 2011, 12:37:43 PM
Hey Statzern, to narrow down the problem can you measure the level at the L-P junction of each pre-amp?
This is the point where a trimmer would be inserted if used and would allow you to see if the different level is due to the second or third amplification stage. I don't think the first amp stage is at fault as this only kicks in for the higher gain settings and you are observing the difference across the whole scale. Cheers, Briomusic

Yeah, I can give that a try. Thanks for the advice. Will report results ASAP.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: statzern on June 14, 2011, 01:57:05 AM
Hey Briomusic,

I measured the voltage at the L-P junction at the negative side of the 10 uF/25V tantalum cap. The voltages are very different at that point. The gain was set to 35 dB.

What do you think might be going on to cause this difference?  ??? ???




Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 20, 2011, 01:40:57 PM
HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI. It being my first build, Iam starting to get a little nervous. I have three questions:

1. Iam "missing" three jumpers per board if I compare to some other pictures here on the forum... should I solder those in?

2. Should I move the output transformer in to indicated position? Wich would mean further away from input transformer, but the output cable would be crossing the power cable

3. can I attach all transformers directly to the case or should the be insulated as well?

Hope you can help this newbee...


cheers

Erik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 20, 2011, 02:13:22 PM
For me transformers has to be linked to the ground ... so to the case...

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on June 20, 2011, 04:26:59 PM
HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI. It being my first build, Iam starting to get a little nervous. I have three questions:

1. Iam "missing" three jumpers per board if I compare to some other pictures here on the forum... should I solder those in?
Those are not really jumpers, they are pcb copper traces and vias. A 'via' is a connection of the top layer to the bottom layer of the pcb. the only jumper you need is already installed if I see correctly. if you are using an output trim, install it at that point INSTEAD of the jumper.
Quote
2. Should I move the output transformer in to indicated position? Wich would mean further away from input transformer, but the output cable would be crossing the power cable
Not a thang as that power cable is DC if I understand correctly (PSU in seperate case - very good idea). but current position is ok too.
Quote
3. can I attach all transformers directly to the case or should the be insulated as well?
As sgenevay said, don't insulate - you want them to be grounded!

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 20, 2011, 04:39:22 PM
Thank you!

First estimated testdrive tomorrow evening.. exciting!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 20, 2011, 07:12:10 PM
I think that dark-burgundy-slightly-wrinkled colour would look nice for a front panel with these.

Cheers,
JoBu

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: briomusic on June 21, 2011, 03:54:49 AM
Hey Briomusic,

I measured the voltage at the L-P junction at the negative side of the 10 uF/25V tantalum cap. The voltages are very different at that point. The gain was set to 35 dB.

What do you think might be going on to cause this difference?  ??? ???
hi statzern, sorry for the late reply hadn't seen your post.
Just to clarify you are measuring AC/sound levels with a scope right? if levels are already different at that stage then it is a sign that the problem is before the BA183AM stage, so either in the gain switch or in the (second) BA183NV. To further narrow down the problem, can you measure the level at the negative side of C8 for each gain setting. be carefull, this C8 exists twice, one shouldn't show any ac voltage except for the very high gain settings. I am talking about the other one! This point is inbetween the gain switch and the first amp. Let me know what you find, especially at the lower gain settings! cheers briomusic
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: letterbeacon on June 21, 2011, 04:43:32 AM
HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI.

This is pretty much exactly the same as what I'm planning to build.  Do you have the front panel dimensions handy so I can see how far apart the Go Between and the DI have to be from the 1290 PCB?

Is it ok to have the ribbon cable that goes from the DI to the Go Between so long?  It's an unbalanced signal, right?  Is there a risk of it picking up any unwanted noise?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 21, 2011, 04:44:42 AM
Hello

For constructional purposes, I would like to move the input transformers pretty close toeach other, as in attached picture.. would that be a problem?

Cheers

Erik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 21, 2011, 04:49:22 AM
On 8 tracks preamps.... i assume that input preamps are closer from each other..... i didn't have any problem with that...
there is 2,5cm (0,984") between all my input preamps....
for me it looks ok...

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 21, 2011, 04:51:10 AM
HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI.

This is pretty much exactly the same as what I'm planning to build.  Do you have the front panel dimensions handy so I can see how far apart the Go Between and the DI have to be from the 1290 PCB?

Is it ok to have the ribbon cable that goes from the DI to the Go Between so long?  It's an unbalanced signal, right?  Is there a risk of it picking up any unwanted noise?

I have a frontpanel express file of the design on the previous page, If you want to I can mail that to you. I also have a word file with all  hole diameters and distances between them, hapy to share that too of course (happy that I can finally do something for someone after been helped so often).
The ribbon cables are the length that were provided with the go between / DI kits. Haven't thought about the cable length though... no clue about that... maybe someone else has a clue about that?

Let me know if you want the files as pm or mail.

Erik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 21, 2011, 04:52:13 AM
sgenevay: merci beaucoup!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 21, 2011, 04:54:51 AM
pas de problème ;)  mais quand bien même ... plus ils sont espacés mieux c'est !!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 21, 2011, 04:58:08 AM
merde... me and my big semi french mouth....
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 21, 2011, 05:04:16 AM
eheheheh i just said the the more space there is between them... the better it is of course.... (i think)
but mine are 0,984" from each other and there is no pb with that:
have a look on it on the pictures i have post page .... 37 i guess
http://www.groupdiy.com/index.php?topic=22828.720

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 21, 2011, 05:10:40 AM
hahaha.. thank you... I can widen the space to about 7 cm.. so I should be safe... that looks like an impressibe build... especially after struggling for weeks with my humble two channel...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 21, 2011, 05:18:25 AM
thx u... but there is no real difference between 8 and 2 channels... same problems, same enigmas, same questions about positions and spacings.....   just 4x longer to do... that's all. And if u look well i didn't dare to use fet DI (maybe I should have try ?)  but i really dunno where i would have place it...
Hope your project will work fine...  soon touching graal ;) eheheh  ...

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 21, 2011, 10:47:30 AM
Hi everyone. I posted here a few weeks ago with some problems I was having with the PS fuse blowing. I put the ACDC on nylon standoffs and it works great now :).

So I've tested the first channel and everything sounds good except my phantom power isn't working. The LED comes on and I hear a popping noise when I turn the switch on and off but it doesn't seem to power any mics. This is my first project, so I'm a bit of a newbie. Anyways I not sure if I wired it correctly so here's a link to some pictures of it. Hopefully you can give me some insight. Thanks!

http://s919.photobucket.com/albums/ad32/themedication/EZ1290/
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: evilcat on June 21, 2011, 02:55:41 PM
Hi everyone. I posted here a few weeks ago with some problems I was having with the PS fuse blowing. I put the ACDC on nylon standoffs and it works great now :).

So I've tested the first channel and everything sounds good except my phantom power isn't working. The LED comes on and I hear a popping noise when I turn the switch on and off but it doesn't seem to power any mics. This is my first project, so I'm a bit of a newbie. Anyways I not sure if I wired it correctly so here's a link to some pictures of it. Hopefully you can give me some insight. Thanks!

http://s919.photobucket.com/albums/ad32/themedication/EZ1290/

It may seems a stupid question but : did you check your +48V on the ACDC rail ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 21, 2011, 02:59:54 PM
Hi everyone. I posted here a few weeks ago with some problems I was having with the PS fuse blowing. I put the ACDC on nylon standoffs and it works great now :).

So I've tested the first channel and everything sounds good except my phantom power isn't working. The LED comes on and I hear a popping noise when I turn the switch on and off but it doesn't seem to power any mics. This is my first project, so I'm a bit of a newbie. Anyways I not sure if I wired it correctly so here's a link to some pictures of it. Hopefully you can give me some insight. Thanks!

http://s919.photobucket.com/albums/ad32/themedication/EZ1290/

It may seems a stupid question but : did you check your +48V on the ACDC rail ?

No question is a stupid question I appreciate all the help I can get ;D. By check it do you mean test it with a Multi-meter? I did test it and it measured +48.0v on the dot.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on June 21, 2011, 03:07:02 PM
what does it measure on the XLR pins?

Also, if your ACDC was blowing on metal standoffs it can only be because something was accidentally something to the case via them. i would double check nothing can short to the case because that could be dangerous.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 21, 2011, 03:25:55 PM
what does it measure on the XLR pins?

Also, if your ACDC was blowing on metal standoffs it can only be because something was accidentally something to the case via them. i would double check nothing can short to the case because that could be dangerous.



XLR pins are measuring like 1.7 volts. Not sure if I measured it correctly, I'm supposed measure between pin 1/pin2 and pin1/pin3 correct? Sorry for the newbishness. I just had an idea. Is the on/off switch for the phantom power supposed to be situated so that on is up and off is down or vice versa? I might have it upside down and therefore my wiring is backwards.

I don't think anything is shorting, I used all plastic standoffs and screws. What's the best way to check if something would be shorting? Again, sorry for my lack of knowledge.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on June 21, 2011, 04:03:20 PM
i meant was there some connection that was previously hitting the leg and shoring to case that may now short directly to case with a knock?

The acdc should not short with metal standoffs.

Anyway, with phantom.. the switch can be either way, its just a toggle thats connected in one position and disconnected in the other. What do you measure at the connections to your switch?

If youve got 48v on the +48 pin of the power XLR, try measuring at each connection after that and see where it goes wrong.

BTW - it looks like you are isolating the only NON conductive part on your resitsors. you really need to isolate all your connections a lot better.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on June 21, 2011, 05:08:05 PM
I dunno man, depending on the stand offs... ive never gotten metal standoffs to work properly with either version of the power supply.  Every one of them shorted.  Ive had to use nylon standoffs on all my JLM PS's. And once its up on all 4 legs, unless it falls off it's not going to hit anything.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: snipsnip on June 21, 2011, 05:18:56 PM
well i cant deny your experience but if you can tell me what you think the problem is / what is shorting then i'd be interested.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 21, 2011, 05:53:58 PM
Even if you use plastic standoffs...the nut/screw combination will probably still make. That's why that connection is there...to make to case, as labelled on the pcb.

So...what is the real problem? I would think it might be wiring somewhere along the line? It's important to find out exactly why something is happening...otherwise there's still doubt in your mind, even if the facts state otherwise.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 21, 2011, 06:04:42 PM
true.... it has to be linked to the case anyway..... with metal standoffs or with wire....   nylon standoffs are for me just a way to avoid the real problem which is still here...
and just a question... after a fast view of your picture... (i think) there is a lot of stripped wires (dunno the exact english word but i'm sure u understand me...)
are u sure there isn't a shortcut somewhere else with all that ?....
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 21, 2011, 11:12:06 PM
i meant was there some connection that was previously hitting the leg and shoring to case that may now short directly to case with a knock?

The acdc should not short with metal standoffs.

Anyway, with phantom.. the switch can be either way, its just a toggle thats connected in one position and disconnected in the other. What do you measure at the connections to your switch?

If youve got 48v on the +48 pin of the power XLR, try measuring at each connection after that and see where it goes wrong.

BTW - it looks like you are isolating the only NON conductive part on your resitsors. you really need to isolate all your connections a lot better.

Hi snipsnip.

So I fully isolated both resistors as you said and success +48v! BUT, it is still not powering any microphones that I test. Here's a picture so you can see what I'm doing.
http://i919.photobucket.com/albums/ad32/themedication/EZ1290/IMG_0847.jpg
I'm not sure how it's getting +48v but it doesn't power the mic? Maybe you or someone else has some ideas?


true.... it has to be linked to the case anyway..... with metal standoffs or with wire....   nylon standoffs are for me just a way to avoid the real problem which is still here...
and just a question... after a fast view of your picture... (i think) there is a lot of stripped wires (dunno the exact english word but i'm sure u understand me...)
are u sure there isn't a shortcut somewhere else with all that ?....

When you say it has to be linked to the case, are you saying there must be a piece of wire that goes from the hole that says case on the ACDC to the rack case? I wasn't sure about this so I haven't done it yet. Did I make a mistake and do I need to connect it?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 21, 2011, 11:19:44 PM
Hey Punkrocker,

Not sure but I see it looks like you have paint scraped off by the PSU where the regulators appear to be connected to the chassis for heat-sink. Are the tabs shorted to chassis or isolated from chassis?

Cheers,
JoBu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 21, 2011, 11:34:33 PM
Hi JoBu,

Yes the paint is scraped off but I don't think anything is shorting because then the PS would not be working right? Everything thing is functioning perfectly, and the pres work great with dynamic mics, its just the phantom power that's not working. Would the paint being scraped of somehow affect the phantom power? Sorry, like I said this is my first time with DIY.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 21, 2011, 11:42:32 PM
The tabs of the regulators normally carry a voltage. They did on a build I recently had opened up. If they short to chassis then you have a short circuit which would theoretically make it fail sooner rather than later. Maybe turn off the power and measure for continuity between the regulator tabs and chassis. If there is continuity, make sure there is none before turning it back on.

Perhaps the ACDC is different. What regulators is it using?

Cheers,
JoBu

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 22, 2011, 12:21:55 AM
The tabs of the regulators normally carry a voltage. They did on a build I recently had opened up. If they short to chassis then you have a short circuit which would theoretically make it fail sooner rather than later. Maybe turn off the power and measure for continuity between the regulator tabs and chassis. If there is continuity, make sure there is none before turning it back on.

Perhaps the ACDC is different. What regulators is it using?

Cheers,
JoBu



Ok I just checked and there is no continuity between the regulator tabs and the chassis. This means nothing is shorting correct? The regulators are 2 LM317 and 1 LM337. Like I said a few posts ago, I'm getting +48v on the mic input pins 2 and 3 but it's not powering the microphones. Perhaps it's a faulty mic input jack? However, I guess that wouldn't make much sense because it works fine with dynamic mics. Any advice is greatly appreciated :).
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 22, 2011, 12:38:30 AM
You have good GND on pin1? Can you confirm that the mic works? What mic is it?

Best,
JoBu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 22, 2011, 01:07:20 AM
0v is floating at 10ohms from GND on the JLM supply.

Do you have continuity between 0v on the ACDC and pin1 of the input xlr?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 22, 2011, 01:31:10 AM
You can also use a phantom powered DI with an led to test for phantom on the end of a mic cable. Do you something like that or a "phantom tester"? If so, you could also unhook everything in the chassis except the parts required to get phantom. Ie; disconnect the preamp boards and test for phantom power with the di/test-plug to help identify where the fault is.

Best,
jobu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 22, 2011, 01:39:42 AM
You have good GND on pin1? Can you confirm that the mic works? What mic is it?

Best,
JoBu

How do I test for GND on pin 1? Sorry for the newbishness again :P. Yes the mic works, it's an SM7b.


0v is floating at 10ohms from GND on the JLM supply.

Do you have continuity between 0v on the ACDC and pin1 of the input xlr?

Yes I have continuity between 0v and pin1. Is this good or bad?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 22, 2011, 01:45:12 AM
Sm7b is a dynamic mic isn't it? Is that the mic you are using to test for phantom?

Cheers,
jb
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 22, 2011, 01:54:45 AM
UPDATE: SOLUTION FOUND

Wow I feel like an idiot right now ::). Turns out that the cable I was using to connect the mic to the pre wasn't passing phantom power. Swapped the cable and everything works great (not to mention sounds like gold!). Thanks everyone for helping out a newbie!

Sm7b is a dynamic mic isn't it? Is that the mic you are using to test for phantom?

Cheers,
jb
Yes sorry I meant I used that mic to check to make sure that audio was passing through so I could verify it was strictly a phantom power problem.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on June 22, 2011, 01:59:07 AM
Awesome! Feed her good music and lots of it.  She'll prolly like that best :)

Cheers,
jobu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on June 22, 2011, 02:30:34 AM
Yes I have continuity between 0v and pin1. Is this good or bad?

It's good. You should measure 10ohms when you try continuity from 0v to GND(case).

Regardless, enjoy your new pre. :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 22, 2011, 04:30:26 AM
If u test ACDC board with ohmmeter, u will see that the 4 holes are linked together (normal) on all versions  (and yes linked to the hole labeled "case").
And on new versions, the 4 holes are linked to the "screwed pin" labeled case (sory for my English again). Joe made new screwed version of the board to make an easier way to link that point to the ground (with a wire).
That means that this point HAS to be linked to the ground by any way (metal standoffs or wire to screwed point or wire to any "case" point).
Why ? ... Cause for me this is the only way to have your 10 ohms between your 0v point and any ground point....
And if u haven't those 10 ohms, your ground wiring is not correct so there is a problem...
Hope my explanation is clear ;-)
best.

Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on June 22, 2011, 09:38:54 AM
My theory on the matter was the metal standoffs are too wide and are touching something else.  Being that i dont have different diameter standoffs, it was just easier to use nylon standoffs and let the wire do the ground work.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on June 22, 2011, 09:43:52 AM
Sure.... Nylon is ok as soon as u have wire.... ;-)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: punkrocker on June 22, 2011, 01:59:04 PM
If u test ACDC board with ohmmeter, u will see that the 4 holes are linked together (normal) on all versions  (and yes linked to the hole labeled "case").
And on new versions, the 4 holes are linked to the "screwed pin" labeled case (sory for my English again). Joe made new screwed version of the board to make an easier way to link that point to the ground (with a wire).
That means that this point HAS to be linked to the ground by any way (metal standoffs or wire to screwed point or wire to any "case" point).
Why ? ... Cause for me this is the only way to have your 10 ohms between your 0v point and any ground point....
And if u haven't those 10 ohms, your ground wiring is not correct so there is a problem...
Hope my explanation is clear ;-)
best.

Sylvain.

Ok great thank you that makes much more sense. I will link it with a wire and test for ohms. And your English is fine. I see you're from France, I don't speak French at all so your English is certainly better than my French! ;)

My theory on the matter was the metal standoffs are too wide and are touching something else.  Being that i dont have different diameter standoffs, it was just easier to use nylon standoffs and let the wire do the ground work.

Thats a good point I wouldn't be surprised if that was what was happening.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on June 22, 2011, 08:41:22 PM
Got cases in from Dan, starting to get things laid out. 

One note regarding the trim-pot.  I ordered 51AAD-B28-D15L from mouser and they won't fit the allotted hole in Dan's panel (1/4"), so be aware, I know this pot was mentioned earlier in the thread.  It feels great but just won't fit. 

sr1200, any chance off the top of your head do you remember the hole you needed to drill for the panel mount trim pot you used? 

Any suggestions on how to drill this 1/4" hole out a tad bigger without tearing the aluminum front panel all to hell?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on June 23, 2011, 12:30:26 AM
I had made my own front panel from FP express.  I can find out tomorrow what the diameter of the hole i used was when i get in the office.  (i have the FPE file there)


  Usually with a drill press, if you bring the bit down slowly it works itself into the existing hole.  With the press off bring the bit down to line it up, bring ti back up, fire the press up and bring it on down.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on June 30, 2011, 06:36:29 AM
Hey All
Just about ready, just wiring the acdc in external box... but I got some small questions.

1. In attached picture you see the instructions forwiring the acdc. I have added in grey the lay out of my power inlet. Bottum one is front, top one back. A,B and C are the soldering points. A is ground, that one goes to the case, and to the screwed hole (eerrmmm...) labeled case. But it also has to be connected to pin 2 of the 4 pin xlr connection between acdc and 1290 to link both cases together right?

2. Wich ones from violet and yellow wires from the transformer have to be connected to B and C and why? (I mean mean not why they need to be connected, but why wich one to wich?)

3. From what I understand, black and red wires from transformer are just connected together and go nowhere right?

4. Last one,on subject of grounding. Some of you seem to have grounded the 1290 pcb's with a wire directly to the case. Is that needed?

Kind regards

Erik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on June 30, 2011, 09:51:25 AM
This is my FPD front panel for anyone that was interested.  Has cut outs for VU meters, trim pot, JLM go between w/ 48v indicator and gain.

http://www.meirecords.com/BJ/21073.fpd (http://www.meirecords.com/BJ/21073.fpd)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: beatnik on July 01, 2011, 02:39:54 PM
Hi guys,

I've finished my two-channel unit and i'm experiencing the often mentioned oscillation at higher gain settings.

Doing some search I've found people suggesting tying the PCBs ground to chassis ground, using metallic standoffs.

Martin build guide calls for plastic standoffs instead, and the JLM AC/DC I'm using specifies that the circuit ground must be connected to the case ground only at one point, and with 10ohm resistor in between.

What do you think is best to do?

Eventually metallic standoffs are ok, or is better to star ground the two boards?

Thanks in advance
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 01, 2011, 03:35:24 PM
Hi guys,

I've finished my two-channel unit and i'm experiencing the often mentioned oscillation at higher gain settings.

Doing some search I've found people suggesting tying the PCBs ground to chassis ground, using metallic standoffs.

Martin build guide calls for plastic standoffs instead, and the JLM AC/DC I'm using specifies that the circuit ground must be connected to the case ground only at one point, and with 10ohm resistor in between.

What do you think is best to do?

Eventually metallic standoffs are ok, or is better to star ground the two boards?

Thanks in advance

The 10 ohm resistor is already on the JLM powersupply. It doesn't matter if you use all metal or all plastic standoffs as long as the case connection (as labelled on the pcb) is made. Martin's recommendation for plastic standoffs, pertains to the 1290 pcb only. It's good to post a picture, so people can get an idea of your layout.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 02, 2011, 12:33:18 PM
I set up a little workstation that enabled me to set bias to each of the 8 preamp cards.

Simply used the bench supply and had the iron wired up, swap the cards in and out, that way I can at least be confident they are all equal relative to one another.

The sound is incredible, with each pre I did a talk test after bias was set, and the amount of gain needed vs what is available is just ridiculous.  I used both an RE20 and 441 and was on step 4/5 most of the time for simple talk test.   Taking the gain up into the upper ranges was just too much oh wow.  Imagine that...too much gain available...

Still need to build the powerstation and then figure layout in Dan's 'Neze' case.

One thing I wanted to ask about, I am not able to produce oscillations from coupling the transformers capacitively or by sticking them right next/on-top of each other.  I wanted to try and create the parasitic capacitively coupled oscillations only for my own personal "ok so that's what this sounds like"....of course hoping that I'd not have to deal with it I do want to be aware of what the issue sounds like.

Anybody reading this thread, stop debating and build some of these preamps.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on July 02, 2011, 09:47:01 PM
What does the 10 ohm resistor between 0V and chassis accomplish in this circuit?

Thx,
jb
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 02, 2011, 09:54:48 PM
What does the 10 ohm resistor between 0V and chassis accomplish in this circuit?

Thx,
jb

I do not know, I thought this was implemented at the power-supply? 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 02, 2011, 11:32:18 PM
What does the 10 ohm resistor between 0V and chassis accomplish in this circuit?

Thx,
jb

Look here jb, i posted a link a while back:
http://www.groupdiy.com/index.php?topic=22828.msg556071#msg556071
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 08, 2011, 08:19:18 PM
 ::)   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 08, 2011, 08:33:36 PM
Using the JLM powerstation in a Nady graphic eq chassis.  I haggled with a fellow at a music-go-round into letting me have the Nady with an IEC cord and some picks for $15.  Am I proud I paid for a Nady product   :-X  but it beats paying full price for a 1RU chassis to house a PSU   ;)

Gutted the EQ and got it all fitted tonight.  Powered up first time, Using V1 and V2 for +24 on each rail.  The transformer is an Avel dual 12V secondary.   Thanks to desol for leading the way on that, worked out perfectly!

I am using metal standoffs and I do see a 10Ohm resistor to ground on the powerstation pcb.  Also note how close the pads for the standoffs are in relation to other pads in close proximity.  It would be very easy to short a standoff without being able to verify the short from a visual inspection.  Double check two times or more just to be sure.

Question for you all, what is the pinout for the XLRF4 on a Vintech/etc...  I want to be consistent should units ever get swipswapped do to a blind plug in etc.  I suppose I could measure but that would mean I'd have to get in the car and drive :P  If nobody posts in the next day I'll just edit and post what I find.

I've wired mine 1:0V 2:24V 3:open 4:48V   this is what I came up with, which should be easy enough to remember. 
2 is hot, 1 is ground, 4 for 48
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on July 08, 2011, 09:09:28 PM
So you wired the toroidal secs on parallel?
That gets you 24VAC isnt it?

Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 08, 2011, 09:28:41 PM
So you wired the toroidal secs on parallel?
That gets you 24VAC isnt it?

Thanks.

Negative, Voltages in series are additive, so 12+12 gives me the 24. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on July 08, 2011, 09:36:33 PM
Sorry bad typo.
How does it react to loads??
Does the regulators get hot?
Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 08, 2011, 09:47:46 PM
Sorry bad typo.
How does it react to loads??
Does the regulators get hot?
Thanks.

No worries.
Sorry, I'm still figuring a way to mount the pcbs and transformers into the chassis, so I haven't actually 'tested' this under a load. 
As expected the regulators are not even warm, but I expect that to change.  Perhaps desol could comment as our psu are nearly identical.
Sorry I don't have more info yet...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: beatnik on July 11, 2011, 01:52:08 PM
I seem to have resolved the oscillation problems, appeared to be a grounding issue. I tied the boards grounds directly to case and now I don't have any psu hum or oscillation at higher gains.

I am using the pres a lot to test them, they do sound very good, but comparing to my api 512c they seem to have less top end.

I was expecting brighter sound from this pres, am I wrong?

Right now I'm in the components-paranoid phase: I have used 2N3055 by ST Electronics, made a research and read they are crap quality. What do you think?

Another thing, regarding the bias. I've set the trimmer as Martin says, to match his recommended voltage. Maybe is not enough?

As I don't have a scope, do you know a software, possibly freeware, which could do the job?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 11, 2011, 11:37:21 PM
Funny I didn't have any oscillation issues until I put the pre in the case.

Fought with oscillations @ around 55/60dB and up.

Finally tying a Jumper to case ground, from the back side of the resistor that is tied to the standoff next to the bias potentiometer, eliminated the oscillations.

Only after assembling the first preamp and a loooooong time troubleshooting a spitting phenomena, microphonic, when I tap on my bench or around I could here a spitting fitzing in the audio.... after awhile troubleshooting this I had no audio   :'(   

Come to find out the out + from the JLM go between I hadn't tightened down, and was intermittent...  stupid problem to have to troubleshoot for that long.

Just goes to show, take nothing for granted double, triple check EVERYTHING, and then double check again.  I could have had all 8 cased up and in the studio, and here I am with only 1....  long night.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 13, 2011, 03:28:03 AM
guts

One of the LEDs burnt out almost immediately.  It lit for an instant and then went dead.  The other 3 are still all lit, and the channel with the dead LED is showing phantom voltage on pins 2 and 3.

Question, what value is good to shoot for regarding phantom voltage?  I have a Dynacord board that has 25V, but I also have a small 4channel rack mixer that is showing 38V.  Currently with the powerstation I'm only able to dial in ~31.5VDC, I do notice when I listen in on a channel with phantom engaged I'm noticing some hum that is gone as soon as the phantom switch is off. 

edit: some quick math tells me 31.5V is all I'm going to get from this transformer setup, but I'm surprised to see my firebox supplies the full 48V and my high end stuff doesn't.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 13, 2011, 03:35:48 AM
I tied a ground wire from each 1290 pcb to its' corresponding output transformer wing mount.  Should I tie the boards to themselves, and then to only one ground point on the chassis?

No oscillations all the way up to 75dB on all channels. 

Compared to my analog board they are remarkably quiet.  Once you get beyond 65+ dB there is some hiss on the noise floor that is to be expected.

@ 75dB gain, with the trim fully pulled back, slowly opening it up to let the audio through gives such a nice texture....of course it's easy to saturate to unpalatable levels, but with a little fiddling it does add a nice bit of character to the sound.



Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 13, 2011, 01:25:52 PM
Hi there....

Quick question... i was making my second 8 channel rack....  and during final tests, my 48v wire accidentally touched the ground...
and i lost the 48v channel on the associated ACDC board...
after a quick look i saw that the 10R was burn... that i replaced... but nothing else seem to be damaged...
i don't understand cause after replacing the 10R my 48 Channel still doesn't work....
does someone know which component is dead even if there no trace on it ?

Thx a lot

Best,

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 13, 2011, 04:10:46 PM
Hi there....

Quick question... i was making my second 8 channel rack....  and during final tests, my 48v wire accidentally touched the ground...
and i lost the 48v channel on the associated ACDC board...
after a quick look i saw that the 10R was burn... that i replaced... but nothing else seem to be damaged...
i don't understand cause after replacing the 10R my 48 Channel still doesn't work....
does someone know which component is dead even if there no trace on it ?

Thx a lot

Best,

Sylvain

There's not a whole lot to fail.  Check what voltage, if any, is coming into the +48V section voltage regulator, and if any voltage is on the out leg?  Do you still have your +24VDC?

You guys that are cramming 8 of these into a chassis are insane!    ;D

Question now for you Sylvain, did you tie your 1290 pcb ground/common to chassis at any point and how?  And do you experience any increase in noise floor with phantom engaged (listening to noise floor with no microphone on the line, engage phantom, I experience slight hum ~60Hzish)  When engaging another channel's phantom, the channel I'm listening in on is not affected.  Only when I engage phantom on the specific channel that I am monitoring, and is the case with all 4 channels.

Also, what voltage are you showing between pins 2 and 3 with phantom voltage applied?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on July 13, 2011, 04:21:01 PM
Question now for you Sylvain, did you tie your 1290 pcb to chassis at any point and how?  And do you experience any increase in noise floor with phantom engaged (listening to noise floor with no microphone on the line, engage phantom, I experience slight hum ~60Hzish)  When engaging another channel's phantom, the channel I'm listening in on is not affected.  Only when I engage phantom on the specific channel that I am monitoring, and is the case with all 4 channels.

Not Sylvain here but I think if you want to test for noise floor without a mic, you should at least have a "mic-termination-plug" connected up with 150R (or 200R, 50R, etc) between pins 2/3. Not sure how much difference it would make in your results either but it would simulate a quiet mic with similar impedance.

Cheers,
jb
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 13, 2011, 04:24:04 PM
The 48v rail is  at 0v right now.. no current at all ... sorry for my stupid question but what is the the out leg of a reg ? that the first time i'm burning one .. can it cut totally the current ?

for the 1290, i think it's only linked to the chassis via the gain switch... and i used, as martin said nylon standoff and screw/nut to fix the board...    the board shouldn't be grounded directly to chassis normally...

By my side, on the first preamp, i didn't have any noise like this at least no particular noise linked to the phantom engaged.
i will check voltage on xlr pins at first tomorrow morning if u want.. everything is in its box for now (yeah hard to make a preamp when u live in a so small flat...)
the only hum i had was when my soldering iron power supply was activate near the preamp, or when i tried to install the ACDC boards inside the  preamp case.
but the first 8-channel rack works perfectly and i didn't have any problem like this on the second one.

Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 13, 2011, 04:32:49 PM
Thanks for the heads up JB, I will try with a dummy load on the end of a cable.

The thing that bites my butt is my analog board, with a cable into the pre, no mic on the end, phantom engaged (shows roughly 25.5V between pins 2 and 3) is dead silent, switching on the phantom power.  There may be a very slight almost inaudible change in the noise floor, but it is negligible.

Completely different behavior with my 1290s.   

Sylvain, see attached datasheet for typical LM317, check the IN leg and the OUT leg of the regulator, with reference to 0V.   http://www.fairchildsemi.com/ds/LM/LM317AHV.pdf (http://www.fairchildsemi.com/ds/LM/LM317AHV.pdf)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 13, 2011, 04:41:26 PM
ok thx... but i have no voltage on the 3 legs of the 48v regulator.... even the input leg when the input leg of the 24v regulator has 33,6 v  ... what is situated before the regulator in the ACDC circuit... maybe i burned something else...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 13, 2011, 04:57:37 PM
ok thx... but i have no voltage on the 3 legs of the 48v regulator.... even the input leg when the input leg of the 24v regulator has 33,6 v  ... what is situated before the regulator in the ACDC circuit... maybe i burned something else...

If you have access to the bottom of the board (makes it easier to poke around traces) just follow the traces/components from the Voltage IN leg of the regulator backwards all the way to where the AC comes in.  Have your DMM looking for DC, and if you find a part with a voltage on one side and none on the other, that part is suspect.  I cannot find a schematic and it's hard to follow the traces on the picture.  Diodes sure are suspect, check all of them that are in the 48V circuit.  Check if there's any voltage on the back side of the 120R?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 13, 2011, 09:41:46 PM
I think my dead LED worked over my powerstation.

C1 and C2 are bulged/puffy, and again I have this 60Hz on any channel when phantom power is engaged.

I haven't dug in, to take a closer look at the gobetween, my guess is I have something shorted or screwy in that section which pulled too much current causing the caps to heat and bulge???  Dunno, I can't find a schematic for the powerstation.

The thing still works, both +24V rails look good, and the +48V is still kicking out voltage.
Obviously both caps need to be replaced, but before I cook another 2 I'm going to need to investigate a little closer.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 14, 2011, 03:34:13 AM
Ok I talked to Joe last night....
Powerstation and ACDC schematics are available on jlm website in powerstation / ACDC build thread section (2 PDF files at the top of the thread) hope that will help you to find the solution...
 ;)

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 14, 2011, 03:19:47 PM
 :o

forgot to install the jumper for the tripler.... 

Have since replaced the 'pump-charge' caps C1 and C2, installed the tripler jumper, set the potentiometer to see +48V.

No more hum on any channel while phantom is engaged.   8)  and now my phantom voltage is a true +48V

I'll chalk up the LED that popped to poor ESD protection (plastic baggies are a BIG no no)

Sounds like creamy butter, if that's an appropriate adjective.  ;D

Thanks you guys for your help!!  Now for this next 4.

Sylvain you and Martin and Desol are INSANE with your 8 channel units   ;)

Sylvain were you able to track down the issue?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 14, 2011, 06:19:07 PM
Yeah !!! The 47R was dead... Even if it looked perfect....
I finished my second 8 channel rack. As I sold the first one to a friend who was finally lazy to build it, I changed a bit the front panel... Will post some pictures again soon... Before starting my third rack (I won't stop before having at least 16 ch ;)

best
Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 14, 2011, 09:06:56 PM
Sylvain you and Martin and Desol are INSANE with your 8 channel units   ;)

I'll take that as a compliment. :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: California Road on July 15, 2011, 06:16:06 PM
Hey guys.  I am trying to finish up 2 channels right now, and am having issues with phantom power.  I have gone through this thread many times, but I still have no luck.  I am using JLM go betweens and the acdc power supply.  The pre functions fine with a dynamic mic, but I cannot power a condenser. 

I get +24 and +48 from the acdc, and I get 11 ohms(?) between 0v and chassis ground.  I can post some pics if that is helpful. 

This is my first mic pre build, and I'm not sure where to go from here so any help will be great.

Thanks,

Josh
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 15, 2011, 06:27:47 PM
Did you check voltage on mic xlr ? Do you find your 48v there ?
If not, it's maybe a wrong wiring somewhere maybe....
Yes pictures would be helpful ofc ;)
best

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: California Road on July 15, 2011, 06:50:14 PM
Did you check voltage on mic xlr ? Do you find your 48v there ?
If not, it's maybe a wrong wiring somewhere maybe....
Yes pictures would be helpful ofc ;)
best

Sylvain

I cannot get 48v at the xlr.  With all this talk about grounding I think that is where my error is.  But I'm not sure.  I will post some pics later tonight.  Thanks for the help!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 15, 2011, 07:41:35 PM
Did you check voltage on mic xlr ? Do you find your 48v there ?
If not, it's maybe a wrong wiring somewhere maybe....
Yes pictures would be helpful ofc ;)
best

Sylvain

I cannot get 48v at the xlr.  With all this talk about grounding I think that is where my error is.  But I'm not sure.  I will post some pics later tonight.  Thanks for the help!

With a DMM start at the XLR and work backwards towards the +48V terminal on the ACDC.  It's a short path and should be fairly simple to find where the voltage is getting lost.  Check to be sure all the correct components are in the correct designation on the gobetween.  Check that you have the two jumpers in the correct positions on the gobetween.  Are you using an LED, and if so does it light with the switch on?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: California Road on July 16, 2011, 10:24:23 AM
Did you check voltage on mic xlr ? Do you find your 48v there ?
If not, it's maybe a wrong wiring somewhere maybe....
Yes pictures would be helpful ofc ;)
best

Sylvain

I cannot get 48v at the xlr.  With all this talk about grounding I think that is where my error is.  But I'm not sure.  I will post some pics later tonight.  Thanks for the help!

With a DMM start at the XLR and work backwards towards the +48V terminal on the ACDC.  It's a short path and should be fairly simple to find where the voltage is getting lost.  Check to be sure all the correct components are in the correct designation on the gobetween.  Check that you have the two jumpers in the correct positions on the gobetween.  Are you using an LED, and if so does it light with the switch on?

I do have an LED attached, and it does light when the switch is on.  I went through the path with the DMM and I have 48v unitl the go between.  When the switch is on I dont hav 48V to + or - on the terminal block to the input xlr.

I have attached a few pics of the case layout and one of the go betweens.

Thanks again,

Josh
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: California Road on July 16, 2011, 10:24:56 AM
and the go between....
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 16, 2011, 12:18:16 PM
Verify that you have +48V at the terminal on the gobetween, the one with the green wire.  If yes, shut off the phantom and just double check that you have good continuity from all three pins of the input XLR, Pin 1 to shield or 0V, pin 3 to -, pin 2 to plus.  Check for any short between any of the 3 pins of the XLR.  Be very sure that your pin 2 pin 3 wire whether if red or blue are correlating with the correct terminals.  It looks like on one side of the JLM you have red as +? and the out side of the JLM red looks to be on the - side??

If this checks good, go over again with a detailed visual inspection for poor/cold solder joints, solder bridge etc.  If no joy, reflow solder joints.  It looks like the electrolytic cap negative leg is towards the smiley which is correct. 


Looking at the furthest to the right, output XLR, you have a red wire (which is typically audio + or hot) terminated to pin 3.  (though I think this is unrelated to your phantom issue)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 16, 2011, 02:11:23 PM
Finally remembered to bring my DMM to the studio and was able to verify the Vintech PSU voltages/pinout.    ;)

1: circuit common/ground
2: Open
3: +24V  (each measured roughly 24.2V)
4: +48V  (each measured roughly 48.5V)

I had +24V on pin 2 vs pin 3.   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: danchez on July 16, 2011, 04:22:42 PM
I've successfully completed 2/8 of my 1073's, very exciting for my first project and these pre's really sound AMAZING. I had a few hurdles along the way (backward caps and a resolder on the input tranny) but for the most part, this ongoing project has gone very smoothly. The power supply was a fun one, the secondary lead of the toroidal met with the 47ohm 1watt next to the terminal blocks, that smell lingered for a few days..... thankfully it only damaged one of the neighboring diodes and replacement of that and the resistor restored phantom power!

Pics coming soon! Thanks for everyone's help and expertise, although I've never posted here before, I've been using a lot of posts from this thread to learn and troubleshoot, so thank you.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: California Road on July 19, 2011, 08:16:50 AM
Verify that you have +48V at the terminal on the gobetween, the one with the green wire.  If yes, shut off the phantom and just double check that you have good continuity from all three pins of the input XLR, Pin 1 to shield or 0V, pin 3 to -, pin 2 to plus.  Check for any short between any of the 3 pins of the XLR.  Be very sure that your pin 2 pin 3 wire whether if red or blue are correlating with the correct terminals.  It looks like on one side of the JLM you have red as +? and the out side of the JLM red looks to be on the - side??

If this checks good, go over again with a detailed visual inspection for poor/cold solder joints, solder bridge etc.  If no joy, reflow solder joints.  It looks like the electrolytic cap negative leg is towards the smiley which is correct. 


Looking at the furthest to the right, output XLR, you have a red wire (which is typically audio + or hot) terminated to pin 3.  (though I think this is unrelated to your phantom issue)

I decided to do a double check of my wiring again, and founf a major issue at the input transformer that solved the phantom issue.  I was shorting pin 2 to ground.  Not sure how I missed that.  But now I am getting a very distorted signal on both channels with phantom engaged, and a perfectly clean signal with phantom dis-engaged.  I have not had a chance to troubleshoot this issue very much, but figured I would throw it out there in case anyone had come across it before.

SOLVED!  Another small wiring issue.  Measure twice cut once right?!  Cant wait to get these in on a session.  Ill post pics when my front panel gets here.

Josh
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on July 19, 2011, 11:21:51 AM
Hi guys,

plugging my EZ1290 straight into my work station seems to dull the output of the ez1290. makes it sound closed as opposed to open. is this an output impedance problem endemic with the design of the ez1290? The original pre was often coupled with a neve eq. This would change the output impedance.The output impedance of the ez1290 is 600ohms? right? But the input impedance of the typical DAW is 10k right? Is there anyway of changing the output impedance of the ez1290? How is this done? Does anyone know what i'm talking about?

regards

michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dmp on July 19, 2011, 11:29:47 AM
Quote
plugging my EZ1290 straight into my work station seems to dull the output of the ez1290. makes it sound closed as opposed to open. is this an output impedance problem endemic with the design of the ez1290? The original pre was often coupled with a neve eq. This would change the output impedance.The output impedance of the ez1290 is 600ohms? right? But the input impedance of the typical DAW is 10k right? Is there anyway of changing the output impedance of the ez1290? How is this done? Does anyone know what i'm talking about?
If you check the schematics I believe the EQ section was inserted before the final output stage in the 1073, etc.  so the final output isn't any different.
My pair of ez1290s do not sound closed when plugged into my soundcard, which have balanced 10kohm inputs.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 21, 2011, 10:58:23 AM
Hi there...
Short question....
is it normal for you.... to have up to 0.8 dB difference between 2 board with a 1kHz signal at same gain settings...  ?
i mean, i don't think i have to worry about this cause it only means that gain resistors maybe don't have the same value.....  but... i was wondering...
Thx

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 21, 2011, 12:02:48 PM
Hi there...
Short question....
is it normal for you.... to have up to 0.8 dB difference between 2 board with a 1kHz signal at same gain settings...  ?
i mean, i don't think i have to worry about this cause it only means that gain resistors maybe don't have the same value.....  but... i was wondering...
Thx

Sylvain

I would expect some variance.  Even with 1% metal films, hand selected, there's going to be some deviation from one unit to the next.  What prompted you to measure, could you hear a difference or did you measure just to see? 

I have only compared one to the next by ear, and they sounded to me to be all reasonably equal.

Comparing them to the X73i, there is definitely tonal/timbre differences, both are in the same ball park.  The level is much hotter on the EZ1290 than the X73i with switch at the correlating gain setting.  I.E. with both pres at 25dB the EZ is hotter.   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 21, 2011, 12:32:57 PM
u can hardly hear the difference... but as i said, it's still 0.8 dB is the highest difference i have between the smallest and biggest level (channel 2 / channel 7)
u can see a little difference on recorded waveform and i measured the difference it in a protools plug.
Of course it's a 1 kHz sine and it's harder to feel the difference with a regular sound... but if it's a normal thing, i don't care and will let it to lives its life  :P )

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 21, 2011, 04:30:04 PM
Just fired up my dual 1290´s for the first time.. no smoke, no fire, no fuses blown! For me that means an improvement over the last time I switched on a DIY device. The external power supply is working fine, all the right voltages on the right pins.

I have done a small pre-listen, channel one is completely dead, channel two is working but distorted, but I can't really say something untill I have the correct cables (My mixer's xlr inputs are mic only, and I can't feed my osc. into the mic input, have to use the jack on front (go between with fet di). But, step by step, let's solder some cables!

I have bought a small Jyetech diy oscilloscope, so Iam ready for biassing. However, I have no clue where to measure the sound for biassing. is it at the output of the board or at the output of the complete pre amp?

Cheers

Erik
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 21, 2011, 05:34:53 PM
erikb1971, yo if you are impatient and want to try to 'bias' them in the short term, just measure the Voltage on the case of the 2n3055 reference to 0V on the 1290PCB.

Dial this in via the trim pot to show 22.66ish and the pres will work (so long as everything else is working/wired proper), when you get your scope you can fine tune the trimmer.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 04:59:57 AM
erikb1971, yo if you are impatient and want to try to 'bias' them in the short term, just measure the Voltage on the case of the 2n3055 reference to 0V on the 1290PCB.

Dial this in via the trim pot to show 22.66ish and the pres will work (so long as everything else is working/wired proper), when you get your scope you can fine tune the trimmer.

Thank you for your reply! I can't get the voltage higher than 19.97 or so.. if I dial in more, the meter goes to 1...
I can't get the V higher then 21,6. If I dial in more, i hear a soft metalic click in the trim pot and the v does not go up anymore...

***edit*** without a 1k sinus wave into it, I can get it at 22.6v. If I plg in the siniswave, it drops to 20.6
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 08:40:33 AM
Hi all

Just to be sure.. where do I check the waveform on attached picture? A, B or C?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 22, 2011, 09:11:42 AM
personally i'm doing it on C point...     but.... personally...    ;)

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 09:23:46 AM
And with the same settings on your oscilloscope as you got the sinuswave at input?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 22, 2011, 09:27:41 AM
I think you won't have same signal level at the O/P point and at the I/P point...  hopefully cause if they were the same.... i would have build 16 channel for nothing  :P
so your Oscillo settings may vary... just adapt the sensibility to the signal level...
Follow the martin's instructions in assembly pdf file to set the bias...
It's really useful....

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 09:32:00 AM
oowww.... that was a stupid question! Do we have a thread somewhere for those? :-)

This is all that was said in martins assembly guide about biassing right:

After you’ve hooked everything up you’ll need to set the bias of
the driver stage. Do this by setting the gain switch to full gain (75dB)
and then running a 1K sine wave into the mic input until clipping.
(It’s ok if you actually hear the mic pre at this point)
Look at the signal with an oscilloscope. More than likely the waveform
is only clipping on one side.
Adjust the trimpot until clipping is equal on both sides of the waveform.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 22, 2011, 09:37:06 AM
this is normally all what u need... set the gain at max... plug your oscillo and send a 1kHz sine wave in the preamp... (adjusting the wave volume with the signal generator u use...  up to the signal to be clipping...  just a bit...)  and then turn the trimpot to have something looking like the draw on the pdf.   When i do this... i use the voltmeter to check V on TR3 too.... in the same time...

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 10:12:55 AM
aaahhhhh now it starts to make sense... would this be a sort of reasonable waveform?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 22, 2011, 10:16:38 AM
mmmmmmm it's clipping on bottom right ???
if yes u can maybe push the volume a bit more...   and then it's ok....  u can turn yout trim pot to have the same clipping on bottom and on top ...

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 10:31:08 AM
Ha! I had the same waveform when I unplugged the oscillator... can't be good :-) I think I have it figured out though, but have to wait for the cables to see how it sounds...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 22, 2011, 10:35:13 AM
Ha! I had the same waveform when I unplugged the oscillator... can't be good :-)

Didn't get it.....

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 22, 2011, 10:45:32 AM
when i pulled the plug of the oscilator out of the input, nothing changed on the oscillator...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 22, 2011, 11:00:58 AM
Are your preamps going into oscillation?  Mine were oscillating at the highest gain positions, and these oscillations were not letting me set bias with gain at max.

I had to dial in the trim pot at lower gain settings (if I remember correctly, there were some late nights.)

With no input signal, and gain at 20, what Voltage do you see on the shell of your 2N3055?

Stick a microphone to the input and monitor output at low levels (protect your ears), if you have audio, start to increase the gain.  See if you are passing audio or if your pres go into oscillation?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 23, 2011, 05:17:25 AM
Are your preamps going into oscillation?
No



With no input signal, and gain at 20, what Voltage do you see on the shell of your 2N3055?
22,6V

Stick a microphone to the input and monitor output at low levels (protect your ears), if you have audio, start to increase the gain.  See if you are passing audio or if your pres go into oscillation?
I have audio, but it is distorted at low gain.... and it seems to distort more at higher gains... But it could be my soundcraft compact 4 mixing console, because I do not yet have the cables to plug the pre amp in as line input, so they are in the mic input right now... but defenitely at low gain I get distortion from the pre amp!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 23, 2011, 05:20:21 AM
I have audio, but it is distorted at low gain....

I had this once when i mistook on a res...  did u double check the components value ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 23, 2011, 05:37:19 AM
can I check them while on the pcb?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 23, 2011, 05:50:45 AM
At Least with color codes.... Are your 2 boards reacting the same ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 23, 2011, 05:53:07 AM
nope, the other board is completely dead :-)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 23, 2011, 06:01:04 AM
Mmmmmmm was near to ask you to compare your board with the other to check the difference.... But it's maybe not a good idea anymore then...
All your transistor voltages are ok ?
Sylvain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 23, 2011, 10:23:29 AM
On my mixer I have to have the gain all the way down, and then I can run the out from the 1290 into any mic input and use the 1290 as a supplemental preamp for the console.  Is the gain on your soundcraft all the way down? 

Take some clear pictures and post them up here.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 23, 2011, 12:49:11 PM
OK.
I made the right balanced output cable, and the clipping is not from my mixer.
I checked the transistor voltages from the document. 1,2 and 3 are exactly the same values as the document, but 4,5 and 6 are a mess:

TR4 C=1,4 B=0,6 E=0,1

TR5 C=0,9 B=1,5 E=0,8

TR6 C=23,5 B=0,9 E=0,3

So there seems to something eehhh wrong :-) But what?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 23, 2011, 01:40:36 PM
It looks like tr 456 designations are used twice...

Rule out basic problems with visual inspection.

Did bending the heatsink leads cause them to short to a capacitor?

Are any of your tr legs shorting against anything or themselves?  Check the 2N3055 as well for any shorts between EBC.

On your picture on the previous page, at designation 7 and 10/shield you noted 'perfect sinus'.  Can you verify that you have a good looking waveform at this point?   

Compare the section of the preamp that is showing good/correct trVoltages with the section that is a mess.  Part by part verify they are correlating. 

Can you remove the bottom of the chassis for a visual inspection of the solderside of the pcb?


try a macro function or a photographer's loupe to bring the components into view more clearly
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 23, 2011, 02:52:17 PM
It looks like tr 456 designations are used twice...
They are, as in M. adriaanse's pdf on page one of this thread.


Rule out basic problems with visual inspection.

Did bending the heatsink leads cause them to short to a capacitor?

can it short circuit when it is touching the house of the capacitor (not the legs?)

Are any of your tr legs shorting against anything or themselves? 

They are not shortening against themselves, but eg both tr5's are touching the 22u/16v caps next to them.. where can i find out if they are supposed to be connected?>

Check the 2N3055 as well for any shorts between EBC.
no shorts

On your picture on the previous page, at designation 7 and 10/shield you noted 'perfect sinus'.  Can you verify that you have a good looking waveform at this point?   
confirmed, signal is coming in exactly as it is leaving the oscillator

Compare the section of the preamp that is showing good/correct trVoltages with the section that is a mess.  Part by part verify they are correlating. 

working on that

Can you remove the bottom of the chassis for a visual inspection of the solderside of the pcb?


try a macro function or a photographer's loupe to bring the components into view more clearly
attached
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 23, 2011, 03:03:14 PM
OhI finally understand the schematics in the building instructions, can check connections there...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 23, 2011, 06:03:21 PM
Quote
can it short circuit when it is touching the house of the capacitor (not the legs?)

The same 22.6V is on the heatsink I believe, though it may not be your problem.

Quote
confirmed, signal is coming in exactly as it is leaving the oscillator

With the same reference, follow the audio with your scope looking for where it goes funky.  The schematic should help with the path to follow.

Poke around visually on the solder side and reflow any joints that look cold or messy.  If you can't see solder coming up on the top/component side via, reflow until the via is at least 50% filled.

Too much heat may piss off the transistors, any chance you cooked them when populating? 

I'm curious do you see a happy sine wave at the input pads 7/10 on the channel that is totally dead?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 24, 2011, 05:41:01 AM
I just  found out that my go between was the problem on the totally dead channel. I placed the working go between on the dead channel, and now it is working, but with exactly the same problems as the first channel. With exactly the same values on TR4-6. That would mean the error is either not on the pcb's or exactly the same on both pcb's. And that makes an accidental sloppy solderjoint less likely right? Iam going to bypass the go between alltogether on one channel and see what happens. My guess right now is that I have used a wrong value component somewhere on both boards... If anyone has a clue of where that might be accoding to the results described ealier, input is very welcome!

cheers!

Erik

***edit*** Bypassing the go-between results in exactly the same results: distortion in the pre amp and the wrong TR4-6 values ***edit***
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 24, 2011, 07:20:01 AM
So u clearly mistook somewhere on the board and made this mistake twice....
I don't think it's a dead part cause having 2 same part having same pb....
Are u sure of your resistor and cap polarity for ex ?
Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 24, 2011, 08:26:51 AM
My thoughts exactly...

I checked all pol's (resistors don't have pol. right?) and that seems to be fine.

Iam working with my oscilloscope now... but maybe I do not know enough of it to do it right. What Iam doing is:

1. put 1k sinus on input.
2. measure 10-7 on board (green lines), result: fine sinus).
3. measure tant cap a (blue lines),  result: fine sinus).
4. measure tant cap b (pink lines), result: bad bad sinus!


So I fugured: somewhere in the middle BA138V is something wrong. So I checked for components that had a nice sinus one one side and a mess on the other and I found C16. So my idea would be: something wrong with C16 (white lines on pic), am I correct?

Cheers

***edit*** changed C16 with one from the other board and still no good... ***
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 24, 2011, 10:44:48 AM
Don't hate me for this, but it may (or may not) prove beneficial to isolate the preamp section from the gobetween altogether.

Set it up so your XLR in hits the carnhill straight to the pcb back to the output carnhill and XLR out.

Take a quick listen for distortions, if distortion is present, we have ruled out the gobetween, if you have no distortions then the gobetween is suspect.

For the same problem to be shared between both boards, either there is a common error in the wiring configuration.  You ruled your dead pcb to actually be passing similar audio when you swapped gobetweens.  I would omit the gobetween altogether and go from there.  Look at it this way, if you ever need to service these pres in the future, you will be a master at assembly.

All of the jumpers are terminated to the correct pins on the in/out transformer, and the cap/series resistor are in the correct spots? 

 
 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 24, 2011, 11:12:49 AM
I have disconnected the go between, and still distortion. All the connections to the transformers are as they should be. BUT.... I think I seem to remember that the input transformes should be connected to the case... so they would be grounded. Mine ae connected to the case, but because of the paint, they do not make contact with the metal of the case... could that be the souce of the poblems?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 24, 2011, 11:15:40 AM
For me transformers has to be linked to the ground ... so to the case...

Sylvain

AHA!

***edit*** linked the input transformes to ground, but still distotion and still v measurements at tr3-6
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 25, 2011, 06:38:11 AM
****FIXED!!!!****

My dad is the Sherlock Holmes of PCB's! Turned out I mixed up the 51K and the 5k1 resistors.... Thank you for helping!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 25, 2011, 08:44:14 AM
I WOOOOOONNNN   ;)
lol

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 25, 2011, 09:01:22 AM
comon say it: I told you so... I deserve it!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 25, 2011, 10:32:14 AM
There is just one word for the sound... SWEET...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 25, 2011, 12:05:38 PM
Glad to hear it was an easy fix.

>90% of manufacturing failures are found (or can be found) during a thorough visual inspection.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on July 25, 2011, 02:45:53 PM
yes but.....  woow... a 51K / 5K1 mistake may have been hard to find...  as it's hard to read it since resistor are hiding it...
really...  good job !!

glad also that u fixed that..

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on July 25, 2011, 06:27:55 PM
Has anybody noticed that the 2K2 and the 1K8 resistors from the bom aren´t sold anymore. Maybe i´m stupid but i don´t find them. I choose the 261-1.8k-rc. Hope that they are ok.

Cheers Martin
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on July 25, 2011, 07:35:38 PM
I used 1/4W 1% metal films for both of those designation.  The 1.8K you listed is a 1 watt 5% metal oxide.

Let me know if you need I order in big batches so I have extras.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on July 25, 2011, 07:54:16 PM
Thanks.

Have not realized that they are metal oxide.

I think it´s cheaper when i just go to my local store an buy them there. But thanks very much for offering.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 27, 2011, 04:19:25 AM
Is there anyone who could help me get one:

C16   23PS210   Capacitor Polystyrene 1010p

I broke mine while trouble shooting, and just can get them at mouser with 20euro delivery costs for a 0,22 euro capacitor...


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: letterbeacon on July 27, 2011, 06:12:03 AM
How about here: http://www.banzaimusic.com/Styroflex/
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on July 27, 2011, 06:26:57 AM
super! tnx!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: justanalogue on August 09, 2011, 01:40:39 PM
Finished my 4 channel EZ 1290 a couple of weeks ago, worked flawless the first time I powered it up!
Many thanks to M Adriaanse, Frank for engraving and all inspiring builds here.

Recalibrated the PSU and 1 channel today, made some pictures.

Willem.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: justanalogue on August 09, 2011, 01:42:08 PM
And the PSU
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: justanalogue on August 09, 2011, 01:42:52 PM
With some good companions.....
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Neily on August 09, 2011, 02:58:57 PM
DUDE! That looks amazing! I really like how you lined up the transformers... I wanna do mine like that. No noise issues?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: justanalogue on August 09, 2011, 03:04:27 PM
Thanks!
No problems at all, massive amount of gain and no hiss, buzz or other noises.
Just follow the excellent instructions of M Adriaanse and it will work.

Willem.

DUDE! That looks amazing! I really like how you lined up the transformers... I wanna do mine like that. No noise issues?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Jazzboms on August 15, 2011, 09:55:01 AM
Hi

I just put my 2 1290 in a 2 unit rack unit, and I have a strange problem.
All preamps worked as they should before i put it in the box.
Here is the thing. After I put them in the box they sound thin and noisy. All of then have the same sound character. Im almost sure this is a grounding issue, and I searched around with a clip - ground. And I put a wire from pin 6/7 on output trafo to ground, and they sound great. Loud and clear, no noise. This is not like the application guide, and I can figure it out.
The box is aluminium.
The power trafo is a 25VA/30V toroidal, and the power supply is a  1176 supply adjusted to 24V, with no phantom.
The 10ohm ground measuring is right.
I have followed the application guide, with plastic stand offs, shielded audio wires, all measuring on the transistors are right, and im as sure as I can get that the components and wiring is right.

Thanks for reading.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: fd10 on August 20, 2011, 12:27:20 PM
Hello,

I`m new here, i want to build a 1290 preamp and had some questions???

@ first can i got with the CA-18-VTB1148 - Transformer: Audio Output (Narrow Board Version)

and i want to make my 1290 without anything, so i don`t wan`t some +48v, DI, phase or so only mic input output and a gainknob!!!

my questions are when i don`t need all these what is the best intern PSU for me???

go somebody with intern PSU???? is this good

and my other qustions are i can buy the bc/vishay, grayhill switch, carnhill`s from audiomaintenance.uk

what is with the other things and from wich trade are the best components i ask for polystrene caps tantalums BC184C, resitors.....

so thats it and good day ur all!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on August 20, 2011, 03:33:03 PM
Hi FD 10

As you can read in this thread, there's a lot of people have build the 1290 with the psu in the box, adn a lot of people have build it with an external psu. I think in general everyone agrees that building an external psu is the best way to avoid problems, and especially if it is your first build, do yourself a favour and build the psu externally.
Internally or externally, with or without al extras the JLM ACDC is a good choice, recommended by M. Adriaanse himself. Also affordable and well documented. You can't really go wrong with that.
Regarding your question of where to buy what, Iam pretty sure there is a bill of materials somewhere in the first pages of this thread completely with order numbers from mouser and so on, could not be easier!
Good luck with a great project!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kquick on August 20, 2011, 06:14:00 PM
Finished my 4 channel EZ 1290 a couple of weeks ago, worked flawless the first time I powered it up!
Many thanks to M Adriaanse, Frank for engraving and all inspiring builds here.

Recalibrated the PSU and 1 channel today, made some pictures.

Willem.

justanalogue
    Nice job!  :) :) :)  Did you use just one PSU to power all 4 channels and if so have you had any issue's?  And were did you get those heat sinks if you don't mind my asking? I am just building my PSU now and I thought I was going to have to build two for four channels.

Cheers
Kim
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: fd10 on August 22, 2011, 03:21:28 AM
Hello,

i won`t to know can i go with this PSU board????

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=14
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on August 22, 2011, 08:46:30 AM
Hello,

i won`t to know can i go with this PSU board????

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=14

Should be fine to power a 1290 or two.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on August 23, 2011, 12:13:20 AM
T-rex is fine for 2 channels max nothing else, no active dis neither!
i did tried it and didnt work fine!
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on August 25, 2011, 06:40:19 PM
Hey guys so I just got my first channel up and running, the only issue I'm having is with phantom power. I'm using the JLM go-betweens with DIs and when I first tested my PSU I was gettin around +46V now I connected 2 LEDs to the 48V rail (with a 2k current limiting resistor) and 1 JLM go between with it's DI. Now the phantom power is sagging way down to +30 sometimes +28V and the the relays on the DI is starting to not function properly, why is it going down so much? I'm using a SSL9K PSU board with a 50VA 25-0-25 Antek transformer
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on August 26, 2011, 05:40:35 AM
Hi,

i'm right now in my planing phase for builing [email protected]
There're 2 things i'm currently not 100% shure about which direction to go,
so i like to ask you guys of your experience directly (after reading the post here :) ).

#1: GoBetween
How are the experience around here? A MUST, nice to have, never really used it?
(Btw. it's a great kit, which i use a lot)

#2: Trimming Pot
How are the experience around here? A MUST, nice to have, never really used it?

Thanks!
 ROCK ON!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on August 26, 2011, 05:50:06 AM
for go between i would say: go for it with di... I love this combi on bass!

Trim: I do not miss it all!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on August 26, 2011, 08:10:31 AM
Let me just say trim is not necessary, although with having the trim, I can dial in some pretty neat sounding gain staging.

 i.e. max/75dB gain with trim pulled all the way down MD441/RE20 sound great with this (condensers not so much). 

Slowly bring the trim up to allow some signal to pass.  The timbre has a very nice texture and is another flavor in addition to the clean gain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: justanalogue on August 27, 2011, 12:29:56 PM
Hi Kim,

heat sinks are made from a bigger heat sink that I salvaged out of a glass ceramic stove.
Till now no problem with 1 power supply, although the aluminum box gets warm..

Kind regards,

Willem.

Finished my 4 channel EZ 1290 a couple of weeks ago, worked flawless the first time I powered it up!
Many thanks to M Adriaanse, Frank for engraving and all inspiring builds here.

Recalibrated the PSU and 1 channel today, made some pictures.

Willem.

justanalogue
    Nice job!  :) :) :)  Did you use just one PSU to power all 4 channels and if so have you had any issue's?  And were did you get those heat sinks if you don't mind my asking? I am just building my PSU now and I thought I was going to have to build two for four channels.

Cheers
Kim
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on August 27, 2011, 03:41:31 PM
Anyone has ideas/advice for my sagging +48V rail? Am I drawing too much on it?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on August 27, 2011, 09:05:03 PM
So while I wait to figure out my phantom power problem, I tested all the channels without the FET DIs (which are what's killing the +48V) and they all sound great except channel 1 which is making sound but has much lower gain and makes a nasty distorted sound when given a louder signal.

- The gain changes with the switch but is way lower than the other 3 channels.
- I jumped from the out of the input transformer to the input of channel 2 and it works and sounds fine.
- I jumped from the in of the output transformer on channel 2 to the output of channel 1 and the gain was still low.

So this means my problem lies within my channel 1 board right? any helpful advice on where to be looking?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 28, 2011, 12:59:42 AM
Maybe the output section? A scope would be good...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on August 29, 2011, 10:33:50 PM
It may be, unfortunately I don't have a scope available :(

I did some more testing and visual checking. For sure it's not the transformers, I used the broken channel's transformers on a working channel and visa-versa, broken channel still sounded bad and the working channel was fine.

I visually checked the whole board, reflowed a few spots but same problem.

So I checked the transistor voltages and I have some big problems:
TR12.87.88.35
TR222.62.872.3
TR322.62.31.67
TR43.72.361.7
TR516.621716.6
TR620.316.615.97

So some serious off voltages. BUT

More visual inspection (made easy by having a working channel next to the broken one) and of course there's a 1.1K instead of a 470R. Switched that out and the world is at peace! Sometimes it helps to work and write methodically :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 30, 2011, 01:09:14 AM
Nice. Good find!
Title: EMI/EMF a problem for anyone?
Post by: MicDaddy on August 30, 2011, 12:01:37 PM
See attached a small rig I put together for location recording.

I'm finding that my 1290s are extremely sensitive to outside electromagnetic field/interference.

Both the PSU for the 1290s as well as the 1176 pictured are interfering with the preamps. 

Perhaps I need to rack the pres only with other pres and no transformers.  Then isolate the powersupply and all other units (with iron) to a separate rack away from the preamps.

With 1' of distance, from either piece of kit, relative to the pres, the hum is gone and everything sounds great.

Perhaps it is crap/poor-quality cable I'm using to patch 1290s to the interface?  Just thinking out loud.

Has anyone else had issues with hum or buzz racking next to transformers?




Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on August 30, 2011, 05:25:04 PM
So since I don't have easy access to a scope, have you guys found adjusting the trimmer to measure 22.66V on the case of TR3 is close enough or do I really need to find a place/time to bias it correctly?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 30, 2011, 05:46:16 PM
Mic daddy -  i've had issues with external interference on my 4 channels with backwards 31267's. The toroid from my api rack(directly above the neve rack) induces hum into just those 4 channels of the eight...so in my case it's a slight issue for those channels at the inputs. I'm thinking of wrapping the 31267's in mu foil/sheilding.

Ben - With scope, my channels seemed about right at 22.8 volts...at 22.6 volts, the wave was still slightly asymmetrical.
I'm thinking there are slight differences in builds due to component choices, etc.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: band_master on August 30, 2011, 10:19:25 PM
hey guys,
getting ready to wrap up my build and start testing...where have you guys been sourcing out knobs? i can find a lot of 1/4" options, but i also have an 1/8" shaft for output a la the collective cases enclosure...having a hard time finding a knob for those.

cheers,
BD
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: band_master on August 31, 2011, 02:39:46 AM
quick word of warning to anyone using the V4 JLM AC/DC power supply. there is a "neve mod" printed on the underside of the PCB...if using the toroidal in the bom IGNORE these instructions and build according to martin's excellent assembly guide. trust me I learned the hard way!

:-)

BD
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on August 31, 2011, 05:00:11 AM
is anyone using metal standoffs for pcbs? I cant find any non conductive solution and I dont want too mailorder it [unless i'll have to...]
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on August 31, 2011, 08:01:11 AM
is anyone using metal standoffs for pcbs? I cant find any non conductive solution and I dont want too mailorder it [unless i'll have to...]

I used steel machine screws and lock nuts for standoffs.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on September 01, 2011, 08:29:06 PM
with bias I cant seem to make it past 22.4v, any idea? power supple works correctly. and using daw as oscilloscope. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on September 01, 2011, 10:18:38 PM
When you measure with a DMM between +24V and 0 do you get 24V?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on September 02, 2011, 06:04:19 AM
yes. exactly 24v.
now I see I measured case to ground instead of power supply 0v, is that it? but still waveform in daw isn't even close to equal clipping
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on September 02, 2011, 06:33:04 AM
are you turning the gain of the channel all the way or almost all the way up?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on September 02, 2011, 07:54:51 AM
all the way, I can get it to 22.6 with many many turns but then it comes back to 22.4 as it seem max i can get. Its like that on both of my channels. maybe its problem with how transistor is mounted but then I shouldn't get any voltage instead of slightly to low, right? 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on September 03, 2011, 01:52:13 PM
ok you were right, I have 22.6 after readjusting power supply. one channel working, but another have really low gain with transistor voltages different than working channel. input transformer and wiring is ok. 2n3055 is ok. checked all the components except polystyrene that have marking anther them, can it be something elst? there are no shortings and I've reheated all the wiring joints
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: benlindell on September 03, 2011, 06:02:30 PM
ok you were right, I have 22.6 after readjusting power supply. one channel working, but another have really low gain with transistor voltages different than working channel. input transformer and wiring is ok. 2n3055 is ok. checked all the components except polystyrene that have marking anther them, can it be something elst? there are no shortings and I've reheated all the wiring joints

I had the same problem, ended up being an incorrect resistor, triple check compared to the working channel and check all the caps, especially their orientation.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sgenevay on September 12, 2011, 09:10:10 AM
Hey MicDaddy !!!  

i just wanted to ask you something about your  Neze 1290-4 Rack front panel ....

What color did u use exactly ? cause it's not looking the same on all pictures u have post...     is it a RAL color ? or anything else ?

Thx for your answer.
Best.

Sylvain
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on September 12, 2011, 10:28:55 AM
You'd have to ask dandeurloo about that, as the cases are the ones he sells in the WhiteMarket.

They are real nice and worked perfectly.

I too would like to know which RAL color it is so I can powder paint the front panel to the PSU chassis I made, right now it's black and I'd like it to match.  I just haven't gotten around to shoot an email asking.

Sorry I couldn't be more help.

 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on September 12, 2011, 02:55:45 PM
is anyone using metal standoffs for pcbs? I cant find any non conductive solution and I dont want too mailorder it [unless i'll have to...]

Using metal (conductive) standoffs is a bad idea for the EZ1290's. It will short the top left mounting hole (0V) to Case Ground, which is not the end of the world, but not a good idea either. For proper star grounding, low hum, low interference, use plastic or some other insulating standoffs. If everything's wired correctly there should be 10 Ohms resistance between the rack case and 0V on the EZ1290.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on September 12, 2011, 10:12:07 PM
I've reinterated this many times in the thread as well Martin...and even pointed out another reference from the designer of the power supply. Now i just leave it up to people to read, believe or disbelieve.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: zmgwg on September 14, 2011, 04:30:06 AM
is anyone using metal standoffs for pcbs? I cant find any non conductive solution and I dont want too mailorder it [unless i'll have to...]

Using metal (conductive) standoffs is a bad idea for the EZ1290's. It will short the top left mounting hole (0V) to Case Ground, which is not the end of the world, but not a good idea either. For proper star grounding, low hum, low interference, use plastic or some other insulating standoffs. If everything's wired correctly there should be 10 Ohms resistance between the rack case and 0V on the EZ1290.

M.
I came around it by installing standoffs [from the 2u build] to top cover and not the bottom and now it sits nicely in 1u.
there's something wrong at 91r in my not working channel, it shows 0 resistance compered to working channel and all the parts are the same and measure the same until that point. I guess I'll switch that resistor and see what happens
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: band_master on September 22, 2011, 03:29:56 PM
took my ez1290s for a test run the past couple nights at my studio...sounds incredibly excellent. thanks martin!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on September 22, 2011, 03:49:49 PM
Nice build band_master, where'd you find the knobs for the trim?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on September 29, 2011, 11:54:15 AM
I just wanted to reiterate the importance of the 'trim' function  (at least for my own personal uses)

Recently I sold my big heavy clunky analog mixer and opted for a single RU interface to handle the routing.

Using the EZ1290s on the front end, I don't miss the faders as I'm able to dial one extra step of gain than needed, and then fine dial with the trim.  It may not be necessary for every builder to incorporate, though personally I would be lost without it.

The 1290s sound so good. 

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 03, 2011, 10:52:29 AM
Was in a session last week and was using my dual EZ for drum overheads, and noticed that one of the channels was a bit "off" gain wise.  Besides the baising, is there any way to calibrate these things? 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on October 03, 2011, 06:38:56 PM
where i can find this boards?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on October 04, 2011, 11:50:05 AM
I have problems in the high frequencies, they are too low.
Attached is a picture from measuring a pink noise.
Output is measured at the output of logic´s test oscillator (Left analyzer). Input is measured from the soundcards input (Right analyzer)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 04, 2011, 02:36:13 PM
Could be a cap value issue somewhere in the signal chain? If you're sure you didn't mess up any values in the build...


I'm guessing since you're going in and out of the same card there's no clocking issue.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on October 04, 2011, 02:49:41 PM
1-Yes
2-I did
3-If I don`t go through the amp the curves are equal
4-If I don`t go through the amp the curves are equal
5-No
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 04, 2011, 03:13:30 PM
Im thinkin you may have to look at the board then and verify that all the caps that are in the signal path are the right values. 
Might want to check to see if the cap on the output TX is right first and work back from there.
When I get in the studio tonight, ill do the same test using the PAS analyzer and post my results so you have a comparison of sorts.  I would expect SOME coloration, but nothing to that degree.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on October 05, 2011, 04:02:34 AM
I will do this today, but I need a pic of the bare PCB to check the values.
The cap on the output TX is 10nF.
Also I forgot to mention that my other preamp (1272 hotrodmod) doesnt have this rolloff, also I dont use a Di box, The EZ 1290 is directly connected with my soundcard...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on October 05, 2011, 06:19:18 AM
Ok, I think I found the mistake, instead of a 180pF cap on the input transformer a 39nF found its a way onto the board  ::)
I have no idea how this was possible!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on October 05, 2011, 01:25:25 PM
hi team,

using the recommended carnhill iron, is there a diy method for changing the stock impedance of the input xformer from 1200 ohms to 300ohms, so that i can use say a ribbon mic?

can someone point me i the right direction of this has already been covered?

regards and thanks in advance of any help

michael de a
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on October 06, 2011, 07:13:23 AM
Yes you can :)
I was actually thinking about something like this.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrcase on October 06, 2011, 07:42:09 AM
Hey all! do you know if martin is still offering these boards for sale? I dropped him an email but didn`t get a response...
cant wait to build those babys :-)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on October 06, 2011, 07:51:25 AM
bought mine a mounth ago, so yes, he's still on the market. be patient, you'll get an answer.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mrcase on October 06, 2011, 07:54:54 AM
good news! thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 07, 2011, 10:37:19 AM
Anyone thats built a 4ch version with the JLM powerstation, any suggestion for power Xformer? Im adding 4 JLM go betweens (which shouldnt really effect the draw i assume)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 07, 2011, 11:41:58 AM
I'm using this one for the JLM Powerstation and 8 EZ1290s with the JLM gobetweens

Avel Lindberg Y236351

Avel Lindberg Sales

800-979-1022, x 1, or fax 860-354-8597
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 07, 2011, 11:52:02 AM
Thanks :) ;D

I opted for the 6amp rectifier (i figured might as well get the most out of it) was this correct to do?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 07, 2011, 12:14:14 PM
Thanks :) ;D

I opted for the 6amp rectifier (i figured might as well get the most out of it) was this correct to do?

I did the same thing by recommendation from Joe and desol.

Don't do like me and forget the tripler jumper  :o  caused no harm but wasn't quite working right.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wimmy7986 on October 11, 2011, 07:44:25 PM
Hey Everyone!  I've got something weird happening....  On my ACDC power supply, I accidentally got the 337 and 317 backwards.  So i removed them, ordered new ones from mouser.com, put them in, powered up, and then my 47r 1W resistor on the PSU burned.  I figured that the regulators were probably shorting to the case, so i took the PSU out of the case, replaced the resistor, fired it up again, and then the same resistor burned up.  I triple checked for shorts and can't find any.  I should note that while I was waiting for the regulators to come in the mail, I used the one I had left and had my 24V rail working perfectly...  Anyone got any ideas??  Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Davo on October 11, 2011, 08:02:25 PM
how are you hooking up the psu to your boards?...... this is a +24v project, you shouldn't need a 337
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wimmy7986 on October 11, 2011, 08:08:08 PM
Thanks for the quick reply!!  I have followed the assembly instructions exactly as indicated on the first page.  For the 337, i threw it back on the board just because it came with the original ACDC package.  I know its for a negative rail, which is unused in this build.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Davo on October 11, 2011, 08:32:23 PM
Good, glad you're not feeding -24v anywhere.  As long as you're getting a steady 24v, that reg is good, so no need to replace. 
Take a look back at page 32 of this thread where something similar is discussed. 

If that doesn't help, you'll need to go through your build with a fine tooth comb, checking every single resistor value etc.

cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wimmy7986 on October 11, 2011, 08:46:45 PM
Thanks Davo!  I've read and searched all throughout this forum for this specific issue, and the common issue is with shorting to the case.  Even after I pulled the board out of the case and put a new resistor in there, it still burned up when i fired it up.  Could i have maybe gotten the incorrect LM317?  The one i ordered was a positive, adjustable, standard regulator that is adjustable up to 57V.  Also, the 47r resistor i replaced the first burnt one with was significantly smaller than the one included in the ACDC package, but was still a 47r 1W. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wimmy7986 on October 11, 2011, 08:48:59 PM
I should also point out that when I originally had the 317 and 337 mixed up, nothing was burning or smoking, I just had the wrong voltages...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Davo on October 12, 2011, 05:30:45 AM
Evilcat wrote this a few pages back: (pg 39)

If I remember correctly, the 47R 1W is a protection resistor for the phantom cicuit. Mine burned too when I accidently did a shortcut between +48V and another rail or ground, I don't remember...
Anyway, check your solderings, shortcuts in the phantom area. Hope it'll help. Good luck.

You got the right LM317, and those resistors come in a bunch of sizes, so I wouldn't worry too much about that.  If you're using a 24v xformer, make sure that your phantom jumper is set as
a doubler rather than a tripler.  In the past when I've mixed up regs, they're usually blown, so you may want to replace the phantom reg (??? the other may be fine, but I don't know)

cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wimmy7986 on October 12, 2011, 04:47:58 PM
FIgured it out!!!!  The 5k TrimPot on the 48V rail was toasted and not working.  When all else fails, rely on the multimeter :)  I stole the 5k pot from the negative rail, fired it up, and all is well!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Davo on October 12, 2011, 08:20:53 PM
Excellent, I knew you'd find it pretty easily

cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wimmy7986 on October 17, 2011, 04:04:47 PM
I've got an odd and slightly, well, really embarrassing question...  Has anybody had any experience removing the stop pins from the switches?  I accidentally put the pin in the wrong spot, and now i can't remove it.  Any help would be much appreciated :-)  Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 17, 2011, 04:11:43 PM
I've got an odd and slightly, well, really embarrassing question...  Has anybody had any experience removing the stop pins from the switches?  I accidentally put the pin in the wrong spot, and now i can't remove it.  Any help would be much appreciated :-)  Thanks!

Try a magnet, or some blue poster sticky?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Chrome Heart on October 17, 2011, 05:26:07 PM
I've got an odd and slightly, well, really embarrassing question...  Has anybody had any experience removing the stop pins from the switches?  I accidentally put the pin in the wrong spot, and now i can't remove it.  Any help would be much appreciated :-)  Thanks!

Try a magnet, or some blue poster sticky?

magnet pencil. it comes in handy.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on October 18, 2011, 05:32:49 AM
hey guys, I got a question here, I would like to add the 300/1200ohm switch to my ez1290, would you recommand a shield cable or a regular one? trannies will be on the back of the rack. as we have to use shield cable from input trannie to pcb, I'm not shure what to do here. I already draw a small pcb (double sided) to put the trannie and switch on the front panel.
let me know what you think.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on October 18, 2011, 11:01:19 AM
You may be OK with shielded cables, but if you are drawing a PCB to do this, include a relay next to the transformer and use that to switch impedances so you avoid running audio back and forth inside the case.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on October 18, 2011, 07:18:16 PM
WHY! Why I didn't think about the relay at the first time... Thanks, sometime, you just need external look!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mjproc on October 20, 2011, 02:16:40 AM
I've just completed my 2nd dual ez1290 in a 2U enclosure  :D

I've had no problems with the build, all voltages are correct. 

My "problem" is the 1st channel is approx 3db louder than the 2nd.  I've checked most of the resistors and compared the two to find any mismatch.  I havn't found any (yet) Anyone have a tip for me what could be wrong? 

Does the posistion of the Grayhill matter (as I noticed a difference in the shaftposition)  I've placed the stop pin @ 12.

(I think I just answered my own question in the above line..... ) hmm..... (I'll check this later today....)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 21, 2011, 04:55:39 PM
I have the same exact issue, but the two shafts are aligned.  (if anyones got thoughts...) Im about to start wrapping up my 4ch version next week.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on October 23, 2011, 12:01:58 AM
Hello, I have a question about the wire used in this poject.  Ordering the mic cable from Markertek  (L-2B2AT).  I ended up ordering the L-2B2AT 2.  This:

http://www.markertek.com/Cables/Bulk-Wire-Cable/Bulk-Audio-Cable/Canare-Corporation-Of-America/L-2B2ATGY-200M.xhtml?L-2B2AT%20BK

It is a 2 conductor shielded cable.....is that correct or do I need 3?

Thanks in advance, I would be very greatful to hear from someone who has completed this project!       
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mjproc on October 23, 2011, 04:22:26 AM
I've just completed my 2nd dual ez1290 in a 2U enclosure  :D

I've had no problems with the build, all voltages are correct. 

My "problem" is the 1st channel is approx 3db louder than the 2nd.  I've checked most of the resistors and compared the two to find any mismatch.  I havn't found any (yet) Anyone have a tip for me what could be wrong? 

Does the posistion of the Grayhill matter (as I noticed a difference in the shaftposition)  I've placed the stop pin @ 12.

(I think I just answered my own question in the above line..... ) hmm..... (I'll check this later today....)

Shaftposition is important.......  ::)

I had to dismantle the grayhill to get the stop pin out of the switch...... Reeeeeal pain!!!!

It´s all sweeeet now :-)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: bjknapp on October 27, 2011, 10:34:14 AM
Newbie here, I just want to say how impressed I am with the support and knowledge of this forum!!!! 

I have just completed two channels of 1290 with minimal issues, but  I do have some questions.  Was I supposed to insulate the 2N3055 from the heatsink somehow?  The heatsink is actually carrying 22.66 of voltage right now!  I didn't see anything in Martin's build guide about insulating.  The reason I ask is I am picking up some high freq noise if I rack it next to my DAW or Echo Audiofire and lots of hum if I move my external PSU too close.  I have reheated all of the solder joints and double checked my grounding and component values.  Any advice?

Thanks,
Brian
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on October 27, 2011, 10:37:34 AM
have you follow the small manual that Martin put together?
heatsink should be not isolate from 2n3055!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 27, 2011, 11:16:12 AM
bjknapp

help with some more info:

what PSU
how are you grounded?


Did you check continuity between ALL XLR connectors, and between ALL connectors/chassis/front-panel?

I didn't clear the XLRs the first time I assmebled, and had nasty nasty oscillation/hum interference issues is why I ask.

Once I pulled the connectors, went dremel happy for an hour or so, reassembled and no more interference.

All transistor heat-sinks should show 22.66 (or whatever you set it to)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: bjknapp on October 28, 2011, 12:51:48 PM
Hey thanks for the reply.  I'm using the JLM AC/DC PSU with the grounding technique described in Martin's build doc.  When you say "clear the XLRs" what do you mean by that?  I have checked that only the PIN 1s are going to chassis.   Also, audio ground connects to chassis ground ONLY when the PSU is connected.

Thanks again,

Brian
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 28, 2011, 01:30:53 PM
When you say "clear the XLRs" what do you mean by that?  I have checked that only the PIN 1s are going to chassis.   Also, audio ground connects to chassis ground ONLY when the PSU is connected.

Thanks again,

Brian

The chassis being clear from paint/powder-coat where the XLR sockets make contact.  The chassis I used was powder painted, which acted as an insulator between the XLR and the chassis.  Once I had sanded/grinded the paint away and checked that ALL XLR had good continuity from each other and to chassis, all went well.

Pin one should not be tied to chassis.

I believe ideally all audio will go through 10Ohm?

I had problems where I didn't have the XLR sockets making contact, which caused oscillations at higher gains (improper grounding/shielding?).  I tried tying audio ground to chassis which did remedy the oscillations, but made the units very sensitive to interference/ground loop.

It also has been stressed to use nylon/insulating standoffs.  I used machine screws that fastened to the chassis bottom which were coupled to nylon standoffs at the pcb end.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on October 28, 2011, 09:16:50 PM
Lol....
Guys i just wanted to let you know that ive built a pair of 1272 with the EZ1290 boards.
Really affordable, you need a 5K pot instead of the expensive grayhill.
Sound is really good...cost me around 125$ a channel.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on October 29, 2011, 11:10:01 PM
Lol....
Guys i just wanted to let you know that ive built a pair of 1272 with the EZ1290 boards.
Really affordable, you need a 5K pot instead of the expensive grayhill.
Sound is really good...cost me around 125$ a channel.

I did the 1290 for the same amount
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on October 29, 2011, 11:21:07 PM
Are you aware that im talking canadians dollars here?
thats around 89 EUros...
Well you probably used the sames bastards iron as i did??

 ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on October 29, 2011, 11:54:46 PM
Are you aware that im talking canadians dollars here?
thats around 89 EUros...
Well you probably used the sames bastards iron as i did??

 ;D

what kind of transformers your are using on your build?Carnhill  or sowter?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 30, 2011, 01:08:52 AM
Guys i just wanted to let you know that ive built a pair of 1272 with the EZ1290 boards.
Really affordable, you need a 5K pot instead of the expensive grayhill.

Why would you build the a 1272 with a 1290 board and why would you substitute a cheap component for a well made, better spec'd component if only building two channels?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on October 30, 2011, 09:50:40 AM
Quote
Why would you build the a 1272 with a 1290 board and why would you substitute a cheap component for a well made, better spec'd component if only building two channels?

because i had plannings to build 4 x 1290 but built only 2 and wanted to have 2 x 1272s too...1290s are good but i heard good things about the 1272 too.
when i say cheap i mean inexpensive not talking QC here....i used the EA 1166 at 29.99 and the input is a recycled Golden Age input.
i might change it later to EA10468 if the GA stuff is crap.

But if i makes you happy its all good stuff i have on my pre...panasonic caps, nichicon caps, ERO caps and NOS Motorola 2N3055. ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on October 31, 2011, 11:06:36 AM
Kind of a silly question.  Has anyone tried to stack these on top of one another (as in have the PC boards using the same standoff locations)  Im trying to make some room in my case, and I just want to know if the transistor/heatsink on the cards get too warm to put one on top of another.  Im attempting a 4 channel build and need to commit to a front panel design in the next few days.  Im trying deparately to NOT have to use an external PS for this one.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on November 01, 2011, 05:17:32 PM
Kind of a silly question.  Has anyone tried to stack these on top of one another (as in have the PC boards using the same standoff locations)  Im trying to make some room in my case, and I just want to know if the transistor/heatsink on the cards get too warm to put one on top of another.  Im attempting a 4 channel build and need to commit to a front panel design in the next few days.  Im trying deparately to NOT have to use an external PS for this one.

That should be fine. Use insulated standoffs to keep them separated, and make sure nothing touches. Also keep the transformers spread apart a little as they can start talking to each other.

M.

PS. check to make sure your transformer wiring is EXACTLY as it should be. If you wire the output backwards you will get a drop in gain.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 01, 2011, 10:22:00 PM
Awesome, thank Martin, still the best sounding pres in the studio man, cant thank you enough.
Last question, for a 4 ch build, fuse rating?  Im thinkin like 3amp but i dont want to high ball it and risk damaging the boards.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on November 02, 2011, 10:22:29 AM
Ok, I didn't populate any of my cards with sockets for the transistors.

I've seen Jim Williams post at Gearslutz about lower noise transistors Toshiba 2SC3329 BL's, and Renesas 2SC2545.  A fellow lifted the hood from another mainstream 'Neve' manufacturer for me and noted 2sc1114 inside....  any thoughts?

Is there anyone out there that did install sockets that would be willing to do a comparison?
Or better somebody that has already put this through the wringer?

I honestly cannot see how these pres can be any better  8)   but I'm always up for a good goose chase.

Before I go and unsolder each of the transistors in each of the 8 cards I'd like to ask the community for your thoughts and in your opinions is the 'value added' (less noise) would be worth the rework.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: gemini on November 03, 2011, 12:39:15 AM
anyone can recommend good power supply kit to power 2 or more (8) pre?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 03, 2011, 02:16:27 AM
2 pres use the JLM AC/DC kit
3-8 use the JLM Powerstation kit (rectified)

Transformer spec may change depending on the amount of pres as well.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 03, 2011, 12:34:27 PM
I just put my 4 pres into my case (which im a little miffed at since i "thought" i ordered a deeper case)  The case is TIGHT to say the least... (id post photos but want to avoid being laughed at) question is, would putting a metal mesh barrier between the input tx's make a difference,  I have the input tx's only a few inches apart.  When i was building my 2 ch. it was mentioned that i wanted them REALLY far apart (how far "REALLY" is i guess is subjective).  Im thinkin a conductive screen like material (similar to what putting chicken wire around larger devices does).  Any thoughts or am i just being paranoid?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on November 03, 2011, 12:40:37 PM
sr1200  my advice is dry fit them and take a listen.  FWIW my output iron is side by side, winged mounting hardware nearly touching one another.  The input iron are only a few inches apart from themselves.

See this post for idea of the orientation/spacing. http://www.groupdiy.com/index.php?topic=22828.msg563186#msg563186 (http://www.groupdiy.com/index.php?topic=22828.msg563186#msg563186)   The input iron rests directly under the pcb where the audio in pads are located.

...another FWIW, I've seen some of these (very Brave) guys cramming 8 pres into unbelievably tight spaces.  You can dig through this thread for photos (desol, sgenevay, Govinda Doyle, madriaanse himself) to get an idea of how close some of them are mounting transformers, though I think some may have used some type of MU shielding etc... 

http://www.musiciansgig.com/neeb/2inside.jpg (http://www.musiciansgig.com/neeb/2inside.jpg)

http://www.groupdiy.com/index.php?action=dlattach;topic=22828.0;attach=6647;image (http://www.groupdiy.com/index.php?action=dlattach;topic=22828.0;attach=6647;image) 

http://www.groupdiy.com/index.php?action=dlattach;topic=22828.0;attach=6902;image (http://www.groupdiy.com/index.php?action=dlattach;topic=22828.0;attach=6902;image) 

http://desmond.imageshack.us/Himg839/scaled.php?server=839&filename=dsc02842z.jpg&res=medium (http://desmond.imageshack.us/Himg839/scaled.php?server=839&filename=dsc02842z.jpg&res=medium)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 03, 2011, 03:44:29 PM
Yeah i got way more clearance than some of these.  I am hoping to power it up tonight and see whats up.  Gotta mock out a face plate for it first though.  My go betweens and trim pots need to be mounted otherwise they're just kinda... hannnngggin out. lol

Thanks mic for the pic list, some really nice wire jobs on there!  Mine's gonna look like the wire section at home depot expoloded.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 04, 2011, 10:57:36 AM
Well i fired her up last night and Channel 1 & 2 (stacked were PERFECT) channel 3&4 not so much.  Im def. going to have to move the power supply outside of the case :(  the 2 channels on the right side of the case were humming like a ... well, something that hums a lot lol.  when i took the input and output txs out of the case all were silent.  So, now i gotta fond some of that alarm wire (5 lead i believe since I'm using 2 separate 24V channels, the 48v the 0v and the case ground)

Gonna be a drill-tastic weekend for me :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: danchez on November 06, 2011, 07:18:38 PM
Been a while since I've jumped on the site, I figured I'd better update the progress on my 8 channel 1073 build (just like martin's). So far so good! I torpedoed the 1w resistor on the powerstation when I was building channel 1, it seems it arced with the secondary leads of the toroidal. I wonder what my face looked like when I heard my newly-built PSU sizzling! I cleaned up the PCB and rigged up the new resistor for the 48v and I was back up and running. Then I built channel two, ran into some issues, as usual, double-checked all my solder points and discovered one of the jumpers on the input tranny had broke loose, so we were getting very weak and noisy signal. I had channels one and two up and mounted for about two months before I started work on 3/4, I picked up two pairs of transformers from hairball audio instead of the carnhills, and no regrets! I did a shootout in one of my classes with six different pre's, and I couldn't hear a difference between channels 1(carnhill) and 3(hairball). I had one little idiot mistake with channel four, but both of those channels were installed and up and running with zero issues (very exciting!). I ended up ignorantly grounding one of the leads for the input transformer and phantom power wouldn't work, but we tracked that down and fixed the issue. I've got four channels up and running and winning mic pre shootouts! Thanks go out to everyone on this site, I've stalked this thread for several months educating and troubleshooting! It's very exciting to have my first build up and running, I'll post up some pictures soon!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 07, 2011, 10:32:12 AM
Finished the build for my 4ch unit.  They sound AMAZING (as expected).

(http://a8.sphotos.ak.fbcdn.net/hphotos-ak-ash4/373971_240900345963561_233521766701419_600648_1494618792_n.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 07, 2011, 06:11:22 PM
Hey sr1200, after calling around quite a bit I found the cable at a theater installation place.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 07, 2011, 06:37:28 PM
believe it or not, I found it at a home depot near my house.  they sold it for $0.44 /ft. It works great, but not very flexible since its not stranded wire.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kooma on November 09, 2011, 04:02:12 AM
Finished 2channel unit (or so I thought). Other channel works&sounds great, the other one doesnt.
Visually everything seems to be ok, I've checked parts and will check them again:)

Main problem was, when I tried to adjust bias the trimmer had no effect -voltage (3055 to gnd) remained near vcc ~23,5V.
And line-N(Vcc to BA183NV) voltage(after r51) was something like 3V.
So trimmer was busted- I replaced it with 2resistors (as voltage div.) since i had no replacement in hand..
that got bias to 22.8V but still N-line was low.

I measured voltages lifting one part at a time, so when I lifted one leg off, the voltage rise up to normal;
r51->c4->r13->collector of tr5 where i gave up.

any clues? :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: manulaudic on November 09, 2011, 09:51:40 AM
Sr1200 did you get the Pad, 48V, Phase from Jlmaudio?

Manu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 09, 2011, 10:00:48 AM
Yeah, I've used em in 6 channels now, they're awesome!  JLM also makes a VU buffer that I've used in a pair as well.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: manulaudic on November 09, 2011, 10:02:44 AM
Sr1200, I want to try building this Neve clone.

So to be clear could you tell from who did you get all the Parts :

PCB?
CASE?
PSU?

Thank you,
Manu
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 09, 2011, 10:09:53 AM
If you go to page 1 of this thread, everything is pretty much there in the BOM.

The only "add ons" I did were the JLM audio GoBetweens for the phantom/pad/phase since its all in a nice pretty package.

If you're doing more than 2 channels, go with the Fully rectified JLM Powerstation (not the AC/DC as stated in the BOM).   The power tranny will also be different (if you check a few posts back, I asked about the correct tx for the powerstation, and someone pointed me to the Lindberg which has been great)

1 AC/DC is good for 2 ch.

I've been told you can get up to 8 on a single Powerstation. (I wont go more than 4 though... I like headroom)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: manulaudic on November 09, 2011, 10:17:41 AM
Sr1200 Thank you so much for your quick and nice response !

I will surely get all the parts and get on building a 2ch unit.
I would like to also build some Trident Clone. Maybe the powerstation could power them all at once and i could get 4 channels in one rack (2neve, 2 trident).

Thank you !

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 09, 2011, 11:07:32 AM
If the voltages required are the same for all 4 you might be able to do that.  I'd tend to keep em separate though.  Makes trouble shooting a lot easier, and a cramped case is never fun to work in.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tomas1808 on November 10, 2011, 04:52:34 PM
Does anyone now if I can use one of these insted of the grayhill rotary switch? :

http://www.ebay.com/itm/4P-24-Step-Rotary-switch-Attenuator-Volume-Control-DIY-/260693714311?pt=LH_DefaultDomain_0&hash=item3cb28e6587#ht_1328wt_1163 (http://www.ebay.com/itm/4P-24-Step-Rotary-switch-Attenuator-Volume-Control-DIY-/260693714311?pt=LH_DefaultDomain_0&hash=item3cb28e6587#ht_1328wt_1163)

Has anyone tried one of these (on a Neve) before?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 10, 2011, 06:57:05 PM
Thats the type if switch thats on the original.  Since the resistors are on the board instead of on the switch, you may have to find a way to insert it into the circuit after the onboard resistors (if u want them on the switch) or just map the pin outs from that switch to the grayhill (honestly, the price difference w shipping isnt that far off, and the grayhills are REALLY good quality.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 10, 2011, 07:50:59 PM
I recommend sticking with the greyhills as well if they're the 1290 boards. Gold plated, mil spec, good quality...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tomas1808 on November 11, 2011, 08:57:03 PM
Thanks!

Yes, I bet the quality difference is undeniable and worth the price difference in the long run .

Unfortunately money is a problem (20yo, still studying) and the only thing I want now is a good sounding preamp. I think quality switches are not my biggest priority, so I think I'll go with the true DIY spirit and see for myself if these cheaper switches are worth it. If not I can always upgrade later.

Plus customs are a big problem here, if I am unlucky the Grayhills will end up being $62 each after tax.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 11, 2011, 10:51:37 PM
Hello,
Im at the wiring stage and still not sure If I have the correct mic cable!  It is a 2 conductor shielded cable with a drain wire.  I know this is a stupid question, but I am pretty new to this and this is my first major project.  can the drain wire be used on pin 1 of input xlr, pin 6 to 10 on 1068 transformer, pcb board, ect?  I think thats what it says in the directions but I am scared to use the bare wire.  Could anyone confirm if it will work or not?  Thank you!  :)   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 11, 2011, 11:58:55 PM
Yes use the bare wire. Its your friend. Just twist it and make it tight.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 13, 2011, 11:48:26 PM
thanks sr1200, it works!  I still have to bias, but I have a friend with a scope.  Also gonna try to silkscreen the front.  Only thing that was a little weird was that for a minute I got a strange noise...sort of like there was a cricket stuck in one of the output transformers.  It wasnt plugged into anything exept power at that point and the transformer itself was making the noise.  Yikes!  Is this normal? ???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 14, 2011, 12:46:21 AM
Ive heard of caps singing, havent heard a tx do that, but my guess would be some kind of oscillation.  How far apart do you have the transformers (input and output).
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 14, 2011, 03:18:25 AM
Transformers are pretty much in the four corners of the box as far from each other as possible (2 channels).  I think maybe I had the gain on that channel cranked, would that cause ocsillation when un-biased?  I guess I didnt know that oscillation was something that you would hear without it plugged into some sort of speaker.  It hasnt happened again.  It sounds really good!  maybe I will post a picture if my next silkscreen attempt works out (the first one was an epic belly flop :P) 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 14, 2011, 10:48:19 AM
I bought a silk screen "kit" a few weeks ago, i haven't mustered enough courage to actually try it out yet.  If you have some tips or advice, maybe w can start a new thread on that matter.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 14, 2011, 09:02:01 PM
Yes that is a good idea....is there one already somewhere? 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kooma on November 15, 2011, 02:32:51 AM
Finished 2channel unit (or so I thought). Other channel works&sounds great, the other one doesnt.
Visually everything seems to be ok, I've checked parts and will check them again:)

Main problem was, when I tried to adjust bias the trimmer had no effect -voltage (3055 to gnd) remained near vcc ~23,5V.
And line-N(Vcc to BA183NV) voltage(after r51) was something like 3V.
So trimmer was busted- I replaced it with 2resistors (as voltage div.) since i had no replacement in hand..
that got bias to 22.8V but still N-line was low.

I measured voltages lifting one part at a time, so when I lifted one leg off, the voltage rise up to normal;
r51->c4->r13->collector of tr5 where i gave up.

any clues? :)
turns out I had 3 broken bc184c transistors :o
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 16, 2011, 08:54:51 PM
Hi folks,
First of all I am so glad that I chose this project ;D  Martin, if you are out there, thank you for all of your efforts!  Its kind of hard for me to decide where to dive into the diy world and the instructions on this project really made it a good starting point. 

That said I think I have wired the cases (psu and 1290) together incorrectly somehow because I get some noise at higher gain settings that goes away when I touch both cases.  does the wire that comes from the power switch to the shield and 1290 case first need to come in contact with the psu case?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 16, 2011, 09:50:53 PM
Can u post pics?  Usually the power switch is just breaking the contact to the IEC.  Shouldnt be ground there.

On a side note, id like to build another pair, but have a single rotary switch for stereo operation (i would use internal trimmers to calibrate levels where that 10K and Jumper are.  Any suggestions for a switch to do this?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kooma on November 17, 2011, 02:14:07 AM
f**k!  >:( :'( :(

this thing works great when I test it with mics, but when I try to do sweeps/ use sw analyzer-
the same transistors 6 and 4(in BA183AV)  burn.
Can I overload these so baddly in anyways that it burns those transistors?
my other channel works perfect, but this one has some really weird sh*t going on..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 17, 2011, 04:26:25 PM
Thanks sr1200,  I think I have the cases connected ok now but cant go anywhere near the psu with a dynamic mic without some buzzing.  I might still have something a little off....anyone else have this happen?  Not really sure how to post a pic :P.  Lets see if this works (http://IMG_2347.gif)  (http://IMG_2348.gif)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on November 22, 2011, 02:12:04 AM
any news about a new batch of this boards?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 22, 2011, 03:01:07 AM
Thanks sr1200,  I think I have the cases connected ok now but cant go anywhere near the psu with a dynamic mic without some buzzing.  I might still have something a little off....anyone else have this happen?  Not really sure how to post a pic :P.  Lets see if this works (http://IMG_2347.gif)  (http://IMG_2348.gif)

Sounds like you have a ground issue.

any news about a new batch of this boards?

I'm still waiting for this project to be discontinued!  :o  But that's just me. I like when things end.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on November 22, 2011, 03:06:54 AM
:))) i think this is a good project , and need to be done a lot more boards for this one
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 25, 2011, 03:18:41 AM
It is sounding good but I have a few other issues I need to sort out......just found out that none of the wall outlets in my apartment are grounded except one in kitchen :P  That sure doesnt help. 
     
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on November 29, 2011, 01:23:08 PM
Hello, Im still having some noise issues (even from the one grounded outlet in my apartment).  Im pretty sure that it has to do with my wiring/grouding like you said desol.  Tried to bias the other night at a friends house and the signal looked like lots of little waves on one big wave (possibly user error though).

If anyone would be willing to take a look at the pictures in the link of where Im at with it I would be really thankful :). 

http://s556.photobucket.com/albums/ss1/travisttaylor/1290ez/

(I have since disconected the yellow wire: LO1166 shield)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 29, 2011, 02:19:32 PM
Try grounding the XLR's to the chassis ground with a wire?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on November 29, 2011, 02:27:30 PM
Best way i found to work on grounding was following the instructions!
But sometimes im lazy and alligators clips are my friends.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on November 29, 2011, 02:42:05 PM
Hi Travis, some things to try...

Check for continuity between all chassis panels, all XLR connectors.  Don't tie pin 1 to chassis/ground.

In photo 3, remove that wire that is terminated to the chassis. 

There seem to be a lot of wiring where you have the Input literally on top of the Output.  Try to separate these a little more.

Also try using shielded 2conductor for audio in/out might work better than what looks like unshielded, maybe it's single conductor shielded hard to tell?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on November 29, 2011, 03:06:30 PM
Ill +1 on Micdaddys use of shielded cable throughout the case where audio is passing.  Also where is the PS in relation to the chassis with the Transformers?  you have the TX's REALLY close to the outside of the box which might not be helping if that power transformer is close to it.  Is the hum on BOTH channels or just one?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 04, 2011, 08:48:33 PM
Ok, I re-did most of my wiring and found a few things that I did wrong with shielding.  Also finished my silk screen after a lot of suffering (next time it will be easy though).  I think that I am pretty much good at this point and it sounds lovely.  I think it looks pretty good too!

http://s556.photobucket.com/albums/ss1/travisttaylor/

I am still a little concerned that I have all cables shielded properly.  The only ones that I am worried about are from output transformer to xlr and from 1290 pcb to 4 pin power xlr.  I am not using a shield on either of those.  Also no sheild on the phantom power.  Looking at pics from other projects I think that this is ok, but if someone could confirm it my mind would be at ease!

 

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on December 04, 2011, 09:37:00 PM
The only ones that I am worried about are from output transformer to xlr

I used shielded cable here, tie shied to pin1 @ XLR but NOT to chassis.

Quote
and from 1290 pcb to 4 pin power xlr. 
  I used single conductor wires for +24/+48/0V and just twisted them.

Nice build, very elegant.  Are those knobs from ChuckD?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 06, 2011, 04:36:37 PM
Thanks MicDaddy,
I have now tied shield to XLR pin 1.

I will twist the single conductor wires if I notice an issue.

Yes, the Knobs are from ChuckD and they are very nicely made.  I had to buy four to get the two I needed but it was worth it.  Especially because the only other similar ones I could find were $30 each!

I just did a little testing and noticed if I wiggle the gain switches I get a little crackle.  It is not importlant to me unless it is an indication of a bigger issue, is this to be expected?

sorry to flood this thread with my questions and thanks to everyone who has helped!   

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 06, 2011, 08:38:49 PM
how much am I approximately gonna pay for a single channel ?

and is there perhaps a mouser cart available ? :D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 06, 2011, 11:54:39 PM
Everything you need to know is onthe first post. Including price and part sourcing.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 14, 2011, 02:16:28 AM
Arrg.  More problems.  This one is really weird.  My 1290 seems to work great on certain things while others it has a very weak and distorted signal.  For instance I have a sampler that sounds great, but a synth that you can barely hear at all!  Pretty weird and kind disheartening.  Has anyone else experienced anything remotely like this?  I keep thinking I am done :-\         
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tmuikku on December 14, 2011, 03:54:28 AM
Arrg.  More problems.  This one is really weird.  My 1290 seems to work great on certain things while others it has a very weak and distorted signal.  For instance I have a sampler that sounds great, but a synth that you can barely hear at all!  Pretty weird and kind disheartening.  Has anyone else experienced anything remotely like this?  I keep thinking I am done :-\       

Propably is due to some interconnection. Check out rane notes about wiring, interconnections and grounding: http://www.rane.com/library.html#apm1_2

Example: I got very weak sound in my G9 at first which was due to my sound card had TRS jack but the ring wasn't connected to anything(!) thus leaving the output transformer floating when using TRS cable... know your equipment and cabling :) If it sounds good with some instruments the unit it self should be ok.

I'm not familiar with the particular transformers this project uses but check out you have connected them correctly so they appear with proper impedances for devices connected.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sisepuede on December 14, 2011, 04:50:02 PM
Arrg.  More problems.  This one is really weird.  My 1290 seems to work great on certain things while others it has a very weak and distorted signal.  For instance I have a sampler that sounds great, but a synth that you can barely hear at all!  Pretty weird and kind disheartening.  Has anyone else experienced anything remotely like this?  I keep thinking I am done :-\       

Hiya,
try DI boxes for synths, samplers and anything unbalanced line, that should work.
mind the lack of star ground in your rack.
mind the too away of your in/out transformers, try those as close as you can to the PCBs.
find some nice spot of ground in your appartment like a metalic pipe, if that is water is better , I did once and it worked fine.
hope this helps.
cheers.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 14, 2011, 05:06:01 PM
could you guys recommend a proper psu to power either four neve or api units each ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 15, 2011, 03:06:33 AM
Quote
Example: I got very weak sound in my G9 at first which was due to my sound card had TRS jack but the ring wasn't connected to anything(!) thus leaving the output transformer floating when using TRS cable... know your equipment and cabling  If it sounds good with some instruments the unit it self should be ok.

Oh I see....Im maybe having something similar happen.  It seemed so baffling to me because on the sampler there are the main outs which work fine but then another 8 outs (for sending individual parts) that do not work well at all!  Thank you for the reading material too.  I wish I would have looked at that a month ago ;D  How did you end up sorting your G9 issue out?

Quote
try DI boxes for synths, samplers and anything unbalanced line, that should work.
I will look into it.  I wasnt planning on buying anything new at the moment but it looks like there are some cheap ones.  Anyone DIY these?

 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sisepuede on December 15, 2011, 08:31:45 AM
Quote
I will look into it.  I wasnt planning on buying anything new at the moment but it looks like there are some cheap ones.  Anyone DIY these?

yeah, of course mine are all DIY, I have a single one and a double one, both with Jensen transformers http://www.jensen-transformers.com/datashts/dbe.pdf (http://www.jensen-transformers.com/datashts/dbe.pdf), switchcraft plug connectors and Neutrik XLRs, metal film resistors and plypropylene caps. That PDF also has the schematics you need to have the job done.

Cheap DI will ruin the sound of your nice preamp I recon.

those boxes sound amazing.

cheers.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 15, 2011, 10:26:12 AM
I'm having an issue with one of my 6 channels, maybe someone can help out.  When using phantom power, I occasionally get a fizzle for a second and then it goes back to normal, it's kind of hard to trace on the board since its an intermittent problem.  Just wondering if anyones had a similar issue.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tmuikku on December 15, 2011, 10:53:14 AM
...  How did you end up sorting your G9 issue out?

I knew my soundcard was unbalanced and believed it uses TS jacks or TRS jacks with ring wired to the shield so I thought the problem was with my G9 (I didn't have anything else to hook it to back then than my soundcard). All it took to figure out was to look into the hole and confirm it was a TRS jack and then hook a TRS cable into the soundcard and measure if there was connectivity between ring and shield from the other end of the cable and voila :) First I used many hours of debugging the G9 for nothing. Well, that way I got familiar with the unit. Used TS plugs from that on with the soundcard and it worked fine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 15, 2011, 12:31:51 PM
Quote
yeah, of course mine are all DIY, I have a single one and a double one, both with Jensen transformers

sounds like a cool project, but Im kind of tapped out from this one at the moment ;D


Quote
Used TS plugs from that on with the soundcard and it worked fine.
   

It is a TRS to XLR cable that I am using......would I potentially be OK with a TS to XLR?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on December 15, 2011, 04:50:49 PM
I'm having a hard time measuring what size stand off I should use for mounting the ez1290 in a1ru case with drill holes for the switches directly in the middle.. Any advic?

Thanks,
Brice
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 15, 2011, 04:52:47 PM
Drill a hole dead center of the front panel, then measure the size you need from the board to the chassis. (thats what i did)   ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 15, 2011, 10:34:46 PM
What is the strongest diy psu you could possibly get?

Otherwise, is there a better pre-built solution / market product offering enough juice to power four units properly within the case?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 16, 2011, 12:33:07 AM
Great  :D!!  TS Cables did the trick!  Ill look into the DI boxes a little more too....I should get a few eventually but for now I think this is fine.  Thanks guys!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tmuikku on December 16, 2011, 05:28:36 AM
Great  :D!!  TS Cables did the trick!  Ill look into the DI boxes a little more too....I should get a few eventually but for now I think this is fine.  Thanks guys!

Cool :)

I'm not sure if you have mic preamps or line amps? If it is a mic amp and has phantom power: Leave the cable shield unconnected to the TS plug since if you connected both xlr pin 1 and pin 3 to the TS plug shield you'll shortcircuit your phantom supply if you accidentally put the phantom on with XLR > TS cable connected to the mic input!

Should be:
XLR pin 1 > not connected on the TS plug
XLR pin 2 > TS plug tip
XLR pin 3 > TS plug "shield"

If it is a mic preamp (no dedicated line input with proper input impedance for line level sources) you should be using DI boxes synths and stuff anyway. Check out for example BO Hansen DI, you can buy PCB's and the transformer from White Market.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 16, 2011, 02:36:27 PM
Quote
you'll shortcircuit your phantom supply if you accidentally put the phantom on with XLR > TS cable connected to the mic input!

Yikes!! :o Thanks for the warning....It does have phantom and Im sure I would have done exactly that at some point!!

I just bought some pre-made cables and pin 1 and 3 are jumpered going to TS sleave.  I cant even fix them because they are single conductor shielded.  Doh!  Should have just made my own based off of Fig. 13 in Rane diagram which is exactly what you describe.

Quote
If it is a mic preamp (no dedicated line input with proper input impedance for line level sources) you should be using DI boxes synths and stuff anyway. Check out for example BO Hansen DI, you can buy PCB's and the transformer from White Market.

I was looking forward to a DIY vacation 8)!  Just kidding, that looks like a project I could manage that doest cost that much.  Have you made one?   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tmuikku on December 16, 2011, 03:24:07 PM

Yikes!! :o Thanks for the warning....It does have phantom and Im sure I would have done exactly that at some point!!

I just bought some pre-made cables and pin 1 and 3 are jumpered going to TS sleave.  I cant even fix them because they are single conductor shielded.  Doh!  Should have just made my own based off of Fig. 13 in Rane diagram which is exactly what you describe.

Yeah Fig 13 is correct. I'm actually not sure what would happen still if you have the cable right. Both xlr pin 2 and 3 would have the +48V so basically your phantom supply could still burn since it would be dumping current to the synth output ground potential?

Quote
... Have you made one?

Not just one but two. They work as advertised.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 16, 2011, 04:28:06 PM
Atticmike:

I got the JLM powerstation (the big one) and am running 4 channels off the one PS.  Only problem was, my case was too small and i was getting noise on 2 of the channels where the PS was close to, so i broke the PS out and put it in another box.  If my case was about 6" deeper I could have done it all in 1 HUGE unit. 

Also, i stacked my pres, 2 channels left/2 channels right

its the 3rd unit down in this pic.
(http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc7/309008_248373848549544_233521766701419_619320_1530445758_n.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 16, 2011, 04:56:02 PM
Quote
Yeah Fig 13 is correct. I'm actually not sure what would happen still if you have the cable right. Both xlr pin 2 and 3 would have the +48V so basically your phantom supply could still burn since it would be dumping current to the synth output ground potential?

hmmm, bummer.  yes it goes to both 2 and 3.  Any other thoughts or options people are using?  Will the Transformer in the DI box have a significant impact on sound?  As much as the mic pre?     
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 16, 2011, 06:42:52 PM
do you think choosing mostly xicon for the resistors was a good idea?

also, what railing options am I supposed to choose ? http://www.whistlerockaudio.com/cart/index.php?main_page=product_info&cPath=43&products_id=107

And which psu would you choose to power four units? Still the whistlerockaudio or rather prefer the JLM PowerStation Ver. 3 kit along with a 6 amp bridge rectifier?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on December 16, 2011, 08:03:36 PM
Have you read through this thread Mike?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 16, 2011, 08:47:54 PM
Have you read through this thread Mike?

Yes I did. I simply lack some basic knowledge which I've gone clean with on the drawing board section. Feel free to help me out :D

My habit of nitpicking in every corner to prevent the worst doesn't necessarily lead to a good outcome without me, connecting the basic dots.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 17, 2011, 07:28:29 AM
also what's your opinion on 1/4 watt xicon resistors?

cause with the original bom I took everything xicon that was declared mouser.

Most of em are Yageo now. What's the impact?

Read that carbon was more true to the original sound despite neve having used metal film resistors for once as well.

Haven't placed my mouser order yet with the xicon, just got the digikey parts from the original list which prolly haven't changed to the updated version.

Whereby the capacitors have gone significantly cheaper with the update bom:

Original: http://search.digikey.com/us/en/products/MAL202135151E3/4018PHCT-ND/263242

Updated: http://search.digikey.com/scripts/DkSearch/dksus.dll?x=15&y=14&lang=en&site=us&KeyWords=P10196-ND+

but then for a few, they have gone ceramic instead of poly:

Original: http://de.mouser.com/ProductDetail/Xicon/23PS110/?qs=VbcEA1k3avOWJgTVfPRUDg%3d%3d

Updated: http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=P4925-ND+

Here, I gotta say that poly caps look a tad more inviting due to a longer lasting lifetime which can plunge with ceramic due to humidity & temperature dramatically.

Anyways, I'd like to know your standpoint on the Yageo because I'll be ordering overseas from digikey and there a few things I can't get from mouser would be a lot more comfortable picking it up at digi right away along with the resistors.

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 19, 2011, 04:19:58 PM
also, at voltage does a neve 1073 run? I need to know this for ordering the right rail setting on my whistlerock purchase.

Thanks in advance.

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 19, 2011, 05:02:28 PM
24v + only (no negative rail needed) and 48v is needed if you want phantom. (all on the first page)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 19, 2011, 06:25:31 PM
24v + only (no negative rail needed) and 48v is needed if you want phantom. (all on the first page)

with you rather second for the jlm 6a or whistlerock's for each 4 units?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Alistair on December 19, 2011, 07:27:26 PM
For 4 units you will only need one of the JLM AC/DC's.   Go for a 6A Powerstation if you want, but it won't matter.
Whistlerock doesn't seem to mention current specs on their PS, but I'm sure it will be fine.  4 x 1290's will only need about 500mA, so double that for safety and anything putting out 1A or more should be fine.  I'm all for over spec'ing PS, but I can't really see how over spec'ing that much will help.

As others have said, make sure you read this thread.  The PS options for these pres have been covered in depth, in every option from 1 unit up to racks of 8.  Madriaanse himself covered it in the beginning.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 19, 2011, 09:12:25 PM
For 4 units you will only need one of the JLM AC/DC's.   Go for a 6A Powerstation if you want, but it won't matter.
Whistlerock doesn't seem to mention current specs on their PS, but I'm sure it will be fine.  4 x 1290's will only need about 500mA, so double that for safety and anything putting out 1A or more should be fine.  I'm all for over spec'ing PS, but I can't really see how over spec'ing that much will help.

As others have said, make sure you read this thread.  The PS options for these pres have been covered in depth, in every option from 1 unit up to racks of 8.  Madriaanse himself covered it in the beginning.

I've just had a chat with Mike from whistlerock and he said that the unit is based on the 317/337 adjustable regulator and can shoot up to 1.5A max for each rail which simply sounds fantastic to me.

Going by the specs, I def recommend the whistlerock board over any other!

Notably, the exception being the +48V phantom voltage rail, which can supply up to about 700mA. This however still exceeds the JLM specs.

As you've said before, I'd be probably good with either psus but honestly, I'll be taking the one with the most output  8)

Mike out
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on December 20, 2011, 07:05:54 AM
Hi,

last night I fired up my build the first time and on one channel i smoked the
12R 1W resistor (the one near the +24V power input).

Any quick hints where to look at?

Now first I'll buy some new... :)
ROCK-ON!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 20, 2011, 11:05:02 AM
yeeeep... i did the same thing. You may have shorted the phantom power.  I replaced the resistor but there's something still a bit off on mine, I'm going to start replacing parts on that channel after xmas chaos is past us.  Ill let you know if I find the other "culprit".

The channel still "works" after replacing the resistor, just every once in a while im getting a nasty drop out with some static for a couple seconds... may just be a cold solder or something from when i took out the charred remains of the old one.  And theres no problem with it when using a ribbon or dynamic mic.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 20, 2011, 11:33:52 AM
Maybe you both have issues with the JLM's +48 voltage?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 20, 2011, 11:40:06 AM
Cant say for Dr_J but i have 3 other channels using the same PS and they all work fine, theres something ONLY on that one board that's hosed.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 20, 2011, 01:31:47 PM
Is this **** feasible for powering four units? http://de.mouser.com/ProductDetail/Triad-Magnetics/VPT48-1040/?qs=sGAEpiMZZMvwUzoUXIIvyTw34uqMHR%252budyV6EVq1EYo%3d
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on December 20, 2011, 09:16:13 PM
Hi!

Smoked 12R (R56) resistor solved!!  ;D

I'm such an El Supidio  :o !!!! Never though of making such a mistake...
I put one of the filtering caps (C7) wrong in.... >:( must have been late at night and maybe one
beer too much...  ;D
But it survived, swapped it and now the unit is working....

ROCK-ON!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 20, 2011, 10:24:43 PM
let me know if you get any noise on that channel after using it for a couple hours.  Im still hunting my gremlin.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 20, 2011, 10:31:32 PM
Any comment on the toroid transformer I've posted?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Ethan on December 20, 2011, 10:44:12 PM
atticmike,

In the future when posting in this community, choose your words more carefully.  There is no reason to arbitrarily use vulgar, offensive language especially when asking other members for help.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 21, 2011, 10:38:27 AM
Can anybody at least recommend me the best toroid transformer you can get for this project? (19" 1RU fitting)

Here is a price ascending toroid transformer list from wholesaler I usually buy at:

http://uk.farnell.com/jsp/search/browse.jsp?N=202981+310021410+310056602+310084864+310037695+310072589+310097531+310078485+310007771+310018924+310007772+310113871+310004946+310106853+310037674+310007781+310107395&Ns=P_PRICE_FARNELL_DE%7C0&suppressRedirect=true&locale=de_DE&appliedparametrics=true&getResults=true&originalQueryURL=/jsp/search/browse.jsp%3FN%3D202981%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Dde_DE%26divisionLocale%3Dde_DE%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D202981
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Whoops on December 21, 2011, 08:41:06 PM
Is this **** feasible for powering four units? http://de.mouser.com/ProductDetail/Triad-Magnetics/VPT48-1040/?qs=sGAEpiMZZMvwUzoUXIIvyTw34uqMHR%252budyV6EVq1EYo%3d

The transformer YES that will do the work,

the problem will be the power supply, you have to check if the regulators in your power supply can handle the 4 units.



Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on December 22, 2011, 02:39:03 AM
Quote
Any comment on the toroid transformer I've posted?

I think that you could just use two acdc's if you wanted to simplify things a bit and stick with the BOM.  Pretty sure thats what the projects creator uses (one acdc per 2 channels).  you could even put them in a rack case if you want.  That doesnt really answer your question, but its an option.

   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 22, 2011, 02:49:35 PM
Quoting: "JLM PowerStation Ver. 3 kit is a Linear based universal power supply with can generate 5 voltage rails from a single or dual 15 to 30vac power transformer."

Does it mean you cannot use 50 VAC transformers in combination with that PSU?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: andreimusic on December 29, 2011, 06:03:15 AM
Hi guys!!

I'm trying to make my 1290 clone as close as possible to the original...  as far as the front panel is concerned.

Does anyone has any info where I can get "phantom" and "phase" switch same an on 1073 Neve Dpa??  :o

http://www.ams-neve.com/Products/Outboard/1073DPA/1073DPA.aspx


Thanks in advance!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on January 04, 2012, 06:29:00 PM
Will the transformer at 22v secondary voltage, provided by the thread op's bom, now server as a toroid transformer for at least four units?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on January 04, 2012, 06:35:16 PM
Hi guys!!

I'm trying to make my 1290 clone as close as possible to the original...  as far as the front panel is concerned.

Does anyone has any info where I can get "phantom" and "phase" switch same an on 1073 Neve Dpa??  :o

http://www.ams-neve.com/Products/Outboard/1073DPA/1073DPA.aspx


Thanks in advance!!

Imo, it's a waste of time. Go with what works and looks fine. YMMV.

Will the transformer at 22v secondary voltage, provided by the thread op's bom, now server as a toroid transformer for at least four units?

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on January 04, 2012, 06:43:23 PM
Hi guys!!

I'm trying to make my 1290 clone as close as possible to the original...  as far as the front panel is concerned.

Does anyone has any info where I can get "phantom" and "phase" switch same an on 1073 Neve Dpa??  :o

http://www.ams-neve.com/Products/Outboard/1073DPA/1073DPA.aspx


Thanks in advance!!

Imo, it's a waste of time. Go with what works and looks fine. YMMV.

Will the transformer at 22v secondary voltage, provided by the thread op's bom, now server as a toroid transformer for at least four units?

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12

so as long as I provide the unit with 1 ampere at 15 to 30 vac secondary voltage I'm fine?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on January 04, 2012, 06:49:24 PM
Yes and no(1 amp)...a 24 volt secondary is fine. 12 + 12 @ ~ 50va.

http://avellindberg.com/transformers/y23_range_specs.htm

1290 wants 300-500ma each, upon powering up. Then settles at 80-100ma.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on January 04, 2012, 07:28:54 PM
Yes and no(1 amp)...a 24 volt secondary is fine. 12 + 12 @ ~ 50va.

http://avellindberg.com/transformers/y23_range_specs.htm

1290 wants 300-500ma each, upon powering up. Then settles at 80-100ma.

yeah but with the suggested transformer by the op, I'll have a delicate matter of 22 V... Meaning I've purchased the transformer for nothing?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on January 04, 2012, 07:44:00 PM
It's not a delicate matter at 22vac...as the powerstation will take 15 to 30 vac....but output 24(dc).

It's a matter of power...and for 4 channels, the amveco is fine at 22vac - 50va.

Do you really live in an attic?>
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 06, 2012, 12:55:39 PM
Issue with one of my 8 pres.

I have 2x 2RU units of 4pres each.

Intermittent static/spitting from one channel (other 3 in same chassis no symptoms)  It comes and goes, sometimes will be hours before it happens, sometimes it is every 5 minutes.

I'll have power to the pres with no gain applied, it starts spitting like crazy (only the one channel), then no output even with full gain... some time will pass, more spitting and then the channel starts working fine. 

I haven't opened the chassis to poke around.  I've not had to deal with a 2N3055 that has failed or is in failure/failing, is this a typical symptom?

Like I said it happens when the channel is at 0gain, and occurs with the trimmer fully closed.  This leads me to believe it's in the last stage, and the big transistor is what comes to mind.. 

any thoughts appreciated. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 06, 2012, 02:11:50 PM
That is the EXACT issue im having with one of mine in my 4 ch 2U unit...  It was the channel i blew the big 1w resistor on by accidentally shorting the 48v.  All other channels are fine... I think my next mouser order will include a 3055 just incase thats the issue...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on January 06, 2012, 05:32:14 PM
Micdaddy...

Got a scope?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 06, 2012, 05:40:18 PM
Yea I have an older Tektronix/Sony 2channel portable which doesn't help as when the suspect channel is working it works and exhibits no abnormalities.  Only then out of nowhere it will start this spitting fit and crap out...spit some more and come back, I cannot reproduce the fault with any consistency. 

I suppose I grab a book and throw it on the bench and camp out for a bit.  When it craps out I'll try to see where the audio goes wonky, any other suggestions?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MatthisD on January 06, 2012, 05:55:55 PM
Regarding the static, have you used polystyrene caps? if you have then something to try is to blow on each of those caps with the unit on to see if this alters the level of noise. I had this same intermittent problem recently in a mic circuit and was able to clean the cap which solved the issue.
Matt
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on January 06, 2012, 07:04:35 PM
It's not a delicate matter at 22vac...as the powerstation will take 15 to 30 vac....but output 24(dc).

It's a matter of power...and for 4 channels, the amveco is fine at 22vac - 50va.

Do you really live in an attic?>

As a matter of a fact, considering how much time I spend in a studio environment, I do :P

I'll be harnessing this spool with 22vac since I kind of hinge on european 230 voltage.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 06, 2012, 07:07:26 PM
Upon visual inspection, I find 2 of my R7 47R 1W cooked.

These photos were taken from the same chassis, 3 different channels.

Channel 6 looks unrecognizable and I'm sure it's only a matter of time before it looks like Channel 8.

Channel 7 Looks perfect, like it hasn't seen much heat.

Channel 8 is cooked to pieces, this is the same channel with my intermittent spitting/dropout.

Channel 5 is not shown but looks exactly like Channel 7, in mint condition.

While I could replace these and hope for the best, I'd prefer to get down to the 'root cause' of the failure.  Obviously these are dissipating much more heat than they are wanting to, why?

It's time to dig into the 'hows it work' in the schematic, and I'm not sure exactly what this guy is doing but hanging off of the emitter of the 3055?   

Edit: I should add that all channels function as what I consider normally, only when channel 8 started spitting did I open the top to find these resistors burnt.  I've been using the pres off and on for however long it's been since they've been completed with no problems.  Lucky me I was just playing around when I noticed the spitting/dropout.

I'm going to open up my other chassis to inspect R7 on those 4 units. 

See photos below
In order Channel 6-7-8
(http://img835.imageshack.us/img835/4836/r7channel6.jpg) (http://imageshack.us/photo/my-images/835/r7channel6.jpg/)
(http://img221.imageshack.us/img221/3847/r7channel7.jpg) (http://imageshack.us/photo/my-images/221/r7channel7.jpg/)
(http://img252.imageshack.us/img252/651/r7channel8.jpg) (http://imageshack.us/photo/my-images/252/r7channel8.jpg/)





Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 08, 2012, 03:32:40 PM
quick update,

I poked at some transistors and found some funky voltages on channel 8

TR1:
E .1V
B .6V
C 13.7V

TR2:
E 13.1V
B 13.7V
C 18.8V

Played some with the 5K trimmer, now TR voltages are as follows:

TR1:
E .33V
B .9V
C 4.5V
 
TR2:
E 3.9V
B 4.5V
C 22.7

The burnt up R7 reads 58Ohms in circuit.  Since adjusting the bias trimmer, no dropouts or static from channel 8 (~24hr burn in, recording via DURec and monitoring waveform)

I'm almost to the point to swap out R7 and hope for the best, unless someone cares to drop some knowledge.  Did I simply forget to bias this channel?  I honestly cannot say 100%, if not properly biased is it possible to dissipate too much heat at R7? 

Channel 6  IS biased properly so why does it also show stress from heat?  Bunk resistors?  ( R7 is unrecognizable from heat)

additional info:

Channel 8 TR3 collector was showing 22.7 for over 24hrs after adjusting the trimmer.  I went ahead and swapped R7.  It immediately burnt up though not as bad as the previous.

TR3 collector is now showing some 15.x volts

I've done some rough comparisons with the trimmer, it appears to be functional though this time it's having no influence over the circuit. 

R7 (all blackened up once again) reads 45Ohms in circuit and has 15V across it  :o  whereas other channels only 2.xV.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Siegfried Meier on January 09, 2012, 12:47:35 AM
Hey guys,

Any reason why the BA183AM section wouldn't be seeing proper voltage?  My TR1 (2N3055), TR2(BC184C) and TR3(BC184C) aren't getting the proper voltage - neither are the caps surrounding this section.  All else seems to check out perfectly.  The PSU is 100% as it's been used on several other units with no problems.  Can't see any shorts or reversed caps/parts etc.  There are 2 channels and they're both doing the exact same thing, which leads me to believe I've done something identically dumb to both units.  Could a pair of bad 2N3055's cause this issue?

Thanks for any advice,
Sig
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 09, 2012, 01:54:33 AM
 ;D  Siegfried Meier you too?  I only kid, out of curiosity what are your voltages at those designations?  Which make 2N3055 did you use?

On my end, I've ruled out the output tx.  My faulty channel is pulling some 340mA while the other 3 in the same chassis combined pull some 200mA.  It's all being dumped into the 47R and I haven't nailed it yet.

Went ahead and pulled 2N3055 and did a diode test.  (Base+ Collector-), (Base+ Emitter-), both read out at some half a volt or so, no conduction in any other configuration.  Could it still have failed and read out ok?

  :o  Gonna run to RadioShack tomorrow for a TR3 and toss it in blind.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Siegfried Meier on January 09, 2012, 11:03:01 AM
How are you determining how many mA you're pulling from each channel?  What device are you using?

I'm using an ST Electronics 2N3055 but 2 of these were sitting in parts shelves in my shop for over a year, not in anti-static bags, which is making me wonder if they're faulty.  Especially since both channels are exhibiting the same behaviour.

I ended up buying 500 BC184's since I got a notification that they were now end of line.  Wanted to have some for the future just in case they get discontinued and nothing replaced them properly.  I doubt those are the problem though.

Can a faulty 2N3055 cause this entire section to be wonky?

Thanks!
Sig
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 09, 2012, 11:37:45 AM
I'm using my bench PSU for +24V and watching the current draw on the meter.  Some maths tells me that 15V across R7 (47R)  E/R=I  15/47=.319

Can you measure what your V drop is across R7 and let me know? 

There's not a lot that can fail in that BA183AM section, I am still suspecting my TR3. 

Are 2N3055 ESD sensitive? 

Quote
Can a faulty 2N3055 cause this entire section to be wonky?
Just a guess, but I'm thinking yes.

Today I'll try a ratshack replacement at TR3, and if that doesn't work, back to the books to try to understand this topology.

Didn't know about BC184c going end of life, Jim Williams has recommended a few replacements that he claims spec much better but I've not tried (but now I might since I've got this thing on my bench already).
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 09, 2012, 02:02:50 PM
 ;D update,

I found the error, C3 was reading a dead short in circuit.  I pulled one leg and the 4700pF(polystyrene) reads ok out of circuit, I measured between C3 pads and dmm reads open.  I looked and looked under magnification both sides of the pcb both prior to and after pulling one leg of the cap and observed no short.  I cannot say why it was shorting in circuit, but after installing, this channel is now operating properly..... wtf.... 

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Siegfried Meier on January 09, 2012, 03:31:15 PM
Really eh??  Very odd.

Well, the fact that both of mine behave identically makes me think my problem is elsewhere.  All voltages are exact from one unit to the next, and each transistor that's dead on one is dead on the other.  Very strange...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 09, 2012, 03:48:21 PM
With no B+ applied, use a DMM and check your capacitors for shorts.  This is how I found my issue... I'm still trying to wrap my head around the way this circuit works.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MatthisD on January 09, 2012, 04:15:56 PM
I cannot say why it was shorting in circuit, but after installing, this channel is now operating properly..... wtf....

Do you mean you replaced C3 or just re-soldered the same one?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 09, 2012, 04:30:59 PM

Do you mean you replaced C3 or just re-soldered the same one?

Re-soldered the same one...

C3 in circuit measured dead short.  No visible short on pcb either side.  Lifted one leg, measured and found no short at the capacitor, and no short between C3 pads (scratching my head) soldered leg back into circuit, measured no shorts....circuit now showing proper voltages.  Chalking it up to Pure F***ing Magic.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 09, 2012, 04:45:49 PM
could have had a cold solder that you couldnt see...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 09, 2012, 04:53:49 PM
could have had a cold solder that you couldnt see...

Sure, but that wouldn't cause a cap to show as shorting, would it?  Did I cook the polystyrene to the point of an intermittent short?  Dunno, I'm really dumbfounded with this one, happy it's at least working for now.  I'll monitor it and report any further issue.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MatthisD on January 09, 2012, 05:17:59 PM
That is strange, as mentioned in the assembly guide polystyrene caps are sensitive to high temp so need to be soldered carefully or with a clip to absorb some of the heat so I don't understand how re-installing the cap, applying more heat would help. If you handled it? to pop out one leg for testing maybe your fingers somehow removed some residue or something from the body although that would seem to have more affect in high impedance areas like the output of a mic capsule like in my situation I mentioned earlier.
Glad its working for you whatever the reason.
Title: NEVE 1073 completed-TRIM POT?
Post by: danjpiscina on January 10, 2012, 07:01:12 PM
hi guys. what's the best way to get a trim pot on one of these 1290s?

i have 4 pairs and i want one pair to have output trim. are there any wiring guides for this?

thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 11, 2012, 12:41:03 AM
Its on page 1.  I believe its a separate pdf file with direction on how to do this.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on January 11, 2012, 06:06:59 AM
HI All.. Iam back... damn!

To celebrate the fact I bought these really AWESOME looking red winged neve knobs from ChuckD (http://www.groupdiy.com/index.php?topic=45767.0 (http://www.groupdiy.com/index.php?topic=45767.0)) I decided to call in an expert to calibrate my dual channel 1290s.... just to find out that there are some things wrong....

On my second channel the input transformer is dead... Colin is helping me out on that one. 

On the first channel, I still have a serious amount of distortion in the audio signal. Plus that adjusting the small trimmer does nothing to adjust the audio signal. The trimmer is working though, adjusting it does affect the v I can measure on its legs.

these are my cap values (first how they should be, second line what I measure.. in bold anything with more than 0.5v difference):
   C      B            E
1   3.6      0.9   0.4
   2.1      0.9   0.3

2   22.6      3.6   3.1
   23.6      2.1   1.5

3   22.6      3.1   2.5
   24.1      1.7   1.1

4   3.8      2.4   1.8
   3.8      2.4   1.8

5   12.4      3.8   3.2
   13.1      3.9   3.3

6   20.6     12.4   11.8
   22.2     13.4   12.8

To make things more complicated, last night I measured perfect values for 24v on the powerinput on the board and the 48 phantom, now they are up to 30v and 60v!

so.... :-)

Anyone?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Siegfried Meier on January 11, 2012, 12:22:17 PM
I replaced The 2N3055 and still no voltage in that section.  Checked and rechecked all solder joints, clean as a whistle.  I even disconnected the input and output transformers just to see if those were doing something weird (I've had 1 bad input trafo before, but it only caused audio hum and buzz).

Edit - ARGH!!  I forgot the make the pin 2-pin 4 links on the output transformer!!  I had no idea this would completely kill that entire section!!

 :o
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 11, 2012, 01:01:59 PM
Quote
Edit - ARGH!!  I forgot the make the pin 2-pin 4 links on the output transformer!!  I had no idea this would completely kill that entire section!!

 8)   did you get it going then?

I've been burning my channel with issues for several hours, and cannot duplicate the fault. 

I hate these mystery issues.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Siegfried Meier on January 11, 2012, 01:16:47 PM
Voltages are great now, but no audio on either channel.  Clearly it's something else I've made a mistake on.

Looking at the schematic though, it shows that the LO1166 is in that BA183AM section, so I should have known better.

Still working away...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on January 11, 2012, 01:18:11 PM
Voltages are great now, but no audio on either channel.  Clearly it's something else I've made a mistake on.

Looking at the schematic though, it shows that the LO1166 is in that BA183AM section, so I should have known better.

Still working away...

Are you using a trimmer?  If yes how is it configured, if not do you have the 10K and jumper installed?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Siegfried Meier on January 11, 2012, 01:32:09 PM
Ahhh so simple, I knew it.  I forgot the jumpers on the JLM Go Betweens.  I actually had to pull these out of another preamp that used the JLM DI, since my other Go Betweens didn't show up.  Since the DI attaches with a ribbon connector, the jumpers aren't needed.

So simple... ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 11, 2012, 02:05:04 PM
The great "AH-HA!" moment... isn't it a wonderful feeling?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on January 11, 2012, 02:12:37 PM
Can I order an Ah-ha moment as well please?

Wow.. I just got one...

I reported a few posts back that I had way to high voltages on the 24v point of the board and on the 48v... after shutting down the machine and leaving it for a while, they are back to normal after I switch them on!!  BUUTTTT, the levels are slowly rising! As are the measurements of tr1 -6. In the beginning everything is pretty good... but as the 24 volt is climbing up, these measurements are going bad as well! What is going on?
 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on January 13, 2012, 02:36:42 PM
OK, very funny... NOT. Battery in my multimeter was running empty... now all values including TR1-6 are correct.. sigh....
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on January 14, 2012, 05:15:06 PM
Hi all,


well i finished my build over Christmas, no big problems.
All voltages are nearly matching perfect martin ones.
How are the calibration experience around? I first check and trimmed
the voltage, after that the oscilloscope check showed good results at the
first place.

Great project, thanks a lot martin!

The push knobs were a bit killing me... I did some planing errors on
the front panel layout. But I and the panel survived  ;D

Also the front panel is "special" edition for lead singers
and lead guitarists, both can have channel 1  ;D  ;D  ;D

Up to now I just did a few quick tests, intensive testing has to be done.
Here are some pics of my build.

ROCK-ON!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 14, 2012, 11:37:45 PM
NICE build!  Care to share what that power supply is?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on January 15, 2012, 02:18:44 PM
The power supply is a Sunpower 48V one
http://www.conrad.de/ce/de/product/510388/Sunpower-SPS-035-48-Netztm-get-35W/SHOP_AREA_17448&promotionareaSearchDetail=005

Plus a additional little RC-Filter and a JLM TREX to get the 24V for the boards.

JLM has nearly the same one.
http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=122

No hum, no nothing. I have used these power supplies in a few other racking projects.
I like them... :)

ROCK-ON
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 15, 2012, 03:44:44 PM
i like the look. seems like theres no torroid... Yes?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on January 27, 2012, 07:47:58 PM
Hello,

i just finished two ez1290. One channel works great and sounds even better. The other doesn´t work until now. The BA183NV stages measures fine but the BA183AM is really confusing me. The voltages i read are the following:
            C       B        E
TR1    23.7     0        0
TR2    24       23.7   23.2
TR3    24       23.2   22.8

Should i try to change TR1?

Edit: Sorry guys there´s a sucker born every minute. I just didn´t solder the 2N3055 pins to the PCB. Now everything works as it should.
Thank you so much madriaanse for the boards. Really great work.

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 30, 2012, 11:25:11 PM
Awesome; glad you got it all sorted out! Enjoy your mic pre's!

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on February 01, 2012, 05:42:44 AM
has anyone of you managed to add an instrument input to the 1073 yet?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: erikb1971 on February 01, 2012, 06:12:54 AM
I have added a di with the JLM audio add on kit
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 01, 2012, 07:31:27 AM
Hi guys!!!
First of all a big hello for everybody. Really impressed with the website.
Since the moment I crashed on this thread I've been really excited with the whole thing. In the past I had the opportunity to work with neve 1073 and u-87 mics recording a grand piano.... just nice.
The other day I received the boards from Martin. Man, thanks a lot, those are extremely well finished boards, great job man.
Also got the components and started to populate the boards.  Did my ordering to Mouser and Digikey sticking to Martin's bom, very happy when I received the items and saw the quality. You'll never find components like that in Barcelona.
The only thing I couldn't get from Digikey was the KEMET 10uF 25v tantal caps, they have a substitute in Mouser, also manufactured by Kemet, but on the ref instead of ending with AT, ends with AS (i think). All other specs seem to be the same. Do you guys think should I wait or I go for mouser ones???

I've been reading on the JLMGoBetweens... Is it possible to  to add the line/instrument input that the channel strip had? I mean, not like a DI, with the original input transformers. (Read something about it but cannot find the reference).

Well, once again, thanks Martin for this great and extensive project, good work pal.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 01, 2012, 09:51:00 AM
Martin made a line-level version of this board.  As far as i know, the mic pre board wont take a line level without some serious alterations.

As far as the components go, doesn't matter WHO you order them from, chances are the manufacturer is the same.  Just make sure the components are the correct values.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 01, 2012, 10:21:43 AM
has anyone of you managed to add an instrument input to the 1073 yet?

Yes, the A-designs REDDI sounds really nice with a 1290.  ;)

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on February 01, 2012, 11:39:03 AM
As far as i know, the mic pre board wont take a line level without some serious alterations.



I made some cables with a -40dB pad inside, this worked well.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dmp on February 01, 2012, 11:52:16 AM
Quote
As far as i know, the mic pre board wont take a line level without some serious alterations.
If you look at the Neve schematic it is EASY to make a line level input with a switch and a line in transformer.
Basically, the switch changes the input from the mic transformer to the line transformer, through a voltage divider. In the original there were a few voltage divider positions for line (something like -10dB, -5dB, 0dB). I just used a single position for -10dB at the lowest gain setting, if I recall correctly, then the gain switch allows you to increase as needed. So, you need a switch, a line in transformer and a couple resistors.

I would not have done this in retrospect, though - I think there would be a better use for the line input transformer. Running a line level signal does not change the sound in my opinion - unless you plan to use this for make up gain or add an EQ, or do something else necessary.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 01, 2012, 01:45:16 PM
I was under the impression that and entire section of the schematic would be removed for line level... ill have to take another look.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 01, 2012, 06:00:03 PM
That's what I thought dr1200, the tantalum caps must be almost the same, I guess that just one number in a 14 number reference is not that bad  ;)

Really never thought about using a DI/micpre to record an instrument Martin, always finish miking an amp. Never saw tube DI's like the one you show on your link either. I'll check that one. ;)

I'll check what dmp says about the schematic and using a line input transformer. I remember using that feature and would like to implement it at least to one channel.

Thanks guys!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 02, 2012, 12:17:48 PM
Thinking about the Gobetweens for pad and phase... do you think this items could degrade signal quality in any way??? I mean thinking about adding it cos is easy and affordable, but would be a complete NO if that was not good for the signal...

And by the way, I know that condensers are a world and the sound of any effect is subjective blablabla, but....

When schematics show electrolitic caps, just go for correct values and choose best quality brands.

When non polarized low values, like pf, avoid always using ceramics???? Is always better styroflex???

When using nF range non polarized.... poliéster or always better mkt or similar...

When any polarized value in uF range, is always better to use tantal if you can reach the value????

Sometimes I find myself doing simple audio effect circuits and I don't know if designers prefer go cheap or they choosed that caps for specific reasons. Could you say that for audio circuits you should always use certain kind of caps¿¿¿

Sorry if the question is a little upside down, bit like my mind! ;P
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: SubhumanRecords on February 02, 2012, 12:25:11 PM
Hello all,I'm trying to finish up my 1290 with dan's collective case,can someone please tell me what size the standoff are..Thanks everyone...Myke
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 02, 2012, 01:53:23 PM
If i remember correctly, martin was very specific as to what "kind' of capacitors to use and where and im sure for good reason.  This is DIY, and yes everything is subjective.  Try different caps if you think they'll sound better and let us know the results :) :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 02, 2012, 02:25:05 PM
Nops, you misunderstood!!!  ;D
I was not even considering to change the components from this projects, I was speaking generally.
Don't have electronic designs skills at all, so I've strictly sticked to Martin's bom.

Just wanted to know about people's minds on capacitors and audio circuits.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 02, 2012, 03:18:31 PM
people say they can hear a difference when there are caps in the audio circuit depending on what "type' they are... Ive built 6 channels of these so far with different caps and I don't hear a difference that would cause me to lean toward one type or another.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 02, 2012, 03:30:39 PM
that's what I was asking for  ;)
thx
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on February 03, 2012, 10:03:00 PM
any objection towards this transformer for four units? http://de.mouser.com/ProductDetail/Triad-Magnetics/VPT48-1040/?qs=sGAEpiMZZMuKmRn7rpQYPRSGU26rTs7Qqq%252bTZQYE73M%3d

Have a bad feeling running the recommended toroid transformer at 44 secondary instead the necessary 48.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 07, 2012, 03:38:04 PM
Really never thought about using a DI/micpre to record an instrument Martin, always finish miking an amp. Never saw tube DI's like the one you show on your link either. I'll check that one. ;)

Well I was mainly talking about bass and/or keys. You pretty much can't go wrong with the A Designs REDDI, or Avalon U5 through a 1290/1073. For guitar I always mic the amp, unless I'm also recording a DI for reamping.

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: travis on February 08, 2012, 02:56:53 AM
Quote
If you look at the Neve schematic it is EASY to make a line level input with a switch and a line in transformer.

I ended up making a line to mic level pad in a short length of cable.  Is described here toward the bottom of the page.   http://www.uneeda-audio.com/pads/

Really easy and its seems to work good!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 13, 2012, 10:28:21 AM
Quote
As far as i know, the mic pre board wont take a line level without some serious alterations.
If you look at the Neve schematic it is EASY to make a line level input with a switch and a line in transformer.
Basically, the switch changes the input from the mic transformer to the line transformer, through a voltage divider. In the original there were a few voltage divider positions for line (something like -10dB, -5dB, 0dB). I just used a single position for -10dB at the lowest gain setting, if I recall correctly, then the gain switch allows you to increase as needed. So, you need a switch, a line in transformer and a couple resistors.

I would not have done this in retrospect, though - I think there would be a better use for the line input transformer. Running a line level signal does not change the sound in my opinion - unless you plan to use this for make up gain or add an EQ, or do something else necessary.

Thanks for the advise. I'll think it twice beffore adding the extra cost of a line input transformer if it does really not make any difference while recording instruments like a bass.
Anyway... I've been looking for Neve schematics around and found some... Really don't know if there are any different versions. Could you point somewhere to find the neve schematics that match our project and also show the line input as it was????
Thanks a lot.
Really never thought about using a DI/micpre to record an instrument Martin, always finish miking an amp. Never saw tube DI's like the one you show on your link either. I'll check that one. ;)

Well I was mainly talking about bass and/or keys. You pretty much can't go wrong with the A Designs REDDI, or Avalon U5 through a 1290/1073. For guitar I always mic the amp, unless I'm also recording a DI for reamping.

Best,

M.
As a bass player that's exactly what I'm looking for. Cannot go for any of those DI for the moment, I'll be reading to see what's the best way to squeeze the pre while recording bass.
But thanks for the advise, will be taking in mind one of those in the future.

Quote
If you look at the Neve schematic it is EASY to make a line level input with a switch and a line in transformer.

I ended up making a line to mic level pad in a short length of cable.  Is described here toward the bottom of the page.   http://www.uneeda-audio.com/pads/

Really easy and its seems to work good!

Thanks for the add, I'll check this as well and see how does it sound!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 13, 2012, 10:35:06 AM
For a bass wouldnt you want the mic transformer and a DI input... keys a line input.  I've used the Mic pre for bass, and its BAD ASS!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on February 13, 2012, 01:08:31 PM
For a bass wouldnt you want the mic transformer and a DI input... keys a line input.  I've used the Mic pre for bass, and its BAD ASS!!
Never thought about using the mic pre for bass "as is", that's why I was considering about adding a GoBetween DI or doing the original line input. My mind is a bit cloudy, but I can remember recording bass straight into a hired 1073 line in input and getting a nice enormous sound (80' Epiphone EBM active bass).
Also recorded once straight into a universal audio mic pre with comp... great sound as well.
Of course I'll try one of those valve di martin mentioned...
Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 0dbfs on February 13, 2012, 02:10:55 PM
I think the 1063 modules use the 10468 mic input trafo for line in with a pad instead of switching a line-in trafo into the path.

Cheers,
jb

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 13, 2012, 05:46:17 PM
Whistle Rock makes a passive and active DI (might need the passive since the Neve doesnt have the rail for it) but you might be able to integrate that into the unit with a switch.  As for the UA (probably a 610... all tube) INCREDIBLE sound for bass, but the neve has a very distinct flavor to it. If you want a fatter. more round tone, the UA 610, if you want that funky in yo' face tone, Neve (Bootsy swears by his...)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuc224 on February 21, 2012, 02:29:10 AM
Is there a jensen or cinemag transfo that will sub for the carnhill or EA input transfo?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 21, 2012, 01:50:56 PM
I had a lengthy convo with dave from cinemag once about this. He does have a replacement, and feels that is more colorful than the carnhill. I will be trying one out later this year (hopefully)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on February 21, 2012, 11:00:58 PM
I used Cinemags on my build....unbelievable sound....
I have a client who borrowed them for a weekend......6 months ago still using them!!

Really CMMI-2C input.
(http://twin-x.com/groupdiy/albums/userpics/normal_neve3.JPG)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: deuc224 on February 22, 2012, 05:30:54 PM
Nice, thats what im talking about. I was looking into this just because i wanted to see if anyone had a less colored input tranny and i would use the the EA or carnhill output, or vice versa, just to be different ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Math on February 28, 2012, 12:13:24 PM
Hello all, can you give me the size of a EZ1290 pcb's ?

Thank you .
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on February 28, 2012, 05:24:10 PM
Somewhere either in this thread or in the Collective Cases white market thread I posted a photo of the pcb against a cutting board with measurements.  I don't recall the dimensions off top of head.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Math on February 28, 2012, 07:08:54 PM
Thank you, I had the answer for Martin.

6-5/8 X 3-3/4 inches
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on March 14, 2012, 11:55:09 AM
Does anybody know a substitute for this part?

http://de.mouser.com/Search/ProductDetail.aspx?R=BC184Cvirtualkey51210000virtualkey512-BC184C
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: bruno2000 on March 14, 2012, 12:57:15 PM
Does anybody know a substitute for this part?

http://de.mouser.com/Search/ProductDetail.aspx?R=BC184Cvirtualkey51210000virtualkey512-BC184C

https://sites.google.com/site/diypartsstore/
Best,
Bruno2000
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Illusionist on March 15, 2012, 06:15:31 PM
So today I was thinking about the idea of building a preamp in the style of Neve and I start Googling. I find this thread and felt very motivated to sign up at the forum. So this here will be my first post on the forum.   :)
It is very exciting to see so many people build their own pre’s here.

Anyway, I have carefully read and saved the instructions of the guide and I am seriously considering to give this a shot, building the 2 channel pre.

However, I have very little experience with electronics. I know how to assemble a computer and that’s pretty much it.
I’d like to know if I am being realistic for wanting to try building a preamp having no experience. I just get a great vibe from this forum and everyone seems to be so helpful.
Some feedback would be awesome!

Thanks guys
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 16, 2012, 12:10:26 PM
Anything is possible provided you have enough ambition to learn(all the information you need is at your fingertips, literally)
and enough determination to see it through to the end. You have to get the case together, powersupply, parts list for everything, wiring, etc, etc... The frontpanels for this(if you don't want to design your own) can be had from Dan in the white market. It's quite a bit of work and will get frustrating at times, but it is rewarding if you do a good job. + there's just a ton of good info about all kinds of things here.

Here's another link where someone asked a similar question: http://www.groupdiy.com/index.php?topic=47771.0
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 16, 2012, 12:44:37 PM
For the record... this project was my first.  I did have previous soldering and electronic experience, but nothing on a build from the ground up level.  My advice....
RUN!
Run as fast as you can and as far as you can... once you make one thing, you're going to want to make more and more and more, and soon your work space and living quarters will look like a Radio-Shack or Mouser exploded and PCBs will build up on shelves in a TO DO pile that will NEVER get smaller because as soon as you finish one 2 more take its place...  Pretty soon you'll stop shaving and take on a mountain man appearance and start looking through peoples garbage to find "salvage" parts like transformers, inductors heat sinks, transistors that are no longer manufactured and other seemingly useful things.  You'll start mumbling ohms law at the supermarket trying to see what the voltage would be if the price of potatoes was the current and the price of cantaloupe was resistance.   Then the A&E network comes to your home asking if you would participate on their show "HOARDERS".  Take heed sir! Take heed!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Illusionist on March 16, 2012, 03:52:10 PM
Thanks for the extra push of motivation! :-)
I've been reading up on this all day long, using wiki, trying to get an idea of what the components do.
I made some accounts at the webshops too.

My question is, they don't have the following component on Mouser anymore  :

Transistors Bipolar (BJT) NPN 45V 500mA HFE/8
nr: 512-BC184C

Could I replace it with another transistor from this list?
http://www.digikey.nl/product-search/en/discrete-semiconductor-products/transistors-bjt-arrays/1376378?k=Transistors%20Bipolar (http://www.digikey.nl/product-search/en/discrete-semiconductor-products/transistors-bjt-arrays/1376378?k=Transistors%20Bipolar)

Or perhaps I could get it from someplace else? I need 8 of them.

Thanks guys

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on March 16, 2012, 06:39:33 PM
... once you make one thing, you're going to want to make more and more and more, and soon your work space and living quarters will look like a Radio-Shack or Mouser exploded and PCBs will build up on shelves in a TO DO pile that will NEVER get smaller because as soon as you finish one 2 more take its place...

 ;D ;D ;D
Ohhhh, that is soooo much the truth  ;D ;D ;D Great!!!

ROCK-ON!

PS. Don't forget the music  ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 17, 2012, 02:50:35 PM
Read a few posts back. Theyre no longer available, a few places like the one listed has some available.  Get em while theyre able to be gotten.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: LesPaul on April 11, 2012, 02:51:23 AM
Anyone tried these?
http://www.ebay.com/itm/BC184C-BC184-Transistors-Sinclair-Computers-50-Pack-/260836680462?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item3cbb13e30e

Would this be a good replacement for the original?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Le Roux on April 11, 2012, 10:11:08 AM
I believe they are the fairchild BC184C.

I just received my package a few days ago, but haven't opened to confirm 100%.
From what I seen through the package, the stuff printed on the transistor appears to be the same as the fairchilds I have.


The ones I ordered were from Retrocomputers off ebay.

They have the same markings as the fairchild ones I have.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: LesPaul on April 12, 2012, 09:47:23 AM
I believe they are the fairchild BC184C.

I just received my package a few days ago, but haven't opened to confirm 100%.
From what I seen through the package, the stuff printed on the transistor appears to be the same as the fairchilds I have.


The ones I ordered were from Retrocomputers off ebay.

They have the same markings as the fairchild ones I have.

Just ordered some myself. They have the Fairchild "f" on them, so they can't be to far from the original... Should be the same as far as I can tell.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Le Roux on April 12, 2012, 02:24:22 PM
Closer inspection last night reveals that my original fairchild's have the "f" then BB13 in small hard to read writing next to it, and the ones I ordered have the "f" with BA41 in small next to it.
I tested the hfe, and they averaged around 450, where as all 8 fairchilds I have tested around 300-350.

I do think they're good to go!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: bruno2000 on April 12, 2012, 05:11:15 PM
Most of the Fairchilds that I got from Mouser before they went away had hfe of 500-600.  I, too, ordered some of these, and will publish the results after I test them all.
Best,
Bruno2000
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on April 13, 2012, 10:37:44 PM
what should i get for replacement on this bc184c?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: tomas1808 on April 13, 2012, 11:26:01 PM
Here are some recommendations:

http://www.groupdiy.com/index.php?topic=48279.0 (http://www.groupdiy.com/index.php?topic=48279.0)

I would go for the BC109c since it was a Neve approved substitute apparently.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on April 15, 2012, 09:34:14 AM
C4, C6 & C7 (Capacitor Electrolytic 82uF 25V) deviate from the board's indicated 100?

Is it still fine to go with?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: domi62 on April 15, 2012, 10:21:38 AM
Hi
Here is an email from Martin :

My understanding is that Neve used BC107/BC109/BC184 interchangeably. BC107 and BC109 have been replaced with BC547 and BC549C respectively. Using the EZ1290 layout from here:
http://s3.amazonaws.com/EZ1290/transistor_voltages.pdf

You can use:
BC549C for TR1, TR4
BC547 for TR2, TR5, TR6
2N3055 for TR3

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: LesPaul on April 17, 2012, 01:58:37 AM
Closer inspection last night reveals that my original fairchild's have the "f" then BB13 in small hard to read writing next to it, and the ones I ordered have the "f" with BA41 in small next to it.
I tested the hfe, and they averaged around 450, where as all 8 fairchilds I have tested around 300-350.

I do think they're good to go!

Finally got mine too. It seems that they have different labelling on them, "BA12", "BA17", "BA35" and "BA41". I haven't tested them yet, but do anyone know what these different markings mean?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on April 17, 2012, 05:04:54 AM
Does also anybody know why there hasn't been the 2200u 25V capacitor on the BOM?

Or has there been a change in value?

Such as C4, C6 & C7 (Capacitor Electrolytic 82uF 25V) which are maybe for this purpose and therefore deviate from the board's indicated 100?

*Edit* I simply chose 100uf 25v capacitors for the not corresponding 82uf and took the missing 2200u capacitors also into my cart. Wondering why it is not listed under the official metal BOM.

Anyways, what I'd still like to know is what it means to draw EH10023. I suppose this is a section of the board but nothing more? Does it have to be tapped (possibly by placing the 180uf capacitor there) in a way of modding it to deliver more gain? Didn't find a hint throughout all the thread's pages.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: thefastvinny on April 18, 2012, 10:30:13 AM
Hi All,

Finally got around to building this pre. I found a stock of BC184C at Future Electronics, OEMS Trade is great for sourcing hard to find parts. I have a problem with this build though. I have not gotten my Carhill Trafo's yet but had some old Neve's laying around.

Mic Input is Belclere TF10016
Output is Big Orange VT24499

Pre is passing signal and amplifying but I have a drastic difference (about 25dB) from 100Hz to 10kHz, with 1kHz in the middle. Frequency response is way off. I wouldn't think that the trafo's would cause this, but I could be mistaking. Let me know if anyone has any thoughts. Solder On!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on April 18, 2012, 10:43:36 AM
@atticmike, The first BOM on page 1 also uses the metal film resistors for the most part and has all the correct values.  Maybe go off that one instead?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on April 18, 2012, 02:15:40 PM
I chose these for that purpose:

http://uk.mouser.com/ProductDetail/Nichicon/UKA1E222MHD/?qs=ZkXqA7GzKJJMuw8S3Hf38Q%3d%3d

http://uk.mouser.com/ProductDetail/Nichicon/UFW1E101MED/?qs=kArNe9LFxXmnkbKvib80gQ%3d%3d

Also noticed that you were all building external power supplies. What if I isolated the power-section with metal plates and anyhow, don't toroid transformer cause the least trouble in audio racks with the unit's transformers?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 19, 2012, 12:07:30 PM
Depends on how many channels your going to build. Toroids are noisy...even to units
above and below in the rack. Placement and good grounding practices is everything.

I used some mu foil to add a litte extra shielding where needed.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on April 19, 2012, 05:07:30 PM
Depends on how many channels your going to build. Toroids are noisy...even to units
above and below in the rack. Placement and good grounding practices is everything.

I used some mu foil to add a litte extra shielding where needed.

Gonna put two neves in the same box with two ssl 9k so it won't be that bad whereby there is another build with four apis in one box.

How for example would be the best placement of a toroid transformer? Horizontal or vertical?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 19, 2012, 06:16:40 PM
I don't know, i think it's noisy either way. You can try looking on a scope or just listening and turning it to see what's best.
One of these probably wouldn't hurt: http://www.don-audio.com/trafo-shield

Make sure the inputs and transformers are shielded/placed properly and you won't have any problems.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on April 19, 2012, 07:31:15 PM
I don't know, i think it's noisy either way. You can try looking on a scope or just listening and turning it to see what's best.
One of these probably wouldn't hurt: http://www.don-audio.com/trafo-shield

Make sure the inputs and transformers are shielded/placed properly and you won't have any problems.

Seriously? I mean aren't builds such as the 1176 also prone to such noise floors and still several people just put the transformers in the same enclosure?

What if I shielded every f**king thing that resembles a magnet as you said including the unit's transformers? :D

And about the grounding I shouldn't have to be worried since a put a lot of effort in grounding the sh*t out of my builds.

I'm just trying to be reasonable considering what people do with their other builds, including people that have also posted on this thread.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 19, 2012, 08:42:35 PM
Well, i mean you wanna use de-facto carnhill inputs as they will be shielded properly. The rest is just common sense and experimentation.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on April 20, 2012, 04:44:54 PM
I'm putting together a dual ez1290 in a 1u case. What length stand off did you guys(who used a 1u case) use in order to have the gain switch remain in the center. I assumed I should simply divide the 1.25" (2u case) in half to a .625" standoff. Advice?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 20, 2012, 10:23:22 PM
That's the tough thing...exact measurements, to avoid unneeded stress on parts. Mine were installed vertically....so there were no feet. But for the things that i did need exact measurements for, i used a digital caliper...then checked...double checked...triple checked, quad, quint, etc....in reference to my frontpanel layout.

Time consuming, but it's worth it. Get as close as you can...then shim with plastic washers, etc...if needed.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: muffy1975 on April 25, 2012, 08:52:30 AM
Hey team,

is the only reason for not using BC184LCs the pinout? I was wondering cos, i have found a stash of them with HFE all around 650 and to rearrange the ECB to EBC is quite easy.

thanks for any help

Michael
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dmp on April 25, 2012, 03:13:10 PM
Quote
I'm putting together a dual ez1290 in a 1u case. What length stand off did you guys(who used a 1u case) use in order to have the gain switch remain in the center. I assumed I should simply divide the 1.25" (2u case) in half to a .625" standoff. Advice?
I'm not sure I understand correctly, but if you center the gain switch on the front panel the pcb won't be in the center, since the pcb mounts to the bottom of the switch. I think I used either 1/4" or 1/2" standoffs when I built mine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: funkymonksf on April 26, 2012, 12:25:06 AM
I wasn't refer to the PCB as the center, I assumed 1.25 length used in the 2u to be relative and therefore the 1u case would require half the length at .625... Hmmm maybe
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on April 26, 2012, 12:32:49 PM
Best thing to do is created or draw a mock up on paper. Do you have the case already? You could use a caliper and take case measurements, draw them exactly on paper(drawing it like a sideview)....assume a standoff size...say 8mm, draw them in, then draw the pcb/switch and find out where it ends up on the frontpanel. That's where your switch hole, etc would go.

Adjust from there...

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on July 04, 2012, 12:57:30 PM
Got a question.. whats the input impedance for the pre (i have 6 of em and dont even know) the 1073 has a switchable impedance and i'd like to possibly mod mine to do that as well.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dustbro on July 06, 2012, 04:09:20 PM
Hey team,

is the only reason for not using BC184LCs the pinout?

I recall reading somewhere that the pinout is the only issue. If the HFE is high enough, you should be fine.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on July 19, 2012, 01:54:36 AM
I've just finished mine, and can't wait to test it on recording session.
You can find on the 4th reply a 48v/pad/pol pcb and an input transfo pcb for switching impedance.
Enjoy!
Another EZ1290 (http://www.groupdiy.com/index.php?topic=45983.0)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on July 19, 2012, 10:03:50 AM
the JLM add on (which i have on all 6 of my pres) doesn't have an impedance selection. :( :-\ :'(
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on July 19, 2012, 11:11:02 AM
Don't be sad, just take the input transfo pcb, a switch, and it's done   ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: rokus666 on July 19, 2012, 11:21:43 AM
I would like to start a 4 channel project.

will collective cases 4 channel 2RU work with this one?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on July 19, 2012, 11:26:22 AM
I don't know, everytging I make is all custom (except the EZ1290 main board).
You can easely draw a drill mask out of it and see if it can fit. If not, just use switches and wires them without the switch pcb.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on July 19, 2012, 03:59:46 PM
Id really appreciate a schematic for this.  I thought there was already input impedence on the main board so wouldn't you have to bypass that or put this in place of?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on July 19, 2012, 06:02:00 PM
I think impedance depends on the way you wire the input transfo. 3 and 4 together or 2 and 3 , and 4 and 5. So no such thing can be already on the board. Go back few pages before, + posted that on pdf. The 48/pol/pad schematic is based on fabio's replica 312. 8ack home, +'ll post this.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on July 19, 2012, 07:14:51 PM
Here it comes.
Transfo infos can be found here :
Reply #1043 (http://www.groupdiy.com/index.php?topic=22828.msg577098#msg577098)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on July 19, 2012, 10:17:44 PM
ok so then the switch connected to the trafo will determine the connection thus determining weather it is 300 or 1200 ohms
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sam system-d on July 19, 2012, 10:46:37 PM
Actually, the switch commands the relay, and the relay determines the connections.
As this particular project is sensitive to noise and you have to use shield wire everywhere, I thought that keeping the relay next to the transformer was better for he signal. Mitsos gaveme this idea on page 53.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mitsos on July 20, 2012, 03:53:35 PM
hey nice!   I ended up doing the impedance thing the same way, no pad though, just polarity, 48V, and impedance.   
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on July 26, 2012, 04:21:19 PM
will be putting my neve / ssl box together by this weekend with the jlm powerstation v3.

just to keep the other transformers for my eq racking, I'd love to know whether I can still use the 22 v transformer from the manual that I bought and thought it was a complete waste since the preamp runs at 24v? (european 230v)

TE62085-ND: http://www.digikey.com/product-detail/en/62085-P2S02/TE62085-ND/299881

*edit* Does it have to do with the capacitors powering up such as 22v * 1.414?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 26, 2012, 09:48:35 PM
Feed the powerstation what it wants...24vac to 30vac.

Edit: actually, joe has a new spec on his powersupply. Apparently 15-30vac now...so you should be ok as long as you have version 3...i guess.

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on July 27, 2012, 02:22:13 PM
Feed the powerstation what it wants...24vac to 30vac.

Edit: actually, joe has a new spec on his powersupply. Apparently 15-30vac now...so you should be ok as long as you have version 3...i guess.

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12

nah, rather talking about 24v the pre needs but still being able to power it properly with just 22v secondary since the capacitors load up and with its saturation  level out the gaps?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on July 27, 2012, 07:56:21 PM
Feed the powerstation what it wants...24vac to 30vac.

Edit: actually, joe has a new spec on his powersupply. Apparently 15-30vac now...so you should be ok as long as you have version 3...i guess.

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12

nah, rather talking about 24v the pre needs but still being able to power it properly with just 22v secondary since the capacitors load up and with its saturation  level out the gaps?

Well, you have to feed the powerstation v2(24-30vac) and v3(15-30vac) then it's rectified, filtered, etc to your adjustable DC voltage...so whatever AC input voltage it wants, is what you need to give it. You have 22vac...so if you have a version 2 powerstation, that's not enough. Or, consult Joe about it...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on July 27, 2012, 08:33:51 PM
Feed the powerstation what it wants...24vac to 30vac.

Edit: actually, joe has a new spec on his powersupply. Apparently 15-30vac now...so you should be ok as long as you have version 3...i guess.

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12

nah, rather talking about 24v the pre needs but still being able to power it properly with just 22v secondary since the capacitors load up and with its saturation  level out the gaps?

Well, you have to feed the powerstation v2(24-30vac) and v3(15-30vac) then it's rectified, filtered, etc to your adjustable DC voltage...so whatever AC input voltage it wants, is what you need to give it. You have 22vac...so if you have a version 2 powerstation, that's not enough. Or, consult Joe about it...

now I get it :D

no it's fine, got the v3
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: orangechili on July 31, 2012, 12:17:41 PM
Hey guys,

I have a dual channel 1290 here that has one channel humming and has a thin output, no low end.  I've built up a number of these, but have never encountered something like this.  I've scoured the thing for hours on end, checked solder joints etc.  Any clue where to look for what might be wrong?

Thanks!
Sig


I have basically a similar issue on a single channel 1290 build, there's no hum but a little less output and lack of low end. It was working well before but something apparently happened. I changed out all transistors(they're socketed) and still same problem. 2n3055 collector voltage is still 22.6v which is normal. I don't have a scope yet unfortunately. I know the input transformer was mentioned as a possible issue but don't have any extra here to swap out. Is there anything else I should check before forking out the cash for another input transformer? Any help in figuring this out is greatly appreciated! :D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: orangechili on August 01, 2012, 12:24:07 PM
OK, Awesome! It was just a loose wire on the output xlr connection. I must have missed that on first inspection, very happy that's all it was ;D
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on August 01, 2012, 09:33:09 PM
Feed the powerstation what it wants...24vac to 30vac.

Edit: actually, joe has a new spec on his powersupply. Apparently 15-30vac now...so you should be ok as long as you have version 3...i guess.

http://www.jlmaudio.com/shop/index.php?_a=viewProd&productId=12

nah, rather talking about 24v the pre needs but still being able to power it properly with just 22v secondary since the capacitors load up and with its saturation  level out the gaps?

Well, you have to feed the powerstation v2(24-30vac) and v3(15-30vac) then it's rectified, filtered, etc to your adjustable DC voltage...so whatever AC input voltage it wants, is what you need to give it. You have 22vac...so if you have a version 2 powerstation, that's not enough. Or, consult Joe about it...

So with the powerstation v3 and the 22 vac mentioned transformer, the one from the assembly documentation, I can smoothly run four neves?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on August 02, 2012, 12:55:22 AM
Yeah, that should be fine. Powerstation with the 6amp bridge rectifier will give you 1.5 amps on the + rail.
1.5 /4 gives you 375 mA each.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on September 03, 2012, 08:54:56 AM
what am I actually supposed to do with the jumper?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: nikonet on September 04, 2012, 12:49:58 PM
Hi every one,

I've got a small question:

I made a 4 préamp rack, with 4 PCB. What to do with the 10R resistor connected between pcb 0v and Ground? Do i need one resistor for each pcb? or do i need only one for all the Pcb? And what does it do?

I ask this question because: when i test ohm between the ground and pcb's 0v there's less than 10R.

Thanks a lot
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on September 04, 2012, 09:51:28 PM
Did you use the JLM powersupply? Powerstation?

If so, it has the 10ohm resistor built in....so no need to add it. This is a floating ground. Leave the grounds unconnected on the outputs... To test it....measure ohms between 0v and case ground...you should get 10ohms.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: nikonet on September 05, 2012, 09:48:16 AM
Hi,

No it"s an Swithed power supply. So i need to test in the PSU between OV and Ground !

If 10R not inside the PSU, do i need only 1 for 4 préamp?

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: bigswole on September 05, 2012, 09:51:21 AM
are these boards still available?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on September 07, 2012, 05:13:36 AM
I know I'm a noob and pester most of the time but I got the following questions:

1: Why doesn't this build require -V?

2: Why is there no separate shielding for the input?

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 13, 2012, 03:48:32 PM
Hi everyone,

i build two channels of the ez1290. One of them has about 10dB more hum than the other. Has anybody an idea where this could come from?

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on September 13, 2012, 03:51:49 PM
post some clear gut shots. maybe someone spots something.

also, do you use an external power supply or do you have the toroidal inside the case with the preamps? if so, is the one closer to the psu humming?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 13, 2012, 07:15:02 PM
Thanks for quick reply. I don´t have a camera at hand just my (old) handy. I´ll take better pictures soon. But optical both channels look the same at least for me. The power supply is in an external case so no interferences from there. It´s time to get a scope again.

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 13, 2012, 07:17:51 PM
And another shot from the pcb.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: bluesbaz on September 13, 2012, 10:34:52 PM
I just finished 4 of these and my advice if you dont have a scope is to try and separate the various sections by grounding their inputs while listening to the output of the preamp. If you still hear noise the problem is after the grounded point if you stop hearing noise the problem is before the grounded point.

ground the hot leg on the output of the input transformer
then C8A
and then C8B
and lastly C1
If you still hear noise
build a stethoscope
listen to the cold leg of a cap of any value (rated higher than the voltage of your project) strapped to the hot leg of a quarter inch cable while the ground of the same cable is strapped to the ground of your project and poke around until you can hear the noise your hearing on the output.
CJ told me about this trick i will forever be grateful!
If the noise is still just everywhere I would look at your power supply

If you still haven't isolated the problem get back to us.
-s
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on September 14, 2012, 05:46:14 AM
MRecordds, the only obvious difference i can see between your two channels is that you swapped the resistor's and cap's posistions on the output transformer.

also, i used the same enclosure from banzai. isn't it total crap? it was the first time for me working with a 19" enclosure but i can safely say that there can not be a worse 1U rack for DIY than this piece or poorly designed junk. that it's made of steel doesn't help either. it's impossible to drill cleanly.

what i noticed when working with the enclosure is that case grounding via srews does happen mostly sporadically. i don't know why but it could be the finish on the enclosure and the crappy mounting methods between the parts of it.
do some tests with your DMM to see if the transformer casings and whatnot are case grounded properly. you may need to do some sanding or filing around the screw holes.

also, you could try to swap the boards and use either board with each possible configuration of transformers to get to the problems cause. (ausschlussverfahren).
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 14, 2012, 07:36:20 AM
I got it or should i say you got it useme. I use the same case for my power supply and it´s really the worst i´ve ever seen.  It really seems like the upper and down plates (hope you know what i mean) from the case aren´t grounded.  The output tranny of the noisy preamp is directly above the power tranny. I thought there is a case so there can´t be interferences but i was wrong. When i move the preamp about two inches the noise is gone.  Sometimes things can be so easy.

I´ll try the stethoscope. Sounds very interesting and can be a problem solver for future projects.

Thank you very much!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: wolfgang on September 14, 2012, 01:53:02 PM
Quote
It really seems like the upper and down plates (hope you know what i mean) from the case aren´t grounded.

You should remove the lacquer or the anodising from the top and the bottom of the case were you bolt them to the Main Chassis. And also on the Main Chassis nera the Screws. A small Dremel ist your friend!

regards,
Wolfgang
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 14, 2012, 09:10:18 PM
Hey wolfgang, you´re still here  :)

I already removed it but it´s a steel case. I´m a little bit afraid of rust and oxidation. Maybe a new case would be the best.

Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on September 15, 2012, 03:57:03 PM
It's tough to remove EMI. I used some mumetal sticky sheet on the case....ultraperm 80...and it helped. I also adjusted/moved things. You may want to place the power supply in a different location in the rack away from the preamps.
For my next unit...i was thinking of trying parmetal's EMI protected case...but it may amount to little improvement for more $$$. Not sure...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on September 16, 2012, 10:55:51 AM
Thanks for quick reply. I don´t have a camera at hand just my (old) handy. I´ll take better pictures soon. But optical both channels look the same at least for me. The power supply is in an external case so no interferences from there. It´s time to get a scope again.

Thanks

looks like there is no star point in your build ;)

Try to collect all the ground to a dedicated point and lead them there separately.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on September 17, 2012, 12:00:07 PM
question about biasing:

i just finished my first two channel unit of four planned dual preamps.

when trying to set the bias am i supposed to turn the trimmer until the clipping is equal on both sides of the waveform and then just stop turning the trimmer? because when i keep turning the trimmer the waveform looks equal on both sides for the whole 15+ more turns till the end.
meaning, when i turn the trimmer,which is a 20 turns trimmer, fully counter clockwise the waveform looks unsymmetrical. so i begin turning the trimmer clockwise and after three or maybe four full turns the waveform begins clip equally on both sides and once it reaches that status it looks like that for the whole 16 more turns of the trimmer. so i assume i just turn the trimmer until it looks good and then stop?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on September 19, 2012, 08:35:48 AM
anyone?  :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on September 19, 2012, 09:28:56 AM
Yeah, as far as I remember, once you have symmetry, you're good to go.  Not a terribly complicated process (unlike the 1176's haha)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: dmp on September 19, 2012, 09:45:57 AM
Quote
when trying to set the bias am i supposed to turn the trimmer until the clipping is equal on both sides of the waveform and then just stop turning the trimmer? because when i keep turning the trimmer the waveform looks equal on both sides for the whole 15+ more turns till the end.
meaning, when i turn the trimmer,which is a 20 turns trimmer, fully counter clockwise the waveform looks unsymmetrical. so i begin turning the trimmer clockwise and after three or maybe four full turns the waveform begins clip equally on both sides and once it reaches that status it looks like that for the whole 16 more turns of the trimmer. so i assume i just turn the trimmer until it looks good and then stop?

I think so.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on September 19, 2012, 04:56:58 PM
so, what are the (dis)advantages of biasing too hot or hotter than necessary?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 19, 2012, 05:49:03 PM
I just set it to what madriaanse recomended when you don´t have a scope. Sounds good t me :) Haven´t tried any other setting.

 Any news for the new cases?

atticmike: my starground is on the 5pin XLR where i connect m power supply. thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on September 20, 2012, 05:57:49 AM
the thing about setting it to the voltages according to madriaanse's voltage chart is that it seems to be way off from what i get with biasing it with a scope.
when biasing it with a scope to just get a symmetrically clipping waveform i get 16V at the collector of the 2N3055 (TR3 on the chart) as opposed to 22.6V while some if the other transistor's voltages not even 0.5V off from the voltages in the chart.

here's m. adriaanse's voltage table again:
ez1290 transistor voltages (http://i48.tinypic.com/103ivyh.png)

EDIT:

about the cases. i'm still waiting for the funds to buy some proper cases from modushop for the pres. i can't wait.
until then i'm stuck with this.

(https://lh5.googleusercontent.com/-t4U-7JEy900/UFrtGZ5RBYI/AAAAAAAABvI/2ouxF_5nAhg/s800/IMG_0861.JPG)

some ideas for front panels:

(https://lh6.googleusercontent.com/-JLZdrC4v8Yk/UFrxN09snaI/AAAAAAAABv4/AYfCQT6YCKw/s912/Bildschirmfoto%25202012-09-20%2520um%252012.28.17.jpg)

(https://lh3.googleusercontent.com/-yLnxySleMvI/UFrxPXEn6hI/AAAAAAAABwA/Q1nzZfHJSAY/s912/Bildschirmfoto%25202012-09-20%2520um%252012.30.01.jpg)

(https://lh6.googleusercontent.com/-Jz5CddOhkyE/UFrxRRf6ImI/AAAAAAAABwI/ZH7pFajWUTw/s912/Bildschirmfoto%25202012-09-20%2520um%252012.30.28.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MRecords on September 21, 2012, 09:14:31 PM
Now that´s a nice one useme.

Haven´t noticed that there´s such a difference in biasing. I´m not a specialist when it comes to electronic but wondering what´s the difference soundwise. Is it just like more third harmonics when it comes to clipping becuse it´s asymmetrical? Maybe a little bit more headroom?

And one real noob question :). Is my star ground on my 5 pin XLR? The only ground connections are the two 0V on the pcb and the LED one..

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on September 21, 2012, 10:41:43 PM
Now that´s a nice one useme.

Haven´t noticed that there´s such a difference in biasing. I´m not a specialist when it comes to electronic but wondering what´s the difference soundwise. Is it just like more third harmonics when it comes to clipping becuse it´s asymmetrical? Maybe a little bit more headroom?

And one real noob question :). Is my star ground on my 5 pin XLR? The only ground connections are the two 0V on the pcb and the LED one..

your star ground is a dedicated point in your chassis where you gather all the grounding to one point separately at best. 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Le Roux on October 13, 2012, 02:57:34 PM
I have original output transformers I'm going to use.

Any benefit to using the original cap and resisitor? Or will this just cause noise?

Thanks
Neil
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 19, 2012, 01:46:36 PM
AHHH I am having serious problems with my ez1290. Signal is passing through but Barely I have to turn the output knob just a little over half way to hear anything and if I turn it up to much is sounds like one of the transformers is whistling. NOT GOOD lats night It smelled like something was burning!!!!!! I turned it off right away. Also I noticed a couple of the resistor measure different they they should. Could this be because they are mounted to the board and things around them are affecting them or is something wrong. (HELP IS MUCH APPRICATED)

Also if using an external power supply should I just run a ground to somewhere on the power supply or ground the power supply and run the signal up to the case and ground the case to???


HERE IS A PIC the Vintage 1272 is working fine just not the ez1290.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on October 19, 2012, 01:52:42 PM
first of all, don't bother trying to measure resistor values in a built circuit. are you building one channel or do you have two channels with the problem happening in both channels?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 19, 2012, 02:03:47 PM
2 one a vintage 1272 and the other a EZ1290 the 1272 sounds fine just not the ez1290 I poasted a pic. Also if I touch the case like the front panel some of the noise stops.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on October 19, 2012, 02:18:11 PM
the first thing you should do is remove the trimmer pot and don't forget to place the resistor replacing it on the board.

also, try moving the input and output transformers of the 1290 apart...maybe begin with turning them 180 degrees in all possible configurations using the already drilled holes before you drill new holes.

make sure that audio grounding goes to chassis grounding at only one terminal...make that terminal a 10R resistor.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 19, 2012, 02:38:41 PM
ok so dont ground the power supply just run the ground up from the JLM AC/DC to the actual preamp case and ground that
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 19, 2012, 10:48:50 PM
For my unit which has an external power supply....i ran the ground from the power supply case(from wall ground) to the preamp case like normal. A 10ohm resistor is built into the ACDC. Simply don't connect your Ov @ the preamps to ground. So, when you measure from your preamp 0v to case ground, you should get 10 ohms.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 23, 2012, 01:04:49 AM
ok so I did what you guys told me and now for 0v to case I get a 10 ohm resistor reading. !!!!!!but now no audio is passing at all the second I plug anything in to that channel Just a REALLY BAD LOUD NOISE COMES THROUGH What is my next step???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 23, 2012, 10:16:10 AM
Double, triple check your wiring....input, output, audio ground(0v), case ground, etc. Sounds like you were having some strange issues before. I'm assuming just the ez1290 is making this noise. Go through and check the various voltages at components using Madriansse's voltage reference chart....you may have burnt something by accident from the sound of your previous post. Check voltages in/around the output section. Be sure to double, triple check things and blow off the pcb before any power up(small pieces of wire/metal). You should also have a fuse connected at the power supply just in case there's any mistaken shorts.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 23, 2012, 04:12:45 PM
ok ya I think Im grounding it right now. I appreciate the response Is there any way for me to check if the transformers are still working. I know something burned cause for about 15 seconds or so it smelt like something burning. Also I have since removed the output knob and the transformer not longer makes a funny sound. But now no signal is passing. AHAHAHA Just a really loud noise comes out. I will check the transistors when I get home today.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on October 23, 2012, 04:48:33 PM
when you removed the trimmer knob you didn't foget to place the 10k resistor and the jumper on the board right?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 23, 2012, 05:35:09 PM
Hey thanks fo the reply. No I made sure that I put those in place. Man it can be frustruating right. This has put my studio on hold. I cant wait till it works. TRIAL AND ERROR TRIAL AND ERROR!!! HAHA


ALSO I JUST noticed I for got to connect 2 points on the output transformer 6 to 7 I completely missed it!!!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 23, 2012, 10:17:04 PM
AHHH been working on it for about 3 hours no luck at all the second I plug in the out put xlr the signal starts peaking even if its not turned on :(
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 23, 2012, 10:37:05 PM
ok  I got signal to pass but there is a horrible horrible HUM
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 23, 2012, 11:51:45 PM
HAHAHAHAH ;D ITS WORKING!!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 24, 2012, 01:15:21 AM
Great to hear! :D What was the problem?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 24, 2012, 01:37:33 AM
Not really sure I replaced the .01uF cap and 1K5 resistor connected between Pin 8 and 5 on the output transformer. And the 2N3055 and a couple of other resistors on the board but still had a very bad hum but had signal finally!!!.  Then I had to ground the 3 pin on the line output to the board the one that says you can connect or not connect and that made it as quiet as a mouse. But I still dont have the JML go between hooked up I removed it to test everything so im gonna put that  back in tomorrow. . . SO IM NOT QUITE OUTTA THE BALL GAME YET!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 24, 2012, 02:18:26 AM
You never really are until everything is measured and sounding good. :) You should be able to still have it quiet though without the output shield connected. I ran into some ground issues and weirdness with other outboard by having the output shield connected...so i decided to disconnect it(as recommended). Didn't make any difference in noise...it was still quiet. Be sure your switch touches ground(frontpanel). I experimented with an alligator clip clipped to ground and touched various non-critical(energized) stuff to see where and when it went quiet. Keep at it and good luck! Just don't short the output transformer.  :o

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on October 24, 2012, 05:33:28 AM
last thing i was about to say before you said "it's working" was that you should check your xlr cords.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 24, 2012, 11:41:39 AM
ok so you dont think i need the output sheild cable??? What else could it be cause that seemed to fix everything. Ya I definatly dont wanna short the transformer AHAHA. Also when you say make sure you swicth is touching ground (front Panel) are you reffering to the Greyhill switch?? Also what would be non critical energized stuff???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 24, 2012, 12:03:22 PM
whats a good potentiometer that you guys can reccomend thats not too expensive???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on October 24, 2012, 12:27:41 PM
look for a decent conductive plastic potentiometer
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 24, 2012, 01:42:59 PM
Get crazy with your DMM in continuity mode.  Make certain all of your Grayhills, trimmers, toggles, XLR in/out, and ALL chassis panels are making good mechanical and electrical connection.  Start with a probe at one switch, touch every other piece of metal that should be shielded with the other probe, listen for chime, then move to the next piece again touching all other shielded pieces.

I didn't do this at first and had some low level hum that was nearly inaudible, along with some oscillations only at the highest gain settings.  The hum was so low we did not observe it when doing audio comparisons with some Vintech X73i.

I found that none of my panel XLRs were making electrical connection between the chassis and each other.  Also my Grayhills were insulated from the panel from the paint, This caused little spitz of static when I'd touch a knob to throw the gain switch.  I had to scrape paint and check with DMM for good continuity. 

The pots I used for trimmers were conductive plastic and ~$8/ea USD.  There's a link for them early on in this thread.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 24, 2012, 02:14:24 PM
???? AHAHAH I really know so little about all this stuff its a blessing that its even up and running. THANKS FOR ALL THE HELP REALLY. . . . ILL PUT UP SOME PICS WHEN ITS COMPLETE.

Also will a linear potentiometer work casue someone told me no???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 24, 2012, 04:05:08 PM
???? AHAHAH I really know so little about all this stuff its a blessing that its even up and running. THANKS FOR ALL THE HELP REALLY. . . . ILL PUT UP SOME PICS WHEN ITS COMPLETE.

Also will a linear potentiometer work casue someone told me no???


It's good advice by micdaddy to be sure you can make 'good' electrical(ground) connections between things...by good it means as close to zero ohms as you can get. It makes things quiet and safe. Continuity is a setting on your meter...it makes a beeping sound between connections when they are made, and should show you the corresponding ohm reading. Search for information on the pot in the build manual.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 25, 2012, 03:49:20 PM
PLEASE SOME MORE WISE WORDS..

What is the difference between the VTB9049 & the VTB9070 on audio maintenance
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 25, 2012, 05:09:02 PM
VTB9049 is a gapped transformer(lo1166). 10 second search reveals:

http://recording.org/diy-pro-audio-forum/41460-gapped-ungapped-trafo-how-know-difference-2.html
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on October 27, 2012, 08:59:41 AM
not sure if im in the right place but im wondering could u help me. i seem to be having a problem with my ez1290. channel 1 keeps cutting out. it kinda cracks with i talk into the mic and then will cut out. weirdly if i tip the case at the front for example it comes back. if i tip it again it goes again.there is kind of a pulsing noise very slightly in channel 2 as well.. id say they could be related. any ideas of what might be the problem? Cheers, Leo
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on October 27, 2012, 11:09:29 AM
i think you should check your ground connections.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on October 27, 2012, 11:17:27 AM
Cheers ill check that out. They seemed ok to me tho. Would that be causing it to cut out?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 29, 2012, 12:13:22 PM
Ok so im still having trouble. when to pre is turned on there is a slight buzz in my head phones. And with no mic enguaged if I tap on the front panel hard enough I can hear it quite clearly in my headphones????? Also when turning gain up it sounds good but turning it back down when I hit 50db it has a slight POP this only happens on 50db. ANY IDEAS ON WHAT I SHOULD CHECK???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on October 29, 2012, 12:36:26 PM
Sounds like ground issues to me.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 31, 2012, 01:10:52 PM
Ok I hope this is the last problem and it can be fixed fairly eazy. Everything is now working fine BUT I have the gain at 50 and the output up all the way and it seems to distort pretty eazy is this normal???? If not what should I check to get this fixed???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on October 31, 2012, 04:19:43 PM
Distorting with what at the input?  A condenser?  That's a lot of gain for a condenser and I would expect overloads.  With 50dB I can make it overload with a dynamic mic.

Are you positive you're not clipping the A/D?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on October 31, 2012, 04:42:28 PM
Ya its a condenser Akg c-414b-uls.  Well its running through a rosetta 200 and the rosettas not clipping for sure... So is that just normal??
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on October 31, 2012, 08:07:24 PM
so i checked my grounds and everything seems to be ok.. channel 2 is working fine. channel 1 however is still getting these weird pops, and when i touch the front panel i can hear is clearly. also when i touch things like the tops of the capacitors i can hear them clearly as well in the headphones or even just rub the card itself can be heard. do u still think its a ground issue? and if so what might i be doing wrong or whats the best way to ground this?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Dr_J on November 02, 2012, 05:19:40 AM
Hi leitrim_lad,

i would bet that you still have a ground or wiring issue.
Just follow straight the documentation of martin and you should be fine.
Good luck!


 
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on November 02, 2012, 04:06:38 PM
I cant seem to find anything wrong with the grounds.. channel 2 seems to be working perfect but channel 1 isnt. i didnt build this you see. i bought it second hand so im trying to figure out whats wrong. i cant figure out how the psu case is wired to the 1290 case or is this needed? der seems to be 2 wires going from the shield on both channels to the outside pin coming out of the output xlr on channel 2. is this correct? Iv included pics.. if you can see anything it would be greatly appreciated. thanks a million
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on November 02, 2012, 04:07:37 PM
pic2
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on November 02, 2012, 04:08:27 PM
pic3
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on November 02, 2012, 04:39:49 PM
Something else i noticed.. There seems to have been 3 50v 82uf caps used instead of 3 25v 82uf on the board where the problem is.. Would this make a difference? Ive included a pic..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on November 02, 2012, 04:42:34 PM
Also the cap beside the switch on the good channel is in the 2 holes closest to the switch, on the faulty card its on the 2 outside holes.. would that make a difference?

Cheers..
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: MicDaddy on November 03, 2012, 02:20:02 PM
Is the shield hooked up to the PCB relating to the wire coming from PCB audio out to output transformer? 

It looks like they are trying to tie the PCB mounting screw to a wire my guess is to the chassis?  Get rid of this...

The wire dress in general leaves much to be desired.

The capacitor footprint I believe should be ok, I think it's meant to be versatile for varying lead spacing.

I don't know what is happening within the PSU enclosure with that big honking resistor.  Yellow electric tape is generally not a good sign.

Caps rated at a higher voltage 'shouldn't' be a problem (someone correct me here if needed).

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 03, 2012, 02:44:06 PM
I'd almost be inclined to suggest (...for your own peace of mind, and learning) to remove and redo the wiring, both in the preamp case and the power supply. It looks like he didn't really know what was going on...then just decided to sell the unit.

You have some good components to work with and the pre's can sound good. Redoing the wiring will give you a chance to remove everything, have a look at what's going on...and then redo it all to your own standards.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on November 03, 2012, 11:33:38 PM
Hey guys! After 20 pages of posts I'm back again. I've been working abroad and this project has been boxed for a while....
Recycled a 2u rack chassis from an old amplifier and started the build, not being really tide cause that's not gonna be the final casing.

I'm at the final stage where biasing the driver stage.
Voltages are ok referred to Martin's chart, but since I borrowed a sine generator and I own a digital osciloscope, I'd like to do it the recommended way. Not really an expert with oscil.loscopes, and since I don't seem to be able to reproduce the same situation Martin describes on the biasing, I've got some questions:

-What should be the input amplitude for the 1k sine? If my pres are half the gain and the generator is also half the gain, I get a normal sine wave. As soon I increase the gain on the pres (via switch), the signal goes off the scale and I can hear my output trannies singing loud.

By having the pres half gain and increasing the volume on the generator, I start getting the distortion, but pretty much the same on both sides. The plain clips on the signal, seem to be longer on the negative clips than on the positive ones. By turning the 5k log cannot appreciate much difference since it flucutates a bit.
Dont' know If I'm doing something wrong. But found the process not to be accurate at all, 5 turns on the 5k log don't make any difference on the scope or the voltages on the transistors.

Maybe I'm doing something wrong...
Should I use the attenuator on the probe?

Haven't been able to hear the pres since I've got nothing to feed at today. Tomorrow will go for a try.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on November 07, 2012, 07:51:24 PM
Well, I'm still on the test biasing process, I mean, stuck on it.
Not really sure about the changes when turning the 5k log, but I have tried an sm-58 and a cheap akg condenser mic... AWESOME!!!
At full gain can hear the crackling of my saliva really loud!  they are quite as... don't know... quite!!!!

I'll keep on testing them out, but for the moment I must say....

THANKS MARTIN!!!!!  ;) ;D ;) ;D best audio diy ever!!!!

Reading about the 2N transistors on this post, I saw the recommended brand is Motorola. I'm not concerned about that at the moment, but the ones I got are StMicro, and the hfe I get on my semiconductor tester is 50. Isn't that too far away from the recommended 600 gain?

Thanks again for this project!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on November 08, 2012, 02:29:02 PM
ok So my 0v on the 1290 board to ground is reading .08 not 0 but when I test it at the JLM it reads 0 I tried messing around with the trim but nothing happens????
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 08, 2012, 07:49:36 PM
Your 0v to ground should be 10 ohms.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on November 10, 2012, 06:33:15 AM
O ya HAH
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: analogstud on November 13, 2012, 04:52:31 PM
Hey Guys! Quick question. This seems to be fairly subjective, and scanning this thread but can't seem to find much detail on a certain (best) replacement for the obsolete BC184C's in the EZ1290. There are a few suggestions but what is the one everyone has settled on? Otherwise, I was just thinking this one: http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/BC550CBU/?qs=sGAEpiMZZMsTKkj12KWLXhbg%252bxayotvaAhLFvgBk94w%3d (http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/BC550CBU/?qs=sGAEpiMZZMsTKkj12KWLXhbg%252bxayotvaAhLFvgBk94w%3d)

Thanks Guys!

Dave.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 13, 2012, 07:57:54 PM
Not sure. This isn't too too bad of a deal: http://www.ebay.com/itm/BC184-BC184C-NPN-TRANSISTOR-FOR-SINCLAIR-PACK-OF-20-/320724381644?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4aaca9afcc
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on November 13, 2012, 08:21:56 PM
Eddie Ciletti has been using MPSA-18 for quite a while now.
I ve been using those too on EZ1084, 1272s and 1290...
Just turn them 90 degrees and you'Re good.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: analogstud on November 13, 2012, 11:38:03 PM
@desol

I suppose that's better than $1-2.00 I've seen others trying to get per unit! I'll keep that in mind.

@3nity

Know of a supplier here in the States? Can't seem to find much info on those :-\

Thanks Guys!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on November 13, 2012, 11:47:51 PM
Analog.
Typo my bad right part is MPSA-18.
Should be available although is going obsolete.

If you really need BC184C contact our fellow member called Bluzzi....the guy for the EZ1084...i think he got some!
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mr.fofith on November 18, 2012, 06:43:38 PM
Can someone give me a brief rundown on how to wire up a JLM Trex to this?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: geetar_king on November 20, 2012, 01:46:12 PM
sent payment for 10 boards!

From the forum most people are using the Carnhill transformers.   Are the Sowters (9145, 9160) for in/out the actual replacement parts Neve uses?    Saw some comments that the Carnhills sound more like the original Neves, but are the Sowters just harder to get/ more pricey?  Maybe I'll do some of each?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kpearsall on November 20, 2012, 06:07:51 PM
not sure about the sowters, but we tried the carnhills against the Ed Anderson transformers from hairball, and couldn't tell a difference in a blind test.
It's in an 8 channel unit, some of each. no problems mix and matching while recording a stereo pair. If the difference is that hard to hear, I'm not sure it bothers me.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 20, 2012, 06:24:09 PM
Can someone give me a brief rundown on how to wire up a JLM Trex to this?

Hey. Welcome to the forum.

Best thing to do is contact Joe @ JLM. He's very helpful.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on November 24, 2012, 05:18:48 PM
powered up my boards without having it sit in the box (without the in & output transformer connected) in order to measure at the testpoints before mounting it and I get really low voltages or nothing at all. If i check the 1W resistor, it's not drawing on the other side, so both sides 24V. Weird, what should I do?

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on November 24, 2012, 05:35:48 PM
In order to measure the testpoints, do I have to connect the in and output transformers?

*update*: it's alright, i was stupid.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on November 29, 2012, 11:07:57 AM
YAAAA EVERYTHING IS NOW WORKING - - - HERE are some PICS Its A original Neve 1272 card and the Ez1290. . . 2 in 1 SOUNDS GREAT.  Its cool cause I can use them to mix just ran my first mix through it the other day. Makes QUITE A difference. .  Now I just gotta work on getting a second DISTRESSOR HAHAHA. Anyway to the people on this FORM Thank you VERY MUCH for the Help I did have a few problems at first but thanks to a Few individuals I was able to get this up and running. This was my first DIY project EVER like this AND it was a LOT of fun. Martin Thanks for the boards TOOO They are great!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on November 29, 2012, 11:21:15 AM
AND 1 MORE OF THE INSIDE
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on November 30, 2012, 12:15:18 PM
Nice work MrGrinch!! Glad to hear your persistence paid off. Here's to big sounding records! :)

Also wanted to thank Desol and 3nity for sharing all their insights on this thread! I am so glad you're on this forum as I don't have time anymore to answer all these questions myself. I owe you guys a beer or two. :)

Cheers,

Martin
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Mr.GrinchSD on November 30, 2012, 06:53:49 PM
Hey THANKS Man. These PREAMP SOUND AMAZING IT IS NOW MY GO TO PRE!!!!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on November 30, 2012, 08:03:39 PM
I owe you guys a beer or two. :)


I like Innis & Gunn.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on December 08, 2012, 10:25:39 AM
I owe you guys a beer or two. :)


I like Innis & Gunn.

Good taste! I'll see what I can do.  ;)

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: LesPaul on December 09, 2012, 07:20:15 AM
What would be a good replacement for this (unavailable at the moment):

http://no.mouser.com/Search/ProductDetail.aspx?qs=VbcEA1k3avOWJgTVfPRUDg%3d%3d

How about this one?

http://no.mouser.com/ProductDetail/WIMA/FKP2D001001D00JSSD/?qs=sGAEpiMZZMv1cc3ydrPrFwgzP98AO9idqD3jXfOTtd8%3d
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: 3nity on December 09, 2012, 09:49:05 AM
1290 boards have pretty large lead size, that wima looks like 5mm or so.
Pay attention to what lead size you need!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: LesPaul on December 09, 2012, 10:05:40 AM
1290 boards have pretty large lead size, that wima looks like 5mm or so.
Pay attention to what lead size you need!

Thanks, didn't notice that. Should probably be axial.

Can't find any replacement at mouser. Any other good source for polystyrene caps? Without ridiculous shipping costs?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sedit1 on December 09, 2012, 02:07:25 PM
1290 boards have pretty large lead size, that wima looks like 5mm or so.
Pay attention to what lead size you need!

Thanks, didn't notice that. Should probably be axial.

Can't find any replacement at mouser. Any other good source for polystyrene caps? Without ridiculous shipping costs?

I ordered mine from ebay, shipment was fast. More expensive than mouer styrenes, but still reasonable..
http://www.ebay.com/itm/Polystyrene-Styroflex-Capacitor-Made-by-Philips-listing-is-for-2-pieces-/281030302381?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item416eb61aad
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: LesPaul on December 09, 2012, 02:30:24 PM
1290 boards have pretty large lead size, that wima looks like 5mm or so.
Pay attention to what lead size you need!

Thanks, didn't notice that. Should probably be axial.

Can't find any replacement at mouser. Any other good source for polystyrene caps? Without ridiculous shipping costs?

I ordered mine from ebay, shipment was fast. More expensive than mouer styrenes, but still reasonable..
http://www.ebay.com/itm/Polystyrene-Styroflex-Capacitor-Made-by-Philips-listing-is-for-2-pieces-/281030302381?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item416eb61aad

Thanks :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: leitrim_lad on December 16, 2012, 04:16:12 PM
Hey there, still havent been able to get my first channel working.. Hardly getting any signal from it now at all.. When i tap the front cover it kinda kicks in but then goes.. Also should the gain be EXTREMELY high? On my channel thats working, even when its switched to just the second gain on the switch its practically going in to hot.. Any advice?

Cheers
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on December 16, 2012, 05:30:22 PM
Did you check your grounds on the channel that isn't working?
If your touching something and it's kicking in and out, it's usually a ground issue.
Solder joints at the switch?


Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: atticmike on December 17, 2012, 05:54:02 AM
By the way, just finished my two units together with two others (ssl 9k by bruno) in one box. They sound astoundingly great. I couldn't be any happier. Def. my go to kick and snare pre.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on December 19, 2012, 03:19:05 PM
Hey there, still havent been able to get my first channel working.. Hardly getting any signal from it now at all.. When i tap the front cover it kinda kicks in but then goes.. Also should the gain be EXTREMELY high? On my channel thats working, even when its switched to just the second gain on the switch its practically going in to hot.. Any advice?

Cheers

The fact that tapping the unit kind of makes it work really sounds like a loose solder joint somewhere. I would re-heat each and every single solder joint on the PCB as well as the ones on the transformers. Also, how are your voltages compared to my voltage chart on page 1 of this thread?

Gain is 20dB on lowest setting, can you compare to another preamp?

atticmike, congrats! Glad you like them.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on December 19, 2012, 06:49:00 PM
is "jumper" a good place for inserting an eq? like the golden age eq73?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 19, 2012, 07:39:57 PM
the eq needs a line level signal, go right out of the back  of the 1290 into the EQ.  I used that jumper area to feed a VU.Also not dealing with a balanced signal there i believe as well, (could totally be off here)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: pedroplanet on December 19, 2012, 09:41:49 PM
the eq needs a line level signal, go right out of the back  of the 1290 into the EQ.  I used that jumper area to feed a VU.Also not dealing with a balanced signal there i believe as well, (could totally be off here)

but the golden age eq 73 has only an "insert" I/O
(http://www.micsdirect.com/eq73pic5.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on December 20, 2012, 09:56:59 PM
the eq needs a line level signal, go right out of the back  of the 1290 into the EQ.  I used that jumper area to feed a VU.Also not dealing with a balanced signal there i believe as well, (could totally be off here)

but the golden age eq 73 has only an "insert" I/O
(http://www.micsdirect.com/eq73pic5.jpg)

That might actually work perfectly. Got a schematic for the Golden Age EQ?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on December 20, 2012, 10:16:12 PM
Id be really interested in seeing how this pans out too :)  Id be interested to see if you could GUT the EQ and case it with the pre.. hmmm
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on December 24, 2012, 10:32:10 AM
SO, here is a very vague question for you all...

some time ago.. like.. almost 2 years.. i bought carnhill output transformers, and jensen input transformers, for 4 channels of 1073-ish preamps.. that i was going to build point to point, on standard fiberglass perf-board.  i have all the caps and resistors as well as a pile of switches, jacks, and even a chassis.  a friend of mine was going to help with this build, but he is missing in action these days.

i know i will have to re-purchase caps that will fit the board..  and maybe switches too.. but im wondering if, in order to get this project underway, there is any reason i shouldn't get the ez1073 pcb's.  getting some new resistors and caps might not be a huge deal.. i just dont want my transformers to go to waste.. if i cant use them (particularly the jensens, not sure that anyone here is using them) then i will try and proceed with the original plan, i dont want to "eat" the  cost of those transformers...

what do you all think?

thanks,

mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on December 24, 2012, 10:56:44 AM
you cant take just blank pcbs...you need to get full kits for those ez1073 channels.i would love to get 4 blank ez1073 pcbs...but...
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on December 24, 2012, 02:01:26 PM
you cant take just blank pcbs...you need to get full kits for those ez1073 channels.i would love to get 4 blank ez1073 pcbs...but...

So no one sells a 1073 or 1290 pcb that is not in a kit?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: spase on December 24, 2012, 02:03:37 PM
you can send a message to madriaanse, he is sellin those ez1290 boards.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on December 27, 2012, 01:49:44 PM
I have four of the jensen "JT-13K7-A" input transformers that i was going to use for a neve-ish preamps that never got built.  Would i be able to use these transformers with an ez1290?

http://www.jensen-transformers.com/datashts/13k7a.pdf
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on January 02, 2013, 11:33:38 AM
Any thoughts on the above transformers?  could they work with a ez1290?  hope everyone had a great new year.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 02, 2013, 01:07:17 PM
Hey there, those transformers might work. They're pretty close to 10468's 4K8 impedance across the secondary. Will it sound like a Neve? Probably not, but happy accidents can and do happen and it might sound great. If you're not happy with the results you can always sell them on ebay and buy some Carnhills. In any case I would recommend getting some VTB9045's so you have something to compare to.

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 07, 2013, 02:49:23 PM
Pedro, any luck with fitting that EQ in there?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 12, 2013, 11:50:24 AM
Hi,

I've been sitting on 4 1290 boards for about 2 years now, and finally getting the gumption to build. I plan on putting all 4 of these in a 3U case. I'm getting ready to pull the trigger on the parts, and am getting a little lost on the power supply. I've read this giant thread almost 3 times now, and thought I needed to ask the experts for advice.

Here is what I think I need for powering 4 1290 pre's, housing the power supply in a 1U rack case:

1 x JLM Powerstation Kit with optional 6 amp bridge

What power transformer do I need?
Will the transformer in the BOM work?
Do I need different heatsinks?
Any other parts that would differ from the BOM?

I would really appreciate the advice from some of the knowledgeable people on this forum. I'm getting lost on the power supply, as it deviates from the BOM. The BOM calls for a JLM ACDC to power 2 units, but I want to power all 4 with a single power supply. What do I need to make this happen?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 12, 2013, 09:27:30 PM
I build a 4 ch unit (in a 2U case) with an external PS... id have to look at what i put in there, but if memory serves the torriod was too big for a 1u case
ill open er up and report back

...OK im back, and yes. the torriod wouldnt fit into a 1u chassis.  (well, not the one I got, and not comfortably... maybe if you didnt put a top on the case lol
(and check out the pic... i was SERIOUS about heat sinking lol i dont remember doing that but it was quite funny when i opened the case)

the TX i got was an Avel Lindberg Model Y236351
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 13, 2013, 01:39:58 PM
Thanks for the reply!

So, I will amend my plan. I will put the pres in a 2U case, and the power supply in a 2U case.

I plan to use the JLM Power Station.

Is there anything different I need for the pres when using the Power Station rather than the AC/DC kit?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 13, 2013, 10:02:29 PM
Not really. I ran leads from the power connector to a terminal block and then out to each board (didnt daisy chain em) but thats up to you.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 14, 2013, 03:07:05 PM
Are the conductive plastic potentiometers that Audio Maintenance sells of any quality or should I look at Alps? I know Martin recommends Penny and Giles, but 4 of those would cost me well over five hundred dollars!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 14, 2013, 03:14:58 PM
Any conductive plastic pot of the correct value will work. I think it should be audio taper.  I believe i used some bournes pots (weren't cheap but solid built, very similar to what Colin has on his site, those are really nice, but expensive... when it gets down to this level, you certainly get what you pay for!)  Only other suggestion I can give you is if you plan on racking them above/below other DIY gear that have torroids in them, make sure the input/output transformers arent located directly above/below where they would be on the other gear.  Had an issue with one torroid that was causing some buzz (albeit at higher gain settings) but was enough to drive me nuts thinking that the problem was in the 1290, when it was in fact not.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 14, 2013, 04:49:43 PM
You can also do this:

(https://dl.dropbox.com/u/9631747/Attenuator.jpg)

Mouser #
271-510-RC
271-470-RC
271-470-RC
271-453-RC
271-453-RC
 271-422-RC
 271-422-RC
271-390-RC
271-360-RC
271-360-RC
271-6.19K-RC

611-A11215RNZQ

Pretty solid, and pretty hi-fi  ;)

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 14, 2013, 07:31:42 PM
Use that in lieu of a conductive plastic potentiometer for the trim?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 14, 2013, 08:01:09 PM
Thats a pretty cool option actually... as long as the steps aren't in 5db incements otherwise you're just kind of having the ability to drive the input stage and not have a lot coming out on the other end (which i gotta say sounds awesome on some things... drums) but reason i went with the pot is so you can dial something back just slightly if needed, but if you're going digital i guess it doesnt matter anyway as long as you have good converters.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on January 14, 2013, 08:28:35 PM
Use that in lieu of a conductive plastic potentiometer for the trim?

Correct. That's 1/2 dB attenuation steps.

M.

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 14, 2013, 08:47:23 PM
Sweet! Thanks!

Has anyone ever used the conductive plastic potentiometer's from Audio Maintenance?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 14, 2013, 09:55:29 PM
ok thats cool... might have to go and do a few of those!!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 17, 2013, 03:42:50 PM
Hey all!

I'm having a hard time finding C9, 100pF Polystyrene. Can I use Polypropylene instead, or should I just go ceramic?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 17, 2013, 03:52:29 PM
Try Newark. Theres also this site, dont remember it off the top of my head but its something like radiorepair or radioparts.  ahhh got it justradios.com

http://www.newark.com/jsp/search/browse.jsp?N=422+2203+200010&Ntk=gensearch&Ntt=Polystyrene&Ntx=mode+matchallpartial

googles a helluva tool!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: drAk on January 17, 2013, 04:14:53 PM
Hey all!

I'm having a hard time finding C9, 100pF Polystyrene. Can I use Polypropylene instead, or should I just go ceramic?

Small Bear Electronics has some - http://www.smallbearelec.com/servlet/Detail?no=1232
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 18, 2013, 09:47:03 AM
doh! Didn't think to check Small Bear. I tried Digikey and Mouser, and neither had them. I was hoping to score some at one of the places I was already ordering and paying shipping from.

I've got one other parts question I was hoping someone could weigh in on. I have read on these threads how some people think the Motorola version of 2N3055 sounds superior to the ST version. I found some Motorola's on eBay, but they are pretty pricey compared to the ST's from Mouser. Does it really make a huge difference?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 18, 2013, 09:49:45 AM
Is that the component thats not being made anymore?  (or is that the replacement for the part thats not being made anymore)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 18, 2013, 10:45:12 AM
The 2N3055 is the transistor. The BOM calls for one made by ST, which is available. I just read in these threads that some people were using a Motorola version of the transistor, and I was wondering if it was worth the extra money.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 18, 2013, 10:52:26 AM
Oh thats the little top hat looking thing.  I used the motorolas on mine, i cant really see how it would be that big of a difference as long as the other is up to spec.

The BC184C is the one thats not made anymore.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on January 18, 2013, 04:00:27 PM
Did a bit of digging around, and it seems kind of risky to purchase Motorola 2N3055's these days. It seems a lot are counterfeited. From what I gather On-Semi bought the Motorola plant, and continues to make the 2N3055 per the original spec. It may be safer to go with On-Semi.

I've got my trannies ordered as well as my power supply and Go-Betweens! I'm finalizing my Mouser/Digikey order. The whole Front Panel issue has me scratching my head. I downloaded the software, and would really love to design my own front panel. I just don't know how to use the program. My backup plan is to order from Dan at Collective Cases, but I was hoping for a customized case.

Does anyone have a Front Panel file to share? I'm building 4 channels in a 2U case, with Go-Betweens and trim knobs. I really, really like the old school Neve designs that people had at the beginning of this thread. I would be very appreciative if someone had something like that to share that I could maybe tweak to make it custom for me.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on January 19, 2013, 07:53:51 AM
Oh thats the little top hat looking thing.  I used the motorolas on mine, i cant really see how it would be that big of a difference as long as the other is up to spec.

The BC184C is the one thats not made anymore.

you can find BC184C here:
http://www.ebay.de/sch/i.html?_trksid=p5197.m570.l1313&_nkw=+BC184C&_sacat=0&_from=R40
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on January 22, 2013, 12:25:06 PM
where are people getting the 12 position grayhill switch right now? digikey has a 2 month wait.

mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on January 22, 2013, 12:27:18 PM
http://www.audiomaintenance.com/acatalog/GR-03-001_extended_info.html

http://www.audiomaintenance.com/acatalog/Rotary_Switches.html
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on January 22, 2013, 12:42:04 PM
thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on January 22, 2013, 03:29:17 PM
hey...

audio maintenance limited sends me to a 3rd part payment site "actinic payments".

i used AML a year or two ago, and i dont seem to remember this "actinic payments"

i have been scammed before... anyone care to confirm the legitimacy of this service?

Thanks,

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: Andreas Pfeiffer on January 22, 2013, 03:39:05 PM
I would get in touch via email
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: kpearsall on January 25, 2013, 01:41:15 AM
I've ordered from there a few times since the actinic thing... Never had any problems. It's just a shopping cart service like any other.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on January 29, 2013, 08:08:01 AM
Yesterday I brought for first time my two finished channels to the studio.
Recorded with a 414 on a digidesign 02, then on a Universal audio 610 , then with the neve.... amazing!
Just makes 02 sound stupid and UA to sound as it's small dumb brother (speaking about presence and clarity). It's so clear  and present on it's highs... really happy man!!

On the other side, I'm having a problem in one of my channels.
It's like a bit deff. At low gain values it's fine compared to the other (the sound is just identique), but when I go further that the fourth step, it will only amplify when there's a big input (when I put a lot of pressure on the diaphragm of the mic). At the beggining I thought it could be a mistake on the switch resistor, but everythin fine there.
Could that be related to a power issue?
Could anybody point me someway? Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 29, 2013, 10:05:27 AM
Did you check that your voltages are correct for your transistors?  Also, how did you check the rotary switch?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on January 29, 2013, 08:04:15 PM
First of all thanks for your reply.

When I say checking the resistors on the switch I mean check the values. After forth step the sound gets much lower, at the beggining I thought I just misplaced any of the resistors, but then I realised that behavior mentioned before, the sound only gets to the correct level when lot of diaphragm movement.
I also checked the solders in there.

As for the transistors values, as soon as I get the pre back from the studio I'll check the values. i remember seeing a value table somewhere on this post, I'll compare them with that values. Do I need to input the 1khz sine while checking?

I'll update my process when I get the pre back. Thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on January 30, 2013, 01:41:58 AM
first things first, check the pre with a dynamic mic and see if you get the same issue. If not you might have an issue with the phantom power (which might not be related to the rotary switch at all)  As for checking the switch, (dont have the schematic infront of me) but on it, find the point after the switch and resistors and measure from there to right before the switch.  if youre finding you have some "off" numbers, you might have a solder bridge on the switch (which isn't that hard to do being the pins are so damned close together and small) and a cold solder on there might not be apparent to the naked eye. (check with a magnifying glass)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: delir66 on January 30, 2013, 03:56:13 PM
In fact when I compared both channels, did it with the 414. Will check with dynamic mic.
Thanks again. I'll update when I have the pre back.  ;)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on February 12, 2013, 08:51:01 PM
Hi, Can someone recommend an oscilloscope that would be appropriate to use for biasing these pres? Preferably one under a hundred dollars (used) that will work for this. Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 13, 2013, 10:00:47 AM
If you find a usable scope for under $100 let me know please!  You can (kinda) bias them using just a multimeter.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on February 13, 2013, 12:06:28 PM
I do have a multimeter. I just don't have a use for a scope other than to bias these pre's. I want them to be set up properly, but I don't really want to spend a few hundred bucks on something that I'll probably not use very often.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 14, 2013, 06:09:56 PM
I found a Tektronix 2215 locally on Kijiji for $50 from a recent university grad...who was more into digital...and had no use for it anymore.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 14, 2013, 10:12:28 PM
My 4 channel unit was biased using a multimeter and sounds just as good as the 2 channel unit that was biased with a scope.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on February 15, 2013, 11:19:58 AM
Hello all,

Im putting together a mouser cart with the parts on the v2.4 BOM.  The BOM seems to have many redundant parts, and perhaps too many to fit on the board.  are all of the parts listed on the BOM for ONE complete channel?  are some of the parts substitutes for other parts?

i see two pre stages, and a driver stage, which i believe makes up one channel, but below that i see EH10023-2, and EK20032, with many parts listed under each.  Do i need all parts listed in these categories as well?  i question it, because i see r3 r4 and r5 (just as examples) listed under EK20032, but also under the "driver stage" section.

I am a newbie, so i guess im just a bit confused by the layout of the BOM.  I am building 4 channels of ez1290. 

i already have chassis, transformers, transistors, switches, power supply.  Most of my questions here are in regards to the resistors and caps on the BOM.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 15, 2013, 04:15:33 PM
My 4 channel unit was biased using a multimeter and sounds just as good as the 2 channel unit that was biased with a scope.

Let's not start validating that a multimeter is the equivalent of a scope.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 15, 2013, 05:02:46 PM
Not at all, just saying that at normal operating levels, I dont hear a difference from using the 2 methods.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 16, 2013, 09:18:56 AM

BC184C is now obsolete. What should I do?

You should be able to find them on eBay if you're really wanting to use BC184. Another option is to use MPSA18. One important detail about using MPSA18 in place of BC184C is that MPSA18 will need to be mounted backwards (rotated 180 degrees on its vertical axis) on the PCB. Other than that it is a great substitute: http://www.digikey.com/product-detail/en/MPSA18RLRMG/MPSA18RLRMGOSCT-ND


Hello,
I am just starting a 4 channels piece !!
Just a question regarding the MPSA18 : when you say to mount them backwards, you mean having the actual transistor underneath the PCB and having its pins to be sold on the top ?

Thanks a lot.
I am very excited.
Alex
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: drAk on February 16, 2013, 11:23:26 AM
No, you just need to spin them 180 degrees and mount on the top. So where the board shows |) you would mount the MPSA18 like (| in that spot.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 16, 2013, 11:54:35 AM
Thanks for the drawing  ::)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 16, 2013, 01:52:23 PM
I have  some doubts:
My PCB is version 2.1 and I have the 1290BOM24.xls

1) In both pre-stage: C13 is 150uF /  16 volts 20 %
On the board I have 150uF/6.3v

2) In the driver-stage: C4, C6 and C7 are 100uF/25V whether it is written 82u/25v on the board ?

3) What does EH10023-2 section refers to  ?

Thank you for your help.
Alex


Thanks a lot.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 16, 2013, 03:02:36 PM
I have  some doubts:
My PCB is version 2.1 and I have the 1290BOM24.xls

1) In both pre-stage: C13 is 150uF /  16 volts 20 %
On the board I have 150uF/6.3v

2) In the driver-stage: C4, C6 and C7 are 100uF/25V whether it is written 82u/25v on the board ?

3) What does EH10023-2 section refers to  ?


The reason alex is that the old capacitor axial packages are difficult to find. 82uf is non-existant....so 100uf is used instead.
As long as the capacitor fits and at least meets the minimum voltage it will be ok. Keep the capacitance values the same for all the capacitors except the 82uf's.

I specifically found some nice BC capacitors(originally used) that not only fit the lead spacing and met the voltage rating...but also were the higher 125 degree temp rating! Plus they look nice. I'm assuming that EH10023-2 is the changed schematic from the 1073.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on February 18, 2013, 09:21:44 AM
I am building a 4 channel unit.  I have the carnhill input transformers..

any reason i can't mount the input transformers on their side, underneath each board?  twords the front near the swithes, and far away from the output trannies.. which would be at the rear of the unit.

thanks.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 18, 2013, 10:06:42 AM
You could if wanted i guess...i'd probably mount them to the side where they wire in to the board, or whatever...just for ease of getting at them if i needed to. As long as they're away from the outputs.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on February 18, 2013, 10:15:11 AM
cool, thanks.

with 4 boards in the case, there is not enough room to mount them to the sides of the board.. i have seen some people mount them at the rear of the chassis, on the right side, and the outputs on the left side.  i was just thinking that since i already have my inputs wired up to the phase and phantom switches, that i would cut down on the amount of wire going from front to back if i kept the inputs at underneath, the pcbs, near the switches on the front panel.

hopefully i dont have to access them too often, as you are correct, it will be a little trickier if i have to remove the PCB to get at it.

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 19, 2013, 12:14:45 AM
Whatever works. I think you want at least ~ 3 inches between inputs and outputs. I probably would've went for a deeper case and kept the inputs/outputs behind each card. Just try to keep the inputs away from the output stage at the back of the card, i would say.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 19, 2013, 12:19:52 AM
Whatever works. I think you want at least ~ 3 inches between inputs and outputs. I probably would've went for a deeper case and kept the inputs/outputs behind each card. Just try to keep the inputs away from the output stage at the back of the card, i would say, if you put them underneath.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 19, 2013, 12:33:26 AM
if you go 2u its really easy to stack them on top of one another and you're left with plenty of room for the transformers (but id still suggest an external PS).  Theres a pic on my website with the 4ch unit on the home page (i think its the 4th or 5th pic in that slide show on the home page, you'll see 2 silver faced 2U pieces, the top is a 2ch version with VU meters, the one below is the 4 channel)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on February 19, 2013, 10:28:29 AM
looks good SR1200.  I did buy a faceplate from Dan already, so they will have to be side by side.  when i get this going i'll post some pics.


mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 19, 2013, 01:07:06 PM
Hello,

Regarding, the BOM :

I ordered all the piece for one channel (everything on mouser, good) and multiply the project by four (I am doing a 4 channel one) without worrying too much about the correspondance of the quantity.

- I have OR DROP 400v 00.1uF which I can't find the use for, its not on the PCB, is that the one on the output transformer ? There are huge to solder there!
- I am missing some 470u/35v which appears at the count of one piece per channel on the BOM where there is actually 3 of those on the PCB Board.
- I got everything else with the good count.

I am wainting for the transformer now.

PS :
another question concerning the Polystyrene caps, how can we know if we have overheated them ? I was extra careful but I am really not shure how much they can handle heat without damage.
Althought as I planned to built another 4 channel piece if I am happy with this project, can we use other cap like ceramic ones instead of those. I have seen many photos here where people did not use polystyrene caps. I know they are 'sounding better' but since the risk of overheating them is real, I am trying to evaluate if caps subsitute would not be worth avoiding the overheat problems.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 19, 2013, 03:52:46 PM
Built 6 of em and haven't melted one yet.  If you're that concerned, you can use a heatsink clip on the lead as you solder them.  (very cheap thing to buy)  Keep in mind also that there are parts that are in the BOM that are NOT on the board.   Theres a resistor and cap that go ON the output transformer.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 19, 2013, 04:01:25 PM
...which is also a good reason NOT to get into the habit of simply copying a BOM and ordering it.
You should specifically go through the BOM and make sure that each of the parts is what you want, will fit, etc etc.

I love making up my own BOM's if i commit to a project. I get to specify and make sure that all parts will work, are the quality i want, etc.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: madriaanse on February 19, 2013, 04:13:24 PM
Not sure if this has been posted up already, but Dan is making frontpanels for this project again:

http://www.collectivecases.com/ez1290.html

Best,

M.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on February 19, 2013, 04:30:28 PM
Bought mine from dan recently and it looks GREAT. cant wait to get it up an running.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 21, 2013, 08:40:47 AM
Thanks for the feedback on the polystyrene caps.
As for the BOM, I did try to sort it out but it's my first time !
Anyway to be sure, is the C9 on the Section EH10023-2 the cap that goes on the output transformer ?
Thanks
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on February 22, 2013, 05:13:52 PM
started my ez1290 using  bc184c and some how ended up short.  i just ordered these on ebay.

http://www.ebay.com/itm/BC184C-Manu-FAIRCHILD-Encapsulation-TO-92-Silicon-NPN-Small-Signal-/380556274486?
they say fairchild so im thinking they're not knock offs. has anybody tried them?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 22, 2013, 09:47:28 PM
sea if you only needed a few shoulda asked bro, i have a few hundred. lol  When they were discontinued, i bought up a bunch of stock.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 23, 2013, 08:13:25 AM
Shame we can display the 73 pages of this thread at once for printing purpose, so I have to admit I did not read it all, I am doing it, though...
Sorry in advance in case the question has already been asked.
My knowledge about PSU is limited.
What is the best solution to power a 4-channel unit knowing that in the near future I will build a 8-channel one.
Is it better to use two external PSU or one for the 8 channels knowing that it will only serve for some time to power up 4 channels ?

Thanks a lot.
Alex
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on February 23, 2013, 10:49:55 AM
sr. thanks for the offer. i would  definitely like to take some off your hands.  not sure how many i need at the moment . i ordered 10 but i think i only need 5 or 6 . i'll have to check. i think  i'd rather eat the $10 and be sure i have a real bc184. when i checked them out on the fairchild web site there was a warning about the prevalance of counterfeit ics flooding the market. i'll pm you.
did you ever make any of those  omni mics with the panasonic wm61 capsules. i hear the capsule is discontinued.i ordered10 of those and will not need them all.  if you never got around to getting and building with them i can share some. if you did i'd like to hear your impressions of the project. i'll contact you soon.(project is at work wont be able to check the amount i need till monday)
 8) 8) 8) 8) 8) 8) 8)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 24, 2013, 04:52:39 PM
Id be interested in seeing if the BC's i got are fake... hmmm... i used em in the last EZ1073 i did from colin, unit sounds great.  As for the lil mic, i did build one, but i have NOT the skill to make the chassis the way i want so the proto was a bit noisy.  I have a bunch of the printed boards here that i haven't done anything with.  Id love to find a nice donor body or something to fit em into.  Maybe ill talk to chunger.  K enough of the hijack lol.  If ya need more BC;s just gimme a shout. :)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on February 24, 2013, 10:33:29 PM
Sorry if this is a silly question, but what are the rubber grommets in the BOM used for?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on February 25, 2013, 09:31:00 AM
I think they were supposed to be used either as standoffs or feet for the powersupply.  Never made much sense to me either.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 26, 2013, 11:50:42 AM
Not sure if this has been posted up already, but Dan is making frontpanels for this project again:

http://www.collectivecases.com/ez1290.html

Best,

M.
I was wondering, if there were some other versions (with the blue neve style face plate ?)
Thanks to let me know.
Alex
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 27, 2013, 12:01:27 AM
I was wondering, if there were some other versions (with the blue neve style face plate ?)
Thanks to let me know.
Alex

Hi Alex. Not to sound dismissive or rude, but it's generally expected that people find out basic questions such as these, on their own. Otherwise we would have a forum (instead of being filled with important questions) filled with generic, easy to figure out filler.

In DIY(do it yourself), it's expect that you help yourself....mostly. Search, email dan, search and keep searching....if you find it very difficult to locate, chances are, it doesn't exist....therefore, spend some time learning frontpanel express(it isn't that tough) and make your own custom blue panel, etc....or take the initiative to inquire to one of the vendors about it.

Years ago....the general forum was pretty solid on this...people that didn't help themselves, were peristantly ignored...while people that showed some hard work, with good questions were happily helped.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on February 27, 2013, 01:39:21 AM
No problem. ???
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on February 27, 2013, 08:40:41 PM
Sry...i kinda feel bad, in this case....cause i re-read your previous messages...and it does sound like you are helping yourself. There's been so many people tho....that just expect everything handed easily to them. I read hundreds of pages of thread info when i started my first build like, 5 years ago. No easy way out.

Quick search on the forum yields: http://www.groupdiy.com/index.php?topic=35422.0

That blue seems pretty decent, although it's only a two channel unit. Dan could definately do something custom.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on February 28, 2013, 11:43:31 AM
Hi,

did some searching, but i have not found exactly what im looking for.

I am building 4 ez1290's, and am adding phantom, phase, and pad.  I have the inputs from the XLR wired to my phase and phantom switches.  But im not sure what the simple schematic for the PAD would look like, before i head off to input transformer land.

I am basically just building the JLM go between i guess.. i had the parts lying around, so i figured i would give it a shot.  Does anyone have a drawing of a typical 15-20db pad that will work here?


Thanks,

mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 01, 2013, 12:14:15 AM
Hey Mike. Quick search yields: http://www.groupdiy.com/index.php?topic=2370.0
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: mikerl on March 01, 2013, 11:57:56 AM
Thanks! i'll try to make sense of that and fit one onto my front panel.

Mike
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 02, 2013, 10:21:03 AM
Hey guys!

I'd like to wire an impedance switch for my pre's. I've read through all of the EZ1290 threads a few times, and took some notes. Here is what I understand:

One can install a DPDT switch that will switch between 300 (Parellel) and 1200 (Series). You get the 1200 impedance by tying the + of one primary to the - of the other and using the other + and - as the primary connections. In parallel you tie your +'s together and your -'s together and are left with the equivalent of one winding, 300.

Here are my questions:

1. Is the impedance switch wired from the input tranformer?
2. Would anyone be able to help me understand the process for wiring the impedance selector switch? Basically, I would like to understand which leg of the DPDT switch gets wired to the corresponding numbered input tranny post.

I'd really appreciate the help!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on March 02, 2013, 12:08:23 PM
the impedance switch is basically explained in this pic:

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 02, 2013, 01:08:44 PM
the impedance switch is basically explained in this pic:

Yep, I have that pic already, but I'm wanting to make sure I get it right. Basically looking for a impedance selector schematic for dummies.

I made up this pic, and would really appreciate if someone could simplify the wiring process, and tell me what numbers from the input tranny I need to connect to what numbers from the switch. I'd be happy to post the completed wiring diagram and post for others to reference.

(http://i475.photobucket.com/albums/rr113/ajoel23/ImedanceSwitchcopy_zps249a396e.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on March 02, 2013, 03:40:12 PM
(http://i47.tinypic.com/2dahnro.png)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 02, 2013, 04:31:23 PM
That's great! Thank you!

Two more questions:

1. Do I still need to jumper between 8 and 9 on the input tranny, as per the assembly guide?
2. When using this with the Go Between, would I run the XLR wires into the Go Between first, and from there the impedance switch, or vice versa?

Again, really appreciate the help!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on March 02, 2013, 04:37:48 PM
1. yes
2. XLR>Go Between>Tranny/Switch
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 02, 2013, 06:46:41 PM
Thank you, good sir!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 04, 2013, 01:05:26 PM
I know this is a lame question, but what is the purpose of putting heat shrink at the ends of all the wires?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 04, 2013, 01:36:29 PM
2 second search on google.

http://en.wikipedia.org/wiki/Heat-shrink_tubing
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 04, 2013, 02:56:25 PM
I see, so basically to protect against abrasions.

One more question, perhaps more important. I've finished wiring and stuffing all the boards, transformers, etc., but I have 10 OHM, 1W resistors from the BOM left over. What are these for? What did I miss?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on March 04, 2013, 03:11:49 PM
use it to connect the audio ground to the chassis ground with 10ohms resistance between em.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 04, 2013, 03:23:35 PM
...and if you used the JLM power supply you don't need it, cause it's built in.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 04, 2013, 05:11:38 PM
Ah, that's it. I used the JLM Power Plant kit, so I guess I don't need it then. Thanks!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 04, 2013, 05:42:13 PM
JLM powerplant is designed to run Neve's, so i'm assuming it has it. I know the acdc, powerstation have it.
Might want to ask to be sure...or simply have a look on the board.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 04, 2013, 07:33:16 PM
Yep, sure enough there's a 10R on the Power Plant. Thanks again!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on March 05, 2013, 03:32:54 AM
Sry...i kinda feel bad, in this case....cause i re-read your previous messages...and it does sound like you are helping yourself. There's been so many people tho....that just expect everything handed easily to them. I read hundreds of pages of thread info when i started my first build like, 5 years ago. No easy way out.

Quick search on the forum yields: http://www.groupdiy.com/index.php?topic=35422.0

That blue seems pretty decent, although it's only a two channel unit. Dan could definately do something custom.

Don't worry, you are right. I have almost done the PCB, I am waiting for the Grayhill switch and some caps. I have ordered the case from Collective Case, its the gray one but that will do :). I have ordered some VanDamme cable for the internal wiring. I also have ordered the PowerPlant Kit PSU from JMLAudio and the Go Beetween kit. I have to wait next month for the transformer and I that will be it. I am excited !
Thanks all of you on this forum and Martin of course. It's a great project.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on March 05, 2013, 05:51:10 AM
Yep, sure enough there's a 10R on the Power Plant. Thanks again!

as a bonus to checking the BOM you can also measure the circuit when it's built and look for the 10ohms resistance between the chassis ground and audio ground. just to be sure.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 05, 2013, 08:24:44 AM
Yep, sure enough there's a 10R on the Power Plant. Thanks again!

as a bonus to checking the BOM you can also measure the circuit when it's built and look for the 10ohms resistance between the chassis ground and audio ground. just to be sure.

I will do it. Thanks for the tip!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 05, 2013, 01:53:06 PM
The electronics store in my town carries 4 conductor shielded wire (for power cable between PSU and Pre's). The BOM recommends 18AWG, but the electronics store only has 22AWG.

I did a bit of research, and it seems that 22AWG is rated .92 amps for power transmission.

I'm using the JLM Power Plant kit. Will I be ok using 22AWG instead of 18AWG?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: desol on March 05, 2013, 09:23:05 PM
That amperage rating has to be wrong.

I'd ask the electronics store to order some in for you, with no additional charge.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on March 05, 2013, 09:32:46 PM
sorry if this has been answered befor. i admit i have not read all 74 pages of the thread. i see that the stand offs for the 2n3055  should be non conductive. but the screws that hold it to the pcb are threaded through two large pads. if the screws are metalic and contact these pads the 2n3055 case is not going to be isolated. i see no mention of nylon screws and washers in any posts ive read. if the 2n3055 is not isolated why is it important to use non conductive spacers??
 8) 8) 8) 8)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 05, 2013, 09:46:35 PM
sorry if this has been answered befor. i admit i have not read all 74 pages of the thread. i see that the stand offs for the 2n3055  should be non conductive. but the screws that hold it to the pcb are threaded through two large pads. if the screws are metalic and contact these pads the 2n3055 case is not going to be isolated. i see no mention of nylon screws and washers in any posts ive read. if the 2n3055 is not isolated why is it important to use non conductive spacers??
 8) 8) 8) 8)

From the Assembly Guide:

"The Spacer can be made by cutting a 3/8” 6-32 aluminum standoff in half. Digikey Part # 2209K-ND. Standoff must be metal (conductive)."

Hope that helps.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on March 05, 2013, 09:55:46 PM
thanks. i misread this part of  madriasse s first post
"What type of standoffs (mounting pillars) should be used to mount the EZ1290 boards?

Any nonconductive (nylon) standoffs will work. Don't use metal (conductive)"
i see this is for the pcb not  the 2n3055
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 06, 2013, 05:36:43 PM
Hi all,

I've got another quick question (and I do really appreciate all the advice!). I'm drilling holes in the bottom of the case to mount the input/output tranny's. Do I need to drill for the standoff's? Meaning, do I need to affix the standoff's to the bottom of the case by means of a screw from the bottom through the case into the bottom of the standoff? Or are the standoff's meant to be "floating" and not attached to the bottom of the case?

Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on March 06, 2013, 08:02:54 PM
there are different types of stand offs. depends on what your using. some are "self stick" and many forum members are ok with them. i prefer those that are screwed from the bottom of the case.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 06, 2013, 08:04:30 PM
there are different types of stand offs. depends on what your using. some are "self stick" and many forum members are ok with them. i prefer those that are screwed from the bottom of the case.

I have the standoff's from the BOM. 6-32 threaded, I believe. So you are saying they should be affixed to the bottom of the case? I suspected as much, but wanted to be sure before I drill a bunch of holes.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 06, 2013, 08:11:21 PM
PSA: I found some 18AWG, 3 conductor shielded wire for sale on eBay.

http://www.ebay.com/itm/18-3-Shielded-Wire-18-Gauge-3-Wire-Conductor-Choice-of-Length-/181002268832?pt=LH_DefaultDomain_0&var=&hash=item2a249370a0

Hope this is helpful to someone.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: seavote on March 06, 2013, 08:32:41 PM
im not familiar with those . but look at the standoffs if there is a threaded insert on both sides they are secured with screws.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 06, 2013, 09:08:18 PM
Seavote, just use some nuts (hex) they fit perfectly and are usually the right height.  Thats what i used on mine.  As for theboards, any nylon standoff will do.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 12, 2013, 07:36:47 PM
Sorry to trouble with another question, but I want to make sure I get this part right. I am currently trying to wire in my mains and rocker switch for the PSU. I am using a JLM Power Plant.

What I am trying to do is wire in a power switch. I have a lighted rocker switch (http://www.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&keywords=360-1731-ND&x=10&y=19&cur=USD).

The switch is a DPST ON-OFF, rated 9A (AC), 125V. It has 6 legs on the back, and I'm confused as to how to go from the mains to the switch, then to the Power Plant. Also, do I need a resistor for the LED on this switch? The illumination voltage for the LED is rated 1.95VDC. Where would the resistor be wired in at?

I also wanted to mention that I used the continuity setting on my DMM to try to determine the legs that would open/close the circuit, and tried every combination with no success. This confused me.

I have a mini SPST, ON-OFF toggle rated 120V AC (http://www.mouser.com/ProductDetail/Mountain-Switch/108-0001-EVX/?qs=sGAEpiMZZMvudeGI7i40XJuO3OFUtqTEvJ%252b1OLTC0W8%3d).

Would that be easier?

One last question. The fuse is built into the mains input. I have marked the ground and neutral terminals. It looks like the hot terminal is jumped to one leg of the fuse. Do I wire hot from the other leg of the fuse?

Again, your help is greatly appreciated! I have learned so much from this, and obviously still learning. I want to be sure not to screw this part up and fry any components, so I have tried to be as clear and direct with my questions that I could be.

Hope to hear from someone soon! Really excited to power these guys up!

(http://i475.photobucket.com/albums/rr113/ajoel23/PowerwiringQuestions_zps0e9f7059.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: useme2305 on March 14, 2013, 08:12:29 AM
this is pretty basic stuff, indiehouse. if you cannot figure out how to wire a simple on/off switch by your self you probably shouldn't attempt a project like this in the first place.

my recommendation: grab a multimeter and the spec sheets of the switch and connector and find out how they work and how you can make them work in your project.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: alexidoia on March 14, 2013, 01:14:05 PM
Hello there,
I can't figure out where this has been discussed (on which on the 75 pages) but I know I read it so excuse me to ask again.
Is there any preference for the cable to be used from the PSU and the preamp. I use the Power Plant kit from JLMAudio so I would need 3 wire plus shield, right ? (0, 24, 48 + ground).


I have another question concerning the place chosen to put the PSU. Since the Powerplant fit in a 1U rack space, is that a good idea to rack it under (or above) the unit of the preamp. Or should it be as far away as possible. Thanks a lot.
Alex
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 14, 2013, 10:02:04 PM
Hello there,
I can't figure out where this has been discussed (on which on the 75 pages) but I know I read it so excuse me to ask again.
Is there any preference for the cable to be used from the PSU and the preamp. I use the Power Plant kit from JLMAudio so I would need 3 wire plus shield, right ? (0, 24, 48 + ground).


I have another question concerning the place chosen to put the PSU. Since the Powerplant fit in a 1U rack space, is that a good idea to rack it under (or above) the unit of the preamp. Or should it be as far away as possible. Thanks a lot.
Alex

I had a 2U rack case in which I was going to mount the Power Plant. However, once I had both and was looking at both, I sent the rack case back and used a small hammond enclosure. The rack case was steel, and Joe recommends an aluminum case to act as a heatsink for the Power Plant. Also, it fits beautifully and is less expensive.

(http://i475.photobucket.com/albums/rr113/ajoel23/d9fd7304-7fd5-4219-a089-7407ff2b24fc_zpsdc2e107d.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 14, 2013, 10:13:21 PM
this is pretty basic stuff, indiehouse. if you cannot figure out how to wire a simple on/off switch by your self you probably shouldn't attempt a project like this in the first place.

my recommendation: grab a multimeter and the spec sheets of the switch and connector and find out how they work and how you can make them work in your project.

Sorry for the newb question. It's true I haven't wired in a mains switch before, but I'm learning, and I really appreciate the advice and knowledge imparted here. The spirit of initiative and learning is what I love about this forum.

I reached out to Joe from JLM, and he gave me some great pointers! I now know how to wire in mains (and referencespec sheets). Really appreciate it!

I am so close! I powered the Power Plant on, and nothing fried! That's a good sign. I adjusted the 48v rail as well as the 24v rail per via the trimpots. Beautiful.

Here's the first weird thing. When I turn the LED rocker switch off, the LED doesn't turn off right away. In fact, it slowly fades down, and I mean slowly. That doesn't seem normal, but the rails are reading fine.

Here's the second problem. I hook up the Power Plant to the pre's via the 4 pin cable, and I don't have signal. Phantom power works, though. I read the voltage across 0V and 24V, and it reads 1.5V. That's a problem.

I go back to the Power Plant, and 48V reads fine, but 24V reads 1.5V. Also, the LED does NOT light up now.

Here's the weird thing. When I unhook the 4 pin cable from the power supply, the LED works again, and I have 24V now. Well, sort of. I actually have something like 23.5, but the trim pot no longer adjusts the value.

I checked my wiring in the 4 pin cable, as well as in the pre. Everything is everything. It appears the 48V is working, but something is going on with 24V. I have attached a wiring diagram below.

Again, I really appreciate your guidance! I am so close here!

(http://i475.photobucket.com/albums/rr113/ajoel23/wiringcopy_zps6546fd39.jpg)
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 14, 2013, 11:34:51 PM
So, I am trying one board at a time. With only 1 board powered, I get 3.5V. I've done each board individually, with the same results. I've disconnected the Go Between, input transformer, and trimmer switch with the same results, 3.5V.

Am I shorting out somewhere? Have I shorted out all 4 boards? Or is my problem with the power supply?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 15, 2013, 12:47:15 AM
Try putting a regular switch without the LED/lamp/whatever or wire it without a switch to test and see if your 24v is ok.  Ive never used the power station, just the one suggested in the BOM. 

Also see, if you fried anything on the 1290 board.  I had one of mine short on the case once and wound up cooking a few components (my own fault for putting too many of em in a 2U case and not paying attention to where the lip from the case cover was touching.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 15, 2013, 05:37:08 AM
I contacted Joe at JLM about the LED issue, and he said it's normal for the LED to slowly fade like that when there is no load on the power supply, i.e., when the power isn't connected to the pres.

That being said, I don't think it's the switch, right? I mean, 24V reads fine, it's only when I try to power a board off of it, then it drops down significantly.

I looked for fried components, and components that may be shorting on each other, and I found nothing. I didn't have the lid of the case on, so nothing was shorting there.

I'm stumped and disappointed. I was so careful with every piece I installed, and read this giant thread about a dozen times. I was hoping to be one of the guys that fired this up the first time without issues.

Again, I appreciate any help I could get here!
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 15, 2013, 10:42:04 AM
if youre getting +24v when nothing is plugged into the unit an then NOT when the board is pluggd in, then one can assume the problem is off the PS board.  You say the cable is good and doesnt have shorts in it (check again. dont just check continuity from end to end (ala pin 1 to pin 1) check pin 1 on one end to all other pins on the other end to make sure theres no short, move to pin 2 do the same and so on and so forth) then remove that from the list of problems.  Next start tracing where the power comes into the board, and follow the schematic and see where it goes wrong. 
You double checked that all solders on the bottom of the board are clean and there are no bridges?  All caps and transistors are in the correct orientation (you used the correct transistors...).  All things that need to be checked over one thing at a time.  Worst comes to worst, post a decent res image of the top and bottom of the board, perhaps someone here can spot something that you didnt.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 15, 2013, 10:54:39 AM
if youre getting +24v when nothing is plugged into the unit an then NOT when the board is pluggd in, then one can assume the problem is off the PS board.  You say the cable is good and doesnt have shorts in it (check again. dont just check continuity from end to end (ala pin 1 to pin 1) check pin 1 on one end to all other pins on the other end to make sure theres no short, move to pin 2 do the same and so on and so forth) then remove that from the list of problems.  Next start tracing where the power comes into the board, and follow the schematic and see where it goes wrong. 
You double checked that all solders on the bottom of the board are clean and there are no bridges?  All caps and transistors are in the correct orientation (you used the correct transistors...).  All things that need to be checked over one thing at a time.  Worst comes to worst, post a decent res image of the top and bottom of the board, perhaps someone here can spot something that you didnt.

Thanks! You're referring to the Power Supply board, right? I should start there?
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: sr1200 on March 15, 2013, 02:32:35 PM
 :o ::facepalm:: no... read it again.
Title: Re: 8 Channel, 3U NEVE 1073 completed
Post by: indiehouse Recording on March 15, 2013, 04:01:26 PM
:o ::facepalm:: no... read it again.

I am so sorry