8 Channel, 3U NEVE 1073 completed

[Chrome Heart]

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.

 

[sam system-d]

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.

 

[mitsos]

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.

 

[sam system-d]

WHY! Why I didn't think about the relay at the first time... Thanks, sometime, you just need external look!

 

[mjproc]

I've just completed my 2nd dual ez1290 in a 2U enclosure 

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....)

 

[sr1200]

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.

 

[travis]

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!       

 

[mjproc]

I've just completed my 2nd dual ez1290 in a 2U enclosure 

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

 

[bjknapp]

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

 

[3nity]

have you follow the small manual that Martin put together?
heatsink should be not isolate from 2n3055!

 

[MicDaddy]

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)

 

[bjknapp]

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

 

[MicDaddy]

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.

 

[3nity]

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.

 

[Whoops]

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

 

[3nity]

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

 

[spase]

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?

 

[desol]

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?

 

[3nity]

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

 

[sr1200]

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.