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Project Specific Discussions => Preamplifiers => Topic started by: Slenderchap on December 25, 2010, 03:53:43 AM

Title: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 25, 2010, 03:53:43 AM
Santa and his little elves have been busy this Christmas .... look what was under the Christmas tree...

(http://www.audiomaintenance.com/downloads/ez1073_prototype.jpg)

and its little cousin...

(http://www.audiomaintenance.com/downloads/ez1073-500_prototype.jpg)

I wish I had been more specific when writing my Christmas wish list as I forgot to say "with metalwork".... so I'll just have to do that later

They are the ez1073 and the ez1073-500.... the clue is in the title ..... mic gain and line gain are on two seperate rotary switches with a toggle switch to select between inputs.... both basically identical but the 1U rackmount has an additional output trim pot

........... "any interest" ?

sound clips: http://www.youtube.com/user/Audiomaintenance

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: SIXTYNINER on December 25, 2010, 04:15:13 AM
a well made tooooooooo much cool "porn" stuff !
 ;)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on December 25, 2010, 04:24:40 AM
WOW! Nice work colin!  :o

Is someone going to make panels? or do we diy... FPE / Schaeffer?

RE:500 series, how are you getting 24v? DC-DC converter? or have you reworked the circuit to run off +/- 16v?

No 51X fingers?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sarcastic Sound on December 25, 2010, 04:38:54 AM
I'll take 8 please  ;D

but seriously... 8. When are you thinking they will be available?

I am showing GREAT INTEREST!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on December 25, 2010, 05:56:02 AM
Wow, spewing that this didn't come out earlier!

So will you be selling a FULL kit, case and all?

Whats the pricing on the full kits for both the rack and 500 series version?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: zayance on December 25, 2010, 06:26:24 AM
Got the goods from China wow  ;D ;D ;D, seems like PRo Audio is not dead SIXTININER  ;D ;D ;D ;D  :) :), the 1073-500 is very tempting and great looking piece of gear you've done, will follow this thread with great interest.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sammas on December 25, 2010, 06:42:57 AM


I'd be keen for a pair of 500 kits!  ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on December 25, 2010, 07:50:27 AM
definitely interested
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on December 25, 2010, 08:21:35 AM
Wow, 1U ez1073 for me please! I am drooling.  ChrsP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: benlindell on December 25, 2010, 09:00:24 AM
Definitely interested!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: lsskmki on December 25, 2010, 09:21:11 AM
Very nice :) I wish I still had space in my rack, but after those ez760s, ez1084s...la3s .... I'll run out of space (at least momentarily  ;D) .
But back to the point, those 1073s must sound ace !  8)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: MikoKensington on December 25, 2010, 10:08:52 AM
Oooooh.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kepeb on December 25, 2010, 10:35:00 AM
sweeeet
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bpucekov on December 25, 2010, 10:38:51 AM
yessssss!!!!!!!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jsteiger on December 25, 2010, 10:52:35 AM
Nice Colin!!! It sure looks like Santa was good to you...and therefore good to all of us.  :D

I'm in. Where do I sign up?  ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mikefatom on December 25, 2010, 12:04:56 PM
Damn, that is beautiful!  There's gotta be $100 worth of grayhills on there too!  :P
Will you be offering full kits? or just PCBs and partial kits?

Merry Christmas everyone!

Cheers

Mike
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kazper on December 25, 2010, 12:09:47 PM
Yes... I'm in!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on December 25, 2010, 04:58:15 PM
Im in!


Forgot to ask, will we be able to use ed andersons  input transfos with these for us US folks?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: south2577 on December 25, 2010, 06:08:28 PM

I'm interested in 120 of the 1U modules  ;D...... but a pair will do for starters.

Keen to know the price? Kits partial or full?

Some of us aussie's could share postage?

Nice work Colin.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: janvanvolt on December 25, 2010, 07:32:34 PM
If the price is fair, i'm in for one 500 one :-)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: JBVries on December 25, 2010, 07:32:52 PM
DEFINITELY IN!!! Mostly for the 500 series. At least 2 for me.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: MicDaddy on December 25, 2010, 09:09:04 PM
I'm in for a pair of 1RU EZ1073s
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brolik on December 25, 2010, 09:33:13 PM
I'm definitely in for a pair. I'm gonna start looking into buyers for my liver right now...
 ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitarguy12387 on December 25, 2010, 09:41:14 PM
Puuurrrrrty. I'm interested.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: fazeka on December 25, 2010, 09:56:52 PM
Interested in two of the 500 series modules.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jackies on December 25, 2010, 09:59:25 PM
 :o
Will those be available as kits?
I would have to get a job to afford this!
 :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: MikoKensington on December 25, 2010, 10:13:29 PM
I would have to get a job to afford this!
 :'(

Ewww.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pacemaker on December 26, 2010, 01:38:57 AM
solder ..........
solder........
give me my solder dose !!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 26, 2010, 03:59:35 AM
Is someone going to make panels? or do we diy... FPE / Schaeffer?
RE:500 series, how are you getting 24v? DC-DC converter? or have you reworked the circuit to run off +/- 16v?

Dan (collective cases) has said he would be happy to make the 1U cases.... not sure about the 500 series version.... I'll draw the front panels out in FPE so you can make your own anyway should you so desire.

It simply creates the 24v using a linear regulator.

Forgot to ask, will we be able to use ed andersons  input transfos with these for us US folks?

No idea..... if it is mechanically the same then yes.... if not then no.

Will you be offering full kits? or just PCBs and partial kits?

I intend to simply pass on the finished files to Gustav.... who (I presume) will be willing to make the PCB's.... won't be doing full kits.... but I will probably do a colourbook for each so that it is easy to make them.

I will need to create a revision 2 of each which will take 3-4 weeks to do....and then I'll get Gustav on the case.

There is also a new mains transformer being designed for the 1U version.... but that is still in development.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Albrebreton on December 26, 2010, 06:51:21 AM
Yes, definitely interested!!!
Merry Christmas.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Matthew Jacobs on December 26, 2010, 06:54:04 AM
I'm down for 2 1U units...

JD
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: snipsnip on December 26, 2010, 07:27:17 AM
verrrry sexy.

is that a line input and a mic input? Can the circuit be partially built without one or the other temporarily for those of us still feeling the xmas sting?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 26, 2010, 07:40:43 AM
is that a line input and a mic input? Can the circuit be partially built without one or the other temporarily for those of us still feeling the xmas sting?

They both have line and mic input (on the 500 type the mic input comes from the connector in "slot 1" and the line comes from the connector in "slot 2").... the selection between mic and line is just on a toggle switch so I see no reason why you could not part build and simply hard wire the toggle switch.... if going line only you could miss out the entire first gain stage.....

The line input goes from -20dB to +20dB in 4db steps (11 way switch 0dB in the centre).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: snipsnip on December 26, 2010, 07:45:53 AM
thats amazing. I love using my 1290's on line sources with a pad, but leaving the pad connected creates some weird load issue ive never quite figured out.

This looks like a great all in one solution with a sexy eq thrown in.

very very nice.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jandoste on December 26, 2010, 08:00:54 AM
Interested in two of the ez1073-500 series !
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: gandhalf3 on December 26, 2010, 12:28:50 PM
interested in two Rack Unit.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Nobru on December 26, 2010, 02:09:07 PM
Ho ho ho !!!  I am in for two rack version.... and plus if prices allow me to....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on December 26, 2010, 02:45:29 PM
Definately be interested in the 1U Rack..
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on December 26, 2010, 05:33:23 PM
It simply creates the 24v using a linear regulator.
Is your method better than the DC-DC converter method in regards to these units? Is there a reason why you didn't go the DC-DC converter method like other 500 series designers for the 16v lunchboxes?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: snipsnip on December 26, 2010, 06:11:00 PM
Power is just power at the end of the day right? Who cares?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Marcocet on December 26, 2010, 08:12:59 PM
I'm super in for a pair of the 19" plus whatever kind of kit you offer Colin. Looks great!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 27, 2010, 01:31:43 AM
Is your method better than the DC-DC converter method in regards to these units? Is there a reason why you didn't go the DC-DC converter method like other 500 series designers for the 16v lunchboxes?

I cannot envisage a single reason why you would use a DC-DC converter (except perhaps unless you owned a factory that makes DC-DC converters).

In no particular order;

They are all different package styles so you would need to choose a brand and stick with it which can be a sourcing problem if the supplier is out of stock.
They are comparitively large.
They generate noise which is not good for a high gain system.
They introduce noise spikes onto the supply line unless you have a very low impedance supply output.
They are generally unreliable.... compared to a linear regulator

.... and of course most importantly..... expensive.... a linear regulator is only a few pence.

Colin
www.audiomaintenance.com



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: [silent:arts] on December 27, 2010, 03:26:58 AM
Collin, why didn't you use Pin 17 ;)
you are the original inventor 8)

however, for sure I'm in (ez1073-500, for sure in stereo)
mhm, looks like I need to build more 511 Racks soon ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: AudioGimmer on December 27, 2010, 04:09:33 AM
Certainly got some interest here.... Lunchbox or 1U though?  ???
Hmmmmm, probably 1U unless I build a 511 rack in the new year

Looks great

The Gimmer
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 27, 2010, 04:16:55 PM
Keen to know the price?

Applying an educated guess I would expect that the ez1073-500 would probably cost about GBP 350 in total .... much of it depends on how many small components you already have from other projects (you cannot order a single resistor from suppliers).... and how many you build at once to save on freight costs.....

The 1U rack version would probably cost GBP 450 as you have more metalwork and a psu to add.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: desun on December 27, 2010, 07:35:30 PM
Interested in 1 of each over here... very neat indeed!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: matta on December 28, 2010, 06:16:26 AM
Colin,

You are a genius and madman, and we love you for it  :P

It was quite funny as on Christmas eve I was thinking to myself, 'I wonder when someone is going to do a PCB 1073, we've spoken about it for years...', lo and behold, not one but TWO surface, genius!

I love the layout, I noticed some of the smaller details as well, the holes around the 2N3055 heatsink for ventilation, preventing the heat potentially damaging the PCB in years to come. It also looks like there is onboard regulation as well if you decided to use it?

Well done mate, top notch as always!

Cheers

Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on December 28, 2010, 08:13:40 AM
Is your method better than the DC-DC converter method in regards to these units? Is there a reason why you didn't go the DC-DC converter method like other 500 series designers for the 16v lunchboxes?

I cannot envisage a single reason why you would use a DC-DC converter (except perhaps unless you owned a factory that makes DC-DC converters).

In no particular order;

They are all different package styles so you would need to choose a brand and stick with it which can be a sourcing problem if the supplier is out of stock.
They are comparitively large.
They generate noise which is not good for a high gain system.
They introduce noise spikes onto the supply line unless you have a very low impedance supply output.
They are generally unreliable.... compared to a linear regulator

.... and of course most importantly..... expensive.... a linear regulator is only a few pence.

Colin
www.audiomaintenance.com
Would you say that using a linear regulator enables your unit to be more true to the original 1073 units as say a DC-DC converter version does?

Have you compared other 1073 - 500 series clones that are using a DC-DC converter and an original 1073, and compared it to your 500 series clone, and have you noticed any sonic differences?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: justanalogue on December 28, 2010, 02:22:00 PM
Now I know were my money goes into next year.
Colin, thank you so much for this!

Willem.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on December 28, 2010, 08:14:39 PM
oh my god this is awesome. i wish i have some money to spend right now.
does it have a DI too?
however that thing is awesome.
are you gonna make a single batch?
because if you keep these regularly in your shop you this would be awesome.
i'm interested only in the 1RU unit, but the 500 one seems awesome too.

please keep a bunch in your shop regularly.
this would be seriously awesome, at least the 1RU unit. nobody has them.
what you did is seriously awesome.
thanks.
don't be that guy, don't stop the production after the groupbuy, people need this

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: shabtek on December 28, 2010, 09:46:27 PM
awesome.

... seriously.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kml23956 on December 28, 2010, 11:54:39 PM
I get back online and this is what I find....awesome.  I need to make room in the rack.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 29, 2010, 06:06:48 AM
Would you say that using a linear regulator enables your unit to be more true to the original 1073 units as say a DC-DC converter version does?
Have you compared other 1073 - 500 series clones that are using a DC-DC converter and an original 1073, and compared it to your 500 series clone, and have you noticed any sonic differences?

No and No....

does it have a DI too?.......are you gonna make a single batch?

No DI input..... that would be a different project.

I will not be making anything.... I am hoping that Gustav will make the PCB's, and a couple of other members will make the metalwork.

I get back online and this is what I find....awesome.  I need to make room in the rack.

Get a big rack because there is more to come.....

I love the layout, I noticed some of the smaller details as well, the holes around the 2N3055 heatsink for ventilation, preventing the heat potentially damaging the PCB in years to come. It also looks like there is onboard regulation as well if you decided to use it?

I would love to say that I had been clever enough to make rectangular vent holes... but they are just the screenprint showing a common heatsink size.... they give off very little heat anyway... holes would be redundant in a 1U box due to the overall volume of air....

All the power supply is onboard.... just need the low voltage AC inputs.... waiting for a new Carnhill 24v/48v power transformer.... should be here soon enough....


Colin
www.audiomaintenance,.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on December 30, 2010, 03:59:33 AM
Ok, you got me with the more to come, spill the beans  ;D

I will definately get a pair of 1RU 1073s.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: briomusic on December 30, 2010, 08:41:50 AM
Ok, you got me with the more to come, spill the beans  ;D

Me 2! As my trusted purveyor of carnhill iron, you must be aware that I am already all neve-preamped-out...   :D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sarcastic Sound on December 30, 2010, 01:52:48 PM
what size case did you design the 1u pcb to fit into?

8 inch, 11 inch depth? or... 200mm/280mm?

already starting to assemble modules in the back of my mind!

GREAT work on this and thank you so much for making this project available.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: braeden on December 30, 2010, 06:18:54 PM

I'm interested in 120 of the 1U modules  ;D...... but a pair will do for starters.

Keen to know the price? Kits partial or full?

Some of us aussie's could share postage?

Nice work Colin.

Here here, happy to share :P
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 31, 2010, 05:15:30 AM
what size case did you design the 1u pcb to fit into?

The PCB in the photo is just a prototype so it has the XLR's on board purely for bench testing... it measures about 16cm x 40cm... I intend to remove the XLR's (although they could probably stay)

You should not attempt to have a circuit board where the pots are fastened to the faceplate and the connectors are attached to the rear panel..... apart from the fact that the mechanical tolerances are not good enough you will eventually find the unit fails as the solder joints fracture due to the expansion/contraction of the chassis over the years....

I'll put some molex connectors for each XLR connection and they can be hand wired.... this way people can choose the type/brand of XLRs etc....

So I would expect that a 200mm depth will probably be OK.... maybe a bit more to allow for an IEC mains inlet.....

I have received confirmation from Gustav that he is happy to do the PCB's

Dan (collective cases) will probably be doing the 1U rack metalwork.... I just have to  do the faceplate drawing for him.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on December 31, 2010, 05:38:06 AM
You should not attempt to have a circuit board where the pots are fastened to the faceplate and the connectors are attached to the rear panel..... apart from the fact that the mechanical tolerances are not good enough you will eventually find the unit fails as the solder joints fracture due to the expansion/contraction of the chassis over the years....
Collin how about if its like grayhill switches that are soldered on the PCB board and the grayhills fastened to the faceplate?
I am really concerned about a 500 series EQ I am doing where there are 3 grayhill switches soldered to the PCB and the grayhills fastened to the faceplate and the PCB fastened to the case. I noticed that when I attached the grayhills to the faceplate and tighten the nuts, I could feel a sort of crackling when doing it.

It would have been OK if the PCB wasn't attached to the case, so that there wouldn't be any tugging kind of thing happening in this situation.

Is there a flexible tolerance on the pcb when a component for example tries to lift the solder and pcb metal part of the pcb?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 31, 2010, 05:55:15 AM
What I wrote above does not apply to a 500 series module as it does not have a mechanically attached rear connection... it can move backwards and forwards in the EDAC socket....

The problem you describe will always happen..... you must tighten the faceplate parts in place before you tighten the PCB screws to the side panel..... if there is a large gap between the switches and the rear of the faceplate use 2 nuts... one on each side of the faceplate

The ez1073 and ez1073-500 will use the "2 nut" approach..... the rear one is that which comes with the component... the front one is a chrome "ring nut" which is partially buried in the faceplate so that the knobs almost touch the faceplate (desguising the fixtures).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sarcastic Sound on December 31, 2010, 04:04:42 PM
Hi Colin,

Molex connectors for the i/o is perfect.

Will you be making the mechanical drawing of the faceplate (or FPD file) available to those of us who are making our own faceplates/cases? Call me lazy but I always hate getting the calipers out and measuring pcbs to find pot/switch placement for panel work.

Thanks again for this project and HAPPY NEW YEAR!!!

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: snipsnip on December 31, 2010, 09:28:03 PM
hey sarcastic

I'll draw the front panels out in FPE so you can make your own anyway should you so desire.

 :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sarcastic Sound on December 31, 2010, 10:57:55 PM
I missed that... thanks for pointing it out!  ::)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pidah on January 01, 2011, 06:49:54 AM
Very nice indeed!

I'd be in for at least 4x 1ru19" and at least 2 500.

Happy new year to all

Pieter
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: earthsled on January 03, 2011, 10:36:04 AM
I'm interested in the rack unit style.

I'm also wondering if these PCBs could be used to do a 1066 clone. I'm not sure, but I think the only difference is the EQ frequencies. Perhaps swapping some RC values could produce an ez1066?

Thanks!


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Siegfried Meier on January 03, 2011, 12:08:26 PM
Sweet!  I'd be in for 2 Colin.  Nice work!

Sig
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 04, 2011, 06:49:06 AM
I'm also wondering if these PCBs could be used to do a 1066 clone. I'm not sure, but I think the only difference is the EQ frequencies. Perhaps swapping some RC values could produce an ez1066?

They are different but you could probably achieve the 1066 frequencies by just swapping some capacitors....and make a sort of hybrid ez1066.... experimentation is much of the point of this exercise...

I expect that the 500 series will be first to "pop" out of the system as we are still waiting for the new mains transformer for the rackmount version ..

It looks as though Pete (Grandmaster Audio) will be making the 500 series metalwork....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on January 04, 2011, 08:25:17 AM
Hey colin, just wondering what is the idea behind the "slots" in the pcbs around the output transformer of the 500 series - visible on the right two images:

(http://www.audiomaintenance.com/downloads/ez1073-500_prototype.jpg)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 04, 2011, 09:17:14 AM
It is just because it is a prototype.... all the boards were made as a single PCB with a single continuous routed profile which means that the transformer hole is made by running the router into the board rather than taking it off the PCB and making a seperate hole (because that just leads to more work for me)..... real PCB's are not done that way.

The production version will not actually need the transformer hole as there is enough clearance anyway.....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on January 04, 2011, 10:25:35 AM
Thanks Colin - sounds like the production ones should be nice and sturdy...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on January 08, 2011, 02:11:04 PM
Wooo, this looks awesome, please count me in.  This would be a great first project, I've been eying up the 1290 for a while now and this is absolutely perfect timing!

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 12, 2011, 11:26:34 AM
Pete (Grand Master Audio) knocked up a quick sample of a faceplate from a bit of old scrap aluminium.....

Shows the general idea:

(http://www.audiomaintenance.com/downloads/ez1073-500_with_proto_faceplate.jpg)

The second revision of the ez1073-500 PCB should be here next week.... after which we should be able to start on the "real" stuf with Gustav and Pete.

Took it to the studio today to play with ...... works a treat.

The second revision of the rackmount type is awaiting the new mains transformer before it can procede... that should be here next week ... at which point it will be possible to complete the PCB layout.

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on January 12, 2011, 11:51:14 AM
Looks awesome, I can't wait!  I'm definitely in for at least 1 rackmount, but I'd really like to get 2.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: DAN_000 on January 15, 2011, 11:03:35 AM
Hi Colin,  great proyects!

I saw you are using simple regulators for 24v supply,  then, your virtual ground is ?   Are you using 1 regulator for +16 and another for -16 ?
Can you post a schemo on how you manage this ?

Congratulations !  You will sell this like kits ? pcbs only ?  let me know!

Cheers
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: snipsnip on January 15, 2011, 06:29:49 PM
im so into this but cant afford it.

might sell my 1290's and give this a go.

amazing project
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on January 15, 2011, 07:11:13 PM
Collin,

Can you explain how your eq section works please?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: okgb on January 15, 2011, 07:16:08 PM

" Turning Knob to the right , Gives more  "

Almost always works , check it out at home

Looks nice colin , can't afford to jump in now ,
so hope it becomes a stocking item ,
otherwise one would need to put down a deposit

best of the new year to you
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: funkymonksf on January 15, 2011, 07:40:19 PM
I'm down for two 1ur! So great to be able to do this legit!

-Brice
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on January 15, 2011, 09:08:54 PM

" Turning Knob to the right , Gives more  "

Almost always works , check it out at home

Looks nice colin , can't afford to jump in now ,
so hope it becomes a stocking item ,
otherwise one would need to put down a deposit

best of the new year to you
He has one knob at the top right? Is that a high shelf, and if so at what frequency?

Also the bottom left knob, is that a high pass filter?

Is the switch on top of it to turn it into low pass filter?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on January 15, 2011, 09:18:38 PM
I'll have a go - these are GUESSES, based on the fact this is a "1073":

He has one knob at the top right? Is that a high shelf, and if so at what frequency?

yes. 12k

Also the bottom left knob, is that a high pass filter?

yes.

Is the switch on top of it to turn it into low pass filter?

No. i'd say that's a polarity switch - or "phase" switch...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on January 15, 2011, 10:16:22 PM
I'll have a go - these are GUESSES, based on the fact this is a "1073":

He has one knob at the top right? Is that a high shelf, and if so at what frequency?

yes. 12k

Also the bottom left knob, is that a high pass filter?

yes.

Is the switch on top of it to turn it into low pass filter?

No. i'd say that's a polarity switch - or "phase" switch...
Thanks haima, yeah cause my EQN which I think is meant to be the EQ section of the 1073 has more than 1 frequency for the high shelf and the mid has switchable q's.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on January 15, 2011, 10:38:52 PM
AFAIK pete's EQN is based on the 1084...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 18, 2011, 01:41:36 AM
I saw you are using simple regulators for 24v supply,  then, your virtual ground is ?   Are you using 1 regulator for +16 and another for -16 ?
Can you post a schemo on how you manage this ? ... You will sell this like kits ? pcbs only ?  let me know!

On the ez1073-500 the virtual ground is at -16v... just a single 8v regulator on the +16v... the Schematic will be in the colourbook..... Gustav will do the PCB's, Grand Master will do the faceplates... AML will do a "partial kit" of the difficult parts.....

"Haima" seems to have answered the EQ questions already..... but just to re-confirm.... the HF is at 12k, the Bottom left is the HPF, the switch above it is phase..... It is clearer on the "real" metalwork as it has the EQ symbols/legends printed on it (they were missing off the lash-up by mistake)....

The second revision of the ez1073-500 should be here today... it is easier to build as the op-amp sub cards are now part of the main card.... the "real" faceplate should be done shortly so you will be able to see what they actually look like... grey with white text.

Still waiting for the mains transformer for the ez1073 so it is on hold at the moment (the custom core for the transformer arrived but was 160mm diameter instead of 60mm).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: south2577 on January 18, 2011, 03:18:27 AM

Still waiting for the mains transformer for the ez1073 so it is on hold at the moment (the custom core for the transformer arrived but was 160mm diameter instead of 60mm).


 :'(

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: [email protected] on January 18, 2011, 08:09:43 AM
Hi Collin,
If you are keeping track of member interest, I would be in for 2 rack mount versions.
Cheers
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on January 18, 2011, 09:46:59 AM

On the ez1073-500 the virtual ground is at -16v... just a single 8v regulator on the +16v... the Schematic will be in the colourbook..... Gustav will do the PCB's, Grand Master will do the faceplates... AML will do a "partial kit" of the difficult parts.....

"Haima" seems to have answered the EQ questions already..... but just to re-confirm.... the HF is at 12k, the Bottom left is the HPF, the switch above it is phase..... It is clearer on the "real" metalwork as it has the EQ symbols/legends printed on it (they were missing off the lash-up by mistake)....

The second revision of the ez1073-500 should be here today... it is easier to build as the op-amp sub cards are now part of the main card.... the "real" faceplate should be done shortly so you will be able to see what they actually look like... grey with white text.

Still waiting for the mains transformer for the ez1073 so it is on hold at the moment (the custom core for the transformer arrived but was 160mm diameter instead of 60mm).

Colin
www.audiomaintenance.com

I'm disappointed the rack mount isn't quite ready yet but this way I'll be able to get enough cash together for 2!  In the end it's a good thing.  I'm really anxious to get started either way.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on January 19, 2011, 07:21:20 PM
Im anxiously waiting the EZ1073 and kinda glad it got delayed as i will be able to save for 2 also lol. Colin thanks again for doing this.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on January 19, 2011, 09:24:53 PM
Im interested in a 1u!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: SimonB on January 24, 2011, 08:39:25 PM
Will your PCB set allow me to add the 1073 EQ to my EZ1290 or does it already have the 1290 preamp section built into the PCB?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: MikoKensington on January 24, 2011, 09:16:41 PM
This has mic and line inputs.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: DAN_000 on January 24, 2011, 10:00:55 PM
51X fingers ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on January 24, 2011, 10:09:43 PM
51X fingers ?

Read back a bit - this has already been discussed a few times... From what I understand, as the unit is transformer isolated on the in and out Colin is just combining the bipolar 16v rails to form one one 32v rail, and then linear regulating that down to 24v. No need for the 51X pins in this case. You can use these in a 51X rack though - no problems!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 0dbfs on January 24, 2011, 10:16:59 PM
51X fingers ?

Read back a bit - this has already been discussed a few times... From what I understand, as the unit is transformer isolated on the in and out Colin is just combining the bipolar 16v rails to form one one 32v rail, and then linear regulating that down to 24v. No need for the 51X pins in this case. You can use these in a 51X rack though - no problems!

That is cool! But I wouldn't think you want to connect your -16/"0V ref" directly to chassis/pin-1 would you? Cap to chassis would return AC but what about DC returns?

Best,
j
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: DAN_000 on January 24, 2011, 10:57:48 PM
Thanks haima, yes, I know. But I would like to use this 24v rails instead of converting from +-16v. If I have 24v in rack, why not to use this ?  +-16 rails will be happy and with more free power  8)  onboard regulator is consuming 25% of power, anyway is a lot better way than DC-DC converter.

BTW, if its not too late, I think 51x fingers will be a good option, and if you dont need this fingers, just break this!

How much current handle 1073 ?

Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 25, 2011, 02:04:01 AM
That is cool! But I wouldn't think you want to connect your -16/"0V ref" directly to chassis/pin-1 would you? Cap to chassis would return AC but what about DC returns?

Between the input secondary and output primary there is no need for any reference to the chassis/pin1....

(http://www.audiomaintenance.com/downloads/transformer_isolation.jpg)

It could probably even be ac as long as it wasn't in the audio band.....

On a dual slot wide module there is no real need to use the 51x extension as you have 260mA available and the module only needs 90mA.... and the number of standard lunchboxes far exceeds the number of 51x type racks....

The design went off to Gustav yesterday for the 1073-500 anyway so it is already done.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Grand Master Audio on January 26, 2011, 09:07:13 AM


Hi Chaps,

Colin has asked me to manufacture the front panels for this project. Pictured here is a prototype panel I made for Colin (winging its way to you now Colin).

But this is not how the panels are being made, if we can get the numbers, 50+, I will machine them and send them off to be powder coated and silk-screened. Powder coat will be the Neve Dark RAF sea grey, silk-screen will of course be white. will look super lovely!

It would be good to get an initial feel as to how many, as 50 is a minimum run, but if more are needed ill get more done in the initial batch. Price for the panel are £25ea + posty and packing yet to be worked out, but they are light so very cheap to ship.

sound cool?

Best
Pete
(http://www.grandmasteraudio.com/ez10845001.jpg)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Infernal_Death on January 26, 2011, 09:42:31 AM
Looks good. I am in for 1 500 board set and 1 panel.

Flo
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jandoste on January 26, 2011, 10:39:07 AM
Looks good. I am in for 1 500 board set and 1 panel.

Flo

Same here!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Albrebreton on January 26, 2011, 01:54:01 PM
I just finished my two 1072,  but now, I must buy another 500 series case,it looks so great that I'm in for four 500 board set and four panel at least. Beautiful work, guys.
Alberto. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: zayance on January 26, 2011, 02:29:15 PM
Count me in for 2 x 500 Panels Pleazzzze...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kepeb on January 26, 2011, 02:37:38 PM
depends on time frame but catch up and be in for two 500 series eventually  ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mikefatom on January 26, 2011, 02:44:46 PM
[...]
(http://www.grandmasteraudio.com/ez10845001.jpg)
[...]

Wow Pete.  That looks sweeeeeeeeeet!  Well... all your panels do really!  8)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: south2577 on January 26, 2011, 02:55:04 PM
Beautiful Pete!

I'll take 2 x panels.
Are you doing any 1 unit panels? I'd like to order everything at the one time if possible.
I'm planning 2 x 1073 500's and 2 x 1073 1U.

cheers
Ben
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pidah on January 26, 2011, 03:48:53 PM
Very nice!
I like this color scheme,but in Neve it will be even better,surely.
Well, I'll take 2 for starters,but surely will end well past 4.

Thanx for wanting to do this,loverly project!
Cheers,
Pieter
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 27, 2011, 09:12:36 AM
(http://www.audiomaintenance.com/downloads/ez1073-500_front.jpg)

Fits and works a treat...

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jandoste on January 27, 2011, 09:18:07 AM
(http://www.audiomaintenance.com/downloads/ez1073-500_front.jpg)

Fits and works a treat...

Colin
www.audiomaintenance.com

Wowwwww ! Great job Colin!
I want it !:)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 27, 2011, 09:26:39 AM
(http://www.audiomaintenance.com/downloads/ez1073-500_overview.jpg)

I have also made it simpler to build by combining the opamp subcards onto the upper PCB.... there was more space than I had originally anticipated.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on January 27, 2011, 02:51:20 PM
Beautiful, how's the rack unit coming along?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sunnen1 on January 28, 2011, 01:19:53 PM
drool : )~
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tmuikku on January 28, 2011, 03:11:53 PM
Jeah, looks cool and possibly doesn't sound that bad (nevere heard one), ,maybe someday :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on January 28, 2011, 05:49:17 PM
I'm wondering if the 1 RU design will allow me to put two boards in a 2 RU chassis and run both of them off the same power supply...  I'd miss out on the stellar panels that are being made for this project, but still... I wonder if the PSU design could handle that and if I'd run into more problems than it's worth...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 30, 2011, 03:11:36 AM
The 1U version is still waiting for the custom mains transformer.... hopefully it will turn up this week....

I am sure you could put 2 in a 2U box..... and I expect that the power supply could handle it (when I came up with the transformer spec I am sure that I made it large enough for 2 circuits in one box on the basis that lots of people will want to use it for a dual mic pre circuit).....

However, you may end up with crosstalk between the output transformers as they would be directly on top of one another.....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: datune on January 30, 2011, 04:47:06 AM
Count me in for 2 x 500 series, including those lovely looking panels!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on January 30, 2011, 06:41:28 AM
The 1U version is still waiting for the custom mains transformer.... hopefully it will turn up this week....

I am sure you could put 2 in a 2U box..... and I expect that the power supply could handle it (when I came up with the transformer spec I am sure that I made it large enough for 2 circuits in one box on the basis that lots of people will want to use it for a dual mic pre circuit).....

However, you may end up with crosstalk between the output transformers as they would be directly on top of one another.....

Colin
www.audiomaintenance.com

That's great news about the PSU. 

Yes the cross talk was my biggest concern...  I am hoping it may be possible to reduce considerably with some custom shielding between the two, or maybe taking them outside of the chassis.  But either way since I have a spare 2U chassis laying around it seems like a great option even with the added difficulty.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dmp on February 01, 2011, 02:16:26 PM
I'm interested in a pair of rack mount 1073s. Awesome project.
I'd probably use an external PSU so would not need a custom mains transformer.
How does the output trim pot work?  
And, do the mic gain / line gain switches interact? If I recall correctly, the 1073 line input gives 6 pad positions feeding into the second gain stage, which has a gain determined by the position of the third deck of the mic gain switch.  I would think it would need a dpdt switch, and from the picture it looks like you are using a spst.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 01, 2011, 04:28:04 PM
Luckily, I had already added spade terminals to the DC rails of the ez1073 rev2 PCB so that you can easily plug in external power on 1/4 inch spades.

The output trim is between the 2nd and 3rd stages.... currently it is set for -10dB trim... but I am sure that with a couple of resistor value changes it could go to -infinity.

On the rev2 PCB it has a DPDT switch with the gain stage 2 boost routed through the second pole so they are independent.... however that is not the case on the 500 series version (so it should really say "cal" in the lowest mic gain position)... there is actually just not enough tracking space on the 500 series to get an extra pin on the faceplate PCB (although I'll take another look at that).... it can easily be modded with a piece of wire but tracking it on the PCB is incredibly difficult (on the 1U version it was trivial).

We should get the mains transformer tomorrow so the rev 2 can be fabricated once it has been checked.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on February 01, 2011, 05:02:40 PM
I'm interested in a pair of rack mount 1073s. Awesome project.
I'd probably use an external PSU so would not need a custom mains transformer.

Yeah I was thinking about that too, were you planning on making one or using one you already have?  I'm just curious what your approach would be, whether it's a fixed dc output, or a variable supply.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dmp on February 01, 2011, 05:41:34 PM
After building a psu for my 51x rack, I decided to use the same connector and pinout for preamps, so all my gear will use the same psu(s). I'm using the Amphenol connectors. So to start with I'll just use the PSU I have (connected to just 48/24/0v). I have plans to build another psu though.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Soeren_DK on February 03, 2011, 02:12:13 PM
Hi Colin.

Thanks for this thread. This is heaven-sent.  :) :) :)

Does Gustav make the 1u PCB version now as well? Did you calculate a approximately price for the 1U?

Cheere
Soren
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 05, 2011, 12:52:37 PM
On the rev2 PCB it has a DPDT switch with the gain stage 2 boost routed through the second pole so they are independent.... however that is not the case on the 500 series version (so it should really say "cal" in the lowest mic gain position)... there is actually just not enough tracking space on the 500 series to get an extra pin on the faceplate PCB (although I'll take another look at that).... it can easily be modded with a piece of wire but tracking it on the PCB is incredibly difficult (on the 1U version it was trivial).

I have now managed to re-track the ez1073-500 so that it also has gain independance.... same as the rack version.... soon as the new PCB is checked out I'll send Gustav the newer version (luckily he hadn't actually started).

I expect to order the rev 2 of the rack version on Monday.... so it should not be too long before Gustav has that as well.

The ez1073-500 colourbook is also well under way.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tommypiper on February 06, 2011, 03:09:52 PM

The ez1073-500 colourbook is also well under way.




Thumbs Up, many thanks for the project.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 09, 2011, 06:10:18 AM
I have just ordered the rev2 PCB for the rack version..... it should be here on the 4th March...... I expect that it will be "good to go".

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on February 09, 2011, 10:02:27 AM
woohoo ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pidah on February 09, 2011, 01:02:27 PM
Massivly Jummi!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on February 09, 2011, 04:13:29 PM
On the rev2 PCB it has a DPDT switch with the gain stage 2 boost routed through the second pole so they are independent.... however that is not the case on the 500 series version (so it should really say "cal" in the lowest mic gain position)... there is actually just not enough tracking space on the 500 series to get an extra pin on the faceplate PCB (although I'll take another look at that).... it can easily be modded with a piece of wire but tracking it on the PCB is incredibly difficult (on the 1U version it was trivial).

I have now managed to re-track the ez1073-500 so that it also has gain independance.... same as the rack version.... soon as the new PCB is checked out I'll send Gustav the newer version (luckily he hadn't actually started).

I expect to order the rev 2 of the rack version on Monday.... so it should not be too long before Gustav has that as well.

The ez1073-500 colourbook is also well under way.

Colin
www.audiomaintenance.com


If you switch between mic and line gain, will there be a click or any issues? Should a person turn off the unit first before switching between mic and line gain?

Any reason why you decided not to leave it all in one knob instead of two separate mic and line gain knobs?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on February 09, 2011, 04:39:55 PM
yeah, i wanna know that too.
personally i'd prefer only one knob as Gain / Line.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dmp on February 09, 2011, 06:32:50 PM
I think you would have to source a 16 pos switch, while this design gets by with a 12 pos Grayhill + another Grayhill for line.
My opinion is that it could be even simpler - with just the mic gain switch (12 pos) and a switch from mic to line. I built my EZ1290 preamps this way, and wired the toggle switch to flip between the mic tx and the line tx. I did a single pad that drops the line input after the Tx by 20 dB (which is all the line positions do, is switch pads), but left the mic gain engaged, so I could bring up the level that way. It works well, but Slenderchap's method will be fine also, in my opinion.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 10, 2011, 08:27:53 AM
If you switch between mic and line gain, will there be a click or any issues? Should a person turn off the unit first before switching between mic and line gain?
Any reason why you decided not to leave it all in one knob instead of two separate mic and line gain knobs?

The click between mic and line is no more noticable than that when changing mic gain... so I would say no issues.

Using a single gain control would be much more expensive.... a triple gang 24 position PCB mount Elma is about GBP 70..... and to fit the PCB's you have to dis-assemble it.... plus the PCB size would increase (and so cost more)..... and the cheaper hand wired version completely negates the goal of it being "ez"......

I would expect a line input device to have a gain control which is zero in the centre and +/- 20dB (or +/- 16dB) at each extremity.... like a console.... so that is why it is done that way.

Some people will only want to make it as a line level device (cheaper) so it is much more logical as +/-20dB.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on February 10, 2011, 10:20:11 AM
oks, i'm in
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on February 27, 2011, 11:12:06 AM
any news on this project?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: NoBass on February 27, 2011, 07:37:58 PM
I'm going to take one 500 for sure ! Great project. I hope the kits, full or partial, will be available soon...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 28, 2011, 03:08:16 AM
The 500 series is done..... just waiting for matalwork to confirm everything is OK with it all..... the faceplates are due about the 3rd March (Friday.... ish)

The rackmount rev 2 PCB is due to me on Wednesday.... should have that built and checked by next week....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sarcastic Sound on March 09, 2011, 01:58:54 PM
bump... update on timeframe of availability?  ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 09, 2011, 04:14:00 PM
The 500 series version metalwork fits just fine..... been building a handful the last few days just to check the accuracy of the colourbook.... no errors but could do with a bit more detail.

We have a whole bunch of PCB's and metalwork so kits could include those..... I'll sort that out asap.

The rack version rev2 PCB came last week... just not had chance to build it yet.

I'll try to remember to do a couple of photos tomorrow of the completed 500 version.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 10, 2011, 07:00:39 AM
Here is a completed one.... (I've just got another 29 more to make).

(http://www.audiomaintenance.com/downloads/prodigy_ez1073-500_finished.jpg)

Faceplate is powdercoated grey with white screenprinted text.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sunnen1 on March 10, 2011, 01:21:37 PM
looks very very nice!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sarcastic Sound on March 10, 2011, 02:02:00 PM
looks like the project is in tip top shape... looking forward to building many of these!  :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on March 18, 2011, 11:56:19 AM
nice. i don't wanna break anybody's balls but, how is it going?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 18, 2011, 12:09:00 PM
The ez1073-500 is done..... just need to add a couple of items to the build instructions (mainly how to fit the faceplate)....

The second revision of the 1U rack version is done and just waiting for another mains transformer....which will be here in a few days (being wound today).... it will need a rev 3 of the PCB (I accidentally drew the library symbol for the toggle switches back to front.... so "IN" is up and "OUT" is down.... oops)......

Soon as the new mains transformer is tested, I'll test and up rev the PCB but on a short lead time.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on March 18, 2011, 12:58:38 PM
nice. thanks Colin.
i hope i can build a couple of 1Us this summer
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on March 21, 2011, 12:05:42 PM
I can't wait to get started on this project!  Thank you Colin for all the work you've put into this.  
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: thestudio on March 23, 2011, 08:32:17 PM
Where can I purchase just pcb's and metal/face plate?????
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kazper on March 24, 2011, 12:03:05 AM
Where can I purchase just pcb's and metal/face plate?????

http://www.audiomaintenance.com/acatalog/kits.html
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: fazeka on March 24, 2011, 12:50:42 AM
 ??? 355 GBP for a face plate and PCB? Don't think so. No, this is for the whole kit-n-kaboodle kit.

Where can I purchase just pcb's and metal/face plate?????
http://www.audiomaintenance.com/acatalog/kits.html
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on March 24, 2011, 03:51:36 AM
??? 355 GBP for a face plate and PCB? Don't think so. No, this is for the whole kit-n-kaboodle kit.

Where can I purchase just pcb's and metal/face plate?????
http://www.audiomaintenance.com/acatalog/kits.html
I think that is just the parts kit with no pcbs or metal work.

Best to email him and ask what it contains.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 24, 2011, 04:16:09 AM
It is for everything..... Resistors, capacitors, transistors, hardware, PCB's and faceplates... absolutely everything to build 1 unit.
[However, the ready assembled version we manufacture has a metal rear cover which is not included in the DIY kit (it is not shown in any of the photos)]

In addition, you will be able to get just the PCB's from Gustav and the faceplates from Grandmaster.... (if they get enough demand I guess)..... and many of the "difficult" parts are stocked in our store anyway.

This is not yet complete, but assembly instructions will be like this:
www.audiomaintenance.com/downloads/ez1073-500_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073-500_colourbook.pdf)

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 12volts on March 24, 2011, 04:43:41 AM
Colin,
let be be the first to congratulate you for a totally splendiferous job on your assembly drawings. ;D


Frank
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on March 24, 2011, 05:12:31 AM
It is for everything..... Resistors, capacitors, transistors, hardware, PCB's and faceplates... absolutely everything to build 1 unit.
[However, the ready assembled version we manufacture has a metal rear cover which is not included in the DIY kit (it is not shown in any of the photos)]

In addition, you will be able to get just the PCB's from Gustav and the faceplates from Grandmaster.... (if they get enough demand I guess)..... and many of the "difficult" parts are stocked in our store anyway.

This is not yet complete, but assembly instructions will be like this:
www.audiomaintenance.com/downloads/ez1073-500_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073-500_colourbook.pdf)

Colin
www.audiomaintenance.com
Maybe put the words full or complete kit to differentiate from your other kits that are only partial.

Will you also be doing a complete full kit for the rack version?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: south2577 on March 24, 2011, 05:26:12 AM
Will the rack versions be available exactly like this Colin?

I have a problem.... I don't know wether to do 2 500's or 2 rack versions. I guess I'll have to do both.

Great work... I think your going to sell a few of these.

Ben
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 24, 2011, 06:14:17 AM
Maybe put the words full or complete kit to differentiate from your other kits that are only partial.

Will you also be doing a complete full kit for the rack version?

Good point... it now says "full kit"......

The 1U version is likely to be a partial kit as we will probably not be making any of them.... probably all the parts but no metalwork.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on March 24, 2011, 09:09:10 AM
My question now is...  How will the price of the power supply for the 1RU compare with 2x 500 series plus building/buying a small lunchbox.  I guess my real question is, will this project send me down the 500 road...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: thestudio on March 24, 2011, 03:08:57 PM
Is there a parts list included?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on March 24, 2011, 10:06:20 PM
Maybe put the words full or complete kit to differentiate from your other kits that are only partial.

Will you also be doing a complete full kit for the rack version?

Good point... it now says "full kit"......

The 1U version is likely to be a partial kit as we will probably not be making any of them.... probably all the parts but no metalwork.

Colin
www.audiomaintenance.com


I thought about it and I think for my case, it would be ideal to get a kit that has everything except the metal work and the power supply...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on March 24, 2011, 11:59:07 PM
hey colin, dont wanna take food out ur mouth, but hows about considering selling just the boards too?? i cant afford the £350 for the whole kit.. :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haima on March 25, 2011, 12:32:43 AM
isn't gustav selling the boards separately?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on March 25, 2011, 12:38:13 AM
just had it confirmed today, hes not selling these boards.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 26, 2011, 07:44:32 AM
My mistake.... thought I had already sent the rev4 to Gustav.... anyway I have sent the files to him now.

Pete (grandmaster) already has the faceplate files (he did the ones we use).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: thestudio on March 27, 2011, 02:33:01 PM
Is there a parts list and please define "difficult" parts" ??
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 28, 2011, 01:31:36 AM
There will be a parts list at the end of the colourbook......  "difficult" parts means transformers, inductors, rotary switches and pots ...... as they cannot be bought from suppliers like Farnell, mouser, digikey, RS etc

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on March 28, 2011, 04:45:44 AM
hey thanks colin u r a gentleman
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sunnen1 on March 28, 2011, 09:37:58 AM
hey thanks colin u r a gentleman

big time!
 ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 04, 2011, 04:28:13 AM
Sorry for the delay.... been a bit busy with the 500 series version..... anyway the 1U version is not too far off..... I put the rev 2 in a case so it can go out for testing..... the new Carnhill mains transformer seems to work fine .... (EIN is -125dBu)

(http://www.audiomaintenance.com/downloads/ez1073_in_a_box.jpg)

.... Just need to correct the "upside-down" toggle switches and it should be "good-to-go".

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: beatnik on April 04, 2011, 05:13:17 AM
amazing!!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: canidoit on April 04, 2011, 05:58:02 AM
Sorry for the delay.... been a bit busy with the 500 series version..... anyway the 1U version is not too far off..... I put the rev 2 in a case so it can go out for testing..... the new Carnhill mains transformer seems to work fine .... (EIN is -125dBu)

(http://www.audiomaintenance.com/downloads/ez1073_in_a_box.jpg)

.... Just need to correct the "upside-down" toggle switches and it should be "good-to-go".

Colin
www.audiomaintenance.com
Does that power transformer sit on top of the PCB? Is that O.K. to do it like that? will it eventually warp the board and how about the heat the PT produces?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 04, 2011, 06:04:36 AM
Mounting on the PCB is fine (that is how it is done on all the AMEK rack units)............  The power transformer produces almost no heat at all (unless you have a fault)..... the centre of the transformer will be resin filled with a screw thread in the bottom..... so it can be screwed directly to the PCB (on mine it has a cable tie holding it in place!).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Marcocet on April 04, 2011, 07:29:03 AM
Looks amazing colin! I can't wait to build a pair.

What's up with the SLB though?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 04, 2011, 09:14:57 AM
SLB ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on April 04, 2011, 10:02:55 AM
do you have like a part list, so i move on with the project while waiting?
i mean the 1U
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dandeurloo on April 04, 2011, 10:31:55 AM
yeah these look super cool.

Colin what is the possibility of powering them off of a Vintech power supply?



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: millzners on April 04, 2011, 10:52:43 AM
I was wondering about the mains transformer/power supply for the 1RU, if it will be included in the kit or separate, and how it will impact people in the US with 120V.  My plan has been to make an external power supply to power 2 1RU since I will be putting two 1RU in a single case.  Any thoughts Colin?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 04, 2011, 10:59:44 AM
Towards the rear of the PCB there are 4 x 1/4 inch spade terminals which connect directly to the +24vdc, +48vdc, Analogue Ground and Chassis Ground..... so you can completely miss out all the power supply components and just power it from another source..... no idea about Vintech PSU ?

The new mains transformer has 2 x 110v primaries anyway so it would be OK worldwide.

Parts list is not yet done..... no idea yet what be in a kit either.

Anyone know what SLB is ?

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: agauchede on April 04, 2011, 11:12:24 AM
Definitely interested in a 1 rack unit.  Looks awesome!

Chris
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on April 04, 2011, 11:38:58 AM
Colin, sorry to break your balls

why a kit for the 1U, those seems to me very ordinary parts that you have in stock in your shop.
(maybe the angled switch and the heat-sinks. and maybe good transistors too.)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on April 04, 2011, 11:59:11 AM
ME WANT!!!! ;D

Is there a line input on this thing?  I would love to build one with an instrument level input as a bass preamp...  Love the way the 1073 sounds with the direct box.

cant wait till its ready!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 04, 2011, 12:01:02 PM
The only reason for a kit is that all I get from people is "do a full kit"..... a lot of poeple do not have the time or inclination to go searching for parts..... the parts can be ordered seperately anyway... most of them are standard store items .... and the rest all come from distributers like Farnell and RS.... the switches and Transistors came from Farnell, the heatsinks from Rapid..... The PCB will come from Gustav and the metalwork (probably) from collective cases......

Yes it has a line input (but no DI).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on April 04, 2011, 12:13:54 PM
a simple mod... :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on April 04, 2011, 12:22:38 PM
The only reason for a kit is that all I get from people is "do a full kit"....

this may seems stupid, but i never thought about it..
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Marcocet on April 04, 2011, 08:06:39 PM
Anyone know what SLB is ?

Colin
www.audiomaintenance.com

Pth.

Safety Loop Breaker. I assumed that's what the huge IEC jack is all about. Is it something else?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: thestudio on April 04, 2011, 10:04:41 PM
Don't need full kit have parts around transformers, inductors...   

Not seeing any post from Gustav about doing pcb's ???
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sunnen1 on April 04, 2011, 11:23:58 PM
 8)
 ;D ;D ;D ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on April 05, 2011, 09:15:32 AM
i think the big IEC connector is actually a mains filter, used to clean up the 230V supply.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on April 05, 2011, 01:20:06 PM
Quote
Colin has them as far as I know. Try contacting him, I wont be doing sales on them at this point.

Gustav
 

 

 :'(
 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on April 05, 2011, 03:55:47 PM
I thought gustav didnt get the info so he though he wasnt doing the 500 series but Colin mentioned that he has to do the last rev(1RU) and then send the files to gustav, no?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: thestudio on April 06, 2011, 09:19:30 PM
Quote
Colin has them as far as I know. Try contacting him, I wont be doing sales on them at this point.

Gustav

Yep, looks like all or nothing........ ??? 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on April 11, 2011, 05:39:50 PM
Colin, what kind of heatsink is that on the 2N3055 1RU version? Ive been looking for one and cant find that one.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 18, 2011, 07:14:15 AM
Colin, what kind of heatsink is that on the 2N3055 1RU version? Ive been looking for one and cant find that one.

Heatsink is from Farnell (462-1372).... because it was lying around

Safety Loop Breaker. I assumed that's what the huge IEC jack is all about. Is it something else?

It is just a filtered mains inlet.... because it was lying around

Gustav has decided that he does not want to make the ez1073-500 PCB's.... anyone else have the ability to do PTH and Hard Gold plate ?
I should have the rack version updated this week.... sorry it took so long.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on April 18, 2011, 07:48:36 AM
cool.
is he going to do the 1U pcb?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 18, 2011, 09:40:33 AM
I presume so..... don't know why he doesn't want to do the 500 series, he has all the gerbers and there were no restrictions.... I even offered to buy 50 to get it started.

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on April 18, 2011, 09:52:59 AM
oks.
thanks Colin, you're a great guy
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 3nity on April 18, 2011, 10:03:56 AM
I think Gustav dont wanna risk anything..
I mean the gssl pcb sells like crazy....and the new 500 pcbs dont sell a lot...
Good luck!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rob Flinn on April 23, 2011, 08:40:26 AM
I just finished building a pair of EZ1073- 500 & I must say Colin has really made a very nice kit here, with the best documentation I've ever seen.  Well done Colin top marks for this one !!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on May 02, 2011, 03:14:26 PM
i'm sorry to break balls about this.
updates?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 03, 2011, 01:43:16 AM
The rev3 PCB is due here on the 17th May..... so a few days after that it should be tested.

I also did a Schaeffer/FPE faceplate (which will probably arrive today/tomorrow).

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on May 25, 2011, 09:29:41 AM
Dare I ask...

Any update on this slenderchap? :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 26, 2011, 07:35:38 AM
Dare I ask...

Any update on this slenderchap? :)

It is done.... just need to take some pictures.

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: matta on May 26, 2011, 08:35:40 AM

Best news all week! Can't wait for those pictures  ;D

It is done.... just need to take some pictures.

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on May 26, 2011, 09:41:11 AM

Best news all week! Can't wait for those pictures  ;D

It is done.... just need to take some pictures.

Colin

Yes indeed ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sam system-d on May 26, 2011, 02:13:08 PM

Best news all week! Can't wait for those pictures  ;D

It is done.... just need to take some pictures.

Colin

Yes indeed ;D

+1  ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 27, 2011, 06:16:21 AM
(http://www.audiomaintenance.com/downloads/ez1073_rev3_faceplate.jpg)


(http://www.audiomaintenance.com/downloads/ez1073_rev3_pcb.jpg)

and in detail:
www.audiomaintenance.com/downloads/faceplate_detail.jpg (http://www.audiomaintenance.com/downloads/faceplate_detail.jpg)
www.audiomaintenance.com/downloads/pcb_detail_1.jpg (http://www.audiomaintenance.com/downloads/pcb_detail_1.jpg)
www.audiomaintenance.com/downloads/pcb_detail_2.jpg (http://www.audiomaintenance.com/downloads/pcb_detail_2.jpg)

[The real power transformer will have a filled centre with a tapped screw in the base so the cable tie won't be needed!]

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: matta on May 27, 2011, 06:32:54 AM
Colin,

Blimey Mate, it looks surreal! I assume all is well with REV 3? I think the only issue with REV 2 was that the switches were reversed? Is Gustav going to be doing boards? I think you mentioned Dan was doing cases and Pete the panels? Any thoughts on if you will be offering a full kit version?

Cheers

Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on May 27, 2011, 06:39:11 AM
Wow!

Pics look great...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: AudioGimmer on May 27, 2011, 07:13:34 AM
Very very nice....


The Gimmer
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: earl on May 27, 2011, 09:58:26 AM
10-4 on the rack version here.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 27, 2011, 01:46:18 PM
I assume all is well with REV 3? I think the only issue with REV 2 was that the switches were reversed? Is Gustav going to be doing boards? I think you mentioned Dan was doing cases and Pete the panels? Any thoughts on if you will be offering a full kit version?

Everything seems to be fine with it (switches are correct way round now).... I'll send the gerbers to Gustav and the metalwork info to Dan (collective cases) but it is up to them whether they will make them.... I just need to start the colourbook build instructions.

There will probably be some sort of partial kit but a full one is not likely.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: earl on June 11, 2011, 07:54:01 PM
any news on this one?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 12, 2011, 03:34:00 AM
It seems that Gustav has decided not to make these PCB's so I will just get a bunch done locally... anyone who is interested should just email me so that I can get a handle on the numbers... I was thinking of 30 pieces (they would probably be about GBP 25.00 each).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on June 12, 2011, 03:57:29 AM
hey colin

does this include the 500 series??
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 12, 2011, 06:57:28 AM
hey colin.... does this include the 500 series??

OK.... you win... I give in.... I'll sort that out now.

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadbreath on June 12, 2011, 09:20:41 AM
he he he ...so i guess persitence pays off hey... ;D 8)

let us know when they're available...

thanks colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on June 12, 2011, 09:54:38 PM
It seems that Gustav has decided not to make these PCB's so I will just get a bunch done locally... anyone who is interested should just email me so that I can get a handle on the numbers... I was thinking of 30 pieces (they would probably be about GBP 25.00 each).

Colin
www.audiomaintenance.com

Feeler thread?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 13, 2011, 02:43:08 AM
let us know when they're available...

Done already....

Feeler thread?

You are correct !

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on June 14, 2011, 02:41:19 PM
It seems that Gustav has decided not to make these PCB's so I will just get a bunch done locally... anyone who is interested should just email me so that I can get a handle on the numbers... I was thinking of 30 pieces (they would probably be about GBP 25.00 each).

Colin
www.audiomaintenance.com

At that price, you are gonna have your hands full sir ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on June 17, 2011, 10:54:30 PM
is anywhere a part list or some sort of paper for this?
i'd like to order some stuff while i wait
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 19, 2011, 10:35:10 AM
is anywhere a part list or some sort of paper for this?
i'd like to order some stuff while i wait

Have not yet done a formal parts list.... but I have started the colourbook which will give you some idea about diodes, resistors, caps and transistors.
http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf)

That document has not yet been checked (and is not complete by any means).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on June 19, 2011, 11:45:43 AM
i'm sorry to break your balls Colin.
btw, i never saw the download section..

thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: earl on June 26, 2011, 02:41:56 PM
Hey Colin I see the 500 series version of your ez1073 boards on your website but not the rack mount versions am i missing something or are they in the works? Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 27, 2011, 05:38:42 AM
The PCB's are expected to be available around the 21st July.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on June 27, 2011, 08:03:32 AM
Put me down for 1 of the 1u anyway colin.. definately interested. Sure let me know when their available.. Do u plan on doing kits?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sam system-d on June 27, 2011, 03:30:51 PM
Put me down for 1 of the 1u anyway colin.. definately interested.
+1, maybe not right now for a complete build, but for shure the pcb (just in case)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dalmaproductions on July 05, 2011, 12:41:48 PM
Hi everyone, I've finished building my ez1073-500 full kit and wanted to show some support for the project. Colin has done an amazing job on the kit. Super simple / clear instruction book, high quality parts, all cut and labeled perfectly. PCB is great too. The sound: amazing! Worked off the bat and use it all the time. Some pics:

(http://digammaband.com/ez1073/1.jpg)
(http://digammaband.com/ez1073/2.jpg)
(http://digammaband.com/ez1073/3.jpg)
(http://digammaband.com/ez1073/4.jpg)
(http://digammaband.com/ez1073/5.jpg)

Thanks colin for the great kit.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: lorcan on July 05, 2011, 12:53:58 PM
Very nice ! Colin, you can count me in for a PCB for the 1U version too.
One little question about cosmetics: the vertical offset between the rotary switches and pots looks ... how should I put it ... creative
Is this going to be the final layout ?

I received a Carnhill 9045 transfo from you and built a Bo Hansen DI with it, it sounds awesome
I'll put up my custom pcb design for it here in a few days

Cheers,
Lorcan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on July 05, 2011, 12:55:00 PM
Congratulations!

Best regards,

Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on July 05, 2011, 01:38:56 PM
One little question about cosmetics: the vertical offset between the rotary switches and pots looks ... how should I put it ... creative
Is this going to be the final layout ?

I received a Carnhill 9045 transfo from you and built a Bo Hansen DI with it, it sounds awesome
I'll put up my custom pcb design for it here in a few days

The vertical difference is simply due to the height of the pots and switches from the PCB... that cannot be changed... so yes it will be like that.

I have in the past used a pair of VTB9046's wired up to create a 16:1 step down for a DI input to a mic..... that sounds good (albeit a somewhat expensive solution).

Great photos Dalma.... glad you got it together with no problems.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: lorcan on July 05, 2011, 02:20:20 PM

The vertical difference is simply due to the height of the pots and switches from the PCB... that cannot be changed... so yes it will be like that.

I have in the past used a pair of VTB9046's wired up to create a 16:1 step down for a DI input to a mic..... that sounds good (albeit a somewhat expensive solution).
Colin
www.audiomaintenance.com

Yes, I understand. I'll try to see if I can find some equivalent offboard pots when the details are available ..
The DI files are here http://www.groupdiy.com/index.php?topic=36569.msg562181#msg562181
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on July 17, 2011, 12:51:50 PM
hi. any news on the 1U?

a couple of questions regarding the colourbook:
-why you didn't mark the tantalum caps? (i think all the 10uF and all the 22uF except two of them are tantalum)
-why a lot of caps are rated for higher voltages?

just curious..

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on July 18, 2011, 09:24:39 AM
-hi. any news on the 1U?
-why you didn't mark the tantalum caps? (i think all the 10uF and all the 22uF except two of them are tantalum)
-why a lot of caps are rated for higher voltages?

PCB's should be here later this week.
We don't use Tants.... (we use electrolytics which we have specially manufactured)..... you can fit anything you wish... it is your project.
The higher voltage is simply because they are parts we stock....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on July 18, 2011, 10:23:10 AM
cool.
why you don't use tantalums?
why your electrolytics are special?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on July 25, 2011, 11:21:24 AM
really awesome work.
so, (2) single gang 1 pole and (2) single gang 2 poles and (1) triple gang gain switch. am i right?

then, which inductors?
9043; 9044; 9050 ?

can i use the VTB1148 as output trafo?
what's the board dimensions?
is (1) power toroid you have in the shop enough to power 2  boards?  i'd like to build 2 preamp in a 2U-3U chassis
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on July 25, 2011, 04:43:44 PM
so, (2) single gang 1 pole and (2) single gang 2 poles and (1) triple gang gain switch. am i right?
then, which inductors?
9043; 9044; 9050 ?
can i use the VTB1148 as output trafo?
what's the board dimensions?
is (1) power toroid you have in the shop enough to power 2  boards?  i'd like to build 2 preamp in a 2U-3U chassis
Yes for the switches and inductors and VTB1148. Main PCB is 407 x 161 mm. Power tx is not yet available (tomorrow)... it should be enough for 2 PCB's.

A lot of your questions will be answered by the colourbook... it is nearly finished.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: domi62 on August 01, 2011, 03:38:45 PM
HI colin

is it possible to insert a comp between preamp and EQ ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on August 01, 2011, 06:46:01 PM
hi Colin.
you told me about the resistors, all 0.6w.
i happen to have tons of 1/4w resistors, can i use some of them somewhere?
i was thinking that maybe just the 6k8s and the resistors in the power regulators and power supply ought to be at least 0.6w
am i right? that would be a good saving for me

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 02, 2011, 01:09:05 PM
is it possible to insert a comp between preamp and EQ ?

Don't see why not.... unless you want to go out of the box in which case you would need an output driver and input return.

i happen to have tons of 1/4w resistors, can i use some of them somewhere?
i was thinking that maybe just the 6k8s and the resistors in the power regulators and power supply ought to be at least 0.6w

I expect that the originals had 0.25w resistors anyway apart from the 47R in the output circuit and the power feeds.... the only reason for 0.6W metal film is they are about the most common type of resistor nowadays.

The 6k81's for the phantom should be as closely matched as possible (0.1% is the usual method but you can simply measure and hand select resistors from a batch).... being identical values is more important than their actual value.

Some more info is now in the colourbook.
http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf)

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 05, 2011, 03:16:32 AM
The schaeffer faceplate file is here:
www.audiomaintenance.com/downloads/ez1073_1u_front_panel.fpd (http://www.audiomaintenance.com/downloads/ez1073_1u_front_panel.fpd)

Added some more mechanical and parts list info to the colourbook;
http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf)

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 08, 2011, 09:48:56 PM
Hi Colin,

Just a couple of questions before I start ordering parts for this.  Please excuse the 'newbie' nature of these questions, but I don't want to cock this project up!

- Can you confirm for certain that ¼ watt resistors will work ok, except for the 3 watt resistor specified in the BOM? Like a previous poster I have a huge stash of ¼ watt and it'll save me some cash to not order 0.6 watt if they're not necessary.

- Do you recommend any particular electrolytic caps for the audio sections of the unit?  And does the quality of ceramic caps matter too?  I've read in other places that these are normally avoided in audio circuits as they tend to be noisy, hence my question about whether a specific type or manufacturer is recommended.

- Finally, the 600 ohm termination.  It's the first time I've come across this in a project, and I'm wondering if it affects the microphone that's connected to the input of the preamp, the line input or whether it is used for matching the input impedance of the device connected to the output?  I'm guessing it's not mic input as there's a separate hi / low z switch for this, but please can you just clarify when these pads should be jumpered just to ease my lack of understanding!

Cheers

Rob



Sent from my android device.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on August 08, 2011, 11:53:53 PM
Thanks again Colin,  the ez1073 PCB is very nice!  Wonderful layout, colorbook, FPE file and partial kit, not to mention all the electrolytics are availiable on your AML site.  A true learning experience made very pleasant by your detailed work.  Many thanks and hopefully many more projects from you to come.  ChrisP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 09, 2011, 04:43:13 AM
1] Can you confirm for certain that ¼ watt resistors will work ok, except for the 3 watt resistor specified in the BOM? .......
2] Do you recommend any particular electrolytic caps for the audio sections of the unit?  And does the quality of ceramic caps matter too?  ..........
3] Finally, the 600 ohm termination.......

1] 0.25 watt will be fine for almost everything.... the ones in the power feeds are probably better as 0.6W
2] 1073's are inherrantly noisy and distorted anyway so it does not really matter what you put in there..... avoid capacitors sold as "audio" caps.... you will pay a lot of money for them because they have low distortion .... which is not what you want.
3] 600 Ohm termination is optional..... try it on and off and see which you prefer the sound of as it is application/load dependent ......

Don't "think too hard" about it.... just plow on and throw some components at it.... it is almost impossible to be dissatisfied with the results you will get regardless of brands.

Thanks again Colin,  the ez1073 PCB is very nice!  Wonderful layout, colorbook, FPE file and partial kit..........
Glad you like it.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 09, 2011, 05:46:19 AM
1] Can you confirm for certain that ¼ watt resistors will work ok, except for the 3 watt resistor specified in the BOM? .......
2] Do you recommend any particular electrolytic caps for the audio sections of the unit?  And does the quality of ceramic caps matter too?  ..........
3] Finally, the 600 ohm termination.......

1] 0.25 watt will be fine for almost everything.... the ones in the power feeds are probably better as 0.6W
2] 1073's are inherrantly noisy and distorted anyway so it does not really matter what you put in there..... avoid capacitors sold as "audio" caps.... you will pay a lot of money for them because they have low distortion .... which is not what you want.
3] 600 Ohm termination is optional..... try it on and off and see which you prefer the sound of as it is application/load dependent ......

Don't "think too hard" about it.... just plow on and throw some components at it.... it is almost impossible to be dissatisfied with the results you will get regardless of brands.


Good stuff - thanks for the info.

Rob
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob61 on August 10, 2011, 10:47:12 PM
Wow, thanks Colin. Already got my two ez1073-500 kits. Really excited about getting these built and trying them out.

I have one newbie question. Since the motherboard and daughter boards come as one piece, what is the best way to cut them apart, and do I need to trim off the connecting material between them?

Thanks for making this full kit available.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 12, 2011, 02:39:09 AM
We just cut them apart using a pair of wire cutters (the ones we use look like a pair of scissors) and then trim off the excess with end cutters.

You could use a cutting wheel but you end up with potentially health hazardous dust everywhere.

You can actually just snap them carefully across the edge of a desk.

Colin
www.audiomaintennace.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on August 12, 2011, 03:25:22 PM
Hi Colin,i have a couple of questions too. (about the 1U)

- i need to fix the input trafo to the board. how do you do that?
 i've seen angled stripes, but mouser wants TONs of money, and i'm not even sure they fit in the place.

- i've seen the rotary switches are a few mms from the border. so they are not designed to sustain the pcb. am i wrong?
 how do you do that?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 13, 2011, 02:47:43 AM
- i need to fix the input trafo to the board. how do you do that....
- i've seen the rotary switches are a few mms from the border. so they are not designed to sustain the pcb........

The input transformer fitting procedure is in the colourbook:
http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf)

The rotary switches are not intended to support a PCB.... the PCB should be supported by standoffs on the base of the metal box.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob61 on August 18, 2011, 04:10:57 PM
Finished the build on both units. I have the 51X rack, no bench power supply. So I plan to insert into the 51X where I can still get my hand in to adjust Output Bias Adjust.

1. Using my multi-meter, can someone tell me how I measure the current per rail as mentioned?

2. Is there a way to use my Digital Audio workstation to calibrate?

3. Also, what is the name of the tool used to tighten the front panel "bolts" that hold the face plate on? Never had one, and wouldn't even know what to ask for.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 19, 2011, 03:22:53 AM
They will work without adjustment..... it  will basically just effect the maximum signal level before distortion.

1] If you do not have a bench power supply it is probably easier to measure the voltage accross the ends of resistor R49.... because it is 1 Ohm, you will read about 70mV before you adjust.... make the bias adjustment (typically about 6-7 turns counterclockwise) until you read 110mV.

2] Don't know the answer to that....

3] We call them "ring nut tools".... there may be an "official" name.... most people just use long nose pliers or shape a piece of metal into a suitable tool.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on August 25, 2011, 03:26:08 PM
hi everyone.
i'm placing an order at mouser's and i need to find some parts.

- i need pcb switches
- input trafos pin connectors
- in&out terminals, preferably the ones where you fix the cable with a screw.

do you have suggestions?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 25, 2011, 03:36:44 PM
Have a hunt is the best suggestion I'm afraid.  Order codes are provided for almost everything on the BOM, though the supplier may not be your first choice.

If you're in Italy, perhaps Farnell is a better (cheaper) option than Mouser anyway?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on August 25, 2011, 03:42:31 PM
yeah, it could be, but i don't have a vat code, that's the point.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: domi62 on August 25, 2011, 04:41:59 PM
Hi Pietro

I've been delivered from Farnell and didn't need to give them a VAT number.
I'm in France.
The only problem I've been facing is the minimum qty they require.
50 pieces for resistors and so on








Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Mzaar on September 01, 2011, 07:56:07 AM
Hi,

just received the last components I needed. So I'm starting to built my ez1073 kit. Thx again Colin, nice kit and pcb.

I just wanted to ask two things I was thinking about while waiting my different orders :

-What is the meaning of R89 aka 1k to ground when line switch engaged ? 'cause I didn't find it on the original 1073-84 scheme I got.
http://imageshack.us/f/706/50231556.jpg/ (http://imageshack.us/f/706/50231556.jpg/)
http://imageshack.us/f/684/originalschem.jpg/ (http://imageshack.us/f/684/originalschem.jpg/)

-Why choosing a 10k linear for the output fader instead of a 5k log like on the original ( even if  R135 // (R149+134) matches with the 5k original impedance). Is it because 10k L are more convenient to find than 5k audio taper ?
http://imageshack.us/f/707/fader.jpg/ (http://imageshack.us/f/707/fader.jpg/)
Anyway thx again to provide this nice kit.

ps:  do you always need to enter anti spam verification thing when you post a msg or if your old enough on the board it stops ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 01, 2011, 11:41:10 AM
R89 is just a gain correction when in line mode.

10K lin is a part that we stock (that is the main reason).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: domi62 on September 04, 2011, 01:46:00 PM
Hi Colin

Just a pic of first steps

Thank you again

Domi
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 09, 2011, 04:22:02 AM
Well done DOMI62 ...... I think we should see a few more completed units in the very near future .....

The colourbook has been updated as there was an error relating to the voltage regulators (locations were swapped over), the output transformer fitting drawing showed spacers which were too tall for some boxes, and the part numbers for the TO220 heatsinks were wrong.

http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf)

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deuc224 on September 10, 2011, 02:31:38 AM
I didnt even know they were available yet :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on September 12, 2011, 01:09:44 PM
The color-book shows how to hook up the power transformer to the board but no datasheet or schematic on the power transfomer hook up to mains(USA).  Unless I am missing something.  Thanks again Colin, almost done!  ChrisP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 12, 2011, 02:42:16 PM
Good point, I'd better add that.

The power transformer has 2 primary windings....

For 100-120v supply the windings are connected in parallel.

For 200-240v supply the windings are connected in series.

You should fuse the live before the mains switch (if you fit one), mains switches should be double pole (switch live and neutral) and the mains earth should go immediately to the chassis and be screwed to it using star washers to ensure good contact that does not come loose.

Colin
www.audiomaintenance.com



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 13, 2011, 07:10:07 PM
Hi, Colin.  Are there any fees we should know about when shipping to the U.S.A.?   There was a thread in the brewery about US Taxes.     I'm interested in the 500-series kit but am waiting on Steiger to have racks in stock. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 14, 2011, 02:44:36 AM
I always say to people that they should budget for 10% import duties/handling charges... but no-one ever tells me what they were actually charged.

The ez1073-500 kits will probably cease next week as the assembled units will become available shortly through a network of dealers (and they will not want "kits" available).... 1U rack kits will remain available for the time being.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 14, 2011, 03:20:13 AM
yikes, I better order the 500 series version this week, then.

If there are any forum members who have bought the kit for the 500 series module and also live in the US, could you send me a PM with the import fees?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 17, 2011, 10:55:04 PM
ordered 2 of the ez1073-500 kits tonight!   Hopefully just in time before you stop selling them as kits!

as a side question, have you considered offering kits to forum members only once you stop selling them on your website?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on September 18, 2011, 09:33:59 AM
(http://chrispsound.com/wp-content/uploads/2011/09/IMG_3242.jpg)

(http://chrispsound.com/wp-content/uploads/2011/09/IMG_3243.jpg)

All done,  sounds great!  Will be putting it through its paces this week.  Thanks again, Colin, for the millionth time.  ChrisP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on September 18, 2011, 09:38:25 AM
Nice!

Mine's coming along too.  I'm just trying to  decide whether or not to go to the trouble of mounting the grayhills off board so all the pots are in a straight single line...

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 18, 2011, 09:45:02 AM
Chris, that looks awesome!   How long did it take to arrive once shipped, and were there extra fees to import it or anything?   Pretty sweet lookin 500-series rack in the background btw!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob61 on September 18, 2011, 09:52:34 AM
Very nice build ChrisP! Does the rackmount kit include everything you need for a build? What about the case? Where did you find that? Did it involve metal work on your end?

Thanks for sharing.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on September 18, 2011, 09:56:45 AM
Nice!

Mine's coming along too.  I'm just trying to  decide whether or not to go to the trouble of mounting the grayhills off board so all the pots are in a straight single line...


It actually doesn't look that bad staggered.  It was a concern of mine too, but thats alot of wiring and I try to avoid wiring when ever possible.  I didn't want to make a ez1073 into a hard1073. ;D  ChrisP
Chris, that looks awesome!   How long did it take to arrive once shipped, and were there extra fees to import it or anything?   Pretty sweet lookin 500-series rack in the background btw!!
Thanks.  Colins stuff always gets to California in a timely manner, usually no longer than 2 weeks and sometimes faster than domestic distributers.  My credit card statement didn't show any fees just the exchange rate(ouch!).
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on September 18, 2011, 10:07:58 AM
Nice!

Mine's coming along too.  I'm just trying to  decide whether or not to go to the trouble of mounting the grayhills off board so all the pots are in a straight single line...


It actually doesn't look that bad staggered.  It was a concern of mine too, but thats alot of wiring and I try to avoid wiring when ever possible.  I didn't want to make a ez1073 into a hard1073. ;D or anything?   Pretty sweet lookin 500-series rack in the background btw!!

Heh.  Yes - good point well put ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on September 18, 2011, 11:14:31 AM
Very nice build ChrisP! Does the rackmount kit include everything you need for a build? What about the case? Where did you find that? Did it involve metal work on your end?

Thanks for sharing.


No, but AML has all the electrolytic capacitors.  Mouser and my stock for everything else.  Dan at Collective cases has the 1U case, it has a little more internal height, no front lip and rear panel all punched and ready to go.  I used a Parmetal 1u case but it required some modification/ nibbling to the bottom  front lip to fit the greyhill switches and LED and requires spacers on the top cover so it doesn't smash the output transformer.  Rear panel XLR punched out and IEC connector nibbled by me.  PCB standoff holes need to be drilled.  Front panel is Colin's in black/no infill made by FPE.  Thanks ChrisP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 18, 2011, 12:11:44 PM
Quote
My credit card statement didn't show any fees just the exchange rate(ouch!).


I was referring more to any tarrifs imposed by FedEx or UPS due to international shipping per that US Tax thread in the brewery
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on September 18, 2011, 03:26:26 PM
Quote
My credit card statement didn't show any fees just the exchange rate(ouch!).


I was referring more to any tarrifs imposed by FedEx or UPS due to international shipping per that US Tax thread in the brewery
Shipping & Handling was 25 bpounds/ $40.00 us for the ez1073 kit, but the invoice from AML didn't specify if any fee's or tarrifs where part of the $40 shipping and handling charge.  No other fees or tarrifs are on the invoice or my credit card statement.  Colin's shipping prices seem reasonable for the size and weight of the package.  Hope this helps.  ChrisP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 19, 2011, 01:40:00 AM
Does the rackmount kit include everything you need for a build? What about the case? Where did you find that?

Originally the kits were just the major parts, but now the "Full PCB Kit" contains all the parts which go on the PCB and the XLRs .... the metalwork, knobs, IEC, fuse holder, mains switch etc are not included.

I believe that both the "Dans" will be doing cases.

In respect of import duties and tariffs, it has always been a mystery to me.... it seems like an entirely random process.... don't be surprised if you receive an invoice from the courier for import processing which can arrive weeks after the shipment..... but similarly you may never get anything.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 20, 2011, 01:20:16 PM
WOW

I ordered 2 kits of the 1073-500 from colin in the UK on saturday evening.

They arrived TODAY, tuesday, in NYC.   

that is AWESOME!!!! I thought this was gonna take like 2 weeks because of Customs!   Thanks, Slenderchap!!   Can't wait to buy a proper soldering iron, and get the racks from JSteiger, and get started!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 21, 2011, 09:12:05 AM
ez1073-500 kits are now no longer available.

The build manual for the ez1073 (1U version) has been updated today to show the mains transformer wiring (page 41);
http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf (http://www.audiomaintenance.com/downloads/ez1073_colourbook.pdf)

Mzaar - Nice to see an alternative version.... it would be possible to modify the voltage regulator circuit to increase the output ... but I doubt it is worth it.... you will probably easily exceed +24dBu output with 23.89 volts... probably >25.5dBu....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 3nity on September 21, 2011, 10:04:00 AM
Hi colin.
Im interested in 1-2 1073 clones whats shipping for 1 pcb with kit..to montreal?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob61 on September 21, 2011, 10:17:25 AM
Hi Colin:

My two kits that just came were short 2 of the SIL header 10 way pin headers  (bag says "Connector SIL Header 10 Way quantity 4"  (for two kits) but the bag only contained 2)

I've checked all my local places and no one has them. I can go online with DigiKey (they offer cheaper shipping than Mousser) to order a couple more.

Could you please point me to the right DigiKey page / product number so I know I'm getting the right ones?

Thanks for making this kit available, and very sad to see the kit pulled. But I understand. I'm sure the built one will be a big seller.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 21, 2011, 12:21:48 PM
Im interested in 1-2 1073 clones whats shipping for 1 pcb with kit..to montreal?

The store will work that out for you.... it is automatic.

My two kits that just came were short 2 of the SIL header 10 way pin headers .........

The closest that I can find is S1121E-36-ND... they are 36 way so you would only need 1 of them....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on September 22, 2011, 10:00:13 AM

rob61, you may find it useful to hear that I got my headers very cheaply from a well knownauction website.  Just get right angle headers with 0.1" / 2.54mm pitch and they ought to be fine.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: domi62 on October 09, 2011, 08:33:06 AM
Hi Colin

Sounds great

Thank you again

http://dl.dropbox.com/u/6205323/1073%20a%20.jpg

Domi
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 10, 2011, 07:47:05 AM
Excellent work.

I see that Dan (Collective cases) has now started making metalwork for the 1U version.

http://www.groupdiy.com/index.php?topic=41963.0 (http://www.groupdiy.com/index.php?topic=41963.0)

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on October 10, 2011, 03:17:37 PM
Getting my 51x racks tomorrow!!!!    Colin, the kits look amazing, you really did make it easy. 

YOU EVEN TRIMMED THE RESISTORS ALREADY!!!    EEEE-ZZZZZZ!!!!!   

Can't wait to start building them!

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 3nity on October 11, 2011, 09:36:19 AM
Oh my!!
i need to get some money....maybe sell my wife! ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mrcase on October 20, 2011, 05:37:04 AM
hey!
I´ve just purchased this great kit (thanks  a lot colin for doing this!!!!) and recognized that there are no polysterene or tantal caps like neve uses.
doesn´t this make a difference soundwise? did anybody try to swap the wimas to polysterene and tantals? I´d like it to be as original as it gets but I´m a newbie so please enlighten me!  ;D Is it worth the trouble or doesnt it matter after all.....

cheers

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Mzaar on October 24, 2011, 09:47:28 AM
I´ve just purchased this great kit (thanks  a lot colin for doing this!!!!) and recognized that there are no polysterene or tantal caps like neve uses.
doesn´t this make a difference soundwise? did anybody try to swap the wimas to polysterene and tantals? I´d like it to be as original as it gets but I´m a newbie so please enlighten me!  ;D Is it worth the trouble or doesnt it matter after all.....
cheers
   
Quote
-why you didn't mark the tantalum caps? (i think all the 10uF and all the 22uF except two of them are tantalum)

We don't use Tants.... (we use electrolytics which we have specially manufactured)..... you can fit anything you wish... it is your project.

Colin
Its a colorful preamp , not a millenia-like preamp, so maybe you'll like it this way or with tant/poly film/styroflex. It's not so much effort to switch the caps. Give it a try.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mrcase on November 08, 2011, 03:59:06 AM
Finished my build! Just waiting for the case to rack it up! Can`t wait  ;D
One question: what fuse should I use? Is 500ma rated to high? Should it be slow blow?

thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 08, 2011, 07:34:27 AM
100mA would be sufficient.... anti-surge.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mrcase on November 08, 2011, 09:51:22 AM
100mA would be sufficient.... anti-surge.

Colin
www.audiomaintenance.com

thanks colin!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: macakinho on November 10, 2011, 11:15:27 AM
Just got an order for two units!!!  ;D ;D

Can't wait to get started! It will be the biggest project I've ever done, but having had a look at the thread and the instructions, am feeling pretty good about it!

Will be bugging you with questions if I run into any problem!

Thanks Colin!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on November 10, 2011, 12:21:25 PM
macakinho, it's a super easy build if you follow the colorbook!   Where did you get your cases from?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: macakinho on November 10, 2011, 05:59:09 PM
macakinho, it's a super easy build if you follow the colorbook!   Where did you get your cases from?

Still haven't got the cases and haven't really looked into it! Any suggestions?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on November 10, 2011, 08:07:11 PM
I went with the EZ1073-500 kit, which uses 500-series racks instead.

But ddt has a thread in the white market where he sells cases and faceplates.  you'll have to drill them yourself, tho.  but the Colorbook from colin includes a drill guide which makes it super easy to figure out where to drill.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: macakinho on November 11, 2011, 04:39:38 AM
I actualy wanted the 500 version, but they are all gone by now!

Cheers for that! I'll look into it!  ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ddt on November 11, 2011, 06:21:56 AM
I'm currently pretty much out of stock with cases at the moment so I'll make more, some of these should be pre-drilled for the EZ1073.

Cheers,
Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 3nity on November 13, 2011, 06:55:30 PM
Colin are you out of boards?
Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Marc Duchesne on November 13, 2011, 07:09:07 PM
Aaarhhh !!! this 1073 project looks fantastic. Will fit nicely beside my Seventh circle N72. Too many projects right now...: )) But this is another one in my do it book. Congrat.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 14, 2011, 02:33:50 AM
Colin are you out of boards?

We have everything for the kits... the blank boards are no longer available seperately as they have been allocated to kits.... when the kits have gone that will be it.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: 3nity on November 14, 2011, 09:22:31 AM
 :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: benlindell on November 14, 2011, 05:12:46 PM
Colin are you out of boards?

We have everything for the kits... the blank boards are no longer available seperately as they have been allocated to kits.... when the kits have gone that will be it.

Colin
www.audiomaintenance.com
Are the boards included in the kit price?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Winetree on November 14, 2011, 09:21:52 PM
Will the 1073-500 ever be available in kit form again.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 15, 2011, 03:30:35 AM
Will the 1073-500 ever be available in kit form again.

No sorry.... it is a commercially manufactured product now.

Are the boards included in the kit price?

Yes the PCB is included.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: macakinho on November 18, 2011, 11:02:43 AM
Heya Colin!

The link for the PDF colourbook is down! Could you please post a new link?

Thank you!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 18, 2011, 12:36:42 PM
Should be working again now.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Math5461 on November 19, 2011, 01:53:40 PM
Hello,

My name is Josh, and yes, I am a newbie here. I just got done with my ez1073 and it sounds amazing!

Great work on this kit Mr. Colin!

So, I do have one issue :(

I am reading 59.9VDC for phantom power with 16.2mA DC. This seems weird. Did I mess something up or do I just not understand something about the load?
     
Big thanks for any info on this, 

-Josh 

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: macakinho on November 19, 2011, 08:04:54 PM
Should be working again now.

Colin
www.audiomaintenance.com

Got it! Thank you!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 21, 2011, 02:15:09 AM
I just got done with my ez1073 and it sounds amazing!

I am reading 59.9VDC for phantom power with 16.2mA DC. This seems weird. Did I mess something up or do I just not understand something about the load?

It depends where you are measuring it..... you should get 48v between pin 1 and pin 2 or 3 of the XLR when there is nothing else plugged in (and the 48v switch is in the down position).

Before the 48v regulator you will have about 60 volts.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Math5461 on November 21, 2011, 03:27:08 PM
Well, sounds like I messed up then. I am measuring Voltage at the output pin 2 and 3. Seems like I must be bypassing the regulator in the circuit? 

Well, this gives me good info to troubleshoot.

Thanks,

-Josh   
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 21, 2011, 03:44:33 PM
Diode in backwards perhaps.... or short between regulator pins ?

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Math5461 on November 28, 2011, 01:26:02 PM
OK, I reworked the 48v section making sure the path was clean. Well, as clean as possible given how I messed up and put the 24v regulator in the 48v slot at first. I realized right away but getting the regulator out was hard. Anyway, all good now. Gave it the first studio test run Sunday. Real clean up to 70dB! I am trying something different for my faceplate labels. I plan on posting a pic when done. Thanks for the help!   
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pacemaker on December 04, 2011, 07:03:51 PM
Hi Colin,
do you sell some EZ1073 wiihtout transformers ?
regards,
Francois
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 05, 2011, 06:40:22 AM
do you sell some EZ1073 wiihtout transformers ?

Sorry they are just "full" kits......while stocks last.... when they are gone we will stop them.

Anyway, all good now. Gave it the first studio test run Sunday. Real clean up to 70dB!     

Excellent... glad you got it sorted.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Le Roux on December 10, 2011, 10:06:08 AM
Just tried mine...again!

First try, blew two caps in the 48V Rect...caps were only rated at 23V!  ::)
Problem Rectified!  ;D

Sounds awesome! Everything works as it should.

Thanks so much for this project!

Neil
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: okgb on December 10, 2011, 06:20:29 PM
Almost full circle on another year !
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mrcase on December 11, 2011, 08:34:12 AM
hey colin!

finally got my case and got my 1073 up and running. but I have some weird problems.
the line in is not really working, the signal sounds very thin and low.
with the mic input I get a loud 50hz hum. my grounding is as follows:
IEC + tranny ground + mains ground at chassis stud. all xlr pin1 are connected to the pcb, pcb is connected to the case with metal standoffs...
what could I try to get rid of that hum?

thanks a lot!

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: beatnik on December 11, 2011, 01:16:34 PM
hey mrcase, it's better if you connect one xlr pin 1 to the star ground point, rather than grounding the pcb via metal standoffs.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mrcase on December 12, 2011, 04:35:23 PM
thanks! I´ve sorted out the hum issue, was a cold solderjoint, but I´m still having problems with the line input.
I´ve been running synths and a bass guitar through it, the synths sounded very thin, no bass and very low signal. the electric bass sound ok, but the level was very low as well. Do I have an impedance problem there? I thought I would be able to feed any line level signals into the 1073 and also instruments???

thanks for your help
cheers
m
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on December 12, 2011, 08:45:32 PM
I had issues with plugging a bass/synth into the line input.   So, when i talked to colin, he suggested I get a CD player and use that as the input, because those actually spit out Line Level signals.    It worked fine, 100%.   So, the issue is that your instruments don't spit out Line Level signal.   You'll need a DI box if you wish to use the line Inputs with something other than a line-level device.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mrcase on December 13, 2011, 02:24:42 AM
ah, I thought that second input transformer would take care of that.... :-X
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on December 13, 2011, 07:21:55 PM
Hi Colin.
i'm a bit late, do you still have 1U pcbs?
i want 2 more
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 14, 2011, 03:30:06 AM
do you still have 1U pcbs?

There are still a few kits left.

.....ah, I thought that second input transformer would take care of that.... :-X

For a guitar you would need a DI input... something which a 1073 never had. The line input has a 10k impedance... you will not get a good guitar signal through that... you need 100k plus... electronic DI inputs are usually 1M or more..... some synths will work fine.

Almost full circle on another year !

Indeed time flies..... sorry but there is no new project for the forum this Christmas as I have been busy with a commercial project (500 series module) which will be launched sometime next week (hopefully).... maybe Christmas Eve ?

I'll try to do another "ez" project for the forum next year... ezGSSL, ez1176, ezS800, ezNite, ez1081... something like that... don't know yet.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on December 14, 2011, 05:03:06 AM
Quote
ezGSSL, ez1176, ezS800, ezNite, ez1081.

we already have a million and 1 of those on the forum.  How about something new for 51X?  make use of those +24/-24 rails!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sammas on December 18, 2011, 05:42:45 AM


Are there any ez1073-500 kits still available?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 18, 2011, 08:17:03 AM
are there any ez1073-500 kits still available?

We no longer do them.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on December 18, 2011, 09:15:36 AM
so Colin, is it still possible to have a couple of 1U pcbs?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: benlindell on December 18, 2011, 10:50:13 AM
Saving Colin some breath, sure he's getting tired of saying the same thing over and over.

so Colin, is it still possible to have a couple of 1U pcbs?

do you sell some EZ1073 wiihtout transformers ?

Sorry they are just "full" kits......while stocks last.... when they are gone we will stop them.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pietro_moog on December 18, 2011, 02:57:24 PM
cool. i didn't pay attention enough, i'm sorry.

@ Colin: i wish you reconsider about not making 1073  1U  anymore. these are really really cool and really well made.
i wish i bought a few of them.
you could sell 500s units built in the house and make a batch of 1U pcbs sometimes. small number maybe, higher price.
these are worth.

thanks for all the work you gave us Colin, very Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on December 18, 2011, 10:07:34 PM
the ez1073-500 IS a commercial product now. 

http://www.mercenary.com/aml-ez1073.html
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sammas on December 19, 2011, 10:49:30 PM
are there any ez1073-500 kits still available?

We no longer do them.

Colin
www.audiomaintenance.com

Thats a shame. Looked like a good kit. I'll scoop up some JLM's instead.

Merry Christmas, y'all.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on December 19, 2011, 11:33:07 PM
it was a great kit!   super easy build!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chefducuisine on December 24, 2011, 06:51:27 AM
Second the 'super easy built'.
I am a bit late, but ordered my Kit two weeks ago on thursday. Kit arrived on Monday (4days later) and it took me two evenings to stuff and solder the board completely - no issues at all !!!

!!! Well done Colin - this thingy really is an 'EZ' built  8) !!!

This is how it looks so far:
(http://twin-x.com/groupdiy/albums/userpics/normal_ez1073_board_web.jpg)

...now this thing needs a nice housing...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 24, 2011, 01:57:09 PM
Excellent work chefducuisine.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: robertbonello on December 25, 2011, 06:16:00 AM
Hi all,

Bit of a noob question. I'd like to have the power switch on the front of the unit. Is this a bad idea in terms of introducing noise to the unit? Or is it simply a matter of running the cables down the right side of the case, off the board?

Any guidance greatly appreciated

Thanks,

Rob
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 27, 2011, 05:39:43 AM
I'd like to have the power switch on the front of the unit. Is this a bad idea in terms of introducing noise to the unit? Or is it simply a matter of running the cables down the right side of the case, off the board?

I see no problem with that.... right hand side would fine...... left hand side would be dubious as it would run past the mic transformer.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: robertbonello on December 27, 2011, 08:12:07 PM
great thanks. The boards are all done. Just waiting on the cases and I'll report back once done. Thanks for the quick reply!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 06, 2012, 08:02:54 PM
Ok I am about to pull the trigger on this preamp but I just wanted to make sure I can get everything.

As I understand it everything is included with the kit except for the knobs, IEC, fuse holder, mains switch and metal work.

I can get the metalwork (rack and face plate) from dan's shop (DDT).  Does it say in the colorbook what exact knobs and IEC fuse holder and switch to get.  I haven't read the colorbook yet.  Will do after I type this.  Getting pretty excited about having a neve replica in my project studio.  Can't wait.

Thanks for all the info you guys rock.



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ddt on January 07, 2012, 06:19:23 AM
...Does it say in the colorbook what exact knobs and IEC fuse holder and switch to get...

The cases will have holes for one of those standard plastic non-EMI filtered IEC sockets with an integrated fuse holder, you'll be able to use knobs of up to 24mm in diameter.

Cheers,
Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 08, 2012, 11:33:58 AM
Hi Guys,
Just wanted some thoughts.  Since I will be recording myself by myself, hahahaha  If I record my sax into Digital performer with the eq bypassed would I be able to send it back out into the preamp with everything down except the eq and eq it to taste using my speakers and rerecord the processed sound back into Digital performer.  I just don't want to record myself having a great take but not like the eq settings cause it was done through the headphones.  If i do this I wont be able to change it.   Headphones sound different from HR824's. 

Also does this kit come with spacers to keep the pcb off the case?  If not I didn't see what size i need.

Thanks
-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Marcocet on January 08, 2012, 11:49:09 AM
I've got one of the 500 series models in the rack this week and put it up against our neves and some BAEs. It's nearly indistinguishable from the vintage Neves, and at least as close to them as they are to each other. Way to knock this one out of the park Colin! I can't wait to hear your comp.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 10, 2012, 05:27:50 PM
.....Since I will be recording myself by myself, hahahaha  If I record my sax into Digital performer ....

Also does this kit come with spacers to keep the pcb off the case?  If not I didn't see what size i need.

You have a seperate mic and line input so that seems perfectly feasable to me... you are doing 2 seperate operations.... first through the mic input, second through the line input...

There are no PCB to Chassis standoffs included.... you need metal standoffs.... 4mm long should be about right..... but it really depends on the style of case you are using...

I've got one of the 500 series models in the rack this week and put it up against our neves and some BAEs. It's nearly indistinguishable from the vintage Neves, and at least as close to them as they are to each other.

Super Cool ... comparisons do not come much better than that !

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 10, 2012, 10:18:23 PM
DDT,

Will this IEC socket fit in your case?

http://www.google.com/imgres?q=Iec+with+fuse&um=1&hl=en&client=safari&sa=N&rls=en&biw=1269&bih=672&tbm=isch&prmd=imvns&tbnid=yZwN-_zh_3nG_M:&imgrefurl=http://www.allelectronics.com/make-a-store/item/ACS-55/IEC-RECEPTACLE-W/FUSE-HOLDER/1.html&docid=wdTnMrtIiBEUvM&imgurl=http://www.allelectronics.com/mas_assets/cache/image/2/5/7/9/9593.Jpg&w=450&h=441&ei=IPIMT4qMCMra0QHuqPDwBQ&zoom=1&iact=hc&vpx=1003&vpy=187&dur=102&hovh=222&hovw=227&tx=146&ty=96&sig=110559413441116649315&page=12&tbnh=143&tbnw=153&start=202&ndsp=18&ved=1t:429,r:5,s:202

I know i need a 100mA anti-surge fuse but what size in mm would I need to fit in this IEC socket fuse holder?

Will 4mm stand offs work with this board and your case DDT?

I wanna try to get everything before the kit
\ gets here so i can just build.

Thanks again guys, this community rocks.

-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 10, 2012, 11:43:13 PM
What size shafts are these so I can order knobs.  I know i need 23 or 24 diameters but what about the shaft size? Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 11, 2012, 03:04:40 AM
in the Colorbook, it should say the knob model being used, and from that, you should be able to pull the Data sheet from the manufacturer.   :D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chefducuisine on January 11, 2012, 03:29:06 PM
Scott,


I thought I written this in my PM already.
You will need Knobs for 1/4" (6,35mm) Stems.
The outer diameter of the Knob is less critical - you can attach anything up to 21mm here.

As an Example see this link on Elma Knobs:
http://uk.farnell.com/elma/023-4510/knob-grey/dp/1209777 (http://uk.farnell.com/elma/023-4510/knob-grey/dp/1209777)
Caps for those Knobs are available in a number of colours
Regards,

Chris
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ddt on January 11, 2012, 04:14:33 PM
Hi Scott,

DDT,

Will this IEC socket fit in your case?
....
Yep, that's the sort of thing you're after.

I know i need a 100mA anti-surge fuse but what size in mm would I need to fit in this IEC socket fuse holder?
Just measured one for you, it's 20mm long, 5mm in diameter.

Will 4mm stand offs work with this board and your case DDT?
I've used 5mm standoffs with the prototype case, these worked well.

chefducuisine... I've made the markings a bit larger than the design in the Colourbook, so you should be fine with knobs of up to 24mm in diameter.

Cheers,
Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 13, 2012, 12:28:07 PM
Thanks for all the answers guys, just one more quick question why is the fuse load so small/low?  100ma is equal to .1amps right?  Not even a half an amp.  That means barely anything is in the fuse.  I can't find them at radio shack so I will order from digikey. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 14, 2012, 03:30:12 AM
Extremely approximately .....  The circuit takes about 120mA (at 24v).... so the mains current at 240v will be only 12mA (or 24mA at 120v).... so a 100mA slow blow mains fuse will be plenty.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 14, 2012, 02:30:10 PM
Here is my build so far,

just wondering if I have to raise the voltage regular as it sits a little below the screw hole.  Just wondering if I have enough meat on the head sink in order for it to stay cool.

-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 14, 2012, 02:31:08 PM
Getting there!!!!!!!!!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 14, 2012, 04:12:19 PM
hellz yeah, bro!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 14, 2012, 04:40:17 PM
Thanks man, can't wait to use it hahaha.

Another question for you guys.  Going to order the standoffs but don't know what to do.  I am going to get 5mm standoffs but do I get 2 short screws for each standoff or a longer screw to go through the bottom of the case through the standoff and then trough the pcb with a lock washer and then the nut?  Would a 10mm screw do the job?  Should I get longer or shorter,  I am going to get DDT's case for this ez-1073.  Just don't know if I should do two screws per standoff or just one long one which seems easier.

Thanks guys
-Scott

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 16, 2012, 11:27:33 AM
Just a quick question,

What ohms setting should I use for my akg c414buls mic?  the 300 or 1200?

My build is done just need a fuse from digikey and the case from DDT.

Can't wait to hear it.

Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 16, 2012, 02:06:11 PM
Ok Guys Build is complete,

I plug it in and though that it didn't work because I did not hear anything buzzing from the transformers and the little led was not lighting up.  What is this little led on the right side for?  Maybe i ruined it when soldering?

I tested it out with my DAW and its sounds fantastic can't wait to work with it this week.  I am just waiting on some screws and standoffs from digikey and can't wait to see the case and panel from DDT.  An easy build for the most part just wish I knew what the led was for.

-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 16, 2012, 02:58:19 PM
The LED is just a "power good" indicator..... it should light if the 48v and 24v DC are both good..... check the 24v and 48v rails (on the power tabs).... if they are both OK then the fault is with the indicator circuit..... did you fit the LED the correct way round ?

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 16, 2012, 03:48:28 PM
yea it was backwards, I though since the capacitors had the positive long stem on the left so did this led, oh well live and learn, now its case ready.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: spase on January 16, 2012, 09:02:40 PM
i think you need to make another run from this 1U 1073 boards...there's a lot of interest about that.I dont have the budget to buy those kits in the moment,but i will buy a few boards if they gonna be available.We can show the interest in this thread and make that run.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 16, 2012, 10:45:00 PM
Chances are, this kit will probably go the same direction as the 1073-500...  Retail only.   better get it while you can!!!    hard to beat a pair for roughly $700/ea
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: buildafriend on January 17, 2012, 12:15:45 PM
I will take PCBs for two 1073s in 500 format provided that I find the price to be reasonable.

Thanks for the great work!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 17, 2012, 12:17:50 PM
the ez1073-500 is a commercial product.  you can't get kits nor pcb's anymore.   
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: buildafriend on January 17, 2012, 12:22:37 PM
Hm the thread popped up in my posts since last visit link. I should try to make my own.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 17, 2012, 04:11:56 PM
that's probably for a different kit, like SoundSkulptor's, probably.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 19, 2012, 12:28:34 AM
Just curious as to what the screws actually do on the r10 and r20 resistors?  Its page 27 of the colorbook.  I did not touch them!!!!!!

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 19, 2012, 02:43:53 AM
resistors with screws are Trimmers!   it's like a potentiometer that you adjust with a screwdriver, except instead of a 360 degree range of movement, you usualyl get something like 10-30 complete rotations for the range of movement.

They're usually for Calibration.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 19, 2012, 08:27:23 PM
I guess I don't need to calibrate as there was no mention in the Colour-book.  And everything seems to be working great.

Any suggestions on a great compressor to compliment this preamp?

Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 20, 2012, 12:10:27 AM
grab one of Ruckus' SA-3A stereo kits :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 20, 2012, 02:37:37 AM
Appologies.... I seem to have omitted the calibration from the colourbook.... without trimming they will work fine anyway.... as you have already discovered.

R10 adjusts the 48v... if you measure the 48v tab (with respect to analogue ground) you will probably find it is about 46.5v.... adjust R10 to give you 48v.

R20 adjusts the bias of the output transistor..... measure the voltage across R26 (1 Ohm)... it will be about 70 - 80mV... adjust R20 to increase the voltage to 120mV.

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 20, 2012, 12:53:46 PM
Can I use my tester on the mic xlr in to adjust the phantom power resistor or should I do it somewhere else on the board.

Thanks
Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 20, 2012, 01:03:46 PM
No, measure the voltage using the power connection tabs to the right of the line input connector.... measure the voltage between the "+48v" tab and the "Agnd" tab.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 20, 2012, 03:28:22 PM
Ok, the adjustments have been made.

Say does anyone know how close this ez1073 sounds to a BAE 1073?  I mean for the price of the kit it was definitely worth it and building it myself felt great but being the  newbie I am I don't know much so how does this thing compare to a BAE 1073 and an orginal neve.  I have never work with any of those.   This ez1073 sounds amazing for my little project studio but just wondering how it compares to others.  I guess there are different sound colors that people talk about.

Thanks

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on January 20, 2012, 08:43:14 PM
Ok, the adjustments have been made.

Say does anyone know how close this ez1073 sounds to a BAE 1073?  I mean for the price of the kit it was definitely worth it and building it myself felt great but being the  newbie I am I don't know much so how does this thing compare to a BAE 1073 and an orginal neve.  I have never work with any of those.   This ez1073 sounds amazing for my little project studio but just wondering how it compares to others.  I guess there are different sound colors that people talk about.

Thanks



I've got one of the 500 series models in the rack this week and put it up against our neves and some BAEs. It's nearly indistinguishable from the vintage Neves, and at least as close to them as they are to each other. Way to knock this one out of the park Colin! I can't wait to hear your comp.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ddt on January 31, 2012, 05:34:14 PM
Hiya,

I've now got the EZ1073 cases back in stock for those waiting for them, you can order them here:

http://www.groupdiy.com/index.php?topic=35422.msg598593#msg598593

Thanks,
Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 04, 2012, 11:11:45 AM
Hello All,
Today I got a Customs Duty invoice in the mail from TNT express here in the USA.  It is for $44.85.  I was just wondering if this is legit.  I don't mind paying it if it is, but would just like to make sure its legit.  I guess there is no way to avoid this for future purchase of oversea items?

Thanks
Scott

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 04, 2012, 12:29:04 PM
That is less than 10% duty ..... sounds reasonable/legit to me.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 04, 2012, 12:45:30 PM
Ok cool I will ahead and pay it. Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on February 04, 2012, 01:36:26 PM
http://www.groupdiy.com/index.php?topic=47321.0 (http://www.groupdiy.com/index.php?topic=47321.0)

Just so you know, the District attorney will be looking into TNT express here in the states for THIS EXACT issue.  Honestly, i wouldn't pay it (i did when i got mine... but you can read the thread for more details) 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 04, 2012, 08:43:26 PM
Errrrrr, This is the same company that Colin sent the package to to ship right?

So they have the package from start to finish, colin all the way to my house. 

I paid colin almost $60 bucks for shipping so why are they charging me again.  I am sure this is what Colin paid them to begin with.

Here is what my invoiced says.

DT = $14.85 which stands for Customs Duty
HDG = $15 which stands for Handling Fee / Flate Rate
PI = $15 which stands for Residence Fee-Duty

Total = 44.85

I can see paying the $14.5 for customs but the other two are ridiculous.

Its almost like I am paying for shipping twice.

I will try calling them on Monday.  If I don't get anywhere I will pay the 14.85 and nothing more online.  What a bunch of idiots.

-Scott





Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 20, 2012, 11:57:10 AM
Wow, ordered a pair of ez1073's on Thursday morning (California) and received them Monday morning.   Colin, great service!  I don't do kits....but couldn't resist having a pair of these.  I actually broke my "never a kit" thing with the MK47 so this is the second kit.  I guess I can't say I never do kits anymore.

Already started on a set of custom panels and I'm looking forward to putting these into service.  I have 2 albums starting up soon.  Need to get these built, tested and burned in.


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 20, 2012, 02:10:37 PM
How long is a burned in period?  Should I leave it on over night?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on February 20, 2012, 08:50:21 PM
@saxmonster, I used mine right away as soon as they were finished.   no burn in.  just simply a check for no smoke or sparks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 20, 2012, 09:37:53 PM
yeeeeep,
Thats what I did too.  I still haven't received the case yet but I am using it. As soon as I tested it and didn't see smoke or hear anything pop I hooked it up to my daw and love it.

-Scott

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on February 21, 2012, 01:58:51 AM
yeah, man.   such a DOPE preamp, especially on sax.   then it's just up to the  mic and mic position!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 21, 2012, 10:18:45 AM
Yes you can use these right away no problem.  I always turn my newly built gear on and leave on while on the bench for 24 hours or so before racking.  Just a habit. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 24, 2012, 02:05:07 PM
For the first time today I have seen one of Dan's (DDT) cases in the flesh.... very nice quality... impressed.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: scott_humphrey on February 25, 2012, 11:06:23 AM
What happens when you get three people in a garage with a case of beer, a few ez1073-500s, a Hammond Organ, a guitar, a drum set, and the Spirit of Elvis Presley? 

Find out here:

http://www.treblebooster.com/mp3/Heartbreak_Hotel_Revisited.mp3 (http://www.treblebooster.com/mp3/Heartbreak_Hotel_Revisited.mp3)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on February 26, 2012, 03:50:59 PM
Nice job! ;D ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on February 29, 2012, 09:10:52 AM

Hi Colin,

Do you mind sharing your source for the Elma ring nuts?  I have one 1073 I bought from you as a complete kit, and one as partial kit only and I'd like to use the ring nuts on the partial kit too if possible, rather than create huge recesses for the nuts supplied with the pots and switches.

I've had a little hunt online for them and nothing has come up - ring nuts generally seem to be a normal nut with a ring welded onto the top in the results I have found.

Cheers,

Rob
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 29, 2012, 09:25:46 AM
Farnell - 1209855

http://uk.farnell.com/elma/046-4000/nut-3-8/dp/1209855?Ntt=046-4000

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on February 29, 2012, 10:00:09 AM

Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on March 02, 2012, 12:45:25 PM

Here's a little sneak preview of the first of my two EZ1073s. 

Unfortunately the wrong type of XLR socket was sent with my most recent parts order so currently I have no line out socket!  It'll be next week before it gets started up properly and tested, but given that it is as good as done, I couldn't resist a photo :)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chocorookie on March 14, 2012, 03:05:08 PM
Nice build!!

Got mine 2 peices also build,

first one started up with no problems, 2nd one has trubbles.

R23( 12R resistor) got hot and smoky. it's the limiting resistor for pre-ampstage 3.It draws hi currents......................
Power -ok led says ok :) but meassuring tels me that the 24V is real 19V and the 48V is real 43V. Trimpot for adjust doesn't respond.
Big guess: Short circuit in stage 3.................
First I will remove the 12R and meassure the voltages again without feeding the 3th stage. A new 12R must be ordered anyways, it degraded itself now to 8R.
Output transformer is also in this circuit, hopefully it isn't fried.

(BTW, I checked everything both 3x before powering up and meassured everything while installing components. And still........troublle)
The funny part in this all is I ordered 18 nice looking knobs for the EZ's, what did i become? 18 SMD resistors................, orderpicking faillure:)

More to come,

Happy building to ya all, fantastic kit Collin!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 14, 2012, 03:47:09 PM
Check C2 and C3 are in the correct way round.

Check that there is not a short between the body of the 2N3055 (collector) and the ground plane (the screw hole pads are a bit small for the M4 screws and they can sometimes touch the Agnd).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on March 15, 2012, 12:29:53 AM
If I have a bass player come over and record parts what is the best way to use this pre?
I know I can do microphone to cabinet but what about a direct version?

Direct out from bass amp into line in?  Can I plug the bass directly into the line in?  1/4 to xlr cable?

Thanks
-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on March 15, 2012, 08:45:24 AM
Line out from bass head, or use a DI box.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 16, 2012, 03:06:46 AM
There is in fact now a new Carnhill DI transformer (VTB9072) which was not available when this was designed, otherwise I would have designed it into the circuit.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 22, 2012, 03:06:59 AM
Seems to be as close as it can be !

http://www.tapeop.com/reviews/88/ez1073-500-500-series-preampeq/

If the link does not take you directly to the review then just go to the reviews section and search for ez1073

[A 1070L is simply a 1073 with the controls laid out differently - AFAIK]

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on March 22, 2012, 12:14:30 PM
nice review!   Congrats, they are really a great preamp!!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on March 24, 2012, 01:53:38 PM
(http://chrispsound.com/wp-content/uploads/2011/09/IMG_3242.jpg)

(http://chrispsound.com/wp-content/uploads/2011/09/IMG_3243.jpg)


I have a very newbish question about the grounding of the pcb board to the 1U case.  I noticed this pic and the Chris has used a wire on the ground of the xlrs to the main ground, but then I noticed the prototype build by Colin and he didn't ground that way.  What is the best way to ground the 1U build?

If I do use the xlr ground, do I need to connect the 1 pin to the ground of the xlr then daisy chain that over to the other xlrs to the main ground? 

Also, I know I need to take off the powder coating of the area were the screw for the main ground it going so it makes better contact with the case.  Do I need to do that with the xlr mounts? 

Thanks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on March 24, 2012, 08:51:34 PM
HELP!!!

ok, I powered one of my ez1073's on to calibrate the 48volts and output.  I plugged it in and started with the 48 volts.  I have the 48 volts on and put my leads for my multimeter on the line input connector.... I put one of leads on the "+48v" tab and the other on the "Agnd" tab.  There was a spark and I quickly took my leads off.  Then the 7824 voltage regulator started smoking.   I unplugged the unit...............then I waited and plugged it back in.......it started smoking again.  Can anyone tell me what I should do and/or what I did wrong?  I am guessing I need to get another 7824 voltage regulator.

I have these metal pieces with two feet.  Do these go into the slots right of the line input transformer (DC Feeds)?

Is this going to be sufficient for the 7824 voltage regulator?

http://www.mouser.com/ProductDetail/ROHM-Semiconductor/BA17824T/?qs=4kLU8WoGk0tve0p5C29gvk92nQGsOjR6Lz3PV6yQMAI%3d

If someone could help me ....I would much appreciate it.  I am freaking out.....there was smoke.  Man, I really hope I didn't fry everything. 

Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on March 27, 2012, 01:23:55 PM
Can anyone give a lost soul some guidance?  I don't want to go further with any of my two 1073 until I am sure I won't further mess anything up.  I appreciate any advise. 

Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on March 27, 2012, 01:41:52 PM
HELP!!!

ok, I powered one of my ez1073's on to calibrate the 48volts and output.  I plugged it in and started with the 48 volts.  I have the 48 volts on and put my leads for my multimeter on the line input connector.... I put one of leads on the "+48v" tab and the other on the "Agnd" tab. 


SO you're saying you put the meter probes on te places in the attached drawing, or somewhere else?

Did you know that your multimeter works properly before starting this testing, or is it the first time you've used it?

Quote
There was a spark and I quickly took my leads off.  Then the 7824 voltage regulator started smoking.   I unplugged the unit...............then I waited and plugged it back in.......it started smoking again.  Can anyone tell me what I should do and/or what I did wrong?  I am guessing I need to get another 7824 voltage regulator.

yes I would say so.

Quote

I have these metal pieces with two feet.  Do these go into the slots right of the line input transformer (DC Feeds)?


Yep - but unless you want to hook up some other device you don't need to use them

Quote
Is this going to be sufficient for the 7824 voltage regulator?

http://www.mouser.com/ProductDetail/ROHM-Semiconductor/BA17824T/?qs=4kLU8WoGk0tve0p5C29gvk92nQGsOjR6Lz3PV6yQMAI%3d


I believe that one will be fine - 1A is enough I think

Quote
If someone could help me ....I would much appreciate it.  I am freaking out.....there was smoke.  Man, I really hope I didn't fry everything. 

Dan

Don't panic - hopefully all that has happened is that the 7824 needs replacing.  Sounds like a short somewhere in the 48V circuit, but I am no expert at this stuff so you may want to wait for a firmer answer.  Have you checked to make sure there's no continuity between 48v and ground

Edit : Ignore all that.  The 7824 has nothing to do with the 48V circuit - that is regulated by the TL783

You still need to double check everywhere with your multimeter to make sure you  don't have a short to ground on the 24V section of the circuit...

Could you have somehow shorted the 24V rail to the ground rail when you were trying to verify if the 48V rail was ok?
Title: Output too hot!
Post by: macakinho on March 28, 2012, 03:34:22 PM
Hi! I just finished my first 1073 (minus the knobs :P) and gave it a test run and everything was good! No smoke or burnt smells, oh, and it did sound amazing! Was completely blown away!

Noob questions:
- The one thing that is annoying is the output wich is way too hot! Do I just need to calibrate the output trim or is there anything else I need to do?

- Also, reading a few post regarding multimeters and smoke, I am a bit scared of calibrating the +48V. Is this such an important step? In wich way does this affect the unit/mic/sound?

Thanks in advance and sorry if these questions were answered before but couldn't find any answers!

EDIT: Found the post where Slenderchap mentions "measure the voltage across R26". How would I go about measuring this value?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on March 28, 2012, 07:01:43 PM
HELP!!!

ok, I powered one of my ez1073's on to calibrate the 48volts and output.  I plugged it in and started with the 48 volts.  I have the 48 volts on and put my leads for my multimeter on the line input connector.... I put one of leads on the "+48v" tab and the other on the "Agnd" tab. 


SO you're saying you put the meter probes on te places in the attached drawing, or somewhere else?  Yes, the same places. 

Did you know that your multimeter works properly before starting this testing, or is it the first time you've used it? Yes, it works.  I tested all of the components with the same multimeter before I soldered them in.  I will note that I am a novice at this.  This is my second build.  My first build was 4 Classic Audio of Illinois VP 312.  I am using a brand new Fluke 115.  This is my first time using this meter, but I have used other meters in the past  :o

Quote
There was a spark and I quickly took my leads off.  Then the 7824 voltage regulator started smoking.   I unplugged the unit...............then I waited and plugged it back in.......it started smoking again.  Can anyone tell me what I should do and/or what I did wrong?  I am guessing I need to get another 7824 voltage regulator.

yes I would say so. Yup, that last part was rhetorical.

Quote

I have these metal pieces with two feet.  Do these go into the slots right of the line input transformer (DC Feeds)?


Yep - but unless you want to hook up some other device you don't need to use them.  Ok, thank you.  That is good to know.  What devices could you hook up to these points? 

Quote
Is this going to be sufficient for the 7824 voltage regulator?

http://www.mouser.com/ProductDetail/ROHM-Semiconductor/BA17824T/?qs=4kLU8WoGk0tve0p5C29gvk92nQGsOjR6Lz3PV6yQMAI%3d


I believe that one will be fine - 1A is enough I think.  Ok, Thank you, 

Quote
If someone could help me ....I would much appreciate it.  I am freaking out.....there was smoke.  Man, I really hope I didn't fry everything. 

Dan

Don't panic - hopefully all that has happened is that the 7824 needs replacing.  Sounds like a short somewhere in the 48V circuit, but I am no expert at this stuff so you may want to wait for a firmer answer.  Have you checked to make sure there's no continuity between 48v and ground. I will check that this weekend, Thanks.

Edit : Ignore all that.  The 7824 has nothing to do with the 48V circuit - that is regulated by the TL783

You still need to double check everywhere with your multimeter to make sure you  don't have a short to ground on the 24V section of the circuit...

Could you have somehow shorted the 24V rail to the ground rail when you were trying to verify if the 48V rail was ok?

I could have, but I don't know what I did wrong.  I will check all the solder points.  I haven't had a chance to touch this thing due to sessions.  The 7824 was the only one smoking and not the TL783.  If someone can verify that these would be sufficient replacements (http://www.mouser.com/ProductDetail/ROHM-Semiconductor/BA17824T/?qs=4kLU8WoGk0tve0p5C29gvk92nQGsOjR6Lz3PV6yQMAI%3d) I will re-solder the new ones.  Could switching the multimeter probes cause the short...polarities...red instead of black and vice versa?  I remember doing it the way you have in the picture you have, but I could have done it the other way.  Thank you for responding to the post.  I appreciate your input very much. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pyjaman on March 28, 2012, 07:51:06 PM
No, black instead of red can't do anything ( you will just read a neg voltage value where you might read a positive one). BUT I remember once when I was a total novice testing between the + and - of power rails in the ampermeter position...THAT was a short !... bye, bye, power transformer... And it was on the HT rail off a stereo tube amp...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on March 29, 2012, 12:41:05 PM
No, black instead of red can't do anything ( you will just read a neg voltage value where you might read a positive one). BUT I remember once when I was a total novice testing between the + and - of power rails in the ampermeter position...THAT was a short !... bye, bye, power transformer... And it was on the HT rail off a stereo tube amp...

Cool, that is what I thought.  What is the ampermeter position.  I just put my meter to read voltage and put the probes on one of the wholes for the "+48v" tab and the other on the "Agnd" tab.  Do you think I damaged my power transformer?  Thanks for your reply to my post.  I very much appreciate it. 
Title: Re: Output too hot!
Post by: macakinho on March 30, 2012, 02:40:20 PM
Hi! I just finished my first 1073 (minus the knobs :P) and gave it a test run and everything was good! No smoke or burnt smells, oh, and it did sound amazing! Was completely blown away!

Noob questions:
- The one thing that is annoying is the output wich is way too hot! Do I just need to calibrate the output trim or is there anything else I need to do?

- Also, reading a few post regarding multimeters and smoke, I am a bit scared of calibrating the +48V. Is this such an important step? In wich way does this affect the unit/mic/sound?

Thanks in advance and sorry if these questions were answered before but couldn't find any answers!

EDIT: Found the post where Slenderchap mentions "measure the voltage across R26". How would I go about measuring this value?

anyone? please?   :-[
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on March 30, 2012, 02:43:02 PM
Why would you be afraid of calibrating the 48v?  Is it worth cutting a corner to damage an expensive studio mic?  put the voltmeter on it and adjust as needed...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: macakinho on March 30, 2012, 02:51:01 PM
Why would you be afraid of calibrating the 48v?  Is it worth cutting a corner to damage an expensive studio mic?  put the voltmeter on it and adjust as needed...

Am on it right now actually!  :P

The one thing I'm not really sure on how to do is to calibrate the output. I googled on how to measure voltage but am not sure where to connect the 0V reference for the multimeter...
Once calibrated, is it supposed to cut the signal when the trim is completely down?

Thanks in advance guys!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 31, 2012, 08:47:39 AM
1] 48v calibration: To measure and adjust the 48v you should put your voltmeter probes as shown in Rob Gould's drawing.... before you have made any adjustment you will typically read about 46.5v anyway.... so condenser mics will work fine without any adjustment at all.... you will certainly not damage a microphone with undervoltage.

[The voltage which the microphone gets will actually be significantly less than 48v anyway because of the 6k81 resistors in the 48v feeds.... for example, a U87 takes about 0.8mA.... when this is drawn through the 6k8 resistors they will drop the voltage by about 6 volts... so the U87 only actually gets 42v..... none of that is relevent to this issue I just thought it interesting to point out].

2] 24v regulator: I expect that any of the 7824 (1 or 1.5A) TO220 style regulators would be fine.... the one supplied is an ST electronics L7824CV.... (Farnell part number 975-6213, Mouser part number 511-L7824CV ... I presume)

3] Output trim control:  The output trim pot only drops the output level by about 9.5dBu... if you wanted it to cut the signal off completely you would need to change some resistor values. (it is not affected by the Output Bias Trimmer... that sets the output transistoir bias).

4] Smoked regulator; If the 24v regulator has smoked then there must be a short circuit somewhere (or you have it in backwards).... check all your diodes are in the correct way round, check that the body of the 2N3055 is not shorted to the Agnd (screws are a bit big for the pads really so they can cause a short to the ground plane).... when you have removed the regulator to replace it just measure the resistance between the 24v tab and the Agnd tab.... if you get a very low resistance (say 1 or 2 ohms) then you have a short circuit somewhere..... maybe a solder splash.

Colin
www.audiomaintenance.com



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on April 01, 2012, 02:03:13 PM
Thank you for the reply.  I guess the EZ1073 isn't easy for some people (pointing finger at myself).  I finished the second unit that i have and turned it on.  I put my probes on the +48v and the Agnd and get 56V!!  I tried to adjust the R10 Trimmer and it doesn't do anything.  Can anyone explain how to measure across the R26 resister for measuring the output?  I know someone else had the same question. 

Thanks again Collin, I appreciate you chiming in. 

Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 01, 2012, 02:40:40 PM
If adjusting the 48v trimmer does nothing then it suggests you have made a mistake.... check every single component is in the correct place and you have soldered every pin and there are no solder shorts.

"How do you measure the voltage across a resistor" ??? ... you put the red probe on one end and the black probe at the other.... is that what you are really asking ?

You are not measuring the "output" by measuring across R26.... you are measuring the amount of current that the unit is taking.... by doing that you can get a good approximation of the adjustment required for the output transistor bias trimmer R20...... bvecause R26 is a 1 Ohm resistor, the voltage across it (in mV) will be equal to the value of current through it (in mA).....

Before adjusting R20 you will probably read about 80mV across R26.... adjust R20 until you read 130mV.... that will do.

[You should in fact be measureing THD+N on something like an AP to make the adjustment but that is too much for DIY.... adjusting the current will be fine].

Colin
www.audiomaintenance.com
 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on April 02, 2012, 01:32:24 AM
Collin, thanks again for chiming in.  The whole Voltage regulator burning out has me second guessing everything I am doing.  I just want to make sure I am doing it correctly.  Thanks again. 

Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: KillerV on April 02, 2012, 12:55:24 PM
New guy here.  I decided to get 2 EZ1073 kits after I had done a couple of guitar pedal mods and builds, mic mods and recapped an Yamaha PM1000.  After I got my rack cases from ddt, I put everything together at the end of last week.  I double checked everything before powering up but I'm having a couple of issues that I can't get sorted out:

EZ1073 A:
Makes crackley/static noises
R10 and R20 doesn't seem to do much
No +48V at the XLR when switch is engaged
Q4 gets hot and smells
 
EZ1073 B:
Also makes the crackley/static noises, but mostly only after I've flipped either the +48V or impedance switches
Line Input doesn't work
Very low level when EQ is engaged.  (Initially I actually thought it didn't pass any signal when engaged but it does, just at an extremely low level.)

LED lights up and apart from Q4 it doesn't seem like anything else is running hot or smoking.  I made very sure that all polarity-sensitive components were the right way around.  I also checked every component on both boards against the colourbook again today and I can't find anything I did wrong.  Also went over the boards with a magnifying glass to check for shorts.

When measuring at +48V and Agnd, both boards measured around 46V.
When measuring at +24V and Agnd, both measured around 23.5V.

I would appreciate any advice immensely.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: domi62 on April 04, 2012, 05:12:38 PM
Hi Colin,

Seems that you've stopped proposing the ez 1073 full kit on your website.
Are you out of stock or is it finished ?

Cheers

Domi
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: zmgwg on April 07, 2012, 06:58:28 AM
would like to know as well.
thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: trancedental on April 07, 2012, 10:37:06 PM
Just built a pair of these, one sounds fine, the other has a bit of hum when the EQ is engaged but I don't have all the metal standoffs fitted to it's case at present. I'm waiting for those to come, probably needs all those fitted for proper grounding anyway!!!  :o

I using the finished one with Guitar & Bass  through my trusty DI / Reamp unit, a Little Labs Red Eye, tried the Line input at first but I think it sounds even better through the Mic input, the Red Eye sends a Mic level signal so that's the probably best match.

My very old knackered Gretsch Country Gent sounds fantastic, plenty of warmth & sparkle & that's without even micing a amp, the Fender Jazz Bass sounds great, a real recorded DI sound without much effort at all.

It even makes my cheapo mics sound good, I really need a decent mic now!!!!

Thanks Colin for the great kit!!!!!  8)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 09, 2012, 03:42:41 AM
Seems that you've stopped proposing the ez 1073 full kit on your website.
Are you out of stock or is it finished ?

We don't have the time at the moment to do these full kits... it just takes too much time to kit.

There are still a handful of PCB's left so it may become a "partial" kit consisting of PCB, wound components, pots and switches etc....  that would not take so long to do....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: lolo-m on April 09, 2012, 06:40:35 AM
That's a good news !!!
I would be in for 2 or 4 partial kits depending on price...
Does the partial kit includes the front plate+bracket or only PCBs + a few components ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: spase on April 09, 2012, 01:59:25 PM
I will take 2-4 pcbs depend on the price :))) i want to have them home :)))
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on April 09, 2012, 03:46:10 PM
yes how much for a pcb?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: briomusic on April 10, 2012, 04:31:21 AM
I would also like to put my flag in the ground for 2 pcb/partial kits for the 1RU version, I was quite :o to see the kit has disappeared from the website.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: lespaul924 on April 10, 2012, 05:25:30 AM
I would be interested in 2-4 pcbs or 2partial kits.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: whomper on April 10, 2012, 07:08:13 AM
Interested in 1-2 partial kits.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 11, 2012, 10:32:44 AM
It is now back on as a "Partial kit" (until the PCB's are all gone)..... contents are listed if you click on its photo.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on April 11, 2012, 11:35:18 AM
Oh the sales pressure... ACT NOW!!!!  yeah... i bought in ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sysexguy on April 15, 2012, 10:01:50 PM
me too, major case of the "snooze you lose" as now the parts hunts begins.....

Couple of questions Colin;

1) is there a substitute for the BC184C? it's showing obsolete/discontinued at all the usual suspects including Farnell. Can one rely on the info here http://www.groupdiy.com/index.php?topic=48279.msg609709#msg609709 ?

2) some parts, like the heatsink, once one finds the substitute, newark numbers are cheaper in USA/Canada, but not stocked....is Newark and Farnell the same outfit or are they parallel businesses, I'd hate to have to order some parts from the UK and others from NJ?

3) the BOM notes many electrolytics pitch as .1 while the ones on the audiomaintence store are .25 pitch.... if this could be verified please

TIA Andy
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 16, 2012, 02:13:42 AM
BC184C's can be got easily from Ebay.... Farnell do list an alternative.

The heatsink is pretty standard (lots of different manufacturers/suppliers)... just get the drawing from the Farnell website and pick an alternative brand.... Farnell owns Newark (and CPC).

BOM list is in Inches... Store is in mm.... 0.1inches = 2.5mm

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chocorookie on April 19, 2012, 02:41:32 PM
This what happened on my unit no.2:

Quote
check that the body of the 2N3055 is not shorted to the Agnd (screws are a bit big for the pads really so they can cause a short to the ground plane).... when you have removed the regulator to replace it just measure the resistance between the 24v tab and the Agnd tab.... if you get a very low resistance (say 1 or 2 ohms) then you have a short circuit somewhere

The 12E resistor began to burn and a lower 24Voltage. (see 15 posts ago) Everyone should take a close look to this when installing the heatsink of the 2N3055. I loosen the bolds and put a M3 for it, this did the trick. Ain't having a 12ohm resistor arround, I checked the old one and it reads 9.1ohm with some burn marks, but good to go for testing, allthow no good voltage drop to 24 V.

Result: non smoking working unit!

The new 12-er is allready on the bench, didn't have the time to interchange it. Also I do a check layer on for all values in the "3-rd section" where the trouble with the screw shortage began.

Good to know 4 all you guys still in the building and troubleshooting stage.

Regards Patrick.

PS, also my 48V voltagesupply mic switch is up-side-down in switching. have to mark it on the chassis before people are starting frying microphones ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on April 19, 2012, 03:53:15 PM
Just wanted to find out if there is a substitute for the WIMA MKS2 caps, there are 3 I cant find as MKS2's but found them as MKP2's.  (One is the polyester and one is the polypro)  Is there a tonal difference between the two, are they interchangable?

Thanks much :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sysexguy on April 19, 2012, 09:33:35 PM
Thanks Colin, package arrived yesterday and ebay was kind to me....

Andy
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on May 04, 2012, 05:32:35 AM
hi :)
i have 2xez1073 1U
i have problems with 2 rotary switch. one is the LF Freq of unit1 and the other the HPF Freq of unit2
i put the Adjustment Pins at 12oclock and 5oclock but when i turn the knob i get 7 positions :p
any idea ?

also a question about the 220-240v Transformer Wiring.
what do i do with the grey and violet wires ? i sold them together ? :o (i noob)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 04, 2012, 06:00:11 PM
i have problems with 2 rotary switch. one is the LF Freq of unit1 and the other the HPF Freq of unit2
i put the Adjustment Pins at 12oclock and 5oclock but when i turn the knob i get 7 positions :p
any idea ?

also a question about the 220-240v Transformer Wiring.
what do i do with the grey and violet wires ? i sold them together ? :o (i noob)

You have either "viewed" the switches upside down (ie your 12 o'clock is actually 6 o'clock)... or more likely, when you put the pins in, the switches had already been turned so they are now in the"wrong half" of their rotation. When you fit the pins, the "D" of the shaft should be in the position shown in the colourbook (flat pointing toward the 7 o'clock position).

The grey and violet wires need to be connected together for 220-240 operation.... but BEWARE... they will be at 110-120volts !... so must be insulated properly from everything.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on May 06, 2012, 03:26:22 AM
I finally got my two ez1073 preamps working.  I used to much solder on some resistors and I didn't not properly mount the Voltage regulators so they touch the heat sinks.  Here are some pics with Chuck of Cathedral Pipes knobs.  They sound really stunning on vocals.  I will be testing them on some guitars soon.....can't wait.

Thanks Colin.  I know I annoyed you with all my newby questions...hahaha, but thanks.

Dan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on May 06, 2012, 03:27:13 AM
here is another one.  Now if I can figure out that dual 1176 it will go in the empty space!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on May 06, 2012, 07:57:13 PM
Looks great Dan, good to hear you have them up and running.

-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on May 06, 2012, 09:37:30 PM
Thanks man.  I am glad too.  Now I just need to work on my dual 1176
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on May 12, 2012, 07:17:38 AM
thx Slenderchap i'm almost done !
about the DC FEEDS gould said :
Quote
unless you want to hook up some other device you don't need to use them
can someone explain me what "other device" he means ?
i have nothing set on these DCFEEDS. is that ok if i power up the unit without anything here ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 14, 2012, 01:28:47 AM
i have nothing set on these DCFEEDS. is that ok if i power up the unit without anything here ?

Yes.... you can just ignore them if you are using the power supply which is on the circuit board.

They are only there if you want to power the PCB from an external power supply.... the PCB was designed with "making a mixing console" in mind.... in which case you would have an external PSU feeding all the channels with DC voltages.... which is also the reason that the XLR's can be fitted to the PCB.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on May 17, 2012, 11:24:18 PM
Finished build of the rack version after doing a pair of the 500-series version last october/november.   This thing is SIIIIIICK.

But, upon doing a comparison of the two versions, this rack version sounds a bit sweeter than the 500-series version.  It's just a little bit more open.   Any ideas what might cause that?   I made a little audio test if anyone wants to hear the two preamps back to back on identical settings.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on May 23, 2012, 07:12:07 AM
hi again ;)

for C53 i miss a 1n5J100
the only thing i found in store next to me is 1n5J63 or "1500 400- P9" (i write what i read on the thing :o ) the sellor says last one should work ..
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on May 23, 2012, 09:55:13 AM
Colin, this thing is a work of art!  Used it for some bass tracking for a couple sessions this past week... one word... WOW. Thanks much for the great project!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on May 26, 2012, 07:41:40 AM
IT's DOOONE (http://smileys.sur-la-toile.com/repository/Content/pom-pom-girl.gif) (http://smileys.sur-la-toile.com/repository/Content/pom-pom-girl.gif) (http://smileys.sur-la-toile.com/repository/Content/pom-pom-girl.gif)
haha my very first DI projecy  8) i'm so happy it's "nearly" working" yeah nearly because i have to check some hum on the mic .. but maybe it's my mic cable or setup because i have the same thing on both units.
but Line is 100% perfect. (missing some catherdral knobs coming soon)

the mic sounds so great (dispite that little hum)! i used my fireface for years and it's night/day compared to the sound coming out of the ez1073 
regarding forward to do some more !
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tmuikku on May 26, 2012, 08:03:05 AM
dgoszillai: Use shielded cable for the input / output connectors to PCB connections. Now you have cool loops in the cable for the magnetic fields inside the chassis to induce hum to the cables ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on May 26, 2012, 10:07:15 AM
 ;D right ... i wonder how i can do such mistakes and got this think up without burning all the building.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on May 26, 2012, 01:41:10 PM
dgoszillai: Use shielded cable for the input / output connectors to PCB connections. Now you have cool loops in the cable for the magnetic fields inside the chassis to induce hum to the cables ;)
......or twist them and cut them to proper length!
You've built some nice "antennas" there.... ;)

Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on May 26, 2012, 05:06:00 PM
hahaha  caman guys please stop laughing at me  ;D
tell me if this version is better ;)
that's right the hum is totally gone now it sounds huge clean musical i love it !
thx for the help
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on May 26, 2012, 05:20:33 PM
Well done!

Udo ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on May 26, 2012, 06:26:21 PM
NICE!!!!!!!!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dryman on June 15, 2012, 06:27:41 AM
Hi,

i would like to build one or two EZ1073 but i can't find a source for the PCB. Audiomaintenance has no PCB or Partkit. Does anyone know, where i can get them?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on June 15, 2012, 06:36:27 AM
Hi,

i would like to build one or two EZ1073 but i can't find a source for the PCB. Audiomaintenance has no PCB or Partkit. Does anyone know, where i can get them?

Audiomaintenance is the one and only source for this project.  If they're sold out there, they're sold out I'm afraid.

Colin from Audiomaintenance periodically checks this thread and may advise whether another run will happen.  If not, you may like to search for posts by user Bluzzi, who has offered a similar project in the past I believe.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: loganchristian on June 21, 2012, 04:49:40 AM
I recently completed two of the ez1073's from partial kits. Everything checked out on both of them, proper voltages, passes audio, both sound good. When using them on a line-level stereo source I noticed that one of the units is about two line gain clicks hotter. I verified by sending an identical mono tone to both and swapping in's and out's of each. What might be suspect? Another issue I'm having with one of them is the LF gain doesn't add or subtract as much gain as my other unit. The other frequencies are matched. I used the exact same parts in both and I wonder if the bc183c's I ordered off ebay are at fault. While sourcing parts I had the most difficulty finding the right WIMA's that fit, I had to mount 5 on the bottom of the PCB. Can anyone please provide me with some places to look as I try to troubleshoot?

Thanks!

Logan
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 21, 2012, 11:46:45 AM
i would like to build one or two EZ1073 but i can't find a source for the PCB. Audiomaintenance has no PCB or Partkit. Does anyone know, where i can get them?

Sorry, all gone.

When using them on a line-level stereo source I noticed that one of the units is about two line gain clicks hotter.

Input transformers possibly the wrong way round ?

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: loganchristian on June 23, 2012, 12:18:35 AM
Good diagnosis Colin.. of course it would happen on the second build. Line gain is fixed but LF Gain is still weak on the boost and cut, any ideas on that? Bad pot? I've looked over both boards many times now and everything appears consistent. Thanks for your help and for the great pre's!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 23, 2012, 07:02:44 AM
LF Gain is still weak on the boost and cut, any ideas on that? Bad pot? I've looked over both boards many times now and everything appears consistent.

Tricky to say really.... wrong pot fitted ?... duff pot ?... op-amp circuit not working properly (wrong resistor, duff transistor, bad joint).... it could be a whole host of reasons ...

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: decentbad on July 20, 2012, 08:22:42 AM


Sorry, all gone.

[/quote]

Hi, any chance for a PCB reissue?

Big thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 01, 2012, 03:23:54 PM
OK ... the ez1073 (1U version) is available again for a short while.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on August 10, 2012, 04:27:34 AM
n00b question; when selecting the WIMA and ceramic capacitors is there a upper and lower limit when choosing the voltage rating? I guess this will help me understand for other projects in the future too.

How would one determine a projects component upper and lower voltage limits if not specified? I understand that it has to do with the amount of voltage it can with stand and that the component size will vary - I dont want it to be too big or blow up! Im just having trouble figuring out how to determine this, this will set me in good stead! :) thanks if anyone could please help I would much appreciate your help 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 10, 2012, 04:53:39 AM

There's no upper limit to the voltage rating of capacitors; the limit there occurs because the body of the component often gets larger as voltage rating increases, meaning that a component won't fit onto the PCB.

With regard to the 1073 project, I think that 63V should suffice in most places.  The WIMAs polys don't actually increase in size that much as voltage rating increases so you can overate them and not have to worry too much about them not fitting.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on August 10, 2012, 07:52:39 AM

There's no upper limit to the voltage rating of capacitors; the limit there occurs because the body of the component often gets larger as voltage rating increases, meaning that a component won't fit onto the PCB.

With regard to the 1073 project, I think that 63V should suffice in most places.  The WIMAs polys don't actually increase in size that much as voltage rating increases so you can overate them and not have to worry too much about them not fitting.

Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

when overating, when does the difference or deviation in rating become too great (that the size becomes too big) ? a difference/deviation of 10V or 50v or 100v from the ideal - for example? (that the size would start impacting the ability to fit)

I know this is a simple question, but just need to wrap my head around this
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on August 10, 2012, 09:39:16 AM
Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

when overating, when does the difference or deviation in rating become too great (that the size becomes too big) ? a difference/deviation of 10V or 50v or 100v from the ideal - for example? (that the size would start impacting the ability to fit)

I know this is a simple question, but just need to wrap my head around this
Hello and welcome to the forum.
rob_gould talks about 63v because it is a standard value for capacitors.
In general it is like this:Given you know the voltages in the circuit you simply give caps a good margin,so they are higher than the max. voltage here.Standard values are 35,50,63 and 100 volts and then their multipliers by 10,100 etc.

The keyword for capacitors is dielectric strength.

When the value is too low the cap will pop or explode.At this point a high current will flow because mostly you will have a short and will destroy surrounding parts too.
Dielectric strength depends on a lot things like the cap type and the inner construction,the surrounding temperature,age and the general charge/discharge and load conditions,on ac voltage the frequency matters too.
There's no general formula to calculate them,just give them a good margin.
Also keep in mind that caps can have high tolerances too.
Some caps like metal film types can even heal themselves ( but will loose capacitance partwhise then),others like electrolytics are polarity dependent (wrong way around means it will be destroyed) etc............

There's a lot of info to be found in the internet.

I don't know this circuit in detail and haven't built it,but 63 v versions seem to be absolutely correct in most places here.

Hope to have helped,

Best regards,

Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on August 10, 2012, 10:00:47 AM
Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

when overating, when does the difference or deviation in rating become too great (that the size becomes too big) ? a difference/deviation of 10V or 50v or 100v from the ideal - for example? (that the size would start impacting the ability to fit)

I know this is a simple question, but just need to wrap my head around this
Hello and welcome to the forum.
rob_gould talks about 63v because it is a standard value for capacitors.
In general it is like this:Given you know the voltages in the circuit you simply give caps a good margin,so they are higher than the max. voltage here.Standard values are 35,50,63 and 100 volts and then their multipliers by 10,100 etc.

The keyword for capacitors is dielectric strength.

When the value is too low the cap will pop or explode.At this point a high current will flow because mostly you will have a short and will destroy surrounding parts too.
Dielectric strength depends on a lot things like the cap type and the inner construction,the surrounding temperature,age and the general charge/discharge and load conditions,on ac voltage the frequency matters too.
There's no general formula to calculate them,just give them a good margin.
Also keep in mind that caps can have high tolerances too.
Some caps like metal film types can even heal themselves ( but will loose capacitance partwhise then),others like electrolytics are polarity dependent (wrong way around means it will be destroyed) etc............

There's a lot of info to be found in the internet.

I don't know this circuit in detail and haven't built it,but 63 v versions seem to be absolutely correct in most places here.

Hope to have helped,

Best regards,

Udo.

Thanks for your welcome and response Udo, very much appreciated

I understand what you mean,  that if the dielectric strength is too low it will pop and as Rob has said that with the higher voltage comes a  larger sized body thus potentially creating problems when fitting them to the PCB,

 but the crux of my problem is, this good margin you speak of, what is a good margin? when do they start becoming margins that are too large? if going for a 63V ideal but 50V or 100V are the only ones to choose from is this margin too large or too small, will the 50V pop or will the 100V be too large? - do you go for the 50V or the 100V how much headroom/deviation/margin does one usually give either way?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 10, 2012, 10:08:35 AM

There's no upper limit to the voltage rating of capacitors; the limit there occurs because the body of the component often gets larger as voltage rating increases, meaning that a component won't fit onto the PCB.

With regard to the 1073 project, I think that 63V should suffice in most places.  The WIMAs polys don't actually increase in size that much as voltage rating increases so you can overate them and not have to worry too much about them not fitting.

Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

Well, firstly I must admit to you that I'm no expert in electronics, I'm still learning so take all my advice with a pinch of salt.

But in the case of this circuit, the highest voltage on the PCB will be around the 48V phantom power section.  Other parts of the circuit are lower than this, and the audio sections will never approach this voltage, so 63V is higher than 48, plus a bit of margin too.  As Kante also explained, these parts don't come in every single unit - look up E6, E12, E24 etc resistor values if you don't know what I mean.

To answer the second question, if I understand you right, there's no correlation between voltage, or any other, rating and size.  You can't say for sure that a 100V rated cap will be twice as big as a 50V rated cap.  It just doesn't work like that I'm afraid.

The way you have to learn this is simply by diving in and, dare I say it, making a few mistakes as you go.  I've definitely bought components which haven't fitted the board in the past but you can always use them for something else - it's all a learning process.  Fortunately, there are also resources like this incredible forum to help out new members and ensure that hey don't waste too much money!

You don't say where you're based, but this sample of my order for this project (purchased from rapid electronics in the UK) will at least allow you to compare part numbers and datasheets to see the sizes of the components that I used even if you don't order from there :

14   10-2208    22nf 63v Mks2 Mini Poly Capacitor Case A

15   10-2216    Wima 100NF Polyester Capacitor Case A 63V MKS2
 
16   10-2212    47nf 63v Mks2 Mini Poly Capacitor Case A

17   10-2204    10nf 63v Mks2 Mini Poly Capacitor Case A

18   10-2206    15nf 63v Mks2 Mini Poly Capacitor Case A

19   10-2220    220nf 63v Mks2 Min Poly Capacitor Case B

20   10-2222    330nf 63v Mks2 Min Poly Capacitor Case C

21   10-2224    470nf 63v Mks2 Min Poly Capacitor Case D

22   10-2228    Wima Mini Polyester Capacitor (Case E) 1UF 63V

23   08-0935    47pf 2.5mm Npo Ceramic Capacitor

24   08-0940    100pf 2.5mm Npo Ceramic Capacitor

25   08-0904    180pf 2.5mm Npo Ceramic Capacitor

26   08-0945    220pf 2.5mm Npo Ceramic Capacitor

27   08-0955    470pf 2.54mm Npo Ceramic Capacitor

28   08-0950    330pf 2.54mm Npo Ceramic Capacitor

29   08-0906    680pf 2.5mm Npo Ceramic Capacitor

30   08-0275    100nf 2.5mm Y5v Dielect Ceramic Capacitor

31   10-1410    220pf 100v Polypropylene Capacitor

32   10-1425    680pf 100v Polypropylene Capacitor

37   11-3822    1000uf 50v 105 Deg Radial Electrolytic Capacitor
    
I'm not sure that this will be everything.  If I recall correctly I had to get some bits from Farnell as well, but there's enough here to get you started...

Hope this helps...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 10, 2012, 10:13:58 AM
Quote
only ones to choose from is this margin too large or too small, will the 50V pop or will the 100V be too large? - do you go for the 50V or the 100V how much headroom/deviation/margin does one usually give either way?

There is a fairly simple answer to this :

overrate them until A : they become too big for the board or B : they become much more expensive.

Just to reiterate, electronically speaking there's no problem using a 630V capacitor when a 63V one is called for.

I'm sure someone much wiser than I will be able to provide a calculation or rule of thumb for this, but I don't have one, and I've never had an issue overrating them by a sensible margin and leaving it at that.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on August 10, 2012, 11:28:06 AM
Thanks so much for your answers, this definitely gives me some more understanding.

So lets say with the 48V being the highest voltage a component is likely to be subjected to and overating to 63V provides enough margin, but there are only 50V and 100V available you would choose the 100V (provided it fits) as this provides a greater margin.

but lets say for arguments sake; if the 100V didn't fit and the 50V fitted but has less margin, its still okay as its marginally higer? - even though not by a large amount

what margin is considered safe.... I know it may not be the case here..... but just for my better understanding and potentially other people who may come across this.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 10, 2012, 05:32:37 PM
I wouldn't use a 50V part in a 48V circuit. Again someone else may correct me on this but I wouldn't.

 In the case of the Wima caps in this circuit it isn't an issue anyway because the footprint is small irrespective of the voltage rating.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on August 11, 2012, 01:35:03 AM
I wouldn't use a 50V part in a 48V circuit. Again someone else may correct me on this but I wouldn't.

 In the case of the Wima caps in this circuit it isn't an issue anyway because the footprint is small irrespective of the voltage rating.
Agreed absolutely,one must remember the caps tolerance.....no margin left anymore.
63 volts is the next step.

Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on August 11, 2012, 02:30:12 AM
Great, yeah that makes sense, thanks so much for your input, the tolerance factor definitely explains that!  :D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on August 11, 2012, 02:35:58 AM
Great, yeah that makes sense, thanks so much for your input, the tolerance factor definitely explains that!  :D
Now go and have fun ;D

Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 22, 2012, 04:28:11 AM
Been asked a few times now about the ring nuts which fit the DDT cases....

They are made by Elma... but you can buy them from Farnell:
http://uk.farnell.com/elma/046-4000/nut-3-8/dp/1209855?Ntt=046-4000

You can get them through newark.com in the USA as well;
http://www.newark.com/elma/046-4000/nut-3-8/dp/01M9696
 
Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: fazeka on August 24, 2012, 02:52:29 PM
Hi Colin,

Are these only for the Grayhills or for the Omeg pots, as well?

Thanks,
Chris
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 25, 2012, 02:01:11 AM
They are for the OMEGs as well.... so there are 9 per unit.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on August 27, 2012, 11:08:12 PM
Hi Guys,

I just wanted to get your thoughts on something.  I am recording my sax through the Ez1073 rack version and I am using a JJ audio modded Apex 460.  It is a tube mic with a 9 pattern selector and was modded into a Elam 251 circuit.  When I record I like to record using a close mic setup.  But with a little more aim at the middle section of the horn so I just don't get the sound directly from the bell of the sax. 

My questions are

When I am recording should I have the Trim knob all the way up to get the sound of both transformers?

If I have the trim knob halfway up at 0 is the sound still running through the trim transformer?  Would turning the knob all the way to the left shut the trim transformer off?

I am asking this because when I record in this close mic setup I barely have to turn the mic gain up.  I usually just leave it on the 2nd click which says +25 with the trim knob all the way up.  Just seems that this preamp is really hot and that I am not using the preamp to its fullest capabilities.  Not really pushing it because the knob is so low.  Even before the mic was modded and with other mics like my Akg 414 it seems like the preamp is very hot with the gain.  I would figure maybe 1/2 way to 3/4 of the way would get the full sound of the transformers. 

Obviously I can back away from the mic and turn the gain up a click or so but I don't like that sound as my rooms are not treated.  I want to record with the least amount of room sound so I can add my own reverb and what not latter in the DAW.

Maybe everything is right and I am just thinking about this too much,  I am new to the tech side of recording and just trying to find what is the right and proper way to do things.  Maybe there is no right way and just go by what sounds best.

Thanks
-Scott

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: abechap024 on August 28, 2012, 03:26:08 AM
Hopefully someone else chimes in, but your going to get the "sound" from both transformers just by running audio through them. But if you really want to overdrive them...do it. Or you could pad your mic...

But really, one thing that will probably really make everything sound better, is getting an office partition or something to treat at least one side of your recording space. Otherwise its not just a matter of the want to add your reverb later, but the weird totally screwy frequency response you get from comb filtering and room resonances that you get from an untreated room. Sometime you can get them to work for your favor, especially in larger rooms (the resonances are lower on the frequency spectrum) But for a mid to small recording space...

Probably more of a response than you asked for ;)! Happy recording :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on August 28, 2012, 11:42:33 AM
Thanks Abe,
Now since this Ez1073 doesn't have a pad I will have to check my DAW.  But since I am using a Tube mic with its own PS and pattern selector.  If I turn the pre-amp gain up quit a bit and still play at the same volume  and I hear distortion its not coming from my mic.   I am not damaging my mic, right? its just that the pre-amp is taking that same signal from the mic and really pushing it and in essence  amplifying it into the DAW a lot.   Now if the DAW has its pad on and its not clipping its just the distorted sound of the pre-amp then right?

Thanks
-Scott
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Brotastic on October 04, 2012, 02:56:08 AM
Are the single Rack versions ever going to be offered as a DIY project anymore?  Please say YES, I need two more.  I love these things. :'( :'( :'( :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on October 04, 2012, 11:40:57 AM
@Saxmonster, you have to pad the signal going into the mic pre, not the signal going into the DAW.   the preamp is where the distortion is occurring. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 05, 2012, 01:06:11 AM
Are the single Rack versions ever going to be offered as a DIY project anymore?  Please say YES, I need two more.  I love these things. :'( :'( :'( :'(

It basically depends on demand.... email me and I will add you to the list.... if the list gets big enough we'll do another limited run.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: spase on October 05, 2012, 04:12:57 AM
I realy want to have a couple of pcb's from this one.Have almost all components...
I just need the pcb's without parts.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Mzaar on October 06, 2012, 11:53:46 AM
Quote from: slenderchap
It basically depends on demand.... email me and I will add you to the list.... if the list gets big enough we'll do another limited run.
my ez1073 is lush but feels alone ....so interested in 2 more full sets or 2 partial sets (pcbs+psu/input trannies+inductors+pots....got some marinair output trannies waiting for that project, depending on what kind of kit you would be willing to sell)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 09, 2012, 07:21:47 AM
Quote from: slenderchap
It basically depends on demand.... email me and I will add you to the list.... if the list gets big enough we'll do another limited run.
my ez1073 is lush but feels alone ....so interested in 2 more full sets or 2 partial sets (pcbs+psu/input trannies+inductors+pots....got some marinair output trannies waiting for that project, depending on what kind of kit you would be willing to sell)

I'll arrange to do a limited run of "full" kits as we did before..... Once I have sorted it out, I'll get it back on in the store, but there will probably be a lead time of about 6 weeks.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on October 09, 2012, 10:05:13 AM
Please add me to that list, I'd love to get another to have a stereo pair and even out my channels. ;-)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 11, 2012, 03:41:31 PM
Im soon ready populating my 4 EZ1073 PCBs...
Just have some questions i be happy if someone could help me answer them.
I had some problems with cold solder joints on the bigger capacitators and on the trimmers solder joints.
The solder joints for these parts on the PCB are quit small and Im not sure if its my solder point being to wide. Tried a smaller tip but didnt get much better.
Anybody else had the same problems? Or anybody have some helping ideas?

Also...Are people using cooling paste between the heatsinks and regulators?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on October 11, 2012, 08:18:51 PM
What temp are you runniing your iron at?   I never had problems as long as I kept my iron around 720F
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: benlindell on October 12, 2012, 09:45:52 AM
Quote from: slenderchap
It basically depends on demand.... email me and I will add you to the list.... if the list gets big enough we'll do another limited run.
my ez1073 is lush but feels alone ....so interested in 2 more full sets or 2 partial sets (pcbs+psu/input trannies+inductors+pots....got some marinair output trannies waiting for that project, depending on what kind of kit you would be willing to sell)

I'll arrange to do a limited run of "full" kits as we did before..... Once I have sorted it out, I'll get it back on in the store, but there will probably be a lead time of about 6 weeks.

Colin
www.audiomaintenance.com
Hopefully I'll have the funds to grab a pair this time.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 13, 2012, 05:33:43 AM
Thanks for youre answer:)
I solder around 350 degree Celsius = 662 degree Fahrenheit.
Is it very unsafe to go further upp. Im afraid to damage some components if I do so...


What temp are you runniing your iron at?   I never had problems as long as I kept my iron around 720F
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on October 13, 2012, 08:54:42 AM
turn it up.  Jeff (ClassicAPI) is the one who suggested running the iron permanently at 720-740F
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 13, 2012, 10:10:44 AM
Thanks, Ill do that:)

turn it up.  Jeff (ClassicAPI) is the one who suggested running the iron permanently at 720-740F
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rooster21 on October 13, 2012, 06:23:09 PM
Quote from: slenderchap
It basically depends on demand.... email me and I will add you to the list.... if the list gets big enough we'll do another limited run.
my ez1073 is lush but feels alone ....so interested in 2 more full sets or 2 partial sets (pcbs+psu/input trannies+inductors+pots....got some marinair output trannies waiting for that project, depending on what kind of kit you would be willing to sell)

I'll arrange to do a limited run of "full" kits as we did before..... Once I have sorted it out, I'll get it back on in the store, but there will probably be a lead time of about 6 weeks.

Colin
www.audiomaintenance.com

I'm in for a second run, never forgave myself for missing the first run.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: grubbyliver on October 14, 2012, 03:09:01 PM
A pair of 1U version pcb's for me please, thanks for offering these again Colin.

Ben
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Studio Mollan on October 15, 2012, 05:21:28 PM
Count me in for 2-4 kits.
Thanks for this!!!!
/
Emil
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Studio Mollan on October 17, 2012, 05:14:28 AM
Hi again,
Is it possible to add a Low pass filter to this design? Like in the 1081.
/
Emil
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 20, 2012, 02:57:54 AM
Is it possible to add a Low pass filter to this design? Like in the 1081.

Add some capacitance between your signal and ground.... that will kill the HF.

We should have availability of the 1U version on the 1st November.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rellister on October 21, 2012, 01:38:38 PM
I had some problems with cold solder joints on the bigger capacitators and on the trimmers solder joints.
The solder joints for these parts on the PCB are quit small and Im not sure if its my solder point being to wide. Tried a smaller tip but didnt get much better.
Anybody else had the same problems? Or anybody have some helping ideas?
Hi Colin, love this project, but I also have some annoying problems with the pads. Solder simply refuses to stick to the small ones. Never experienced this before.  Higher tempereature doesnt help. Should I use different solder?

Cheers
Rune

Edit;
I discovered it´s all about technique, using a pointy tip, more heat, and sliding the tip forward while applying solder solved it;)


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 22, 2012, 04:15:48 AM
I discovered it´s all about technique, using a pointy tip, more heat, and sliding the tip forward while applying solder solved it;)

Cool (no pun intended).... Lots of people have made these without problem so didn't think there would be a "PCB" problem..... and we get lots of other PCB's from the same manufacturer.... I would imagine that the most likely place to have issues is when soldering pads which are part of the ground plane.... there are thermal spokes on those pads but it can still be a little tricky if the iron is not hot enough..... using leaded solder will make it easier.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Studio Mollan on October 22, 2012, 04:36:05 AM

Hi Colin and thanks for your reply.
Where's the Best place tp put this filter? I've heard it will start messign upp the high pass if placed directly after/before it. Just after the second stage?
/
Emil
Is it possible to add a Low pass filter to this design? Like in the 1081.

Add some capacitance between your signal and ground.... that will kill the HF.

We should have availability of the 1U version on the 1st November.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 22, 2012, 07:28:46 AM
Where's the Best place tp put this filter? I've heard it will start messign upp the high pass if placed directly after/before it. Just after the second stage?

Just experiment and see what results you get ! .... you could start by altering the zobel network on the output transformer.... after all it is just a low pass filter !

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: manulaudic on October 22, 2012, 04:59:05 PM
How much does the 1U pcb runs for? Do you have any more to sell?

also, what's the approximate price for building the whole thing, if anyone can give about... would be great :)

Cheers,
Manu
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on October 23, 2012, 03:16:07 AM
Here in the states, all of the parts including case from ddt and cheap RadioShack knobs ran roughly $800.  here's what my breakdown was:

$570 preamp kit (355 British Pounds)
$128 Case (96 Euros)
$2    Power Entry Module/w fuse holder
$2    fuse
$3    PCB standoffs
$3    PCB Standoff Screws
$2    Wiring
$15   XLRs
$65   9 front-panel Knobs.  <-- fancy knobs from Cathedral Pipes

I ended up going with Radio Shack knobs that cost about $6 for 9 of them.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: manulaudic on October 23, 2012, 11:28:21 AM
Thanks mulletchuck

That gives a perfect answer. Though still don't know the price of the PCB and if it's still available. Anyone?

I got the Golden Age Pre-72 MKII for 300 euros, and it's quite nice, it's not a kit and a cheap copy using cheap transformers but has a nice built quality and good sounding if not driven too much. then it gets noisy...

Is it possible to turn that 1073 into a 1272? because i don't think anyone needs 80 db of gain...

Manu
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 23, 2012, 12:35:55 PM
Though still don't know the price of the PCB and if it's still available.

The PCB will not be available seperately.... it will only be a limited number of kits of the 1U version ... 1st November.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: manulaudic on October 23, 2012, 12:42:27 PM
I see,

and what's the price for that kit?

manu
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 25, 2012, 01:29:30 AM
and what's the price for that kit?

Probably GBP 365.00.... Depends on how much it costs to do the kitting.... I'm not doing it again, it's a mercy-less task.... I am paying someone else to do it.....

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: grubbyliver on October 25, 2012, 04:55:46 AM
Quote
The PCB will not be available seperately....
I'll have to dip out in this case, can't spring for full kits right now sorry.
Some other time perhaps...

Cheers
Ben
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rellister on October 25, 2012, 01:39:35 PM
it's a mercy-less task....

I can imagine. The BOM contains all part numbers for "special" parts, and you also have the AE caps in stock.
The partial kit was fine with me...but I cant´t speak for everyone.



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 03, 2012, 04:08:06 AM
I can imagine. The BOM contains all part numbers for "special" parts, and you also have the AE caps in stock.
The partial kit was fine with me...but I cant´t speak for everyone.

The kits contain all the parts that go on the PCB.... 134 different items.... 396 items in total....  takes a couple of hours

They are now back in stock.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rellister on November 11, 2012, 04:05:11 PM
Hi,

My EZ1073 works fine, apart from a small hum when the eq is engaged. It gets stronger when selecting mid freqs, 360 and 700Hz in particular. When turning the eq off its quiet. At line level its somehow worse, present at a small level even without eq engaged. Could it just be toroid related? Could try moving the toroid off board. Also tried removing ground at xlr input/output, removing toroid ground and "mains safety earth" with no luck. Any suggestions from people familiar with this circuit? What I´m trying to find out if this is just a "normal" toroid hum or something not being earthed properly, maybe in the opamp A+B circuits.

Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on November 13, 2012, 07:29:52 PM
these builds are dead silent, so something got messed up.  double and triple check all your solder joints and wiring. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 15, 2012, 04:32:28 AM
They are generally hum free..... not sure where the problem lies with your unit. The only one I can think of which had hum issues had the XLRs wired in a strange way.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rellister on November 20, 2012, 04:55:25 AM
After thorougly checking solderjoints and wiring I tested the EZ1073 in studio today, strange, hum was not an issue here.
Maybe something to do with my home testing "environment", a mbox and a fridge on the same mains circuit.
It is still there on mid freqs, but so low it sits below the noisefloor. Compared it to a Amek CIB on some voiceover work, with a U87,  to my ears it sounds better.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on November 20, 2012, 06:29:57 AM
how do you hear the hum if it is below the noise floor?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rellister on November 20, 2012, 07:12:58 AM
Good question. I have a sixt sense that picks up hum, even if its coming from the other studio down the street ;)
No, maybe the term "noise floor" was used a bit unscientific...pre works fine!

Cheers
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on November 22, 2012, 01:58:58 AM
......pre works fine!

Excellent news... (they usually do).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tof on December 08, 2012, 05:37:49 AM
Hi collin just to tell you that your kit is awesome ,quick deliver  etc...Just brilliant!
 I started to solder yestreday and it went very easy to populate the board it's nearly done but on some pads (specially for some electrlitycs an trim pots)it's impossible to stick the solder on the pads!
I hope i didn't break those pads with the heat!
Do you have any tricks to fix this???
Thanks
Christophe
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on December 08, 2012, 09:00:29 AM
set your soldering iron temperature around 720-740F :-)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tof on December 08, 2012, 09:39:50 AM
I don't think it is a heat issue because ther's nothing on the pad to solder things together then the pins of capacitor or the trim pot move along the hole i hope i don't destroied the pads by the way it's funny because all the bad pads are on the - pins so maybe i can't solder them P2P and then solder them to the ground???
Thanks anyway for the advice
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: [silent:arts] on December 08, 2012, 09:49:11 AM
I don't know this PCB, but if you have issues with Ground connections: there might be a ground plane but no "termal pads"?
Heat the soldering iron up. the ground plane is eating the heat, making the tip too cold for the solder ...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 10, 2012, 08:39:21 PM
Damnit, i have been using mine for a long time but only through the Mic stage as i was not able to mix with it until recently. The Line input sounds thin and has a very low output. I've come to the conclusion that nothing beneath ~250hz gets in/out. I've desoldered the transformer to doublecheck that i didnt have it in backwards and i didnt...

Any ideas?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 11, 2012, 02:34:44 AM
Check that the transformer is actually getting both the hot and cold input signals...

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 11, 2012, 01:30:09 PM
Check that the transformer is actually getting both the hot and cold input signals...

Colin
www.audiomaintenance.com

The inserts on the console are unbalanced, i soldered a bridge between the hot and cold on line in just now but now it's even lesser volume :(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on December 11, 2012, 02:02:20 PM
I believe you're supposed to solder a bridge between Cold and GND, not Hot and Cold lol.   that's how TS cables are wired.  the Ring and the Sleeve are electrically connected, unlike with a TRS cable.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 18, 2012, 08:08:33 AM
I believe you're supposed to solder a bridge between Cold and GND, not Hot and Cold lol.   that's how TS cables are wired.  the Ring and the Sleeve are electrically connected, unlike with a TRS cable.

Yeah that deffinatley made a difference volume wise...but the sound is very thin sounding. The EQ makes some difference in the low frequencies but not alot and the sound coming in is not the same as coming out. High freq's are working properly though.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 18, 2012, 10:03:37 AM
That thing should sound fatter than a redneck at a country buffet. 
If the sound is thin with the EQ disengaged, start tracing the circuit from the input backwards.  See how big of a difference you have after the input tx.  From my exp. its rare to get a bad input tx, but it does happen.  (never seen a bad carnhill personally).  If your tranny is good, keep tracing back. 

As a test have you tried the line input? If so, same issue?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 18, 2012, 11:12:42 AM
Yeah it's with the EQ disengaged aswell as in, i tried the mic input by using a re-amp box which also turns the line signal into mic impedance and i noticed the same thing there. So i dont think it's the TX as it's on both of them. Any guide measurements?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 18, 2012, 11:40:31 AM
Are you on the 500 Series or the rack version?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 18, 2012, 05:08:21 PM
Are you on the 500 Series or the rack version?

Rack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 18, 2012, 10:17:06 PM
OK so your comment on the line in confused me. 
Youre normally using the LINE input, you have the issue; and you used the re-amp box to plug a line signal into the mic input (just trying to clarify for my own understanding)  If thats correct, break out the probe and scope and start tracing.  If you think its dropping everything below 250, put a 100hz signal through and trace to see where the signal goes bad or gets drastically lower on the scope, then reference the schematic in that area.  Colin did a great job of "departmentalizing" the different areas of this circuit in the color book.

Just out of curiosity, does the polarity switch seem to make any difference if switched? (and does it do what its supposed to?)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 19, 2012, 03:49:46 AM
OK so your comment on the line in confused me. 
Youre normally using the LINE input, you have the issue; and you used the re-amp box to plug a line signal into the mic input (just trying to clarify for my own understanding)  If thats correct, break out the probe and scope and start tracing.  If you think its dropping everything below 250, put a 100hz signal through and trace to see where the signal goes bad or gets drastically lower on the scope, then reference the schematic in that area.  Colin did a great job of "departmentalizing" the different areas of this circuit in the color book.

Just out of curiosity, does the polarity switch seem to make any difference if switched? (and does it do what its supposed to?)

Correct, i just moved the studio home so i'm gonna use it more for mixing instead of recording as i did in the old studio. Unfortunatley i dont have a scope, i might be able to borrow one though. Yes the polarity makes a difference, but only in level (as far as i can tell), when switched in it increases a bit in level, estimatley 2-3db.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 19, 2012, 09:36:45 AM
The polarity shouldn't effect level as far as I know, should just make + into - and vice versa in respect to the audio coming in.  Used for things like micing the top and bottom of a snare for instance where 2 mics or signals are out of phase, you flip that and put them in phase.  You're sure you have the inputs wired correctly now?  Also, make sure you didnt accidentally make a solder bridge anywhere, esp. on the greyhills.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 19, 2012, 09:59:42 AM
Sounds a bit like one of the input or output connections is no connected ... try connecting it to a completely different piece of balanced gear using different cables...just in case you have some sort of wiring oddity....... if it is the same then it may be an open circuit inside the box somewhere.... maybe the molex pins are connecting to the cable sheath instead of the wire core... seen that a few times.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 19, 2012, 03:56:09 PM
Been pointing around with the multimeter in the patchbays and everything is wired correctly. Been doublechecking the connections in the 1073 and it seems correct. Molexes are fine, but when checking the ones soldered to the board hot and cold is getting connection on both inputs and outputs, is that normal? Been looking around with a magnifyingglas but cant find any bridges and i've resoldered everything that could be a cold joint.

It's odd because when thinking back the mic input worked perfectly in the old studio, not the line though but now both act the same...
I'm gonna try and set up the mobile rig to see if i get any changes there but i need to solder some patch cables first.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: glimmertwins on December 20, 2012, 02:39:20 AM
Hey guys - see if you can help me out with something. I got my 1u EZ1073 put together a few months ago.  Everything appears to work correctly with the exception of two things:
  - when I touch the mic gain knob, I get a sudden jump in hum.
  - The mic side has a low hum(kind of sounds like steady wind actually) that I can't seem to figure out where it's coming from.  You have to crank everything to hear it, but it's pretty noticeable with all gains stages maxed out.  The hum does not exist when I switch to Line input.

 Any ideas where I can look or how I would go about troubleshooting that?  I admit to being a little green so any bit helps.  Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 20, 2012, 09:34:59 AM
WNS, I recall you miswiring the XLR connectors a while back.  Is it possible that you have a solder bridge on the actual XLR connector somewhere?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 20, 2012, 10:39:23 AM
WNS, I recall you miswiring the XLR connectors a while back.  Is it possible that you have a solder bridge on the actual XLR connector somewhere?

Yeah i've quadruple checked every connection i've made since then, no bridges, it's on the PCB part of the molex when the XLR's are unplugged. I am borrowing a scope today for an undecided future, hopefully i'll be able to figure it out.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 20, 2012, 10:42:15 AM
Dont need a scope to see where thats happening. Just set your multimeter to beep and see where its open.  Keep in mind that solder can work its way UNDER the molex header if you really globbed it in there, Remove the header all together and wire it directly... see what happens.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 22, 2012, 07:17:44 PM
Apparently the entire Mic/line switch is connected to ground? And in turn same with the Line switch...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 23, 2012, 12:13:02 AM
Check near your relays.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on December 29, 2012, 07:12:29 AM
Check near your relays.

There are no relays....

I am borrowing a scope today for an undecided future, hopefully i'll be able to figure it out.

Did you figure it out ?

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on December 29, 2012, 09:10:14 AM
Check near your relays.

There are no relays....

I am borrowing a scope today for an undecided future, hopefully i'll be able to figure it out.

Did you figure it out ?

Colin
www.audiomaintenance.com

No it's even worse now...Apparently hot and cold are connected to ground now, aswell as most points on the mic/line switch and line gain...I've been checking both top and bottom of the board and cant see a single bridge, even resoldered the switches just to see aswell as took away the molexes and soldered the leads directly to the board. I'm not getting any continuity between input and output except for grounding...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on December 29, 2012, 02:54:14 PM
Dont think you would get continuity btwn in and out.  Is it possible you mixed up the line/mic trafo mounting boards!  Also. There might be a solder bridge on one of the pins for the trafo connections. Either on the main board or one of the mounting boards. Bit of a pain to get em off with all those points. Did you test the xlrs with nothing conected to them?  Bridge might be IN the xlr chassis.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on January 02, 2013, 12:52:19 AM
Hey, just finished my 2nd unit.  Got a question, cause I dont remember running into this the first time through.  My 48V trimmer is only allowing me to get to about 45.1v.    Seems the trim pot needs to be turned multiple times for there to be a change in a tenth of a volt.  (possible i either got the trimmers mixed up or got a bad one?) or did i put a wrong resistor somewhere in the 48 v section)  Im putting in a mouser order in the AM, perhaps I should order one just in case.   The bias voltage section worked fine btw.  Other than that... Unit sounds amazing (as expected!)  You made this kit WAY too easy man... (not a complaint ;) )

EDIT.  i opened up my "good" unit and i have identical voltages up to the VR (so the recitifiers and torroid are good.  Im thinkin bad pot for sure now) double checked all the resistors and caps in the area, everything was correct in respect to values.  Im gonna order a new one tomorrow from mouser, that should take care of er.  I was also quite impressed withmyself in that I drilled out my own front panel for the thing and it actually fit!  (im aweful with measuring and cutting... im cut 5 times measure nonece) lol

NEW EDIT: yep bad trimmer, works fine now!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on January 02, 2013, 05:43:34 PM
I'm recording all week so i wont be able to work on it for a while but i know the trafoboards are right. I have however not tested the XLR's yet but i will do as soon as i have some free time.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 04, 2013, 04:44:16 AM
Did you figure out the problem yet ?

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on February 04, 2013, 01:59:48 PM
Mines been up and running and have already tracked with it.  Was a bad trim pot. :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 06, 2013, 02:03:04 AM
I see that Dan (Collective cases) has now started making metalwork for the 1U version.

http://www.groupdiy.com/index.php?topic=41963.0 (http://www.groupdiy.com/index.php?topic=41963.0)

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: yannsound on February 11, 2013, 07:43:57 AM
Hey guys - see if you can help me out with something. I got my 1u EZ1073 put together a few months ago.  Everything appears to work correctly with the exception of two things:
  - when I touch the mic gain knob, I get a sudden jump in hum.
  - The mic side has a low hum(kind of sounds like steady wind actually) that I can't seem to figure out where it's coming from.  You have to crank everything to hear it, but it's pretty noticeable with all gains stages maxed out.  The hum does not exist when I switch to Line input.

 Any ideas where I can look or how I would go about troubleshooting that?  I admit to being a little green so any bit helps.  Thanks!

I Got the same problem, I have checked all solders. Big Hum with Mic, No hum, when i switch to line...
Anyone have an idea?
Yannick
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: yannsound on February 12, 2013, 06:14:50 AM
I have rechecked all solders and now it works!!!

Very good sound as expected   ;D

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Antipodes-jag on February 13, 2013, 03:50:08 PM
Hi!

First post on this forum.

I've just finished my EZ1073, but I can't seem to get it running. Every time I connect the power, the fuse blows. I've looked for solder bridges and cold solderings as well as comparing it to pictures of some of your finnished projects, and I can't seem to figure out where the problem is.

Do you guys have any idea what I could have done wrong?

I'm kind of a noob, so probably it's something very obvious.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on February 14, 2013, 10:19:34 PM
U able to post pics of your iec/power trafo to the board and VRs? Pics can help a lot.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Rellister on February 15, 2013, 09:06:37 AM
Extremely approximately .....  The circuit takes about 120mA (at 24v).... 

Do you have the correct slow-blow fuse?



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: glimmertwins on February 18, 2013, 04:47:09 PM
Hey guys - see if you can help me out with something. I got my 1u EZ1073 put together a few months ago.  Everything appears to work correctly with the exception of two things:
  - when I touch the mic gain knob, I get a sudden jump in hum.
  - The mic side has a low hum(kind of sounds like steady wind actually) that I can't seem to figure out where it's coming from.  You have to crank everything to hear it, but it's pretty noticeable with all gains stages maxed out.  The hum does not exist when I switch to Line input.

 Any ideas where I can look or how I would go about troubleshooting that?  I admit to being a little green so any bit helps.  Thanks!

Anyone got some advice to set me on my way here?  Here is what I have done so far:

for #1 - tried to reflow solder points on the mic pot.  Again tested the continuity as I did on original install of all components to make sure I didn't have a cold solder joint somewhere.  No improvement to the original problem though.
for #2 - Read as many posts as I could about sorting grounding issues.  Well the word, "the dark arts" pops up a lot in these types of conversations...  I took another pass at revisiting my grounding scheme to make sure I didn't introduce hum somewhere there (star grounding) and I think my build visually looks the same as everyone else's I have seen.  I had the XLR casings wired together and then to star ground and thought that might be an issue so I removed it with no noticeable detriment to the sound but also no improvement to my original issue.

...I'm kind of stuck here - anyone got some suggestions of how I should approach troubleshooting these two issues.  The mic pre sounds fantastic but in a quiet room you can tell there is obviously a faint hum there when the mic side is engaged and when the gain knob goes up, it gets pretty obvious and of course introducing hum by touching the gain knob is problematic with metal knobs. Thanks for your help teaching me to fish so to speak.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: WNStudios on February 18, 2013, 06:43:20 PM
Did you figure out the problem yet ?

Colin
www.audiomaintenance.com

Have not had the time to check it and now i have to move the studio once again. But once i'm back up and running i'm gonna take a look at it with my dad and see if we can figure it out.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on March 07, 2013, 05:42:52 PM
I have read so many great things about this pre and have seemed to miss every time the diy stuff is available ,  well the sky's parted , the angels sang , the banker grumbled , Collin opened the door , Rupert blessed it, I am just ecstatic to build a pair, hope two more follow .

getting there....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on March 25, 2013, 08:19:54 AM
Well this is about as far as I can get this time home, I work offshore and gotta leave monday,  did not get my cases yet from collective cases, maybe next time I am home? anyway, some notes on my build.
Hits:
This has to be the most well thought out pcb, I have ever worked with, all caps,  + face the same direction, transistors...ect, even the output wiring ….very cool.
Off board wiring is next to nothing, just b+ and xlrs.
The way the gain stages and op amps are screened on the pcb,
the grayhills switches and all resistors on the pcb, that my friend was truly brilliant.   
misses:
my only  complaint is the pre formed and cut resistors, pre formed is ok, but cut? Turned something I love to do into a huge pain, some leads  were cut too short,  and none of them had enough lead to bend and hold them in place, I tried many things, but it came down to one resistor at a time and took a whole day on just the resistors, cant stress enough Collin, just send uncut leads on resistors...
Wishes:
I wish sw-1, for 600r or unterminated, had holes so one could mount a switch.
In the op amp area, c 23, 23,27 and c39,48, and 50, I wish had wider hole spacing for alliterative cap options.
????
I wonder what the unmarked holes are for around the lo-z switch and input mic transformer were for?
Flux capacitor connection? SSSNC? Super secret sonic nirvana, connector?   
HFE, it is said that the first transistor in gain stages and op amps is selected for an hfe with a gain of 600 or more, testing all the the bc550C I had a range of 450 to 550hfe, “cheep dmm test”, and a lot of 50 bc547c I had 425 to 590, with only one in 50 came in at 650.....
is this critical for low noise ? Am I being stupid ???
geoff tanner has said that the high frequency response with the eq engaged drops about -4db @ 20khz, due to roll off capacitors in the two inverting sections? Is this the op amp sections ? C 23 and c 40?
anyone try this mod, [reducing to 10 pf or removing the cap completely]  even notice it? Is this just cork smelling with an o-scope?

I have kind of copied  ruperts ideas here in  caps where I could,in the signal path  transposing from neve schematic to the ez1073  has been fun and a learning experience.

Sorry for the long rant, kinda of excited …
HYS
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on March 25, 2013, 01:19:43 PM
It is easier to fit the pre-bent components.... either use an assembly frame (cost about 150 USD).... or just put the resistors in... lay some sponge over them... lay a sheet of wood over the sponge and flip it all over (that is basically all you are doing with an assembly frame anyway).... bending the legs is not a good idea ....

Fair point about the SW1 switch.... but you could just wire your switch to the phase switch and resistor.....

The unmarked holes are vias not connection holes.

1073's are noisy and distorted anyway.... I wouldn't get too worried about HFE values.... we don't select and no-one ever has an issue with noise floor.


Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on April 12, 2013, 10:52:27 AM
Cases are now available from Dan Deurloo at www.collectivecases.com ... they are not shown on the website but they are available so just email him.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bigbeaty on May 02, 2013, 09:17:47 AM
Hi all,

Long time lurker, first time poster...

I know that it's already been said, but these units are stellar! Thanks Colin - my two units have added more to my studio than I could possibly have imagined...

If , like I was, you're contemplating the ez1073 as your first major build, I'd say go for it! It's a very rewarding experience, and Colin's colourbook makes building a doddle - Almost like a grown up Lego! (technics of course...)

Seriously, you won't regret it... The EQ is incredible, which took me by surprise, as I initially just fancied a couple of neveish preamps. My drum bus now pops with life and character, and acoustic guitars reach out of the speakers with incredible depth and tone; I'm a very happy man  ;D

Cheers,
Richard
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on May 04, 2013, 07:22:53 PM
there done, and just sound, uhh fatter than a redneck at a country buffet?  muhahaha
first one fired right up, and voltages were exactly where collin said they would be, brought bias up to 130ma from 82ma, plugged i into the computer and the worst noise,
I had my  rme interface  pre's running at 60db, yikes, turned that off and all is good, and didn't fry my rme pre, 
second unit, all voltages as before, bias however was at 400ma and change, it was a bad  moto 2n3055, swapped that out and it biased right up...
so 2 more ez1073's are a running in this world....
I did add the unterminated and 600 olm switch to the rear of the panel,  cases are collective, knobs by cathedral pipes....
few 312s up next

thank you collin

HYS
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 07, 2013, 09:26:14 AM
They should sound like the 500 series version:

http://www.youtube.com/user/Audiomaintenance

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on May 07, 2013, 12:21:10 PM
they do sound great, the line in is a ton of fun to pump tracks through .... eq is very musical...
and truly the best pcb layout I have ever seen...
 just love it, thanks again collin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on May 13, 2013, 02:21:14 PM
Finally gotten the chance to build my 1073, I just have 2 questions, does the Voltage Regulator and 2N3055 require any thermal paste or any insulation of any sort? Or is it safe to just clip it on with the clip fastener and place the 2N3055 on the board freely touching?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on May 13, 2013, 08:10:50 PM
I used themal paste , and the clips , everything is running fine.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on May 14, 2013, 12:47:24 AM
I used themal paste , and the clips , everything is running fine.

on the Voltage Regulator and the 2N3055?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on May 14, 2013, 09:52:28 AM
I did use it on both, the heatsink on my 2n3055 is on top, not the one that goes
under, I would not use paste on that type.

I also used A smaller size bolt on the 2n3055, after reading this thread a few times ,
Did not want to short that area to ground ,  no insulators were used , 

Everything works great,   left em pluged in for 3 days and no issues .
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on May 14, 2013, 12:46:47 PM
I did use it on both, the heatsink on my 2n3055 is on top, not the one that goes
under, I would not use paste on that type.

I also used A smaller size bolt on the 2n3055, after reading this thread a few times ,
Did not want to short that area to ground ,  no insulators were used , 

Everything works great,   left em pluged in for 3 days and no issues .

Ok never mind the voltage regulator - I know that needs paste now.

the 2N3055 - did you use any thermal paste or insulator between the PCB and underneath of the component? - From what I understand you are saying that you also used thermal paste on the between the PCB and the 2N3055?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on May 18, 2013, 08:13:51 PM
No nothing between the pcb and 2n3055 , pull up a data sheet, and its pretty clear why you would not do that. Look at the pin out. Not trying to be smart , but I would not short all pins and expect the thing to work, just work off Collins color book, it works perfact.
My heat sink sits on top, paste is between transistor and heatsink.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on June 07, 2013, 05:17:15 AM
Thanks for your reply, I understand now. I have my case now and every thing soldered I just need to wire the unit up, do I need to use shielded cable for the Xlr to pcb connection or can I use standard hookup wire, what gauge wire, does it need to be twisted, I also see a few units linking each connection to the earth, do I need to do this too? A bit confused in this area
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on June 08, 2013, 10:32:28 PM
use shielded wire.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chipss36 on June 09, 2013, 10:16:51 AM
I would like to help but am 1000 miles from home , offshore and working right now, but everything you need to know is in the color book,  a layout for 120 and 220 vac , if your still stuck there are plenty of pics in this thread, I am very fond of mogami console cable for shielded wire, makes for a very neat clean wire runs, but there is so little wiring needed for this kit, an old mic cable would work  in a pinch,
Get it running , you'll be amazed, just a killer pre/eq.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 10, 2013, 11:10:55 AM
You need to use screened cable for the XLR connections... for the mains I would probably just find an old length of mains flex (0.5 - 1.0 sq mm) and strip the 3 wires out of it... that way you have the correct colours.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on June 12, 2013, 02:33:13 PM
Thanks for the replies guys - appreciate it, I used shielded balanced Microphone cable, and I cut up an old power cord I had laying around.

I apologize for the n00b questions, but this is my first build,

I have everything good to go except for a power switch, I know this is a simple question but could some one please give me a part number for a power switch, Ive searched all the posts and come up with nothing, Ive searched mouser and I understand it should probably be 240V+ 5A+ but when it comes to ON-OFF / (ON)-(OFF) / (ON)-OFF SPST/SPDT etc Im lost. Is there a part number you could please give me? Or an explanation. Thanks again

(The colour book does not mention any thing about any of the questions I have raised)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on June 12, 2013, 02:42:32 PM

The best option is a double pole single throw switch so that both live and neutral lines are disconnected when the switch is off.

You also need to ensure that the switch is rated for mains voltage.  Not all of them are.

The hardest bit is finding one you like the look of that fits your project...

All these will work :

http://uk.farnell.com/marquardt/1552-3102/switch-dpst-16a-250v-black-i-o/dp/7892527

http://uk.farnell.com/arcolectric-switches/c1350xbaaa/rocker-switch-dpst-black-red-i/dp/273247

http://uk.farnell.com/marquardt/1935-3112/rocker-switch-lamp-dp-100/dp/7892489

http://uk.farnell.com/lorlin/rms1130/rotary-switch-dpst-pcb-terminal/dp/1360551

etc
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on June 13, 2013, 01:35:51 AM

The best option is a double pole single throw switch so that both live and neutral lines are disconnected when the switch is off.

You also need to ensure that the switch is rated for mains voltage.  Not all of them are.

The hardest bit is finding one you like the look of that fits your project...

All these will work :

http://uk.farnell.com/marquardt/1552-3102/switch-dpst-16a-250v-black-i-o/dp/7892527

http://uk.farnell.com/arcolectric-switches/c1350xbaaa/rocker-switch-dpst-black-red-i/dp/273247

http://uk.farnell.com/marquardt/1935-3112/rocker-switch-lamp-dp-100/dp/7892489

http://uk.farnell.com/lorlin/rms1130/rotary-switch-dpst-pcb-terminal/dp/1360551

etc

Thanks Rob - That explains the DPST

2 Questions:

1. From what I understand the Voltage Rating will need to be 250VAC or more (EU) and 1A or more to be suitable for mains voltage, is that correct?

2. I'm still not sure what the difference between ON-OFF / (ON)-(OFF) / (ON)-OFF / ON-(OFF) is?

Regarding style, I need a Toggle Switch as Dans Case has a hole with which the switch needs to fit through. (Im sure with the two questions above answered I will be well on my way to power switch purchasing for this and the next couple of projects)



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on June 13, 2013, 05:10:39 AM

1 - it depends on the project.  Yes - 1A should usually be enough, and it is in the case of this project.

2 - I'm not sure about what the brackets indicate there either.  Where did you read that?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on June 13, 2013, 06:30:08 AM

1 - it depends on the project.  Yes - 1A should usually be enough, and it is in the case of this project.

2 - I'm not sure about what the brackets indicate there either.  Where did you read that?

Great, thanks! that clears that question up for me, I understand some other projects may require a higher amp rating but I think 5A is a safe bet generally speaking.

The brackets are indicated on the mouser site - If you select the "switch function" menu you will see the options presented there.
 
http://uk.mouser.com/Electromechanical/Switches/Toggle-Switches/_/N-5g2j?Keyword=Electromechanical+Switches+Toggle+Switches&FS=True

Farnell Also has these available options under "Switch Operation"

http://uk.farnell.com/toggle_toggle

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jona on June 17, 2013, 04:39:48 PM
hi all,

i finished my first ez1073 a few weeks ago and everything worked great.. until yesterday. as soon as i engage eq i do not have output signal anymore. if i disengage eq again, there is output signal again. i measured the output between hot and cold with all gain controls at zero, eq bypass, and 1k sine 0,775V at line input. meter shows 0,558V. if i measure between hot and ground meter shows ca. 0,136V, between ground and cold  ca. 0,417V. thats not normal as well, isn't it ? can somebody help me troubleshooting ?

thanks..

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: JW on June 19, 2013, 11:14:05 AM
Hey folks,

I saw Colin has the full kits back in stock again. I don't have any experience with ordering these. Are people in the U.S. generally being charged customs? Trying to factor that into the cost.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on June 20, 2013, 10:09:23 AM
As long as you dont get stuffed shipped by TNT. lol. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: JW on June 20, 2013, 12:25:50 PM
Hmmm

Can you explain that? I'm asking about customs fees. Bad experience w/ TNT? I don't think that's how Colin sends them. Maybe I'm wrong though.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on June 20, 2013, 01:54:34 PM
Let's put it this way, TNT has been reported to the DA in my area for numerous fraudulent activities surrounding "duties" and import "fees".  There's a reason that TNT has an F grade with the BBB.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dandeurloo on June 20, 2013, 04:59:55 PM
TNT tried sending some of that crazy stuff on me as well.  I just didn't pay it.  It's like they are fishing for suckers to give them free money.  I maybe would have paid it if it was 30 bucks but not 250!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jona on June 21, 2013, 06:00:38 AM
if disengage eq and dial all gain controls to zero and put a 1k sine in the line input and adjust output level of the sine generator that my DMM reads 0,778V between hot and cold at line in. (if i measure between scn and hot or scn and cold get approximately 0,389V. thats how it should be so far). when i now measure the output of my EZ1073 between hot and cold i get 0,590V and between scn and cold 0,389V / scn and hot 0,191V. where are the 0,200V gone ?
 i replaced the output tranny, but it´s the same with both output transformers.
if i measure between yellow and brown (input VTB1847) meter shows 0,348V. if i multiply this with 1,7 get ca. 0,590V and this is what i read between hot and cold on the output. i think there must be a very easy answer to my question, but i don´t get it.
it would be very cool if someone could help me with this.. i really want to understand this.


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on June 22, 2013, 07:01:24 AM
Well guys, this was my first project ever..... and it works!! :D

powered the unit up today, the first good sign was the red LED lit up, tested the terminals and R26 all readings were as per the colour book, adjusted the trims correctly and now it is working in my studio.... wow!?

Thanks so much to everyone for putting up with my n00b questions, at least now they are available for others who may come along and search for the same questions.

And most of all thanks to Colin, who has provided us with this superb project....

Just 1 question, when the EQ section is engaged and the High Pass Filter is set to off, then no audio passes through, if the High Pass is set to 50> then the signal becomes audible - is it supposed to be like this?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 22, 2013, 07:36:36 AM
..... when i now measure the output of my EZ1073 between hot and cold i get 0,590V and between scn and cold 0,389V / scn and hot 0,191V. where are the 0,200V gone ?

You cannot measure between a floating transformer terminal and ground.... you will only get a sensible reading between the transformer terminals (unless one end of the transformer winding is attached to a fixed voltage (eg ground))....

... when the EQ section is engaged and the High Pass Filter is set to off, then no audio passes through, if the High Pass is set to 50> then the signal becomes audible - is it supposed to be like this?

No.... there is something wrong.... if it is set to "off" you should get full bandwidth signal.

Next projects (Pultecs) are easier than this.... just built an ezP-1A in 1 hour and 51 minutes from a blank PCB to a fully finished unit.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on June 22, 2013, 07:48:49 AM
No.... there is something wrong.... if it is set to "off" you should get full bandwidth signal.

Next projects (Pultecs) are easier than this.... just built an ezP-1A in 1 hour and 51 minutes from a blank PCB to a fully finished unit.

Colin
www.audiomaintenance.com

Do you have any clues as to what it may be? I mean, everything else seems to be fine except this? Possibly the pin in the rotary switch placed incorrectly? - I think I may have called it - I have 6 Turns on my High Pass, I think there should only be 4?

** Problem solved! - I had turned the High Pass Switch when inserting the pins because it was giving trouble when trying to insert them - My gosh, what a task it was to get the pins out!  So it was switching to the incorrect positions, Plugged it back in and the unit is working 100%

Looking forward to the Pultecs! :D

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 22, 2013, 10:47:01 AM
Getting the pins out of the Greyhill's can be a struggle..... but you can use a magnetised screwdriver to encourage them to pop out as they are made from steel...

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on June 23, 2013, 09:33:12 PM
Hi EZ1073 builders,

I have built 6 x EZ1073 and all have a small problem with hum. I've spoken to Colin a little about this but wanted to get some other thoughts as I'm sure Colin is also very busy.
If I plug it into my system (fireface 800) and then apply 6db input gain and 6 db output gain and turn my headphones up full I can hear hum when the EQ is engaged. It is not there with the EQ out. Also the line in has a much smaller amount of hum but more than the mic in. The mic amp on it's own is totally clean.
I was wondering if anyone can confirm that this is "normal" for these preamps.
I have been meticulously over the circuit board on at least one of the units and can find absolutely nothing wrong and all functions seem to work properly and all the units are the same with regard to hum and performance. Also I have the transformers off the board at the back of the case and a mains filter installed
The amount of hum is not loud enough to be a problem in general use though if recording something with a wide dynamic range or if allowing a lot of headroom and the possibility of compression later it could be a problem. It would definitely be better if it wasn't there.
Also if anyone else has this same hum or has tried running from an external or different power supply has it helped?

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on June 24, 2013, 09:13:55 AM
Hi Again,

Ok I've done some measurements.  I've just realized that the RME digicheck software has a convenient noise measuring function. So not as bad as I thought.
So the figures I get are into the line in set at +4 mic level +15 (input not shorted, no mic connected) output trim on full level. When the EQ is engaged all switches are off and gains set to zero.
EQ out  =  -99.7db  (RMS +3  20hz -20khz)
EQ in  =  -92.6    (RMS +3  20hz -20khz)

so about 7.1 db more noise. It sounds like mostly hum.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: alex81 on July 01, 2013, 08:31:26 AM
Hello all,
i received 2 ez 1073 kits.
i started populating the 2 boards with all resistors, capacitors and transistors.
I stopped there, just before the voltage regulators step in ez1073 colourbook.
I had a lot of trouble trying to solder those components... THE SOLDER DOESN'T WANT TO STICK ON THE PADS, especially the small ones...
i don't know what to do, so many of my solder joints are bad looking... i'm 100% sure my builds are not going to work

I really don't understand.
I use Antex sw25 25watts solder iron with 0,55mm tip and good quality solder Sn62 Pb34 Ag2 with flux 0,8mm.
I tried with other type of solder, no change...
I did 2 Hairball Audio 1176 kits before and never had this kind of problem.
I thought it would be fun to build the ez1073 and it has become a nightmare.
The only solution i see is to order 2 new PCB with resistors (with uncut legs because some of them were really ttoo short), capacitors and transistors, buy a new soldering iron and try again.
I'm lost

Please help me guys
Regards

Alex


I had some problems with cold solder joints on the bigger capacitators and on the trimmers solder joints.
The solder joints for these parts on the PCB are quit small and Im not sure if its my solder point being to wide. Tried a smaller tip but didnt get much better.
Anybody else had the same problems? Or anybody have some helping ideas?
Hi Colin, love this project, but I also have some annoying problems with the pads. Solder simply refuses to stick to the small ones. Never experienced this before.  Higher tempereature doesnt help. Should I use different solder?

Cheers
Rune

Edit;
I discovered it´s all about technique, using a pointy tip, more heat, and sliding the tip forward while applying solder solved it;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on July 01, 2013, 09:52:43 AM
Pads that are connected to larger ground planes are going to need a bit of heat to get the solder flowing over them.  I use a 40 watt iron set to about 2 o'clock on the temperature dial (4/6).  Some of the larger ground areas i may have had to bump up the heat a bit to get it flowing properly.  Also, a conical tip will work better (IMO) than a chisel tip.  Dont know what you're using.  But mine looks like a finely sharpened pencil.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: alex81 on July 01, 2013, 02:34:37 PM
The ground plane was definitely the problem. My soldering iron was not adapted (even though it worked with other kits such as 1176).
The tip was too small (0.5mm) and conical thus not heating the pads enough
I went to the electronic shop and the guy there told me to buy a larger tip (2,3mm) and chisel
I went back home, tried again I soldered all the components left without any problem !
Now i have to look for all the bad solder joints on resistors and capacitors and do them again.
I really hope it's going to work...
I also hope i have not damaged ant component

Pads that are connected to larger ground planes are going to need a bit of heat to get the solder flowing over them.  I use a 40 watt iron set to about 2 o'clock on the temperature dial (4/6).  Some of the larger ground areas i may have had to bump up the heat a bit to get it flowing properly.  Also, a conical tip will work better (IMO) than a chisel tip.  Dont know what you're using.  But mine looks like a finely sharpened pencil.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on July 02, 2013, 04:23:18 AM
I use a Hakko FX-888 with the smallest tip size.  I keep the temperature around 750F and I've never had any of the problems you've described.   Get a better soldering iron and stick with the small tip size.   No point using a sledge hammer when you need a jeweler's screwdriver...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on July 02, 2013, 03:05:48 PM
Gonna +1 Chuck on this.  larger and chisel tips are not really good to work with for this kind of stuff, especially if you have tiny pads like on the greyhills. 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on July 03, 2013, 03:52:32 AM
lol it's called the "like" button
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on July 03, 2013, 02:15:58 PM
Its called IM NOT GIVIN' YOU A LIKE!!  :P :P :P :P :P ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: alex81 on July 04, 2013, 06:12:12 AM
Actually, my tip is not that large.
I think chisel is not the right word in english.
The contact point with the board is actually about 1mm (see picture attached)
I finished soldering all the components without problems and repaired all bad solder joints from 1st attempt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on July 05, 2013, 12:44:57 AM
Yes, that's a chisel tip.  Conical looks like a sharpened pencil.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: alex81 on July 08, 2013, 01:15:33 PM
I just finished the 2 units !
I did the calibration and they both seem to work.
Mic inputs are ok, eq's ok, switchs ok
I didn't checked the line inputs, i'll do this tomorrow
I wait for the knobs from Cathedrale Pipes
Thanx Colin for the kits
I start a recording session next week so i'm gonna try them !

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: exspence on July 21, 2013, 09:57:52 PM
Hey,

 Just powered up my ez1073 for the first time and... i'm getting some weird numbers.  J5 & J6 read .583 Volts.  J3 & J5 read 56.6 Volts. The LED isn't powering up, but it appears that the ac/dc conversion is ok. Any ideas on where I went wrong?

Spence
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on August 20, 2013, 01:15:18 AM
The trim pot on the front panel turned all the way down = no output...    Why would you mess with what's included in the kit?  Colin knows his stuff, and chose accordingly...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 20, 2013, 02:05:37 AM
The trim pot on the front panel turned all the way down = no output...    Why would you mess with what's included in the kit?  Colin knows his stuff, and chose accordingly...

Hi Chuck,


Not questioning Collins work at all. I just want to be able to drive the pre without clipping my converters. Collin has stated earlier in the thread that it's a 9.5db trim and if you wanted to be able to use it as a complete attenuator a few resistor values would need to be changed.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on August 20, 2013, 04:09:21 AM
Just a guess, but R134, R135 and R149 are all that sit between the EQ output and the final amplifier stage, so i'd start looking there.  the schematic is near the end of the colorbook on colin's site for this build.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 20, 2013, 05:36:57 AM
Just a guess, but R134, R135 and R149 are all that sit between the EQ output and the final amplifier stage, so i'd start looking there.  the schematic is near the end of the colorbook on colin's site for this build.


I'm thinking the same thing. I think R134 and R135 are going to need to be changed but I just don't know what to. Hopefully somebody with further experience can chime in and comment further

Thanks!
Aaron
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 20, 2013, 06:53:43 AM
The 10k pot and R135 aren't in the original circuit. R134 is. I guess they are set up that way so the output and input impedance of the two stages stays reasonably constant. So you would need to change the pot and R135 to get the same effect but with more attenuation.
It sounds like it would be a bit pointless as you can either turn the gain down on the input or just put a fixed attenuator built into an xlr on the output, much easier and won't effect the circuit. Also that way you get to drive the output stage which will be part of the desired sound if that's what you are after, rather than just driving the input stage.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 20, 2013, 08:15:43 AM
The 10k pot and R135 aren't in the original circuit. R134 is. I guess they are set up that way so the output and input impedance of the two stages stays reasonably constant. So you would need to change the pot and R135 to get the same effect but with more attenuation.
It sounds like it would be a bit pointless as you can either turn the gain down on the input or just put a fixed attenuator built into an xlr on the output, much easier and won't effect the circuit. Also that way you get to drive the output stage which will be part of the desired sound if that's what you are after, rather than just driving the input stage.

cheers  Greg


Thanks Greg,

What type of xlr attenuator would you recommend? I'm just worried about impedance mismatching, and aversely affecting the output transformer (possibly feedback or some type of impedance loop) Forgive me, I'm pretty new to building gear.

Aaron
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 20, 2013, 08:53:14 AM
well I'm not an expert either, but I think if you build a 600 ohm attenuator you should be fine.
You can build it into an XLR to XLR adapter. It just consist of a few resistors.
Here's a calculator here
http://www.nu9n.com/tpad-calculator.html
and an idea on how to build
http://www.uneeda-audio.com/pads/

you could always wait for another expert to confirm. I would just go for smothing around 10 db then 20 db. I've never built one actually but was planning on it.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on August 20, 2013, 12:01:23 PM
The trim all the way down doesn't turn the volume "off" unless I built something wrong on both of mine.  It's there for when you need to either boost or cut a little bit between steps.  The center position is 0 meaning unattanuated, you can go up a little or down a little, but not off.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 20, 2013, 11:23:30 PM
The trim all the way down doesn't turn the volume "off" unless I built something wrong on both of mine.  It's there for when you need to either boost or cut a little bit between steps.  The center position is 0 meaning unattanuated, you can go up a little or down a little, but not off.

Yes, I'm wondering what resistor values would need to be changed to make it around 30db of attenuation instead of 10db. I have very sensitive converters
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 21, 2013, 09:11:59 AM
Hi everyone,

Sorry to spam the thread with questions but I have a few more questions. I'll be building 2 EZ1073's. I went ahead and ordered the knobs (the same ones Neve uses) costed a cool $150 ouch! I'm about to order 2 kits from Collin. Here's my questions...

1) I've seen pictures of peoples builds but I'm not sure how they are doing the power switches, there's not really any detailed pictures on the back of the unit for me to follow. Regarding the switch fuse and IEC could someone give me a link to the correct parts to order? I just want to make sure they will work with my collective cases from Dan for the EZ1073

2) I read earlier that 5mm standoffs will be good for the case. Can anyone point me in the right direction for the standoffs and screws as well as how many to order. Also if there's anything else that needs to be ordered not included in the case let me know. I want to have everything here so I can build right away.

3) Lastly, what type of solder would be good for this build? I would prefer to use lead free solder, will silver solder work okay? Is there a better formula you guys would recommend?


Thanks very much everyone, I'm very excited about this being my first build. I used to have 1084s but recently had to sell them. I have a feeling these are going to make me feel right at home again.

Cheers!
Aaron
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on August 21, 2013, 11:08:45 AM
Quote
Yes, I'm wondering what resistor values would need to be changed to make it around 30db of attenuation instead of 10db. I have very sensitive converters
Not sure what that means, everyones converters are sensitive. But if you just leave the gain at the lowest it will go and use the attenuation, unless you're sending a recording of a jet taking off or some ordnance going off, not sure why you would need 30db of attenuation. 

Any properly rated spst switch will work (depending on where you live will depend on value but since you can use a 250v min rating anywhere shouldn't really matter)
Look for nylon standoffs, I used ones that have an adhesive back on them (like stickers) really work well.
I use really fine silver bearing solder on almost all my builds.  People look down upon lead free solder, not sure why, but i've never used it.  Rosin core solder tends to leave a residue behind more than other solder i've used. Just be neat about everything and clean your board properly.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 21, 2013, 01:18:52 PM
Quote
Yes, I'm wondering what resistor values would need to be changed to make it around 30db of attenuation instead of 10db. I have very sensitive converters
Not sure what that means, everyones converters are sensitive. But if you just leave the gain at the lowest it will go and use the attenuation, unless you're sending a recording of a jet taking off or some ordnance going off, not sure why you would need 30db of attenuation. 

Any properly rated spst switch will work (depending on where you live will depend on value but since you can use a 250v min rating anywhere shouldn't really matter)
Look for nylon standoffs, I used ones that have an adhesive back on them (like stickers) really work well.
I use really fine silver bearing solder on almost all my builds.  People look down upon lead free solder, not sure why, but i've never used it.  Rosin core solder tends to leave a residue behind more than other solder i've used. Just be neat about everything and clean your board properly.


Thanks sr

Put it this way... On my 1084's I had to turn the output fader almost all the way down so I didn't overload my converters. I want to buy better converters when I can afford it but for now I'm gonna have to attenuate the signal somehow. I don't think it would be very hard to do... But I'll wait for Collin to chime in on that.

For the spst switch will I need to drill a hole in the back of the case for the switch or make a cut out? I'm not sure if dans case has this already but either way I'm sure it won't be a problem. Also what silver solder do you use. I might as well use exactly what you're using since you can confirm it works well.


What do you think about this? It's filtered and has a switch and fuse. Could possibly fit sideways
http://www.alliedelec.com/search/productdetail.aspx?SKU=70133406#tab=specs
With this fuse
https://www.divinelighting.com/gdc-100ma-slowblow-fuse-t100ma-250v-gdc100ma-gdc-100-ma-p-635.html
If you guys are sure a 100mA slow blow is enough!


Many thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tommypiper on August 21, 2013, 02:10:28 PM
Guys, where to get these PCBs?  Has Gustav quit them?  (I'll ask him in meantime, but in case anyone knows additional info, please let us know.)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on August 21, 2013, 02:10:37 PM
Pretty sure dan has the part numbers listed in his thread for the case.  The one youre looking at at allied is too big.  The one that he normally uses is more like
http://www.mouser.com/Search/ProductDetail.aspx?R=161-0717-187-Evirtualkey11180000virtualkey161-0717-187-E (http://www.mouser.com/Search/ProductDetail.aspx?R=161-0717-187-Evirtualkey11180000virtualkey161-0717-187-E)

(PS allied is WAY over priced)

Radio shack .022 (i think)  silver bearing solder, its like hair lol.

For my two units i drilled a hole to the right of the trim knob below the Power LED and that did it for me power switch wise.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on August 21, 2013, 03:22:19 PM
i got a problem with 2ez1073 (!) i just built.
one (A) has no sound at all just a buzz.
the other (B) works on line (+eq) but mic gives a buzz also (no mic signal just noise)

dam ...  :P
they are racked so i have to dimount them all to check again any solder problem
but i was wondering if you had any way to start testing these
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on August 21, 2013, 03:53:37 PM
Trace the schematic and follow the signal from input.  If its a voltage issue, follow the voltage from the PS section through.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on August 21, 2013, 04:55:44 PM
m... :) that's why when i do a DIY it has to work right away i really don't have the skills to do that :p
it will take me month only to know what to "trace" anyway thx for help ;)
Title: PCBs
Post by: tommypiper on August 22, 2013, 12:28:31 AM
EDIT:

Are the PCBs no longer available? 

EDIT:
I found it in full kit form on AML website.   :)

EDIT 2:
I see Colin's reply below now too... Thanks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ubxf on August 22, 2013, 01:15:34 AM
Hello Tommypiper,
i had an email exchange with Colin regarding another project of his and asking the same question.He said may be in the future but not right now . So it might be the same for this one
francois
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 22, 2013, 05:20:13 AM
R134 (5k1) effectively sets the bottom of the trim pot signal level....just imagine if it were zero ohms, then when the pot was fully counter-clockwise the wiper would be attached to ground (through the zero ohm link) and there would be no signal going into the stage 3 amplifier.... so for 30dB attenuation it would need to be somewhere between 0 Ohms and 5k1.... I'll let you calculate that !

Usually converters have the ability to select input sensitivity ?

Mains switches should be Dual Pole.... you should switch the live and neutral.

Gustav has never made the PCB's for the ez1073 project (cannot remember why)... they are only available as part of the AML-17-020 kit.... we do still currently sell that kit (but that may change in the future).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 22, 2013, 05:28:28 AM
R134 (5k1) effectively sets the bottom of the trim pot signal level....just imagine if it were zero ohms, then when the pot was fully counter-clockwise the wiper would be attached to ground (through the zero ohm link) and there would be no signal going into the stage 3 amplifier.... so for 30dB attenuation it would need to be somewhere between 0 Ohms and 5k1.... I'll let you calculate that !

Usually converters have the ability to select input sensitivity ?

Mains switches should be Dual Pole.... you should switch the live and neutral.

Gustav has never made the PCB's for the ez1073 project (cannot remember why)... they are only available as part of the AML-17-020 kit.... we do still currently sell that kit (but that may change in the future).

Colin
www.audiomaintenance.com

Thanks Collin! That pretty much answers all my questions. I will document my build and report when I'm up and running. Or if I need help (let's hope not!)

Cheers,
Aaron
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 22, 2013, 05:44:28 AM
One last question,

If I do end up changing R134 to a lower ohm resistor, what wattage would I need to get? I will likely just stick with the originals but if I end up wanting more attenuation I will probably just experiment and put some 2K resistors at 1% for both units and that should be plenty of resistance.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on August 22, 2013, 09:11:33 AM
Hi
I started to build this kit and now noticed that the knobs i purchased for it does not fit the pots. Could anyone say an example of knobs that would fit really well? (As cheap as possible) :p
Also the lock nuts that was supposed to be for the output transformer won't tighten it up totally, obviously because of the lock nut.. Anyone else had this problem?
And one last question: What nut size and screw size would I need for the standoffs?

All the best
Isak
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on August 22, 2013, 11:35:45 AM
i'm back to my 2 units.
one is working now !  ;D it was the one where the line level + eq was ok.
i figure out that the connectors i used for the XLR was not great. so i sold the wire directly to the pcb instead of using this and now it works fine.

but the second unit is still dead. i also sold the wires of XLR directly to PCB but i still have nothing just a constant tone buzz.
But i found this :
R23 = 12R is burned  :-[
i don't know if i maybe put a wrong value here .. i can't read it anymore but there's little chance because i build the 2 units side by side and i would have ended with an extra 12R and a value missing for another place.
i checked the other side of PCB no chance i did a mistake soldering here there's lots of space.
5min after unplug the VTB1847 is still very hot maybe it's damaged ?
all wires from VTB1847 are in right position.
https://lh5.googleusercontent.com/-nSV-dAtQcVE/UhZCrWJGH5I/AAAAAAAABOA/Pvg3FFAdGRQ/w958-h639-no/IMG_2285.jpg (https://lh5.googleusercontent.com/-nSV-dAtQcVE/UhZCrWJGH5I/AAAAAAAABOA/Pvg3FFAdGRQ/w958-h639-no/IMG_2285.jpg)

something else bu't im not sure
the VTB9044 has a strange look one leg looks dark as if there was some heat. but i don't know if it was like this at the origin or if it happened during the problem.
https://lh5.googleusercontent.com/-1lLZFVmyi-A/UhZCreNqVqI/AAAAAAAABN8/3SPTCO-BcFM/w958-h639-no/IMG_2286.jpg (https://lh5.googleusercontent.com/-1lLZFVmyi-A/UhZCreNqVqI/AAAAAAAABN8/3SPTCO-BcFM/w958-h639-no/IMG_2286.jpg)
i can replace that resistor but do you guys know if i have to check other components around that could have been damaged by this ? or do i have to change it to find out ? if the problem comes from something else then it might burn again right ?

thx for help
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 22, 2013, 01:07:46 PM
I had r12 overheating on one of my units at first. I think it turned out one of  the power transistor heat sink bolts was shorting to ground. There isn't much clearance there.
But could be caused by anything that draws to much power.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tommypiper on August 22, 2013, 01:33:10 PM

Gustav has never made the PCB's for the ez1073 project (cannot remember why)... they are only available as part of the AML-17-020 kit.... we do still currently sell that kit (but that may change in the future).

Colin
www.audiomaintenance.com

Thanks!  If you do offer just the PCB, I'd be interested.  I'd prefer to get just the PCB, or with perhaps the inductors and possibly one or two transformers and such.  Thanks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on August 22, 2013, 01:35:55 PM
thx Gregg,
the power transistors looks ok .. solder is fine and no sign of heat there .. but i don't know if it means they'r ok ?
did your shorted transister looked burned also ? how could i test it to know if it's ok ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 22, 2013, 07:33:14 PM
I don't think the transistor was actually shorted just the main power rail going to the transistor via the transformer is connected to the heat sink (I think this is right). The heat sink mounting bolts are isolated on their own pads on the board but there isn't a big amount of clearance between the pad and the board. If you have a loose fitting shake proof washer there it could easily short. The result is all the power supply power goes r12, through the transformer then through the heat sink to earth.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tommypiper on August 23, 2013, 01:25:33 AM
I have built 6 x EZ1073 and all have a small problem with hum.
cheers  Greg

Greg, have you tried holding a sheet of steel between the power transformer and the PCB while listening to the hum? Any piece of steel.  Doesn't have to be grounded.  Doesn't have to be thick.  You can cut open a tin / steel can and try that.  If it works, find a way to mount it against the toroid. 

PS: (Just a word of safety to anyone who reads this.  Be careful mounting metal round the toroid.  Don't use a shield that makes a complete loop connection around the toroid, or connects to the steel bolt on the inside and the chassis on the outside, as that will create a new coil around the toroid which is apparently dangerous.  If you want to mount like that, use a nylon or plastic bolt in the center of the toroid to break that conducting loop.  Others can explain further.)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 23, 2013, 02:40:56 AM
Hi Tommy,

I tried that, in the end moved the transformer to the back of the case and rotated to the best spot, I compared that to having the transformer out side the case. Once the transformer was moved to the back of the case most of the residual hum is from an earth loop in the supply so moving the transformer further back than the back of the case wasn't worth it. The hum is at about -90db and only present when the EQ is engaged. Apparently that level of hum in the EQ circuit is about 10db better than the original Neve layout. It maybe possible to get a better result by having a completely external supply or even a 24 volt battery supply would give zero hum. Aside from that I was about to experiment with splitting the round plane on one unit but decided to leave it for the moment as in practice the noise is negligible for most applications that you would use a Neve pre for.
I will build an external supply in the not to distant future.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dgoszillai on August 23, 2013, 06:00:27 AM
hi,
sorry i'm not that great at english (and electronic !) .
you mean the short could be from shakproof and red arrow or bue arrow ?  :P

https://lh3.googleusercontent.com/-_izQyN0uJ4U/UhcyVf9siXI/AAAAAAAABOo/BPW-JqoOdXM/w1000-h666-no/IMG_2288.JPG (https://lh3.googleusercontent.com/-_izQyN0uJ4U/UhcyVf9siXI/AAAAAAAABOo/BPW-JqoOdXM/w1000-h666-no/IMG_2288.JPG)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 23, 2013, 06:40:41 AM
the short could be from the shake washer to the surrounding ground (earth plane), that is the large areas of copper (under green lacquer). It would not short to the tracks the arrow is pointing to. The lower one in the picture looks like it could be the problem. Although the green area is an insulator if the shake washer is a rough surface and done up very tight it could go through.
All I know is that one of my units was heating up and I loosened those bolts and centre them and the washer and when I did them back up it was fixed. So worth a try. After centring the bolts, measure with a multi meter from r12 (the side that goes to the transformer not the power supply) to earth to see if there is still a short before turning it on. It might even be worth measuring with the bolts removed and also check there is no small flake of metal from the shake proof washer or solder mask.

cheers  Greg
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tommypiper on August 23, 2013, 02:01:34 PM
Hi Tommy,

I tried that, in the end moved the transformer to the back of the case and rotated to the best spot, I compared that to having the transformer out side the case. Once the transformer was moved to the back of the case most of the residual hum is from an earth loop in the supply so moving the transformer further back than the back of the case wasn't worth it. The hum is at about -90db and only present when the EQ is engaged. Apparently that level of hum in the EQ circuit is about 10db better than the original Neve layout. It maybe possible to get a better result by having a completely external supply or even a 24 volt battery supply would give zero hum. Aside from that I was about to experiment with splitting the round plane on one unit but decided to leave it for the moment as in practice the noise is negligible for most applications that you would use a Neve pre for.
I will build an external supply in the not to distant future.

cheers  Greg

Hi Greg.  Good info.  Did you try cutting the earth loop?

I've been able to get an original 1272 modded with extra gain to run incredibly quiet at full gain with an external PSU.  I'm skeptical about claims that original Neves are noisy.  However, I know they do often test as you mention, with noise floors in the 70s or so....

It's a question of proper grounding and using a high quality, shielded, external power supply.   (BTW  It's very good that Colin put tabs on these boards for external PS.  Adds flexibility.)  My experimental original modded 1272 was turned up with gain beyond the original gain and there was no hint of hum or noise.  I put an RCA Jr Velocity dynamic ribbon mic in a shoe in a closed closet in the next room with two closed doors between me and that closet and I could still hear my voice and all ambient sounds throughout the house amplified with no apparent noise.  I was stunned.  I never did measurements - someday!  Anyway, the classic 2 and 3-stage 1272 and 1290 based amp Neve circuits are capable of very high quality and quiet operation.  They are not just for rock and roll.  :)  I've seen 1073s credited on classical recordings.   :D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ruairioflaherty on August 23, 2013, 05:28:35 PM
1272 doesn't have the EQ inductors like a 1073, this is the most vulnerable point for noise pick up in a 1073.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: guitar4444 on August 23, 2013, 08:07:44 PM

Hi Greg.  Good info.  Did you try cutting the earth loop?

[/quote]

No maybe when I get some spare time. I'll try the external supply route first.
cheers  Greg

P.S. if you put the ribbon mic in a high quality boot rather than a shoe you get better noise reduction.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bigbeaty on August 28, 2013, 11:26:07 AM
I've just ordered another two units, I'm so stoked with the two I've already built!

Thanks again Colin, the EZ1073 is an awesome bit of kit; mine see daily use on recording and mixing duties.

I think I'd better start saving for a pod of Pultecs now....  8)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 30, 2013, 05:38:30 PM
Hey guys I just got my kits in. Does anybody know if grey hill makes pots with longer poles? They aren't long enough for my neve knobs
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 30, 2013, 05:40:04 PM
Also the EQ poles are too big to fit the EQ knobs on but I could just widen the hole with a drill
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tommypiper on August 30, 2013, 09:57:04 PM
Hey guys I just got my kits in. Does anybody know if grey hill makes pots with longer poles? They aren't long enough for my neve knobs

Where did you get those knobs? 

Did you check the Grayhill website for models and options?

The gray knob you show is meant to go on a concentric pot inside a rotary switch in the original Neve design... as you may know.  So if it's an original knob it will have to be drilled, which would be a shame. ...Or find a thinner shaft pot.

You can also try drilling your blue knob for a lower positioned grub screw to reach the shaft.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 31, 2013, 12:51:57 AM
Hey tommy,

Yes they are all original neve knobs, I figured out a work around and got them all to fit now.

Thanks man!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on August 31, 2013, 09:27:19 AM
Hi
I seriously got problems with getting the power into the circuit board.. I don't really have  a clue what could be wrong, everything seems to be right according to colins color book. Although i'm a newbie at diy not so much could go wrong there, white and red wires soldered to their place, and brown to the live tag of the IEC and blue to the neutral of the IEC (220-240 v). And slow blow fuses is what I used. Iec grounded together with the transformer green/yellow and the mains safety earth. That's how it should be done I guess? Oh and yeeah the purple and grey secondary wire is soldered together also of course. What the hell could be the problem here?! :O I read 0v DC between J5 and J6, the led lamp doesn't light up, pretty sure no power is coming into the pcb actually.

All the best
Isak
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on August 31, 2013, 12:08:03 PM
I have just found an incorrect mains transformer in the VTT2326 stock box.

Please can you check that the power transformer you received is indeed a VTT2326.

If you have something else, don't use it.... and let me know asap.

If you have already built your ez1073 and it is working correctly please ignore this.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on August 31, 2013, 02:15:01 PM
Hey Colin I have to correct transformer. 8)

@Sillen
Have you checked the simple things, like making sure you're getting power at the outlet and testing it with the multimeter to make sure you're getting the correct voltage? also checked the fuses etc... If all those are fine I would suggest you have a bad power transformer. It would help allot if you could upload pictures though.

Aaron
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on September 01, 2013, 10:38:38 AM
Hey Colin I have to correct transformer. 8)

@Sillen
Have you checked the simple things, like making sure you're getting power at the outlet and testing it with the multimeter to make sure you're getting the correct voltage? also checked the fuses etc... If all those are fine I would suggest you have a bad power transformer. It would help allot if you could upload pictures though.

Aaron

No power is coming into the outlet it seems. And the reason for that I believe is that the IEC I bought had a missing fuse drawer which i didn't realized should be there untill now :o This must be the problem right? lol
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 01, 2013, 10:55:00 AM
Lol yes that would be the problem. I haven't got to that stage yet but I think you're going to want to put a 100mA slow blow fuse in there.


Also did anybody build power switches into their units? I'm a bit confused on how to wire up a DPDT any DPDT switch I could find we're stated as on-off-on. Wouldn't it make more since to just use a DPST on off?  Seems like using a switch where you can terminate both the live and the neutral feeds with the flip of one switch seems best but a DPDT has six terminals. A DPST has 4.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on September 04, 2013, 02:37:49 PM
Hi
The power issue of my preamp is now fine. I measured 23.89 v DC between J5 and J6 though but that shouldn't be a problem huh? I've also been trying to figure out what may be causing the crackling noise and hum of my build, searched around the forum etc, didn't really find anything about it.. What is most likely the problem do you think?

Link to picture:
http://tinypic.com/view.php?pic=mvookg&s=5

/Isak
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 08, 2013, 12:07:50 AM
I've read through the thread but I have some grounding questions...

On most builds I see everyone is grounding the XLRs through the circuit board (HOT,COLD,SCN) and they are also grounding the XLRs to a star ground on the case.

Couldn't this cause ground loop issues? It seems like one should either ground to the star ground point or the PCB but not both. Can someone confirm what is the best way for grounding the XLRs?

Also I'm thinking of using self adhesive plastic standoffs for the pcb. Will this affect the grounding in any way?

Lots of people are complaining of hum and noise when first powering on their units and it could be a simple grounding issue that hasn't really been described in detail yet.

Thanks!
Aaron
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on September 08, 2013, 12:34:10 AM
I used the nylon adhesive standoffs on both of my units, no problem with hum, ground or anything else.  I ran ground lines to the chassis ground but didn't connect the XLR chassis to pin1 either, dunno if thats much help.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 08, 2013, 01:42:24 AM
I used the nylon adhesive standoffs on both of my units, no problem with hum, ground or anything else.  I ran ground lines to the chassis ground but didn't connect the XLR chassis to pin1 either, dunno if thats much help.

Cool, so your saying you didn't connect the SCN pin on the PCB? And just grounded it the the chassis instead?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on September 09, 2013, 09:30:16 AM
no I grounded the pins of the XLR to the board and grounded the separate chassis pin on the XLR to chassis.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 09, 2013, 01:18:18 PM
no I grounded the pins of the XLR to the board and grounded the separate chassis pin on the XLR to chassis.

Oh ok that makes sense! And you say yours is whisper quiet right? No issues whatsoever
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on September 09, 2013, 02:11:09 PM
If you start cranking the gain to +60 theres noise on it, but the neve desk i used years ago had about the same "hiss" to it when it was cranked.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 09, 2013, 03:41:24 PM
If you start cranking the gain to +60 theres noise on it, but the neve desk i used years ago had about the same "hiss" to it when it was cranked.

I've worked on a few neve consoles too but never noticed any hiss. My AMS Neve 1084s I sold a few months back could be cranked up to 80 and I would start hearing room noise and outside traffic at that point! but still never noticed any hiss.

Hopefully the noise specs are similar on the ez1073
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on September 09, 2013, 04:18:57 PM
Hiss was probably more mic self noise than the pre.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 09, 2013, 05:22:49 PM
When I get to that stage of my build I will do a measurement with only pin 1(ground) of the XLRs wired to the PCB ground and then additionally wire the XLR grounds to the chassis and make another measurent and see what I come up with.

Maybe it will make a difference maybe not but I'll post all my findings here to help future builders. I'll measure with and without a mic.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on September 11, 2013, 07:13:54 PM
Hi,
I just finished my first of 4 channels of EZ1073.
Im having problems with my unit blowing fuses. I use 220-240vv and 100mA Slow blow fuses.

Just to get it clarified.
I connect the brown transformer cable to my Live and the blue to the Neutral and the Violet and Grey are only connected to each other.
The green yellow is connected to the star ground on the case and to this point is also connected the ground from the IEC socket and the Earth from the PCB connection.

Are these connections right?

I also tried to unsolder the 2 white and 2 red secundary cables and when that is done the fuse doesnt blow. With that I suppose the power transformer is working as it should and is wired as it should or am I wrong?

Really appreciate some expert help so I can get all the units upp and running:)

 

 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mulletchuck on September 11, 2013, 08:23:34 PM
Ninuz, draw a schematic of how you have it wired on a piece of paper and post it.   
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on September 11, 2013, 09:13:39 PM
Ninuz, draw a schematic of how you have it wired on a piece of paper and post it.   

Thanks for youre answer. Ill get a drawing as soon as possible but here is a picture also....
On the picture there are no heat sinks mounted but there was when testing.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on September 12, 2013, 05:37:06 AM
Ninuz, draw a schematic of how you have it wired on a piece of paper and post it.   

Here is a picture of the drawing.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 12, 2013, 06:03:36 AM
That is correct for 220/240v operation..... it should only take about 15mA from the mains so a 100mA Slow Blow should be OK

Do you have a bench power supply with current limiting outputs ?

If you can.... power up your unit using the DC feed spade terminals and limit the bench power suply to about 400mA at 24v..... see if it power up OK..... this way you will know if the fault is in the audio circuit or power supply circuit.

Also check that the case of teh 2N3055 isn't shorted to the analogue ground plane..... the screw pad is only just big enough for the shakeproof washer.

Colin Adshead
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on September 28, 2013, 02:22:42 AM
That is correct for 220/240v operation..... it should only take about 15mA from the mains so a 100mA Slow Blow should be OK

Do you have a bench power supply with current limiting outputs ?

If you can.... power up your unit using the DC feed spade terminals and limit the bench power suply to about 400mA at 24v..... see if it power up OK..... this way you will know if the fault is in the audio circuit or power supply circuit.

Also check that the case of teh 2N3055 isn't shorted to the analogue ground plane..... the screw pad is only just big enough for the shakeproof washer.

Colin Adshead
www.audiomaintenance.com


I been putting some time aside to try and get 2 of my units to work but still get blown 100mA fuses.
The 48v rail works fine with the rail connected to the secondary wires from the main trafo as long as I don't have the white 24v cables connected to the PCB.
I got a bench power supply to Feed the 24v tab limiting to 400mA as Colin recommended and then I get the power led glowing.
Feeding the 24v rail I get a current draw of around 100mA without adjusting the BIAS Output.
Yesterday I tried connecting Line audio through both units one att a time and both units seems like they work as they should including the EQ section. This was done taking 48v from the main trafo and 24v from the bench supply.
I measured the white cables ( sec trafo ) and get around 27v AC
From this I suppose the problem is somewhere between the main trafo and the 24v tab. Looked for shorts and components placed facing the wrong side but can't find anything wrong there.
Any suggestions anybody? Places to measure or other tips?
Would really like to get them racked up so I can start using them.

Thanks in advance!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on September 28, 2013, 08:41:50 AM
I don't get my preamp to work when putting in  a mic in it. No sound coming through it even with the mic trim maxed out) Allthough, if I send something out of my daw into the preamp sound is actually coming through it but with a heavy distorted sound.. The EQ section works fine and the power section too, so we probably know that there's problem in the audio section.. A tech had a quick visual inspection of it but couldn't see anything that looked wrong.
It does seem like 2 pins that shouldn't make continuity of the vtb9045 are actually making continuity. But not visually so they have to be connected in the circuit or something. Could this affect the whole gain stage though? Is the signal always passing the mic transformer first even if you connect to the line input? :O
Anyone have any idea?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on September 28, 2013, 09:13:12 PM
Hey Colin,

Do you remember the part number for the 100nf ceramic capacitors? Several of mine cracked during soldering.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on October 01, 2013, 01:32:50 PM
I replaced the ceramics.

I tested the mic input hot and cold for continuity and the fluke is beeping. This is happening on both units, is this normal? I'm not getting continuity between the cold and hot line inputs, only the mic inputs. Upon closer inspection I'm guessing that it's happening somewhere in the transformer windings.

Here's a update of my build. After studying the original 1073 schematic religiously, I've replaced all the caps in the audio path with vintage polystyrene caps, tantalums and NOS fairchild BC184C's. Thanks to everyone on this forum for the help. I can't wait to power these up!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on October 03, 2013, 05:29:53 AM
Okey I discovered that there's a problem with my output Bias now. I only measure 28.3 MV Dc across R26 and it doesen't change in value when turning R20 ( the output bias trimmer ). I may have damaged the semiconductor D3 with my dmm at some point could this be the problem? Edit: Wasn't the diode..

No one have any clue why the output is so low? The tech I left it to didn't leave it back for like 3 months and said he lost his wife and children and couldn't help me for a year at least. And there's no other technicians that want to help me for a fair price down here really.

/Isak
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Sillen on October 10, 2013, 01:34:44 PM
.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 16, 2013, 06:21:00 AM
Sorry
That is correct for 220/240v operation..... it should only take about 15mA from the mains so a 100mA Slow Blow should be OK

Do you have a bench power supply with current limiting outputs ?

If you can.... power up your unit using the DC feed spade terminals and limit the bench power suply to about 400mA at 24v..... see if it power up OK..... this way you will know if the fault is in the audio circuit or power supply circuit.

Also check that the case of teh 2N3055 isn't shorted to the analogue ground plane..... the screw pad is only just big enough for the shakeproof washer.

Colin Adshead
www.audiomaintenance.com


I been putting some time aside to try and get 2 of my units to work but still get blown 100mA fuses.
The 48v rail works fine with the rail connected to the secondary wires from the main trafo as long as I don't have the white 24v cables connected to the PCB.
I got a bench power supply to Feed the 24v tab limiting to 400mA as Colin recommended and then I get the power led glowing.
Feeding the 24v rail I get a current draw of around 100mA without adjusting the BIAS Output.
Yesterday I tried connecting Line audio through both units one att a time and both units seems like they work as they should including the EQ section. This was done taking 48v from the main trafo and 24v from the bench supply.
I measured the white cables ( sec trafo ) and get around 27v AC
From this I suppose the problem is somewhere between the main trafo and the 24v tab. Looked for shorts and components placed facing the wrong side but can't find anything wrong there.
Any suggestions anybody? Places to measure or other tips?
Would really like to get them racked up so I can start using them.

Thanks in advance!


Sorry for nagging all of you;)
Anybody with any thoughts on my problem?
Have all 4 units with the same problem so Im wondering if the problem is in the PSU Wire'ing. They are all blowing fuses immediatly when the main transformer is conected to the main power outlet ( 240v ). Fuses used 100mA slow blow. 
Att this point I even tried to feed current with my Lab Power Supply all the way back att the + point on the bridge rectifier on the 24 DC rail. I get the unit working powering this way with the 2 white transformer wires diskonekted. All the units are taking around 100mA in current. With the Lab power supply I get no indikations of problems.
Att the same time I do have the 2 red wires on the 48 rail connected to the main transformer and getting the "power ok LED" to light upp.
Any thoughts?

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 16, 2013, 06:32:16 AM
If it is working all the way from the +ve of the bridge rectifier it would suggest that the problem was the bridge rectifiers.... if you have removed them then you could test them with a diode tester.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 16, 2013, 06:41:48 AM
Thanks Colin. Ill try that on one of the units to see if thats the problem.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 16, 2013, 07:05:36 AM
Looks correct for 230v operation.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 20, 2013, 02:58:54 PM
After spending quite some time trying to find the problems of my 4 units it seemed to be a stupid one.
The fuses I been buying from a big supplier here in Sweden ( Kjell & Company ) were the ones of bad quality even it the specifiactiones were right. Blown around 25 of them and after getting some Schurter fuses of better quality my 4 units have been working without problems.
Calibrated them and they all work like they should and sounds wonderfull. Big headroom, very pleasant sounding Eq and very quiet.   
Thanks everybody for helping answers. Specially Colin...and thanks for a very nice product.
Will post some pictures of the finished units soon:)


Sorry
That is correct for 220/240v operation..... it should only take about 15mA from the mains so a 100mA Slow Blow should be OK

Do you have a bench power supply with current limiting outputs ?

If you can.... power up your unit using the DC feed spade terminals and limit the bench power suply to about 400mA at 24v..... see if it power up OK..... this way you will know if the fault is in the audio circuit or power supply circuit.

Also check that the case of teh 2N3055 isn't shorted to the analogue ground plane..... the screw pad is only just big enough for the shakeproof washer.

Colin Adshead
www.audiomaintenance.com


I been putting some time aside to try and get 2 of my units to work but still get blown 100mA fuses.
The 48v rail works fine with the rail connected to the secondary wires from the main trafo as long as I don't have the white 24v cables connected to the PCB.
I got a bench power supply to Feed the 24v tab limiting to 400mA as Colin recommended and then I get the power led glowing.
Feeding the 24v rail I get a current draw of around 100mA without adjusting the BIAS Output.
Yesterday I tried connecting Line audio through both units one att a time and both units seems like they work as they should including the EQ section. This was done taking 48v from the main trafo and 24v from the bench supply.
I measured the white cables ( sec trafo ) and get around 27v AC
From this I suppose the problem is somewhere between the main trafo and the 24v tab. Looked for shorts and components placed facing the wrong side but can't find anything wrong there.
Any suggestions anybody? Places to measure or other tips?
Would really like to get them racked up so I can start using them.

Thanks in advance!


Sorry for nagging all of you;)
Anybody with any thoughts on my problem?
Have all 4 units with the same problem so Im wondering if the problem is in the PSU Wire'ing. They are all blowing fuses immediatly when the main transformer is conected to the main power outlet ( 240v ). Fuses used 100mA slow blow. 
Att this point I even tried to feed current with my Lab Power Supply all the way back att the + point on the bridge rectifier on the 24 DC rail. I get the unit working powering this way with the 2 white transformer wires diskonekted. All the units are taking around 100mA in current. With the Lab power supply I get no indikations of problems.
Att the same time I do have the 2 red wires on the 48 rail connected to the main transformer and getting the "power ok LED" to light upp.
Any thoughts?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 20, 2013, 03:26:22 PM
2 of my finished units.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Ninuz on October 20, 2013, 03:27:41 PM
And all 4 units but missing some knobs...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: BryanJHarris on October 21, 2013, 11:37:18 PM
are you not doing the 500 series kits anymore?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on October 22, 2013, 09:38:53 PM
are you not doing the 500 series kits anymore?

No longer available. They are a commercial product now. Check on vintageking
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: pfandlermichael on October 25, 2013, 03:45:42 AM
Hey my name is Michael and I´m new here.

I built the EZ1073 as my first bigger project and so far it sounds amazing (thanks Colin!).

But I have one problem:

There is a crackling noise when I switch to Mic. It´s not there when I select Line.
Moreover it´s just there when I switch on the 48V-Phantom Power. First it´s louder and within some seconds it gets quieter but it doesn´t go away completely.
The crackling is louder if there is no microphone connected to the Preamp and gets quieter as I connect the microphone but still doesn´t go away completely.
To me that sounds like there´s a problem in the Mic-Section or the Phantom Power-Section.

I checked everything for dry solder joints (re-soldered every joint) but it didn´t fix the problem.

As I first turn on the Preamp there was smoke from the r23 because of a short in the 2N3055 and it´s heatsink, but I fixed this and changed the resistor.
Is there a chance that the crackling problem has something to do with that?

Has anybody an idea what to check next?
I have a basic multimeter so I can measure some components but I don´t realy know where to start.


Greets
Michael
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on November 14, 2013, 02:12:50 AM
Well guys my 1073s are done! They have been for a while but I've been having too much fun with them to post. So a few things I did differently. I used polystyrene in all the gain stages and opamps... As well as tantalum capacitors and since I'm a Neve freak I ordered fairchild BC184Cs all over 600hfe from a Neve tech.

I can crank this thing all the way with absolutely zero noise. I haven't got a chance to compare them to a vintage unit yet but believe me I will. Also grounding the unit properly makes a big difference. I noticed the noise floor dropped after grounding the xlr jacks to star ground.

I have to thank Dan for the incredible cases he custom made me. We worked back and forth over email for nearly 2 months to make them, he's gotta be the coolest diy guy around here... So thanks Dan

I gotta thank Collin too for creating such a easy straightforward kit. It was a blast to build and they both fired up with no issues... So people with hum issues check your solder joints and make sure you ground things properly.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on November 14, 2013, 02:14:09 AM
Picture 2
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dane999 on November 22, 2013, 11:53:51 AM
Hi there,
I've got a problem with my ez1073. I finished the build, calibration went very well, no problem, all voltages checked ok. At first, the bias adjustment went fine, but after a while something went wrong with my output stage. I had scratches which came I guess from a wrong contact of the 2N3055, but sound. Then a strange sound, and then next to nothing…
(The sound can be heard here : http://pygmeestudio.wordpress.com/2013/11/22/1073-test/ (http://pygmeestudio.wordpress.com/2013/11/22/1073-test/) )
I swapped the 2N3055 that died because of a wrong contact between the case and the pcb. This fixed the scratches.

My problem is now that I can't set the output bias, it's stuck at +/- 340mV, as it was after the crash, and the 48V rail, which also worked fine before can't go above 47,1V now.
Other symptoms are a very very low output level with intermittent hum, and the fuse blowing when I try to measure output bias across r26 (sparks appear before that…). I'm running it at 230V through a filtered block…
Gain switches and EQ seem to work fine, and this happens both on mic and line inputs…
Something else than the 2N3055 must have been damaged but I can't figure out what it could be, could someone please help me with that ?
Thanks for your time and help !
Cheers !

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dane999 on November 29, 2013, 01:42:56 PM
I tried to find by myself everything my small knowledge allows me, rechecked every solder, every resistor, AC transformer wiring and input transformer feeding, tracked signal, hunted shorts everywhere, and still have the same problem. It can't be something very complicated, because I'm kind of a noob, and because the most part of the circuit seem to work fine.
I'm really sorry to annoy you with that, but I think I really need some help, and hope I can be helped…
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dane999 on December 10, 2013, 04:25:56 AM
Allright, the machine works fine now  8). Somehow R26 was connected to the ground plane, causing all the trouble… EQ is very very nice, and the pre fabulous… Thanks a lot Slenderchap for making these !
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on December 16, 2013, 07:19:46 AM
Just finalizing my built, go the collective case and have some problems. The  grayhill/bourns holes in the front panel are not countersunk so I end up having the PCB pretty close to the front panel in order to have sufficient threads to mount the nuts. Because of that there is not enough clearance and the grayhill/bourns pins touch the bottom plate. Anyone else encountered this problem?
Of course I could route out  the 14mm countersunk holes but the faceplate is already painted and I'm afraid the paint will chip...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dacapitan on December 24, 2013, 01:23:55 PM
Hey my name is Michael and I´m new here.

I built the EZ1073 as my first bigger project and so far it sounds amazing (thanks Colin!).

But I have one problem:

There is a crackling noise when I switch to Mic. It´s not there when I select Line.
Moreover it´s just there when I switch on the 48V-Phantom Power. First it´s louder and within some seconds it gets quieter but it doesn´t go away completely.
The crackling is louder if there is no microphone connected to the Preamp and gets quieter as I connect the microphone but still doesn´t go away completely.
To me that sounds like there´s a problem in the Mic-Section or the Phantom Power-Section.

I checked everything for dry solder joints (re-soldered every joint) but it didn´t fix the problem.

As I first turn on the Preamp there was smoke from the r23 because of a short in the 2N3055 and it´s heatsink, but I fixed this and changed the resistor.
Is there a chance that the crackling problem has something to do with that?

Has anybody an idea what to check next?
I have a basic multimeter so I can measure some components but I don´t realy know where to start.


Greets
Michael

I have this exact same problem  :( - is there any solution? :( :( :(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on January 05, 2014, 10:13:56 AM
Just finalizing my built, go the collective case and have some problems. The  grayhill/bourns holes in the front panel are not countersunk so I end up having the PCB pretty close to the front panel in order to have sufficient threads to mount the nuts. Because of that there is not enough clearance and the grayhill/bourns pins touch the bottom plate. Anyone else encountered this problem?
Of course I could route out  the 14mm countersunk holes but the faceplate is already painted and I'm afraid the paint will chip...

Nevermind, tweaked it out. Anyhow, power is up! Measuremnts are OK, ez calibration (130mV across R26) done, time for a test drive....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on January 05, 2014, 12:55:48 PM
Sound check passed! The low mid section of the EQ is amazing!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Aaronrash on January 06, 2014, 05:24:20 AM
Lol,

Dan gave you my Silkscreen design
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on January 06, 2014, 12:54:56 PM
Lol,

Dan gave you my Silkscreen design

I noticed it was a little different form the design posted on his webpage. I hope I can get another one like that, now that I've tried it I want to have a pair.....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: olebrom on January 06, 2014, 03:43:28 PM
Hi,

I am just about to get starter on my ez1073 build and I was wondering if anyone on this thread has done a A/B test with a Vintage or AMS 1073 vs. the ez1073. I just saw this thread :  http://groupdiy.com/index.php?topic=54748.60   and it got me a little bit curious. Anyone else on this thread experiencing what Aaronrash is having troubles with? So far i have only heard good things about this project :)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on January 18, 2014, 06:41:13 AM
Did some more tests with my ez1073, I really like this pre. Can't compare it to an original, but I like it better on guitars then the 312 I have (API A2D). Great low mids. The EQ is also very useful, it really shines in the lower freqs.
A short clip of some electric guitars: sm57-ez1073 (EQ off) through a RME multiface into cubase. right channel is dry, left is a lexicon hall plugin (a little bit too much hall..)
   
https://dl.dropboxusercontent.com/u/27310277/The%20Beast%2063%20PAF%207.7.k.mp3 (https://dl.dropboxusercontent.com/u/27310277/The%20Beast%2063%20PAF%207.7.k.mp3)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on January 21, 2014, 06:17:31 PM
Are the ez1073 kits gone forever??? :'( I looked at the site and the page is gone, 404!!! I was hoping to get a kit within the next few months. Forget Christmas, I need a spring solstice present.

http://www.audiomaintenance.com/acatalog/aml-17-020_extended_info.html (http://www.audiomaintenance.com/acatalog/aml-17-020_extended_info.html)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 21, 2014, 08:08:00 PM
There are no kits anymore unless you find someone selling one on here that they never built.  You best bet it to purchase one from Jeff as they are commercial products now.

http://classicapi.com/catalog/product_info.php?cPath=66_114_68&products_id=239

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on January 21, 2014, 09:47:13 PM
I am not a 500 series guy. Are the 1U kits gone too?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on January 22, 2014, 02:13:43 AM
Seems like they are out of stock, Maybe Collin can chime in.

I just received my second kit yesterday, ordered it last week so it's something recent.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 22, 2014, 02:37:46 AM
We have run out of GR-03-003 switches... so a bunch of kits are affected. I believe that we should have more switches soon as they were ordered on 1st November.... then they will be available again.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dribro on January 24, 2014, 06:13:11 PM
Hi Colin

Me and a friend are in need of one your ez1073 kits. Can you estimate when will it be online?
regards, Adriano
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 28, 2014, 06:47:25 AM
For the moment it is available again.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on January 28, 2014, 11:49:37 AM
How many do you have in stock and will you stock them in 2/3 weeks time do you think?

Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on February 02, 2014, 10:41:11 PM
I used polystyrene in all the gain stages and opamps... As well as tantalum capacitors.

I image you replaced all the wima caps in all 3 stages and both opamps with poly's but which caps did you replace with tantalums?

Thanks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on February 03, 2014, 10:25:22 AM
So from what I can gather the tantalums would be...

Stage 1,2,3
------------------------
C45, C68, C54, C8, C37, C64, C42

Opamps
------------------------
C26, C18, C46, C36

The poly's I'm going to do are...

C43,C53,C49,C55,C58,C60,C10,C21,C35,C19,C29

Does that sound about right? I was also reading that to prevent a common high frequency rolloff when the EQ is engaged that C23 and C40 should be lowered to 10pF but I imagine since this was not done that this is a non-issue.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on February 04, 2014, 09:08:18 AM
After reading a bit more I think I am going to skip on the tantalums as the might make the preamp "too clean sounding" and stick some audio grade electrolytics. I'm probably going to put in the poly's in the audio path since I think that will not change the sound too drastically and it is closer to the original specs.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on February 04, 2014, 12:33:55 PM
1073's are inherrantly noisy and distorted anyway so it does not really matter what you put in there..... avoid capacitors sold as "audio" caps.... you will pay a lot of money for them because they have low distortion .... which is not what you want.

Colin
www.audiomaintenance.com

Maybe not.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: SKJGProject on February 07, 2014, 07:37:30 PM
unfortunately my ez1073 raised it's noisefloor over night and it is not a steady noise...i recorded one
minute of it while playing with the controls...sometimes the noise goes away instantly when i switch from mic to line
for several times which you can notice at around 50 seconds.

i have no clue what could be causing this but maybe someone can help me?

https://dl.dropboxusercontent.com/u/499952/ez1073_noise.mp3 (https://dl.dropboxusercontent.com/u/499952/ez1073_noise.mp3)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 08, 2014, 01:01:56 PM
I've got 2 EZ1073's that I had completely stuffed and mounted but just not wired up in the chassis yet.  Yesterday I finally I got one of them completed for a mic comparison I was doing for a couple of friends/musicians.  I used my API's for the mic comparison since I have multiples and needed a similar mic pre so we could focus on the mic differences.  Well, the mic comparison was a success but the icing on the cake was the EZ1073!  I am impressed with the sound of this thing and all I can say is it sounds damn good.  I threw it in when recording a Tyler Telecaster-->1955 Fender Deluxe.  There were 2 inexpensive AKG mics (my friends gear) and Telefunken 251 clone at about 2' out from the Jensen speaker, all into API's.  Just because I had the 1073 done, I slapped a SM57 in a "normal" 3-4" distance just off the voice coil, into the EZ1073, 60dB of gain, the trim all the way back, no eq.    The EZ1073 sounded very, very good.  It was a bit compressed due to the high gain and trimmed output but it sounded wonderful.  Now I can't wait to get the other one wired up!  Based on what I heard in this comparison I'm really interested in a vocal with the Tele251 and the EZ1073.

As for the mic test, nothing surprising to me.  As expected they all sounded a bit different.  It was really a LDC comparison to see how cheap mics stood up to a custom 251 style mic.  In my view, the 251 sounded the best of the LDCs on both snare and guitar.  More open with no hyped frequencies.  It also was better at capturing the attack of the stick on the snare head.  Not my usual use of this style of mic though.  The SM57 through the EZ1073 was the best on the guitar amp even though it was not supposed to be in the comparison! 

Colin, great job on the EZ1073!  As I've said before I'm not a purist.  I don't have an authentic 1073 to compare to, but in my opinion this piece really does sound great.   Its another tool in the arsenal.

Btw: the cheap mics were AKG 420, AKG 120.   Not my cup of tea on either one.  Maybe I should have put them through the 1073!

Also, absolutely no problems with the EZ1073 build.  Wired up the power, adjusted the 48v supply and bias....use it!

regards,
Jeff

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 11, 2014, 09:26:43 AM
Finishing up the ez1073 build and awaiting case to arrive. Hopefully everything will go ok on power up.

Just 1 (probably daft) question:
Which way to solder the LED on the extreme right of the pcb (as you look from the front)?Does the longer lead go in the right or left
hole?

Thank you to anyone who can help.

Hay
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on February 11, 2014, 09:30:25 AM
Looking from the front, the long lead is to the right (i.e., closest to the edge of the PCB).

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 11, 2014, 09:34:33 AM
Crikey that was quick! Thank you Colin.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 11, 2014, 08:10:37 PM
Got both of my EZ1073's running now.  Measured both with RMA and found 60hz (and harmonics) at about -99.2dB.  Rest of noise is at -129dB.  May have to spin the toroid or move it back off the pcb and away from the board.  Anyone else see this with the transformers mounted?

Regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 12, 2014, 06:44:02 PM
I pulled the entire circuit board out of the chassis (to disconnect all ground connections), and removed the power transformer from the pcb.  Level of 60hz changed a bit but the rest of the harmonics were there at -99.8dB.  Disconnected the grounds from all the in/outs just leaving the balanced signal wires.  Still the same.  Disconnected the chassis ground connection on the pcb with no change.  Both units behave exactly the same.  I have a set of custom 512 style mic pre's and they run clean with the using same AC outlets.  Since the level of 60Hz is so low its difficult to debug!  They are definitely usable as is but I sure like to get it down.    Here's the actual RMA test.  60Hz and all its harmonics are visible during the noise test and are peaking at about -100dB.  The rest of the noise is down below that at about -129dB and consistent across the frequency range.  White is loop back.

Colin,  have you ever run into this?  Never mind, found Post#579 regarding 60hz.  Will try external supply.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 14, 2014, 10:57:28 AM
Quote
Hi Again,

Ok I've done some measurements.  I've just realized that the RME digicheck software has a convenient noise measuring function. So not as bad as I thought.
So the figures I get are into the line in set at +4 mic level +15 (input not shorted, no mic connected) output trim on full level. When the EQ is engaged all switches are off and gains set to zero.
EQ out  =  -99.7db  (RMS +3  20hz -20khz)
EQ in  =  -92.6    (RMS +3  20hz -20khz)

so about 7.1 db more noise. It sounds like mostly hum.

cheers  Greg

Greg,
I've measured the exact same thing (although I didn't measure with EQ in).  Did you try using an external supply?  I've moved the transformer and it doesn't change anything.  This thing sounds great and I'd love to get rid of the 60Hz.  Did your results show the harmonics as well?

I'm going to experiment and try running from a bench supply.  If that works I'll just build an single external supply with enough juice for 2 units. 

regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 14, 2014, 06:14:14 PM
I've done some research on the 60Hz ripple I'm seeing on my 1073's.  This appears to be a "normal" thing.  Now my noise measurement of -99.8dB seems pretty respectable!

 To quote Geoff Tanner: 
"If we take the 1073 as a classic example, one of the biggest flaws in its design is that it takes the negative feedback for the output stage from the collector of the 2N3055 which puts it the primary winding impedance and a 12 ohm resistor away from the dc supply. So, if you don't have gobs of capacitance after that 12 ohm resistor, then the noise and crud on the power supply can get into audio via the feedback".   

 This may explain why moving my transformer or experimenting with grounding had no effect.  Adding more capacitance to the supply filtering may have an impact where moving the 24v supply to remote may not necessarily reduce the ripple!  So no external for me.  I'd love to drop this down another 3-6dB though.  My custom API's are at -105dB and its not audible. 

regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 15, 2014, 02:25:42 PM
Just been reading about the 2n3055 and the possibility of it shorting underneath the pcb. Would it help if nylon washers were used?

Also, for the IEC, do you use a separate fuse holder after the IEC inlet then add a rocker switch?

Thanks for any feedback...

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 17, 2014, 11:02:42 AM
I reduced the hum just a bit by disconnecting the shield from chassis on the output XLR.  Will try reconnecting that and disconnecting the input shields as that's the "preferred" method.  But something happened to one of the units.  Now I don't have signal at the output of the line input transformer (at R30 termination resistor).  Absolutely nothing at pin 2 of PL11 even though there's continuity between them.    I doubt I could damage the transformer as they should be hard to break, especially if I haven't moved or un-soldered them!    I didn't remove the pcb and I wasn't even close to working in that area.  Oh well, more debug on unit 2.

Anyone have a working one open to measure the resistance across R30?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 17, 2014, 07:43:30 PM
I have noticed the hum in my 1073 too.  I have to put the headphones up really loud in order to hear it.  Sounds like a ground loop type of sound.  The gain settings don't increase or change it.  I don't hear it when i record because the headphone are not up that loud.  The eq section does change the sound but not the volume of it. 

Would love to get rid of it to just to have the cleanest signal.

-Scott

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 17, 2014, 08:14:41 PM
Scott,

There could be more than one source of hum.   One is described by Geoff Tanner in post 700 and is related to power supply ripple.  That's the tough one to tackle.   Another source for me was from the shields on the in/out connectors.  You can try disconnecting the input shields or disconnect the output shield.  Then try your headphone test again.

Regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 18, 2014, 12:15:40 AM
Issue solved.  Trying to debug when there are 3 issues at once is a challenge.  Found them all finally and the both units are working.  No transformer problem as it turns out.  Just a bad connection for that one.  Now for the fun stuff....making some music.

Regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 18, 2014, 02:51:40 AM
Deveng

What were your issues and how did you fix them?

cheers

Hay
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 18, 2014, 07:42:59 AM
Deveng

What were your issues and how did you fix them?

cheers

Hay

are you talking about the shield in the wires that connects\ the xlr's to the pcb or the wire that connects the ground to all the xlr's outer metal parts.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 18, 2014, 09:21:40 AM

Hi Saxmonster

I have not yet turned  my 1073 on as it is awaiting the chassis and wiring-up. So I wondered about various issues people were having with theirs.

Deveng seemed to resolve his issues and I was interested in how/what.

Incidentally, what are the shields in the wires that you refer to?

As for hum, it looks as if that is inherent with the 1073 design??

cheers

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 18, 2014, 11:02:06 AM
Saxmonster, Hay,

My triple issues were a single cold solder joint on the line input transformer (nothing to do with buzz), an intermittent cable and finally a bonehead wiring issue (output XLR mis-wire).  So you would not likely have these issues.  The buzz I hear is very low at about -102dB now when measuring noise with RMA.  In most recording uses this is not a problem. 

The shields I was referring to are the pin 1 connections at the XLR's.  Typically these are wired to chassis at the star ground point (and I've disconnected the shield running from pin 1 to the pcb).  If you have ground loops the best way to get rid of them is to diagnose your system, but if you absolutely have to, you can disconnect this pin at the receiving end.  My problem turned out to be a wrong connection at my output XLR.  That's why I shouldn't wire them at 2am!   

As for 1073 inherent hum, its all about the power supply ripple and the design.  Colin's design is good and these units sound and work great.  Get them running and have a listen.  If your noise measurement is above -100dB you probably have a wiring issue or ground loop in your system. 

Regards,
Jeff

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 18, 2014, 11:41:03 AM

That's great Deveng, thanks for the reply. Interesting to know about the issues folk have be it soldering problems or wiring etc.
The trick is know how to diagnose the problems should they occur.

Cannot wait to fire mine up!!

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on February 18, 2014, 12:34:27 PM
I don't think my issue is a ground loop hum its just the inherit hum of the machine like you said.  I don't hear it at all unless I turn up the headphone amp all the way and then it is still far in the background but I would never ever monitor at those levels any ways.  How can i measure how many DB the noise is in my daw.  I have digital performer.  Do a need a scope to measure it? 

Thanks
-Scott

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 19, 2014, 10:54:50 AM
Scott,

If you have an Intel based DAW you can download RMAA (Rightmark audio analyzer) for free.  It uses your sound card for measurements.  For MAC, I think Fuzzmeasure does the same thing. 

Since you can only hear the "buzz" when your level is at extreme, what you're probably hearing is power supply ripple.  Measure it with the above mentioned analyzers and if you're down in the -100dB or better you're going to have a battle to get it any lower.   The best these 3 terminal regulators can do is about 75dB so the rest has to be filter caps.

Regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 26, 2014, 11:26:27 AM

Ok, just finished everything on ez1073. Sounds great (and a relief of course that it works).

Does anyone use the LED as I found it impossible to solder in and align and stay in the chassis. Now I think I have damaged it after trying to re-arrange it to fit into the tiny hole on the chassis in the corner. Everything else works great, so I assume the led doesn't affect the 'pre circuit generally.
I will get another and re-solder but it is nice to have some kind of mains lamp.

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: deveng on February 26, 2014, 01:40:23 PM
Haystack,

Yes I use the LED.  It is a bit difficult to line up with the hole in the front panel.  What I do is bend the leads so the LED will feed through the front panel hole correctly.  Then solder to the pcb from the top side.  You can then "tweak" the leads if you need to. 

Its not required to have the LEDs in place for the unit to work but it is nice as it will not only let you know the unit is on but also let you know both the 24v and the phantom power are working.

Regards,
Jeff
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on February 26, 2014, 02:27:45 PM

Thanks Deveng for your reply. Yes I will sort the LED out. It's good to know all is well with the unit by looking at
a healthy light!

I have really enjoyed building the unit and collecting the bits and bobs- IEC, spacers etc etc and ending up
 with a great unit as this. lovely sounding thing.

cheers haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on February 27, 2014, 01:41:31 AM
I found it not so difficult to align the LED, I aligned the LED with the hole in the faceplate (not to deep, just to enter the hole slightly) and used a marker pen on the LED leads to mark the position of the LED lead holes in the PCB.  Then take the LED out and bend the leads in the marked positions to a 90 degree angle, trim off the leads to get the needed height (they shouldn't be to long or they will ground with the case bottom, some 5mm from the bending mark should be just enough) then just place the LED in the PCB, fix it slightly in the LED hole on the faceplate and solder from top.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Meyer on February 28, 2014, 06:13:50 AM
Hi

I've bee lurking here for a while, reading and learning, but now I have a issue with my ez1073 that I can't solve.

It worked fine at first, until I turned on the phantom power. There where some strange noises and distortion and now my bias is stuck at about 260mV. By adjusting R20 I can only bring it up higher but not lower.

Everything else is working, there is sound coming from the unit, but it is distorted. I checked for shorts and reflowed solder joints, but there has been no improvement. There are no visual clues for burnt components, but maybe something shorted to 48V and got damaged, but I have no idea what.

Any suggestions are much appreciated

Thanks

Meyer
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: spneca on March 03, 2014, 12:06:35 PM
Hello all,

I just finished a build, and the line input and eq works great.  I checked the power voltages and adjusted the output bias and everything was fine.  My problem is that the Mic Pre section is not passing any signal.  I did some probing and found that there is continuity between pins 2 and 3 of the mic in.  Looking around the board , I could not find any obvious short.  I did some trace cutting and the short does not appear to be near the connectors.  One thing I noticed is that all of the contacts of SW4 (the impedance switch) have continuity.  Could it be that I have a bad switch?  Could this be the cause?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on March 03, 2014, 01:59:46 PM
Hello all,

I just finished a build, and the line input and eq works great.  I checked the power voltages and adjusted the output bias and everything was fine.  My problem is that the Mic Pre section is not passing any signal.  I did some probing and found that there is continuity between pins 2 and 3 of the mic in.  Looking around the board , I could not find any obvious short.  I did some trace cutting and the short does not appear to be near the connectors.  One thing I noticed is that all of the contacts of SW4 (the impedance switch) have continuity.  Could it be that I have a bad switch?  Could this be the cause?
Hi there, I'm by no means an expert but I can share my experience after two successful builds, since I had similar issues.
Continuity on the mic input between pins 2 and 3 is normal as these pins are connected through the mic input transformer which has a low DC resistance. I have the same on my two builds and everything is working fine. One hint if you are using a dynamic mic, make sure the phantom power is not on. The 48V switch pointing downwards is the phantom power on position, so if you are using a dynamic mic it should be pointing upwards otherwise it wont pass any signal. The labeling on the frontplates (from both Dan's) are a little bit confusing regarding this, and there is no led indicator for the 48V on/off position.
J.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: spneca on March 03, 2014, 08:49:33 PM
Hello all,

I just finished a build, and the line input and eq works great.  I checked the power voltages and adjusted the output bias and everything was fine.  My problem is that the Mic Pre section is not passing any signal.  I did some probing and found that there is continuity between pins 2 and 3 of the mic in.  Looking around the board , I could not find any obvious short.  I did some trace cutting and the short does not appear to be near the connectors.  One thing I noticed is that all of the contacts of SW4 (the impedance switch) have continuity.  Could it be that I have a bad switch?  Could this be the cause?
Hi there, I'm by no means an expert but I can share my experience after two successful builds, since I had similar issues.
Continuity on the mic input between pins 2 and 3 is normal as these pins are connected through the mic input transformer which has a low DC resistance. I have the same on my two builds and everything is working fine. One hint if you are using a dynamic mic, make sure the phantom power is not on. The 48V switch pointing downwards is the phantom power on position, so if you are using a dynamic mic it should be pointing upwards otherwise it wont pass any signal. The labeling on the frontplates (from both Dan's) are a little bit confusing regarding this, and there is no led indicator for the 48V on/off position.
J.

Thanks for the reply.  Unfortunately, this did not solve the problem.  I used an SM57 to test, and I got the same result with the phantom power switch in both positions.  If I hit the top of the mic I can hear a very quiet impact sound, but the gain doesn't seem to affect it at all.  I tried the mic and cable on another pre to verify that they are working, and they both checked out fine.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on March 12, 2014, 11:42:36 AM
How is everyone getting their 6.35mm pots to fit the 3.23mm holes on the grey fluted neve style knobs from classicapi?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on March 12, 2014, 01:23:57 PM
I'm not sure they are, are they? I thought they were for thin shaft pots - I may be wrong here. I am
ordering - when in stock - the blue/grey and maroon ones. You can get grey elmer knobs that are 6.23 mm which are a bit like
the marconi type.

cheers

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on March 12, 2014, 01:35:43 PM
I could swear that Aaron said something about drilling into the aluminum knobs to make the hole bigger but now I can't find the quote. Is this an option or will I just screw up some nice knobs?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on March 12, 2014, 01:43:20 PM
Oh perhaps you can, I wondered where people were getting the fluted ones as well as the pointer 6.4mm ones.
I would like a mixture on my 1073 not all pointer ones and would also like some fluted knobs if they fit.

Hay
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on March 14, 2014, 08:25:31 AM
I drilled the grey fluted marcconi style knobs from CAPI (I think I used a 6mm drill), no big deal just use a vice to hold them down and be careful on the depth when you drill.
 
However, a bigger problem is that the shafts of the pots are a little bit to short for these knobs and it's a tight fit to lock the knobs as the knobs locking screws position is too far away from the knobs edge. A managed to do it on one unit but on the other one two knobs are constantly getting loose. I'm trying to figure out how to extend the shafts for 2mm with an epoxy glue. The best solution would be to use pots with at last 2mm longer shafts if you want to use these knobs.

They sure look cool but it's a hustle to get them fixed with Collins kit.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on March 14, 2014, 08:51:56 AM
Are you using the 15mm shaft length pot?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on March 14, 2014, 02:44:12 PM
Are you using the 15mm shaft length pot?

Hmmm, I used the ones coming with Collins kit and although the Colorbook's BoM quotes 20mm shaft the ones that came with my kit are 15mm. Just opened the case to measure them, didn't notice this so far. The part of the shaft which is sticking out of the case is barely 8mm and this is approximately the position of the locking screw of the grey CAPI flutter knob so it's very difficult to lock the knob which this shaft length.

Are you guys getting pots with 20mm shafts with the kits you ordered?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on March 14, 2014, 02:55:50 PM
Are you using the 15mm shaft length pot?

Hmmm, I used the ones coming with Collins kit and although the Colorbook's BoM quotes 20mm shaft the ones that came with my kit are 15mm. Just opened the case to measure them, didn't notice this so far. The part of the shaft which is sticking out of the case is barely 8mm and this is approximately the position of the locking screw of the grey CAPI flutter knob so it's very difficult to lock the knob which this shaft length.

Are you guys getting pots with 20mm shafts with the kits you ordered?

Actually, just figured that the 20mm reference for the pots in the BoM is referring to the diameter and not the shaft length.


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on March 14, 2014, 03:08:35 PM
Are you using the 15mm shaft length pot?

Hmmm, I used the ones coming with Collins kit and although the Colorbook's BoM quotes 20mm shaft the ones that came with my kit are 15mm. Just opened the case to measure them, didn't notice this so far. The part of the shaft which is sticking out of the case is barely 8mm and this is approximately the position of the locking screw of the grey CAPI flutter knob so it's very difficult to lock the knob which this shaft length.

Are you guys getting pots with 20mm shafts with the kits you ordered?

Actually, just figured that the 20mm reference for the pots in the BoM is referring to the diameter and not the shaft length.

This is what I'm talking about, notice how the locking screw comes to close to the shaft edge.


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: stribor1 on March 14, 2014, 03:10:34 PM
One more tip of you are going to drill the grey CAPI knob, don't forget to remove the locking screws prior to drilling.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: delichef on March 17, 2014, 02:48:48 AM
First post here, I just completed 2 of these kits. Both worked straight away and sound fantastic! Hats off to Colin/AML for making such a quality kit and to Dan of collective cases.

The last bit I need to get sorted is the knobs. I have the red/blue/gray Marconi style from CAPI, they fit and look great. The gray round knobs from CAPI were out of stock, so I've been waiting for those to finish it up...but it looks like those may not fit?

I see the Elma vintage round knobs with the plastic skirt (cae041189). Has anyone tried these or know of a source to order them from?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: littlesicily on April 11, 2014, 09:10:48 AM
1st time post, 1st time build (ez1073)

Hello to all,

1) What are the proper fuse ratings to be used for the IEC connector?

2) Am I correct that Mic and Line transformer 8-pair of connection closest to the back (PL8, PL9) of the PCB are NOT connected to anything?
I only see traces on the underside of the PCB going to/from the PL10, PL11.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on April 11, 2014, 10:47:36 AM
1st time post, 1st time build (ez1073)

Hello to all,

1) What are the proper fuse ratings to be used for the IEC connector?

2) Am I correct that Mic and Line transformer 8-pair of connection closest to the back (PL8, PL9) of the PCB are NOT connected to anything?
I only see traces on the underside of the PCB going to/from the PL10, PL11.

1) use the search feature and search the thread. Could come in handy to know how to do that.
2) seeing as there are no audio connections on top of either transformer it would be funny of Colin to have wired those pins to anything.  ;D

Good luck
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: littlesicily on April 11, 2014, 10:50:34 AM
1st time post, 1st time build (ez1073)

Hello to all,

1) What are the proper fuse ratings to be used for the IEC connector?

2) Am I correct that Mic and Line transformer 8-pair of connection closest to the back (PL8, PL9) of the PCB are NOT connected to anything?
I only see traces on the underside of the PCB going to/from the PL10, PL11.

1) use the search feature and search the thread. Could come in handy to know how to do that.
2) seeing as there are no audio connections on top of either transformer it would be funny of Colin to have wired those pins to anything.  ;D

Good luck

Thanks Ding. Being a noob, I just wanted to be sure and not assume anything :-)  Thanks for your reply.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: delichef on April 21, 2014, 12:22:12 AM
Has anyone connected a fader in place of the final 10k pot (and shunt the resistor to make it a full fader)..and used the 1073 like a mixer channel?

I was thinking about running 8 channels into an Api 8200(a?). Since the 8200 doesn't support connecting a fader pack, could I just run the gain levels up on the 8200 and mix into them with the 1073 faders for volume?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Beauvais on April 24, 2014, 07:32:21 AM
Just got two ez1073 kits and am populating the board now. First question: The two voltage regulators touch the heat sinks without insulation, so their 'back' is connected to ground, right? Also, do I need to solder the big pins from the heat sinks? Thanks!

EDIT: OK, to answer my own question in case somebody might be unsure about the same thing. It's yes to both.  :)

I can say this with certainty, as both my units work flawlessly and sound great!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 11, 2014, 08:25:15 PM
I just finished my ez today and no smoke! I am only getting 23.8 volts. Is that sound right? Also, changing the output bias trim does nothing. I am at -300mv. Maybe the trim resistor is shot?

Edit: The output sounds very distorted so I am guessing this is normal when the output bias trim resistor is not working.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 19, 2014, 10:23:15 PM
Hello groupDIY comunity! I am stumped with my ez right now. Maybe someone can offer me some assistance. The preamp will not give me any output (maybe undetectably low) unless I turn the mic level grayhill switch all the way up and then I get a mountain of distortion. I am getting 28.5mv across the 1 ohm (R26) resistor and it wont change no matter how much I turn the bias trim resistor. I have replaced the 5k trim resistor just in case it was damaged. I have also replace the 2N3055 thinking that could be the problem with not joy. Some things of note: my 1R resistor is 1/4 watt and sometimes when I am measuring the current across it I blow a fuse (100mA). I looked below to see if the resistor was touching the chassis but it is not. The resistor does not look burned or smell. Any ideas where I can start to trouble shoot this? Thank you all so much. I am really looking forward to finishing this project.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 20, 2014, 07:58:23 AM
Okey I discovered that there's a problem with my output Bias now. I only measure 28.3 MV Dc across R26 and it doesen't change in value when turning R20 ( the output bias trimmer ). I may have damaged the semiconductor D3 with my dmm at some point could this be the problem? Edit: Wasn't the diode..

No one have any clue why the output is so low? The tech I left it to didn't leave it back for like 3 months and said he lost his wife and children and couldn't help me for a year at least. And there's no other technicians that want to help me for a fair price down here really.

/Isak

Similar problem. There has to be something I am missing here. Sillen is still no closer to figuring it out either. /headscratch/ -  :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Harpo on May 20, 2014, 08:19:51 AM
..and sometimes when I am measuring the current across it...
:o when you measure current across it, you shorten out this resistor and maybe paralleled parts (and maybe blow up parts connected to it that rely on the presence of this not shorted resistor).
Measuring current is in series to this resistor, or calculate the current (I=U/R) by measuring the voltage drop across this resistor with known resistance.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 20, 2014, 08:52:22 AM
Sorry, my bad grammar. I was measuring voltage across the resistor not current.  :o You are correct.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Gustav on May 20, 2014, 11:21:24 AM
Just finished building two of these.

Functionality seems fine on both. Mic gain works, eq works etc.

Channel one - I can measure continuity between the AGND and CGND points on the PCB.

Channel two - I cannot measure continuity between the AGND and CGND points on the PCB

I cannot identify a single difference between the two channels. Mounted in cases from Dan using kits from Colin. I feel Ive poked my meter at everything in there, but I can't figure out whats up.

Any help?

Gustav
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 20, 2014, 11:40:10 AM
I am getting 28.5mv across the 1 ohm (R26) resistor and it wont change no matter how much I turn the bias trim resistor.

That would suggest that the output section was not working at all.... has R23 become open circuit....

... maybe R23 burnt out because of a short between the screw/shakeproof of the 2N3055 body and the ground plane ?... the pad is only just large enough for the washer.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 20, 2014, 12:42:52 PM
I am getting 28.5mv across the 1 ohm (R26) resistor and it wont change no matter how much I turn the bias trim resistor.

That would suggest that the output section was not working at all.... has R23 become open circuit....

... maybe R23 burnt out because of a short between the screw/shakeproof of the 2N3055 body and the ground plane ?... the pad is only just large enough for the washer.

Colin
www.audiomaintenance.com

Thanks Colin. I will check on that. What should the voltage read across R23?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Gustav on May 21, 2014, 02:20:07 PM
Just finished building two of these.

Functionality seems fine on both. Mic gain works, eq works etc.

Channel one - I can measure continuity between the AGND and CGND points on the PCB.

Channel two - I cannot measure continuity between the AGND and CGND points on the PCB

I cannot identify a single difference between the two channels. Mounted in cases from Dan using kits from Colin. I feel Ive poked my meter at everything in there, but I can't figure out whats up.

Any help?

Gustav

I thought I had checked the connections on R1, but apparently, not good enough.

All good :)

Gustav
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 22, 2014, 10:15:11 PM
I am getting 28.5mv across the 1 ohm (R26) resistor and it wont change no matter how much I turn the bias trim resistor.

That would suggest that the output section was not working at all.... has R23 become open circuit....

... maybe R23 burnt out because of a short between the screw/shakeproof of the 2N3055 body and the ground plane ?... the pad is only just large enough for the washer.

Colin
www.audiomaintenance.com

Thanks Colin. I will check on that. What should the voltage read across R23?

Testing it further I think you are right that the output section is not working. If I crank up my audio interface preamp to the max I get sound but the hum/hiss is obviously insane. I removed the washers and tested R23 and it tests fine, 12.8 ohm. I also tested C2 and C3 (ohm test) and they seem fine also. Anyone know any voltages I should be checking in the output section? I don't want to have to replace all the components. Thanks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on May 23, 2014, 07:11:34 AM
I had this sort of thing with a diy project.
I had hissing, crackles and terrible noise etc.
I settled down with a magnifying glass and examined EVERY joint and realised that
even with care - I thought!- I had left a tiny gap in a soldered joint in a couple of places.

I re- soldered problem looking joints and touched up any that seemed remotely dodgey . It's all good now.
I am not saying that it's the same with your situation, but it was worth it to  start again and check all of my work in detail even though I was convinced my soldering was all fine.
hope you get it sorted
Hay
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 23, 2014, 07:50:53 AM
Thanks Hay. I usually do this before I run power thru any of my projects. No reason not to go thru it one more time.  :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 23, 2014, 10:33:17 AM
I have checked r20, r23, c2, c3 and c12 plus replaced the r20 and the 2N3055. I have also made sure that the washers that could have been touching ground are removed for now. I am still getting 28.5mV across r26. No change when I turn r20. I can't even measure any voltage across r7 but c12 seems to measure fine both with my capacitance metering and an ohm test. I can't test c2 and c3 with capacitance metering cause my meter will not go up that high but the ohm test checks out. 48v and 24v power checks out. I imagine the output transformer has no part in whats happening but I could be wrong. Will keep poking around and see what is going on. Any ideas welcomed. Thanks everyone.  :D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 23, 2014, 08:48:04 PM
I discovered that R6 is gounded on both sides. That means part of the 2N3055, R20 and the - of c12 are somehow making continuity with Aground. I am not sure how. I have checked all my solder points. Mmmmm. Wonder where that gound point is?  >:(

Edit: never mind. 47ohm is too small of a resistance to use the continuity function of my meter. Tested R6 and also tested continuity with the ohm function and it checks out. Still on the hunt.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 25, 2014, 03:09:41 AM
I imagine the output transformer has no part in whats happening but I could be wrong.

If the output transformer were open circuit it would not work.... DC current flows through it all the time.....

Measure the dc voltages at all points in the output circuit... it may lead you to the fault.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 25, 2014, 04:48:58 PM
It took me a while but I checked all solders with glass again, resoldered any questionable points, followed the voltage down the path and found the bad component that was causing all the trouble. Q4! Replace that little bad boy and was able to bias with no problem. This thing sounds fantastic!!!!!!! Thanks everyone for all your suggestions. I am one happy camper! ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on May 26, 2014, 07:31:13 AM
This thing sounds fantastic!!!!!!!....... I am one happy camper! ;D

Excellent news.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on May 27, 2014, 08:18:26 AM
One thing with my build is that the switch for fantom power is upside down. Meaning I switch down to turn phantom on. I know one day i'm going to send 48v down the wrong mic. Ribbons I'm looking at you. :P I was thinking an easy dirty fix would be to cut the last posts off the switch and wire a jumper from the last pad to the front post. Would there be a better way of doing this? Another option would be to wire up a led but that seems a little more complex.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 07, 2014, 12:05:53 AM
Here we go again.  :( I made the stupid mistake of not inspecting my work before I put it together and it seems as though I left an old transistor in there rolling around. I imagine it eventually made contact with something as I jostled the unit around. Now the preamp smells like something is heating up, it makes static noises but no sound from a mic.  :'( I am getting 320mv at R26. By the time voltage gets to thru R19 it is 0v. R14 is at 2.7v. R6 is getting about 13.75v, gets very hot and smells. R9 about 1.83v. Nothing looks burned but it sure starts to smell like hot plastic from R6 if I leave it on for a little bit. Anyone have any ideas that pop to mind? Thanks.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 07, 2014, 09:24:42 AM
One more clue, the staticky noise is not constant. It comes up and down. Strange.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 07, 2014, 02:54:46 PM
Q4 had gone bad again. I replaced it but now I get 0v at R6. R7 is getting 23v on one side and 1.1v on the other. 0v at R8, R9, R14 etc. Basically something is not letting voltage thru the output stage.  ??? It seem like voltage flows from R26(23.8v) thru R23(23.8v) thru R7(23.8v) to R6(0v). C12 is fine. wonder what it could be?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ruairioflaherty on June 07, 2014, 04:21:34 PM
Do you know that your output transformer is good?  The DC flows in the primary.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 07, 2014, 04:56:49 PM
I imagine it is since it was working properly before.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 08, 2014, 11:03:03 AM
I've been measuring wrong. I'm actually getting 49.5mV from R6. It seem like the voltage coming out of C12 is 49.5mV. That goes to R6 and R20. That seems way low. I pulled out C12 and it checks fine but I replaced it anyway and still???
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 09, 2014, 09:50:02 AM
I am sure I am missing something elementary here. Should I be getting 49mV from the negative lead of C12?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 10, 2014, 10:36:42 PM
Transistor voltages are off.

Q4
c=23.8V
b=1.13V
e=670mV

Q3
c=1.13V
b=27.6mV
e=0.4mV

Q2
c=23.8V
b=670mV
e=49.4mV

AFAIK the should be Q4 22.6v, 3.1v, 2.5v Q3 3.6v, 0.9v, 0.4v Q2 22.6v, 3.6v, 3.1v I have checked for open resistors. My voltage is 23.8 so there is no voltage drop at either Q4 or Q2's collector. Still getting 29.8mV across R26. The hunt continues.  :P
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on June 30, 2014, 03:29:38 PM
I'm really sad to say that I've run out of ideas troubleshooting this preamp. I have figured out what happens but I am not sure why. Here is the order of things.

1. Replace Q4
2. R26 starts at 95.5mv for 10 to 15 seconds
3. mv at R26 start rising until it reaches 328mv and stays there
4. If left turned on too long Q4 gets damaged.
5. Rinse and repeat.

All other voltages on all other transistors check out fine. I have replaced all three transistors on the output stage several times just to make sure. I replaced R23 for a 1 watt. Replaced R7 with 1 watt just in case. All resistors and caps test fine on the output stage. All resistors and caps are the correct value. Nothing is grounding that shouldn't be. Quadruple checked all solder joints with magnifier. Checked the 10k potentiometer R149.

I am not going to quit but I just don't know what else to do, what else to check, where to look next. I am really hoping someone can give me a clue as to what to check or test for. I am at a complete loss. I think I can draw out the output stage schematics with my eyes closed.  :'( If anyone has any ideas, no matter how strange they may sound, please let me know.

Thanks,
Alain
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on July 15, 2014, 05:48:42 PM
Hi all,

I am about to start on this project, and I'm working on sourcing together the parts that are not included in the kit from AML. Has anyone compiled some sort of shopping cart, or excel spreadsheet, or whatever really, on the other stuff that's needed? That would make my head swim a little less from counting together M4 and M3 screws from the different pages of the colour book. I'm sure it'll be fine anyway if I order it all by my lonely self, but I also know that I will overlook something obvious and walk around for, at least, a whole day muttering "you're such an idiot" under my breath, and to be honest, I'd rather not do that.

Looking forward to diving into this project. A whole lot! I promise pictures and anecdotes from the process, and whatnot.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: allprod on July 30, 2014, 01:53:07 AM
Hi Ding!

Did you find the solution to your problem with the ez1073?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on July 30, 2014, 08:36:55 AM
nope sure didn't. and since I am moving right now its going to be a couple of weeks before i can bash my head against a wall with this again.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: allprod on July 31, 2014, 03:10:07 AM
The problem surely come from a transistor that ask too much for current as it is not working properly.
Test all the transistor dc voltage between base and emiter you should find 0.6V.
If you find a lot more then change the transistor.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: fripholm on August 11, 2014, 04:35:40 PM
Hi all,
I've just finished soldering my first ez1073. Although everything worked from the get-go, I'm reading only +23.5 volts between J5 and J6 which is slightly out of the range of the 2 % tolerance of the 7824. But everything seems to work fine so far, line and mic input, phantom power as well as the EQ. The unit sounds great and even the amount of hum is negligible which I find a bit strange as I don't have an enclosure yet.

When adjusting the output bias I measured THD using a software scope when the unit was connected to my Fireface UFX. THD is at its lowest value when the voltage across R26 is just 55 mV - far below the recommended 120~130 mV. When I adjust R20 to get a reading of 125 mV, THD is getting much higher.

Could this be related to the low voltage on the +24V rail? After all, is something wrong with my build or are those readings within tolerance?



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on August 22, 2014, 12:38:52 PM
Just a thought-

What other output transformers could I try in the ez1073 (diy 1 unit version). Heritage Audio have a red/maroon transformer
 in their 1073 clones. AML have a good range of these transformers in stock. Would they work in this preamp?

Haystack
 ::
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on August 25, 2014, 09:29:52 AM
EZ1073 output transformers:

Instead of VTB1847 would VTB2290 or VTB9049 work I wonder? Or are they the same?If not what are the differences?

thanks

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on August 25, 2014, 01:45:17 PM
Hi

I was looking at the color assembly book and would like to confirm one thing. The pcb is made of 2 layers and the for the ground plane (analog gnd) it's the bottom surface of the pcb? So, when mounting, for exemple, the Q2 heat sink, we probably have to isolate the screw with some king of pad or washer??
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 25, 2014, 04:32:42 PM
Yep - you should pretty much always isolate the Vreg from the heatsink.  It is the correct habit to get into
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on August 28, 2014, 10:31:15 PM
Sooooo.... I've got 2 units built. And neither works   :'(

1. The first one powers up and I'm reading 24V and 48V, but the signal is really quiet. I've have to crank the mic input to get any sound, and that is negligible. Any suggestions on where to look?

2. The second one blows the fuse within a second of powering up. I'm getting around 33-40 ohms between the 24V rail and the ground rails, so I'm assuming there's some sort of short, or maybe I misplaced a resistor? Any suggestions there?

Thanks for all the future help guys!  ;)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: rob_gould on August 29, 2014, 06:46:45 AM
Sooooo.... I've got 2 units built. And neither works   :'(

1. The first one powers up and I'm reading 24V and 48V, but the signal is really quiet. I've have to crank the mic input to get any sound, and that is negligible. Any suggestions on where to look?

2. The second one blows the fuse within a second of powering up. I'm getting around 33-40 ohms between the 24V rail and the ground rails, so I'm assuming there's some sort of short, or maybe I misplaced a resistor? Any suggestions there?


Thanks for all the future help guys!  ;)

Grab a magnifying glass, start checking for correct components values and also for bridges / solder splashes which are shorting connections together.

For #1, what happens when you try a different mic? And what about the line input? Does that work?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on August 29, 2014, 11:09:47 AM
Sooooo.... I've got 2 units built. And neither works   :'(

1. The first one powers up and I'm reading 24V and 48V, but the signal is really quiet. I've have to crank the mic input to get any sound, and that is negligible. Any suggestions on where to look?

2. The second one blows the fuse within a second of powering up. I'm getting around 33-40 ohms between the 24V rail and the ground rails, so I'm assuming there's some sort of short, or maybe I misplaced a resistor? Any suggestions there?


Thanks for all the future help guys!  ;)

Grab a magnifying glass, start checking for correct components values and also for bridges / solder splashes which are shorting connections together.

For #1, what happens when you try a different mic? And what about the line input? Does that work?

I've already looked for bridges / solder splashes and cleaned the board a few times, so I don't think it''s that. But I'll be sure to go through the components next.

For #1, I tried a dynamic mic that's usually pretty loud. I didn't have any success with the line in.

Also, for #2, I did find that if I took r26 out, I lost the short between the 24V rail and ground.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on August 31, 2014, 01:17:30 AM
Ok, figured out #2. The heat sink on Q2 was causing a short for some reason. I fixed it by taking it off and putting it back on.  :-X  Maybe I just had it on too tight?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on September 01, 2014, 01:27:59 PM
Any thoughts on what might cause the eq to pass a really distorted signal? With all the filters turned off and the HF around 0db, I'm getting a lot of distortion on the eq with a big volume drop. I'm assuming there's a problem with one of the the op-amps, but I wanted to see if anybody had a suggestion.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on September 06, 2014, 12:28:26 PM
So while trying to troubleshoot my eq section, something must have gone wrong and now all I get is pops and static coming out of the ez1073. When I have a microphone plugged in, it seems to act like a speaker and I can hear the pops and cracks coming out of it. My voltage rails are reading fine. I've tried replacing a couple transistors (Q3, Q4) but that didn't seem to do anything. Does anybody have any ideas where to look? Not sure if I should just start emailing Colin.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: philipNL on September 06, 2014, 04:43:53 PM
Does anyone know if this ez1073 sounds the same/as good as a pre built ez1073-500 in lunchbox format? Or are there different components used?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on September 19, 2014, 01:25:41 AM
Good news is that I was able to get the preamp sections working on both my units. I had a few bad transistors between the two units. Checking for around 600 mA between the base and the emitter is the key there.  But be really careful when you pull those things out when replacing. These boards can be pretty fragile.

Bad news is that the EQ's are not working correctly.
- On the first there is a lot of distortion and the signal is pretty low.
- One the second there is a lot of pops and static

Anybody have any thoughts about the EQ sections?

Thanks!

*Edited for grammar*
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on September 19, 2014, 02:02:05 PM
Look, I know this isn't very technical,  but the pops and static I have had when completing a project were down to
soldering errors. I too had loud pops and building of static noise in one project.  I look over the pcb and all joints under a glass and found  some joints that I hadn't soldered properly. The joints were not easy to spot but once gone over with a soldering iron/solder
the pre amp in question was sorted but it took a couple of goes.

Hope you get your ez's sorted out. Don't give up.

Haystack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on September 19, 2014, 06:15:23 PM
I'll check the soldering around the eq sections again, but I've gone through the joints with a magnifying glass and checked for bad joints a few times already.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on September 25, 2014, 09:20:38 AM
Hi guys

Quick one for you. Concerning the heatsink installation HS-1 and 2. Do I have to put some TO-220 insulating pad between the regulator and the heatsink? Secondly, Do I have to solder the heatsink pin on the pcb pad? Thanks folks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on September 26, 2014, 07:10:05 AM
The amount of heat it generates is minimal.... the 24v regulator heatsink only gets luke warm... and the 48v heatsink is really only there for mechanical support.

So there is no need for insulators.... soldering the heatsink pins is desireable for mechanical stability.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on September 26, 2014, 11:22:17 AM
thank you colin. I'm finishing mounting it all and now, I have a question about de main switch. In the color book tt asks for a DPDT switch. Why not a DPST? I'm a little confused about which one I need (On-ON, ON-none-ON, etc. etc). ON-ON seems the simpler to find.

I linked a drawing with a configuration of DPDT and one SPST. I would like to know if I'm correct.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: brewbacca on September 26, 2014, 01:57:52 PM
Figured out the unit with distortion.  I had a short to ground somewhere between r65, c61 and q14. I couldn't figure out what specific component was responsible and didn't see any solder bridges, but replacing them seems to have done the trick. So now the EQ is working.

Edit: Got the second unit to not make pop/static sounds by yet another touching up a couple joints connected to ground and then yet another cleaning with alcohol.

So now I'm in business.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: KJ on October 01, 2014, 11:06:46 AM
Hi all,

I've spent hours reading the forum but I still don't quite understand what's not working with my ez1073. I read 24V between J5 and J6, as it should, but between J3 and J5 it's 45V and nothing happens when I adjust the R10. And I get 360mV at R26 and nothing happens when adjusting R20. I understand there might be a problem with the 2N3055 that the shakeproof washers causes a short, but I don't quite understand how. I tried with M3 screws and washers instead, but the problem remains. Does anyone have any idea what might be wrong?

Cheers
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on October 02, 2014, 09:22:37 AM
Finished building 1 EZ1073. No issues, everything run as expected. Calibration went fine, no noise, no hum, totally silent. Huge sound, fat, nice eq. Awesome job Colin. Thank you.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: olebrom on October 20, 2014, 01:24:17 PM
Hi,

Finallly got around to build this. Had to change q4 and the 2n3055 before the unit passed any sound. Everything seems to be working so far except the mid freq pot. The following frequencies are working : Off, 360hz, 700 hz, 1600hz. The rest are not working or occasionally working. If I fiddle the pot back and forwards a few times suddenly its all ok. Fiddle back and forwards again and its not working.  When its not working I can sometimes "push" the pot and it works. I have re- soldered  all the points that corresponds to this pot so my guess is that the pot is not working correctly... ? Any tips or hints? Change the pot?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: andrea19837 on October 23, 2014, 09:04:07 AM
my MID FREQ don't work at all. all the others are perfect, and VOLTAGE is perfect, no hum no noise, the line and mic pre work like a charme, only the mid FREQ don't work at all..any advise? maybe a fault inductor, or transistor in OP AMP B? or a POTENTIOMETER faulty? :(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: andrea19837 on October 23, 2014, 06:45:27 PM
OK, i fix it.. now everything work 110%.

COLIN SUGGEST AND FIND THE RIGHT FAULT:

"Andrea,
 
I expect that the switch was rotated when you fitted the pins.
 
Remove both pins… put the switch in the position which it shows in the build manual… refit both pins.
 
Regards,
Colin Adshead"


wannabe mistake :) bytheway It's sound wonderfull .

thank you.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on November 29, 2014, 02:14:53 PM
Hey there. . Just a quick one for ye. I built two of these units..  both worked first time when I plugged then in.. just one issue tho.. one unit is 4db louder than the other.. don't notice it when doing anything on solo channels but when working on stereo channels it's an issue.. just wondering would anyone have any ideas? Am I right in saying the output knob should always be up full to get same level as input or should it be half way? I seem to be able to get both units matched in level when one units output level is half way and the other is fully to the right..

Thanks

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on November 29, 2014, 03:03:31 PM
Just a quick thought-

you don't have the eq  on,  on one of the units and not on the other?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on November 29, 2014, 04:34:14 PM
have you tried switching the cables going into the preamps?  maybe one of the cables is bad and if you swap them them the other channel is then louder?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on November 30, 2014, 08:23:06 AM
Hey thanks for the replies..

No tried both units with the eq off and the eq on but everything at 0 and its the same problem..

Ive also tried changing the cables to the unit and the same issue is there.. Its not a cableing issue

Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: haystack on December 01, 2014, 04:38:52 AM
Could be worth just checking your resistor values carefully.
Hay
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on December 21, 2014, 05:18:09 PM
hey there ive checked all the resistors on both units and they all match up..

thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on December 22, 2014, 03:14:15 PM
Hey there, just a quick one.. i seem to be able to make up the levels close enough by turning the line in gain down one notch on the unit thats 4db louder. Would it be possible i put the pin in the wrong place when in stalling the knob?

I was running a 1k tone through each unit and then knocking one out of phase.. Should the tone cancel itself out completely? Its dropping level but not canceling out completely.. Would this be normal?

Thanks a million
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on December 27, 2014, 08:17:41 PM
Hey there,would anyone have any ideas on what might be causing the 4db difference? thanks in advance
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on December 28, 2014, 11:21:43 AM
are you sure you have the xlr hooks ups right?  from the pcb to the xlr sockets on the case.  Do you have the same wiring on each unit?   Just trying to think of things I have done in the past.

I don't think the stop pin would affect it  that would allow you to turn it past the writing on the front panel.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on January 02, 2015, 04:25:19 PM
I get 360mV at R26 and nothing happens when adjusting R20.

New Year and I finally got everything together enough at my new place to start fiddling with DIY again.

@KJ
I am having similar issues with R26 going up to 360mV, the Q4 transistor starts to get really hot. I went all out and replaced all of the transistors (checking each one carefully) just in case but that did not fix the problem. All of my other transistor voltages measure correctly. I have measure carefully around the output stage and everything seems to be soldered correctly. I even rigged Q3 and Q4 to be easily replaceable but haven't found what the problem is yet. Here is an image of my output stage. I'm kind of out of ideas and there is no tech in my area that can help me. I would love to get this working.

Anyone have any ideas or similar problems????
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 15, 2015, 12:05:29 PM
Hi All,

I have just finished my ez1073 1U build and all seemed to go well but I can't power the unit - I keep blowing fuses.

Anyone who had similar experiences - what are the first things to look for?

My build was a bit of a squeeze into the Collective cases unit - to the extent where when the unit is all connected up the bottom plate bows quite a bit - I also couldn't get a standoff under the front right of the PCb near the mic gain - not sure if this is an issue? the unit is on standoffs apart from that one so hopefully nothing is shorting underneath.....

I am using standard 100mA slow-blow fuses from Maplin in the UK and have followed the build diagrams religiously. A picture of my build up to now is attached. Any help anyone??? Eager to get this unit powered up.... ;0)

Spadehead
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 15, 2015, 12:38:04 PM
God help me - I think my blood sugar is low - making silly mistakes but I think I figured it - wired the power switch up wrong. Doh!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 16, 2015, 07:02:10 AM
Okay so the unit is working -  calibration worked a treat first time. Just goes to show that one silly mistake can cause a headache.

Problems aren't over though. I'm getting nothing on the Mic input. Nada.

Line input works fine, as does the EQ - everything working as it should but no Mic signals. Thoughts anyone???

Spadehead
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on January 16, 2015, 07:43:15 AM
Double check your connections from the pcb to the xlr connection.  I had an issue with that where the molex wasn't touching properly.  Good luck.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 16, 2015, 08:24:55 AM
Double check your connections from the pcb to the xlr connection.  I had an issue with that where the molex wasn't touching properly.  Good luck.

Thanks for that - I have just checked the soldering - I am going to the PCB direct without the molex headers - can't stand those things! All seems good. Must be a fault somewhere else....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 16, 2015, 12:31:00 PM
Minor update. I can get a very faint signal with dynamic or condenser but only when mic gain is at +70 and trim is up all the way. At this point the noise is louder than the signal!!

Seems that 48v is working but almost non-existent mic signal. I have gone over all the soldering on components and switches in the mic section. Any ideas anyone??
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 19, 2015, 04:54:31 AM
Anyone?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mickdundee63 on January 20, 2015, 11:09:21 PM
Minor update. I can get a very faint signal with dynamic or condenser but only when mic gain is at +70 and trim is up all the way. At this point the noise is louder than the signal!!

Seems that 48v is working but almost non-existent mic signal. I have gone over all the soldering on components and switches in the mic section. Any ideas anyone??

I am having a similar problem - line level Ok but mic input very very low. Weird thing is I know this unit was working a couple of months ago and I have just pulled it out again and having the problem. I have a second unit I know is working fine so when I get it back later today I'm going to do some continuity and voltage comparisons to see if I can figure this out.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: mickdundee63 on January 20, 2015, 11:38:28 PM
OK i figured  my error, it was the mic gain switch. I had not soldered in the first deck pole pin. It must have been leaning against the pad when I first fired it up. I see you said that you checked all the switches so this might not be your issue but thought I'd let you know.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 21, 2015, 05:37:40 AM
Thanks Mick, I'll take another look. I also read a few pages back to check Dc volts between B and E on the transistors so I'm going to take a look at that today as well. Fingers crossed, thanks for the reply.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 21, 2015, 06:48:23 AM
Okay so I have removed the PCB again, taken off the front plate and checked all transistors between B & E and all check in at around the 0.6V mark. Switches seem to be soldered ok - still no mic signal and running out of ideas. How would I check the mic transformer or is that not a likely culprit?

Anyone with some more suggestions of things to check?

Spadehead
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on January 21, 2015, 07:28:47 AM
Anyone have listed voltages for the schematic? I'm trying to track down issues and this would probably help!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: porkyman on February 06, 2015, 12:51:41 AM
Okay so I have removed the PCB again, taken off the front plate and checked all transistors between B & E and all check in at around the 0.6V mark. Switches seem to be soldered ok - still no mic signal and running out of ideas. How would I check the mic transformer or is that not a likely culprit?

Anyone with some more suggestions of things to check?

Spadehead

have you checked phantom power. my switch seems backwards. up is off down is on.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on February 06, 2015, 08:24:04 AM


have you checked phantom power. my switch seems backwards. up is off down is on.
[/quote]

Thanks for that but I think that's the way it's supposed to be - mine's the same at any rate.

Just a follow up on my unit for anyone that's interested or maybe having the same issues - my unit is now fixed and working correctly.

I was getting a clean Line input and the EQ was all working correctly so that narrowed down the search area considerably - thanks to Colin as well - a quick phone call and some advice on trace checking helped no end.

I had some bad soldering on the mic transformer - around the sil headers and trying to remove all this from the board led to me essentially wrecking the unit so I decided to start again with a new 9045. I got the small PCBs cleaned nicely so could put them on the new transformer and get it neater.

I was also losing the trace at c28, the small ceramic right by the mic transformer and one of the first places the signal goes after the input. Once this was swapped out for a new one and the input transformer was put back neater then the signal came through clear and strong!

Happy days!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: toobnoob on February 06, 2015, 01:39:31 PM
Up for Off is pretty British. My Trace Elliot Amp is the same way

 8)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on February 23, 2015, 07:26:45 AM
Hey everyone.. Im wondering if anyone would be able to give me a dig out.

Ive built 2 of these units. Both units are working away, 1 unit is perfect but one unit seems to be 4db louder.

Ive tried every test i can think of.. running signals through etc. Ive also brought it into a tech in a local electricial store but to no avail.

Ive attached 3 pics of the unit and just thought maybe if anyone had any time to take a look a fresh eye might notice something we missed..

I would really appreciate it if anyone had the time to look as it driving me mad having these beautiful units sitting in the rack and not been able to use them as a stereo pair.. :-P

Thanks in advance

L

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on February 23, 2015, 07:27:21 AM
Pic 2
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on February 23, 2015, 07:27:49 AM
Pic 3
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on February 23, 2015, 09:03:53 AM
Someone has a similar issue in this thread so maybe check back a few pages?

Also were the small pins out into the grey hill switches with them rotated fully CCW? You may have one gain pot set one notch further on than it should be if this is the case....

Best of luck with it.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on February 23, 2015, 01:05:29 PM
Hey thanks for the reply.. i think that was me who was having the issues a few pages back.. never got it resolved tho unfortunately :(

thanks

Someone has a similar issue in this thread so maybe check back a few pages?

Also were the small pins out into the grey hill switches with them rotated fully CCW? You may have one gain pot set one notch further on than it should be if this is the case....

Best of luck with it.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on February 23, 2015, 01:07:56 PM
Also i dont think its a pin in the switch issue as im having the same issue on both the mic and line.. if it was a pin id only be having it on 1 of them i reckon.. could be wrong tho..

regards
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: who on February 25, 2015, 11:08:20 AM
i did a nice classic frontpanel design for this great project and here is the complete Rack kit:
(http://www.don-audio.com/bilder/produkte/normal/EZ1073-Frontpanel-DON-EZ1073FP.jpg)
http://www.don-audio.com/Frontpanel-DON-EZ1073
  :) Don
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on March 06, 2015, 04:34:29 PM
Maybe someone can help me understand what just happened. Q4 was overheating and getting way too much voltage. After trouble shooting forever I found a tech in town. 2 months and $170 later he told me that the 2N3055 was not functioning because of the insulator between it and the heat sink. He removed the insulator and was able to bias properly. I'm confused.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on March 07, 2015, 04:47:46 PM
I am having difficulties with this project and I am hoping someone will be able to guide me. After my whole ordeal with the transistor insulator now the preamp passes audio as expected but the sound is missing all the low end. It has no hum but absolutly no low or high end. I am hoping that my output tranny is not fried. Anyone have this problem before? Anyone have any ideas on what can be going on?  Here is a quick sample. Preamp 1 is the ez1073, preamp 2 is the focusrite interface. I was pretty close to the mic so there is lots of proximity on the focusrite but absolutly no low end or high end on the ez1073.

https://soundcloud.com/palevoid/preamp-test

EDIT:
Ok, weird thing happened. I plug it into my interfece XLR to TRS and I get no low or high end. Plug it into the interface XLR to XLR and get a little of the high and low back. Not where it should be. I also get a bit more noise/hizz XLR to XRL. I guess I will have to take it to the studio at work and run it thru the protools interface and see what is really going on. Any opinions?

https://soundcloud.com/palevoid/preamp-test-2
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on March 11, 2015, 08:24:00 PM
hi guys

I build a unit for a friend and he used it for 2 months now and suddenly, there is no more sound coming out of the unit. The led still lit, so I guess it's after power supply. no smoke, nothing burned, everything was good before now. No special use, just vocal sessions. the unit is powered through a furman. I really don't know what it can be
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on March 12, 2015, 07:42:25 AM
ok little update. The trouble seems to sit in the trim pot area. When playing with the trim, the signal become intermittent. Could it be a defective pot or it's more like  a cold solder joint symptome?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leitrim_lad on March 12, 2015, 07:51:47 AM
Hey Colin. . So I checked the stage 2 circuit.. checked all resister value.. resoldered everything to make sure of no soldering issues but I'm still getting the same 4db more at the output trim.. would you have any other ideas? Thanks a million..
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: RJS on April 23, 2015, 04:10:12 PM
Hello,

I would like to add an LED to the phantom power switch so it lights when phantom power is switched on--or at least when the switch is in the on position.  Basically to help me avoid accidentally putting phantom power through my ribbon mic.  Are there any issues with adding an LED indicator to the phantom power switch, tapping off the 48v?  Will doing this effect the mics that need phantom power?  Should I get the voltage from somewhere else to power the LED.

Thanks,
Robert
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: saxmonster on April 23, 2015, 07:17:38 PM
Does phantom power really hurt ribbon mics?  Maybe the newer ones are ok with it but I guess the vintage ones might have issues with it.  I thought I read that it would be ok if it was left on.  I'll have to read  up on it.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: RJS on April 23, 2015, 09:59:26 PM
Does phantom power really hurt ribbon mics?  Maybe the newer ones are ok with it but I guess the vintage ones might have issues with it.  I thought I read that it would be ok if it was left on.  I'll have to read  up on it.

It's an AEA R84, not a vintage one, but I've heard conflicting reports about possible damage, so I'd rather be safe then sorry.  Then again I could just be extra careful when using the preamp.  I guess I'm  just used to seeing something light up when I hit the phantom power button  ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on April 24, 2015, 04:01:07 AM
I've had issues with ribbons and phantom before and it's well documented so not worth risking - especially with more expensive mics.

Cheap option is to just ascertain the switch "on" orientation and mark it somehow on the faceplate - maybe a small round sticker or some sort. It's what I've done and certainly avoids mistakes without going back to the workbench......
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on April 28, 2015, 09:09:36 AM
ez1073 with no low end.  Anybody?  :'( My guess would be a bad transformer or cold solder on the transformer points but I have checked the solder points. Plus I am getting plenty of gain. Also a good amount of hiss  :( . If any of the transfos were shorted or if I had cold solder joints wouldn't I have loss of gain? Any ideas? please.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Spadehead on April 28, 2015, 11:18:27 AM
Someone had a similar issue a few pages back so have a look - are the switches oriented properly with the stoppers so you don't have the HPF engaged when you think it's off?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on April 28, 2015, 06:57:12 PM
Someone had a similar issue a few pages back so have a look - are the switches oriented properly with the stoppers so you don't have the HPF engaged when you think it's off?

Thanks for your help. Switches are oriented properly and I have lack off bass even when the eq is off.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ding on April 29, 2015, 12:44:40 PM
I noticed the hiss is irrelevant of my gain settings. it is always as loud. Both mic and line inputs sound similar. I did some measurements on the line input and also noticed a small dip in the high end.

Here is the hiss

(http://s14.postimg.org/bbhufuy2p/hiss.png)

Here is the sweep

(http://s22.postimg.org/g3dyr49a9/plot_2.png)

Anyone ever run into this? I know it almost never is but could it be the output transformer? Any cap that would cause this? I have searched this forum well but have not found this problem here. Anything would help.  :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: burtoni on May 06, 2015, 05:44:45 PM
Hi this is my first post..

I have built 6 AML units.. EZP-1A,  EZ2254 AND 4x EZ1073....

All went very smoothly and work fine until I got to my last 1073.. I get no LED, only 4v on the 48V tab, a hum and low level on the output.. and the 48V rectifier heat sink it red hot.

24v is fine and I was able to set the Output bias ok.

Sounds like some kind of short but I can't see anything visually. Anyone come across this
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Squeaky on June 04, 2015, 07:46:45 AM
Hello Everyone. I have a problem similar to what has been mentioned here before.  The preamps (two of them) both fired up fine and I was able to get correct voltages and then audio passed fine, eqs worked, &c. Then I screwed everything fully in place in the cases (lids on and so on), plugged them in again, and I burnt out r23 (it smoked) on not just one but both preamps. Methodically, one after the other (in my infinite and bottomless stupidity) I sequentially killed both preamps. Given that they only just fit into the cases, (and one of the bobbins on the OT on one of them was a bit askew making it even worse) I have just assumed I have created a short somehow when I screwed the PCBs into their cases (they barely fit, if squeezing can be considered fitting). Just to be clear, the squeeze is top to bottom and it is only the OT that is in contact with the chassis.

My first thought always goes to killing the OT, probably because I always think the worse. The OT bobbin is definitely hard up against the chassis top, but I didn't think this would matter. This is my first PCB kit (not quite true, I bought a ua-175B PCB, which I subsequently threw away and built the thing on a turret board instead), so I find it hard to follow the ground, power and audio paths, because I didn't lay them out myself I guess.

I replaced r23 to no avail, and now I have the problem of 28mV - 29mV over r26 un-adjustable with r20, which is an open circuit in the output section I understand. I have ordered a few of transistors for replacement.

I think the screw to the heat sink on one of the 2n3055 transistors might have been in contact with the chassis creating a short? This wasn't the case on both pres though. This is my first foray into the transistor world, only valve projects before this. I am at a bit of loss. Might be time to get back to that V76 I was working on (daunting as that is).

I can't help thinking that I killed the OT, would anyone be able to suggest a way to test the OT on the board? Otherwise I'll just replace transistors in the output I suppose.

I'm really hoping I can sort this out because the little I heard of the operational pres was very promising.

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: weiss on June 04, 2015, 08:31:33 AM
I noticed the hiss is irrelevant of my gain settings. it is always as loud. Both mic and line inputs sound similar. I did some measurements on the line input and also noticed a small dip in the high end.
Hey can you tell me where to find this analyzer application? Is it free?

thanks
weiss
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Squeaky on June 07, 2015, 06:21:41 AM
Managed to get them back up and running, OTs are fine. I bought a transistor mica for the 2N3055 and just cut the end off so as to maintain circuit continuity (bottom plate is still in contact with the screw hole that is part of the circuit). I think the original problem was a short at the 2N3055 transistor through a bolt touching the bottom of the chassis. I'm using a bolt with a lower profile head. I put a 2N3442 in instead of the 2N3055, seems good so far. Still trouble shooting one of the pres. I'm maintaining 130mV over the 1r resistor but it sounded like a component started failing somewhere when switching the eq in and out? Time to check my soldering and other components in the circuit.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: colonel_sanders on August 20, 2015, 12:43:31 PM
Hello,

I've just finished two units.  One works perfectly and sounds great! The other, well...

When I power the unit on, all voltages are correct, but there is a large hum when I listen to the output of the preamp.  Then when I tap the the input transformer with my finger, I hear a huge huge sound, like the transformer was microphonic...?

Does anyone have any idea on where to start troubleshooting?

Best regards,
C_S
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Deepdark on August 21, 2015, 08:55:05 AM
maybe one of the pad isn't well solder (the thermal pad are hard to solder sometimes with that big groundplane). did youtest all your ground point to check for continuity, etc?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: colonel_sanders on August 24, 2015, 12:38:05 PM
Thanks deepdark!  I'll check now  ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sysexguy on September 16, 2015, 10:53:02 PM
Super happy, my pair are 100% from the first power-up. Thanks for offering this great kit (mine were from the partial kit era which meant for a bit of scavenging, the least fun part)

Andy
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on October 01, 2015, 05:09:31 AM
Andy,

Glad it worked first time..... partial kits were from years ago..... all the painful scavenging is no more...... we have gone one stage further with the ez2254 as it contains the chassis and everything else as well...

Colin
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chefducuisine on October 01, 2015, 05:24:46 PM
Colin,

I just wanted to thank you for making the ez1073 available to us.
Mine is in heavy use since I built it and I couldn't be happier.
Please check the link below for an example.
http://groupdiy.com/index.php?topic=59704.0 (http://groupdiy.com/index.php?topic=59704.0)

Regards,

Christian
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jackiegreene99 on November 24, 2015, 05:11:26 PM
HI there! Is there a build guide that's been consolidated to a single thread somewhere on GroupDiy? I'm searching, and I can't seem to find it.   My main concern is wiring.  The PDF colourbook download is pretty comprehensive, but I'm a little confused on wiring.  I haven't bought the kit yet, as I like to look over all the info/instructions that I can before I get in too deep! Thanks kindly - jack
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jackiegreene99 on December 07, 2015, 09:44:41 PM
Hi all - I'm almost through building this wonderful kit.  The colourbook was super helpful and logical.  Lots of thought went into making it a simple project for dummies like me.  I have a few questions:

My kit was missing the 510r resistor, so I linked a couple together to get 510r.  Is that going to be a huge issue? 

I lost a couple of the greyhill pins.  They are so freaking small...I just cut the leg off of some unused caps.  Is that going to be a problem?  They aren't made of titanium or anything, right?

I'm also slightly confused at how to wire the power transformer to the ground/IEC inlet.  Does anyone have a photo of theirs? I'm in the USA, btw. 

Thanks kindly and i'm really excited about this great project.

Jack 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jackiegreene99 on December 11, 2015, 04:59:34 PM
Hi all - I'm having trouble with my z1073 kit.  Well, I assume there's trouble.  I'm through building it and wiring it and I'm in the "calibration" stage.  The very first thing the colourbook says to do is measure the V across J5 and J6 spades.  I'm supposed to get 24v.  I get like .587 something DC.   I'm pretty sure I wired the AC inlet correctly. (I'm in the US).  I get 120v on the money. 

Can anyone help me? I have no idea what the problem could be. 

Thanks!

Here are some photos:
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jackiegreene99 on December 12, 2015, 12:53:57 AM
Well, as it turns out I accidentally swapped the Voltage Regulators.   Now all is fine! The Mic Pre sounds good but I have an awful buzz when I flip the EQ channel on.  Any suggestions?  I read about folks grounding the XLR directly to the chassis, but the buzz is only when the EQ section is on.  Seems like it would be buzzing on just the mic pre as well. 
Any hints?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: schrobbelbop on February 15, 2016, 10:14:46 AM
Just finished up my ez1073. A few problems!

-Midband freq selector is @ off, almost no audio passing
-Constant boost  when mid freq is choozen but whay higher freq's and nog
-Mid boost/cut pot acts way to extreme, when turned down audio is gone and does like tons of boost!

-HF Shelf /LF Shelf seems to be ok.

who knows where to start searching, i already  checked for bad soldering
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: schrobbelbop on February 15, 2016, 10:36:08 AM
Well that's fixed by now, a damaged path on the pcb by the mid gain pot.

but the output of the unit waaaay to hot!

even with the line in at -20 db gain, the output is still more then the original signal
same with mic inputs, way to hot and distorting the output even with gains all down.


Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: schrobbelbop on February 16, 2016, 05:33:46 AM
all right, fixed it!

there was a short between analogue ground/mic/line switch and the 2nd gain stage R80
i've cut the traces and made a bypass, all fine! sounds amazing.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: topistudio on February 16, 2016, 04:05:12 PM
Hi everybody,
I'm pretty new to the forum and have just finished soldering a EZ1073.
Coming to the calibration process, I measured the right voltages for the 48 V supply and the 24 V power, but as I try to adjust R20 to get the 130 mV for the minimum output distortion I cannot get either than 50 mV, turning the screw to both ends...
Trying to feed the mic input with a dynamic mic yelded no result, no output at all even with high gain settings - no buzz or other noise, actually. I've checked the soldering with a magnifying glass and believe there are no evident shorts or misplaced components, but hard to be sure about it..
My electronics skill is quite basic, I've tried fo feed the input with a signal generator (about 1V p2p sine wave) and catching the signal with an oscilloscope, I have been able to follow it through the trafos and the gain switch until the beginning of the first gain stage (R67, I guessed) but then no more...
Anybody could give me some advice about where and what to check first?
Many thanks in advance for the help.

Pietro
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: glazer56 on February 17, 2016, 06:01:17 PM
Are you measuring from both sides of R26? I origanally measured from ground to one side, which will gov you different readings...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: glazer56 on February 17, 2016, 06:01:31 PM
Hi all,
I've recently bought one of Colin's kits and love it. I've been thinking I would love to add a fader to the unit though to have more control over the output, ride levels ect... My thought would be to build a NEVE switching unit, minus the sends and busses to patch in after the pre. I've looked all over but haven't found what R value NEVE used for their faders, as it's not on any schematic. The other option would be to replace the trim knob with a fader before the output section, but again, need to find what value the fader would be. Does anyone have this info by chance? Working the math has never been my strong point!
Many thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: topistudio on February 18, 2016, 04:15:14 PM
Hi Glazer,
Thanks for the hint. I'll do a check as soon as possible.

Pietro
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: topistudio on February 21, 2016, 03:52:35 PM
Hi,
I did the check suggested by Glazer, the reading from both sides of R26 to ground gives 23,6 V (being a 1 Ohm resistor I guess it is correct, from the schematic I believe it is a resistor placed there to have a point to measure the current flowing towards the amplifier stages): the same value I get reading across the 24V "spade" terminal to ground.
The voltage drop across R26 is more or less always 39,6 mV, either turning the R20 trimmer.
The only thing I'm able to think is that there is a short somewhere in the signal path, I'll do a triple check..
Any other hint?
Many thanks,
Pietro
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: samguaiana on May 11, 2016, 10:19:25 AM
Bit of a random question, but does anyone know if the Neve 8816 knobs would fit on the ez1073-500?
Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jaymz168 on June 13, 2016, 10:55:39 AM
I've finally got some time off to get started on this build and run into a tiny problem:  I seem to have cracked to the outside of two resistors.  I was placing two different resistors with my multitool (don't ask) and I seem to have squeezed a little too hard and cracked the outside.  I'd like to replace them, codes are easy to read and all, but I'm not 100% sure on the wattage. 

Can you confirm that the  3k9 and 4k3 are 0.25W metal film resistors?

PS I really wish we could search within topics.  Also thanks for providing this kit and for the super fast shipping!

EDIT:  A little google-fu with the "site:" argument lead me to the answer of .6W metal film.  BTW, if I wanted to be weird and match the looks what brand did you use?



Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 14, 2016, 11:26:04 AM
http://www.rapidonline.com/vishay-metal-film-resistor-1-0-6w-box-of-1000-561947

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jaymz168 on June 14, 2016, 10:57:15 PM
http://www.rapidonline.com/vishay-metal-film-resistor-1-0-6w-box-of-1000-561947

Thanks, incidentally Vishay is headquartered about 40 mins from me.  Anyway, I had already ordered some 1% 1/4W metal film, they should be fine for R92 and R145, right?

It's coming along nicely, btw:

(http://groupdiy.com/gallery/0/thumb_42133-140616225156.jpeg) (http://groupdiy.com/index.php?action=gallery;sa=view;id=419)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jaymz168 on June 16, 2016, 02:53:08 PM
OK, while waiting for the replacement resistors to come in I've finished up as much as I can.  I've gotten to the output transformer and it looks like the leads don't match the pcb.  I've checked a ton of pics and it looks like mine has the blue and orange reversed compared to everyone elses.  Do you know if this is just an insulation color issue and the winding leads are the same?  Should I just go ahead and solder the orange to the blue terminal and vice versa?

(http://groupdiy.com/gallery/0/thumb_42133-160616144903.jpeg) (http://groupdiy.com/index.php?action=gallery;sa=view;id=423)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on June 18, 2016, 05:41:39 AM
1/4 watt resistors should be fine.

Solder the blue wire to the blue contact and the orange wire to the orange contact......

[the order that they come out of the bobbin changes depending on which person made it].

Colin
www.audiomaintenance.com

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: jaymz168 on June 18, 2016, 11:22:13 AM
1/4 watt resistors should be fine.

Solder the blue wire to the blue contact and the orange wire to the orange contact......

[the order that they come out of the bobbin changes depending on which person made it].

Colin
www.audiomaintenance.com


Thanks, I had a feeling I may have been over thinking the transformer leads haha.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on August 28, 2016, 09:54:10 AM
Hi guys...
I have some little(???) problem with my unit:
1. for the first 7step, the mic gain work fine....on the other, no audio is present (except for a very very low signal lpf filtered)...for this 5step I have a high bump when I switch it; the spectrum analyzer software, marks a high signal in the low end (below 30Hz).
2. no phantom power (but the 48V is ok on the power supply)

All other sections is ok (line IN, mic impedance, polarity, eq IN, all the eq section).
The hum and noisefloor are very low, except for the 5 mic step with no signal (in this case is present some hum).

I have not much experience with circuits , anyone can give me some suggestions?

thanks..
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on August 28, 2016, 10:34:06 AM
OK, while waiting for the replacement resistors to come in I've finished up as much as I can.  I've gotten to the output transformer and it looks like the leads don't match the pcb.  I've checked a ton of pics and it looks like mine has the blue and orange reversed compared to everyone elses.  Do you know if this is just an insulation color issue and the winding leads are the same?  Should I just go ahead and solder the orange to the blue terminal and vice versa?

(http://groupdiy.com/gallery/0/thumb_42133-160616144903.jpeg) (http://groupdiy.com/index.php?action=gallery;sa=view;id=423)

Hi,
control some welds on the resistor...
it seems be there to much solder:
(https://cdn-learn.adafruit.com/assets/assets/000/001/978/medium800/tools_Header_Joints.jpg?1396777967)


I hope I was helpful...and sorry for my english :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on August 28, 2016, 01:38:29 PM
ok...
I find the problem on the 48V, now work fine.
I bought and used a little tip (0,3mm) for small reophore and I resolder some bad welds  ::)


I still have the problem in the last five step of the mic input... :(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on September 10, 2016, 04:10:44 PM
I find a short in the gain stage1 on a transistor (soldering error).
I check the hfe (about 600), seems work fine; you think is ok or is better to change it?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on September 16, 2016, 06:43:22 PM
Problem solved....
The unit now work fine!

No hum, very low noise and no bump when I switch the pots (except the pot of impedence 300/1.2, but it is normal).

The pre is very good and the eq is "special"...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Daniel S on September 20, 2016, 03:09:43 PM
Hi guys, first timer!  8)

I just finished the build but I'm not reading the correct value on R26, it should be 130mV regulating R20 but I'm not shure I did it right, I had no problem trimming the 48v.
Powered up the unit and transistor Q4 in the Stage 3 started smoking 20 seconds after... it did not happen at the first power up,  it happened after I plugged the XLRs for trying it out. No apparent short between the chassis and the pcb.  :o
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Daniel S on September 22, 2016, 05:24:20 PM
Update, I made sure nothing touches the case below the pcb, replaced Q4 and R26 just to be sure they're working, no smoke now, the unit stays on but only with 200mA fuse, it blows 100mA everytime. I'm in Italy, 220V here.
In the measurements I read 23.8V, the 48V is ok but the damn 130mV on R26 trimming R10 doesn't show up... just can't get it to move plus the reading is really difficult, value keeps on jumping from 1 to random numbers.

Someone has an idea of what the problem could be? Please  :'(
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EstockAudio on September 26, 2016, 01:40:58 PM
For those of you using the EZ1073 w/ the Collective case, what standoffs are you using?  I can't seem to find any that fit properly. 

Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on October 16, 2016, 05:16:24 PM
Update, I made sure nothing touches the case below the pcb, replaced Q4 and R26 just to be sure they're working, no smoke now, the unit stays on but only with 200mA fuse, it blows 100mA everytime. I'm in Italy, 220V here.
In the measurements I read 23.8V, the 48V is ok but the damn 130mV on R26 trimming R10 doesn't show up... just can't get it to move plus the reading is really difficult, value keeps on jumping from 1 to random numbers.

Someone has an idea of what the problem could be? Please  :'(

hai usato un 100mA T?cioè timed?Magari lo spunto del toroidale te lo brucia se è fast...
è solo un'ipotesi eh....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: delichef on October 23, 2016, 08:53:41 PM
For those of you using the EZ1073 w/ the Collective case, what standoffs are you using?  I can't seem to find any that fit properly. 

Thanks!

I'm curious about this as well as a couple of other things. I've built two already and the issues were minor enough that I didn't worry about them. Now that i'm building a few more, i'd like to take the time to finish them all off properly.

- To echo the question above, which standoffs did you use? Are they just providing support to the PCB or do they actually provide a ground of some kind? Some people have mentioned a nylon standoff with an adhesive bottom...could you just use these and not need to drill the chassis? Any links to what you used would be super helpful.

- Connection and ground wiring on the back XLR inputs and outputs...I used a hacked up mic cable for wiring...which was big and hard to work with. What's better wiring to use for this? Shielded vs. non-shielded? I've seen some pics that just have 3 separate wires going from the XLR to the chassis. Could I just use regular 18-22g solid core wire?

- One other question...I've seen some that have a switch added to the back panel next to the IEC power receptacle. Are people adding power switches or ground lifts to these?

thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EstockAudio on October 29, 2016, 01:57:15 PM
I'm curious about this as well as a couple of other things. I've built two already and the issues were minor enough that I didn't worry about them. Now that i'm building a few more, i'd like to take the time to finish them all off properly.

- To echo the question above, which standoffs did you use? Are they just providing support to the PCB or do they actually provide a ground of some kind? Some people have mentioned a nylon standoff with an adhesive bottom...could you just use these and not need to drill the chassis? Any links to what you used would be super helpful.

- Connection and ground wiring on the back XLR inputs and outputs...I used a hacked up mic cable for wiring...which was big and hard to work with. What's better wiring to use for this? Shielded vs. non-shielded? I've seen some pics that just have 3 separate wires going from the XLR to the chassis. Could I just use regular 18-22g solid core wire?

- One other question...I've seen some that have a switch added to the back panel next to the IEC power receptacle. Are people adding power switches or ground lifts to these?

thanks!

I'm still stumped on these standoffs, too.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EstockAudio on November 06, 2016, 11:52:45 AM
Hi Guy/Gals,

I thought I just finished my first one of these and upon powering up I have no signal, so I'm trying to troubleshoot this bad boy before I start the second one.  Here's what I know:

- I get -24V across J5 and J6 and I get the proper voltage for phantom and output bias.
- I don't get any level of any kind out of the unit no matter how cranked the mic pre is
- Turning phantom on and off does generate a small pop and meter indication. 

Any recommendation as where to start?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on November 12, 2016, 09:55:38 AM
If the power supply is ok (24V rail and 48V rail), check the audio signal path.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EstockAudio on November 17, 2016, 04:57:32 PM
OK guys.  Here's where I'm at:

- The mic gain, line gain, and EQ are all working and passing signal.  All frequency points seem to be working.
- Everything lines up with the calibrations steps. 
- There seems to be a low level hum/buzz that's present all the time. 
- 48V doesn't seem to be working at all.  When I engage it, I get a pop and some level into my A/D but it quickly dies off.  I went back to the 48V section of the board and checked all my solder joints.  Everything seems fine. 

Any ideas?

Thanks all!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on November 20, 2016, 03:55:26 PM
99,9% bad solder joint
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EstockAudio on November 21, 2016, 07:14:54 PM
OK guys.  Last one, I promise.

I've got one pre up and running 100% and it sounds AWESOME. 

The second unit works perfectly with one exception:  when the EQ is on, but the low and mid frequencies selection points are set to "off" I get no audio.  The moment I move the EQ's to a selected frequency, I get level.  The is much more noticeable on the mid-band.  It's almost like I'm not getting the original, dry signal.  It seems like I'm only hearing what's added. 

Any tips?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: delichef on November 25, 2016, 02:04:25 AM
How quiet should these be? I've built three so far, and they sound awesome...but I get hiss on the two highest gain settings of the mic input. I assume these are the +60 and +65db settings. Nothing connected to the input. Is that normal or have some people figured out a way to make it dead quiet all the way up?

For people looking for answers on the standoffs and wire...I went with 3mm standoffs and added an extra 1-2mm nut to the screws furthest from the front  panel and the 3mm standoffs by themselves on the row closest to the front panel. This seems to work well on the collective cases.

I used Mogami console wire for the wiring. Which is 2 conductor cable with a shield. I use the conductors for hot and cold, and the shield from the XLR to SCN on the pcb. I didn't ground anything else on the XLR's. For star ground, I did PCB main, Toroid and IEC to star ground. If there are optimizations here that reduce hiss...i'd love to hear ideas. Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EstockAudio on November 29, 2016, 08:18:45 AM
Any help on the post above?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: delichef on November 30, 2016, 08:29:38 PM
The second unit works perfectly with one exception:  when the EQ is on, but the low and mid frequencies selection points are set to "off" I get no audio.  The moment I move the EQ's to a selected frequency, I get level.  The is much more noticeable on the mid-band.  It's almost like I'm not getting the original, dry signal.  It seems like I'm only hearing what's added. 

Any tips?

For no audio problems, I built the billm audio probe. Basically a nail, a capacitor and a computer speaker. I used an app on the iphone to generate a test tone and feed it into the mic pre. Super simple and if you don't have a scope...gives you a way to listen to the signal as it goes through the circuit. It was really helpful in figuring out where the signal stops to narrow down where to look for problems.

For the issue you describe...are you sure the pins were inserted correctly when setting up the pot? Assuming yes, then i'd check for grounding issues and solder joints. But knowing what connections to look at can make it easier. Using the probe, you can actually hear the signal make it to various stages...comparing it to your working one will also help make it easier. Good luck.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on December 17, 2016, 05:44:53 PM
How quiet should these be? I've built three so far, and they sound awesome...but I get hiss on the two highest gain settings of the mic input. I assume these are the +60 and +65db settings. Nothing connected to the input. Is that normal or have some people figured out a way to make it dead quiet all the way up?

My 3 unit don't have a noise/hum/hiss problem.
The noise floor is very very low.
If I still have the screenshot of the spectrum analysis, I post it.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on December 21, 2016, 03:01:31 AM
OK guys.  Last one, I promise.

I've got one pre up and running 100% and it sounds AWESOME. 

The second unit works perfectly with one exception:  when the EQ is on, but the low and mid frequencies selection points are set to "off" I get no audio.  The moment I move the EQ's to a selected frequency, I get level.  The is much more noticeable on the mid-band.  It's almost like I'm not getting the original, dry signal.  It seems like I'm only hearing what's added. 

Any tips?


What the guy above you said. I had a similar issue with a different preamp engaging the HPF, and it was a bad solder joint/, even though I was certain it wasn't.  So either that or a bridge, which could also be considered a "bad" solder joint in certain circumstances.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on December 23, 2016, 10:29:13 AM
My 3 unit don't have a noise/hum/hiss problem.
The noise floor is very very low.
If I still have the screenshot of the spectrum analysis, I post it.

Here is the noise floor
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dane999 on January 01, 2017, 09:14:26 AM
Hi,
my unit was working perfectly, but since recently, a light buzz appears when I switch the EQ circuit on. Any of you have noticed this issue , or have a lead I can follow to track this ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on January 08, 2017, 11:10:54 AM
Is a problem too general.
Control the eq section; and FIRST, check for bad solder (re-check the joint for each component connected at the analog ground).
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: delichef on January 08, 2017, 04:20:20 PM
Here is the noise floor

Thanks for posting! Mine are very quiet, the hiss on the two highest levels of gain seem in line with other units I have tried...but I do notice a tiny bit of hum on a couple of mine that is only audible if you're looking for it. I ordered a couple of Trafo shields to see if that will help. I can hear the difference when I turn off power to the units...there's a window of time between power off and when the sound goes off where you can hear what it sounds like without the toroid in play.

It does make me curious tho...what is involved in moving the toroid out of the box? If I built a box and put the IEC inlet and transformer in it...could I just run the red/white/green wiring up to the pre? Has anyone done this yet?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Gbracam on January 20, 2017, 11:47:38 PM
Hey guys, I need a little guidance on building this ez1073 correctly. This is my first project so I opted for the built up option, I just do not have the time to solder and I still need a little practice at it. I have ordered my case enclosure from Collective Case (should be here any day now), and a few parts from Mouser (XLR’s & IEC – Schurter).

1 - Should I desolder and remove the existing XLR's that were installed?

2- Do I need to add a power switch, and if so is there any particular one I need to get.

3 - Will there be any surprises / additional items I will need to get this installed in the case (mounting screws, stand off's)

4 - What fuses are you using and where can I get them? I think I saw 100mA, anti-surge or slow-blow.

Thanks for the help..!



Gib
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: BluegrassDan on January 22, 2017, 01:57:33 PM
Hey Gib,

1. If you're using Dan's case, you will need to remove the PCB mount XLR connectors and use TWO of these for mic and line inputs: http://www.mouser.com/Search/ProductDetail.aspx?R=NC3FD-L-B-1virtualkey56810000virtualkey568-NC3FD-L-1-B

...and ONE of these for output: http://www.mouser.com/Search/ProductDetail.aspx?R=NC3MD-L-B-1virtualkey56810000virtualkey568-NC3MD-L-1-B

2. I widened the IEC inlet cutout to accommodate an IEC with fuse drawer and power switch.

www.mouser.com/Search/ProductDetail.aspx?R=DD11.0114.1111virtualkey69300000virtualkey693-DD11.0114.1111

and the fuse drawer is sold separately...

www.mouser.com/Search/ProductDetail.aspx?R=4301.1405virtualkey69300000virtualkey693-4301.1405


It installs horizontally and requires only a slightly wider cutout than the suggested IEC without power switch.

3. You will need a couple dozen 5mm nylon standoffs and screws/nuts to mount the PCB, IEC, and XLR connectors.

4. 250V 100mA 5X20 glass fuses are what you need: http://www.mouser.com/ProductDetail/Schurter/00343107/?qs=sGAEpiMZZMtxU2g%2f1juGqbdCHRI5TALuDi72lbWGCM0%3d

Good luck!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Gbracam on January 24, 2017, 02:59:29 PM
It seems I am on the right track. I just received the case and it looks great! I am just waiting for a few more items then I can start the installation.
I appreciate the the help!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on February 02, 2017, 01:00:34 AM
Thanks for posting! Mine are very quiet, the hiss on the two highest levels of gain seem in line with other units I have tried...but I do notice a tiny bit of hum on a couple of mine that is only audible if you're looking for it. I ordered a couple of Trafo shields to see if that will help. I can hear the difference when I turn off power to the units...there's a window of time between power off and when the sound goes off where you can hear what it sounds like without the toroid in play.

It does make me curious tho...what is involved in moving the toroid out of the box? If I built a box and put the IEC inlet and transformer in it...could I just run the red/white/green wiring up to the pre? Has anyone done this yet?

I just finished one and I wrapped it in transformer shielding from Don Audio. No hum.

For the hiss, I get this at the higher gain settings when I have a line from my converter plugged into the mic input (following calibration). When I plug a dynamic mic in, it's super quiet. Plus, the higher gain settings with the trim all the way open is way too much signal for converters. At least any one that I've used.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on February 22, 2017, 12:43:55 PM
Hi everyone,

I've just finished building my EZ 1073 and... It just doesn't't work. The led doesn't light up. I measured the voltage between J5 and J6 and I got a poor 0,5V. I measured J3 and J5 and I get 56, 7. I tried to trim it to obtain 48V but the trimer seems to have no effect. I get no voltage at R26. I have 12,5 and 12.7V ont the white secondary wires from power transformer. I get 19,7 and 20,4V on the red wires.

It seems that I need some help.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on February 23, 2017, 04:00:24 AM
Ok I found the problem... I inverted the two regulators  ;D  now it's time for desoldering.  :-\
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on February 23, 2017, 05:12:03 AM
Ok so,  bulls...t repaired. I get the correct values now. I've been able to adjust the Phantom Power and the Output. Great! Now it's time to put a mic on it... 8)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on February 23, 2017, 06:29:20 AM
Unit tested with a mic on it and it works great, so nice!!! But I got an issue with the line input. Very low signal even when putting the line gain and trim to maximum, the sound is sharp... No bass, no low mids... but no buzz or hiss.
I'll continue reading the 45 pages of this thread and see if someone experienced that already, but any help would be welcome.

Pierrick
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on February 23, 2017, 05:03:37 PM
I have the same problem with the new unit.....
I have a bump when I switch the pot (not in all position).

In the week I check the line section....
mmm, first the stage2.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on February 24, 2017, 04:52:53 AM
Problem solved. In fact it was as simple as the connection with the molex on the PCB. I don't know why the wires are not clipping into the molex. It's supposed to be like this right? when you fit the wire inside withe the special pin, it clips on it ? I didn't hear any clip sound even with trying hard to put them in so, now that my unit is just working as it should, I think I'm gonna solder the wires coming from the XLRs to the board.

I look forward to build a second unit for stereo tracking or feed them with my mixer'x main output buss to get that warm sound on my mixes.

Thanks Colin for this project!

Pierrick
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: U87610 on March 19, 2017, 05:24:37 PM
Hey Everyone!

Quick question for the group.  I have completed my build for the 1u rack ez1073 and am about to fire it up, but am concerned about a possible grounding issue.  The paint on my faceplate came slightly "pooled" in the through holes and was preventing the switches and greyhill's from fitting through the holes so I took a drill and carefully ground the paint down (using reverse and slow speed).  Although the pcb successfully fits in place now, there is continuity to ground on the greyhills and switches that is not present without the faceplate connected.

Will this cause any issues with the circuit?  Will I ruin the greyhill's if I fire it up?  I have everything else grounded to the star ground and am using nylon spacers.

Thanks!

Edit: So I checked for continuity between the pins on the greyhills and ground with the faceplate on and off and did not find any short to ground, so decided to risk it and fire it up since the rest of my build went without any problems.

So other than my light not coming on, the calibration was easy and the unit works perfectly!!

Thank you for putting this kit together Colin!  I am amazed at how incredible sounding this unit is.  I've not had a chance to work with an original 1073 or a clone (BAE, Vintech, etc)  but have a buddy who has a BAE and I'm planning on doing a shootout with his unit.  Either way, I'm really happy and can't wait to rack it and start mixing!!

I'll try to post pictures in a bit.   
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on April 06, 2017, 04:17:57 PM
Hi all.

I'm putting together one of these units now and have a quick question:

the m3 nylon washers between the mic and line transformers and their small pcbs are too thick for me to be able to fit them between the transformer and the pcb and still get the screw to catch inside the transformer casings. Is this just me or is this a general problem? And how have you made them thinner if so? Sanding them down seems fiddly. Am I just too weak? Force them in hard?

Hmmm, questions question.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: phaedra74 on April 13, 2017, 05:33:35 PM
In the kit, you can find the m3 screw to fit it, without problem.....
take off the screw of the transformer and change it with the other similar screw (is simply a bit longer).
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on May 09, 2017, 06:16:47 AM
Been a while since I logged in. Thank you for the reply. I already soldered the transformers in place without the spacers, and it seems to be fine, but I'll might unsolder them and do it properly again.

Title: ez1073 build diary
Post by: TwentyTrees on May 12, 2017, 06:35:23 AM
Hi all,

Just finished my 1U ez1073, and it's an absolute beauty! Huge congrats and thanks to Colin for such a quality piece of kit, and such a (relatively) easy build. It sounds *fantastic* - a wonderful compliment to my CAPI VP28s.

One point - picking up what Colin said about R134 connecting the bottom of the 'Trim' pot to ground, I've simply jumped that resistor with a snippet of wire (socketed) and the 'Trim' pot now attenuates down to silence at its full range.  I am assuming that's not going to cause any complications anywhere (can't see why it would) but if anyone thinks differently, please shout!

Like some other builders, I had problems with intermittent pops / crackles / static type noises on first test. That was a bad solder joint (or two) somewhere - I went over the whole board with a magnifying glass and redid any joint that looked wobbly, and it's fine now. The noise floor is insanely low.

I also (clearly) misread the schematics when I was planning my front panel, and had the 'EQ IN' and phase labels on the wrong side of the switch (doh!). Phase was an easy switch (simply flipped the pins in the molex header), and for the 'EQ IN' switch I just snipped the terminals and popped in some wires so that the switching matches the panel.

For the panel and the cases, I went with Frank at frontpanels.de. I've used Schaeffer a few times and this panel is every bit as good as their best from what I can see. The case itself is one of Frank's NRG 1U cases, and it's leagues ahead of the modushop cases I've used before - much more robust and user-friendly (on my previous modushop 1Us, the back panels actually bend when inserting XLRs, no chance of that happening here). Can't recommend highly enough.

For the knobs, I got some of the Chinese Marconi-style cheap - and the grub screws are mounted too high to bite on the very short pot and switch shafts. Have popped some random ones on for now, and will get some push-fit ones to tap for grub screws myself lower down where they'll bite properly.

OK, time to head off and sell those GAP Pre573s to fund a second ez1073!

Cheers,
Andy
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on May 19, 2017, 03:44:57 AM
Hi everyone,

my unit was working perfectly, I did some very good recording takes with it but yesterday when trying to record some vocals I got an issue with the pre... Signal seems to be filtered, no lows and mid lows, only mids and highs... Really weird ! As I said, my unit was working well before. The line input signal is ok, eq is ok. EQ works on signal coming from the preamp but a big lack of lows...

Any ideas ?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tmuikku on May 19, 2017, 04:30:49 AM
Hi everyone,

my unit was working perfectly, I did some very good recording takes with it but yesterday when trying to record some vocals I got an issue with the pre... Signal seems to be filtered, no lows and mid lows, only mids and highs... Really weird ! As I said, my unit was working well before. The line input signal is ok, eq is ok. EQ works on signal coming from the preamp but a big lack of lows...

Any ideas ?

Hi, such sound can happen if one of the output transformer secondaries is floating so check your cabling. Also if it is a different device than before you are outputting to, it could have weird connector in it and leave other side of the signal floating. Check your cabling :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: innercityman on May 21, 2017, 04:31:58 AM
Quote
Also if it is a different device than before you are outputting to, it could have weird connector in it and leave other side of the signal floating. Check your cabling :)

Same device, I take the output from the ez1073 and plug it in one line input of my console, like I always did. I'll check my cables and let you know. The weird thing is that I only have this issue with the Mic Preamp, the line input works great.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: tmuikku on May 21, 2017, 05:11:44 AM
ah sorry, then it must be issue in the mic pre. Hopefully some one following this can give you more help
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on May 22, 2017, 08:58:14 AM
Just recently hooked up a NTI MR-Pro Minirator to the MIC input of my ez1073.  In the 300(low Z) setting it is showing an input impedance 3.6k  at 1khZ.  Is this normal?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: chrispsound on May 25, 2017, 07:10:54 PM
Just recently hooked up a NTI MR-Pro Minirator to the MIC input of my ez1073.  In the 300(low Z) setting it is showing an input impedance 3.6k  at 1khZ.  Is this normal?

Apparently(duh), in the 300 position, the mic input impedance is supposed to be 300 ohms and in the 1200 position its supposed to have an impedance of 1200 ohms.  I am getting 3.6k in 300 and 16k in 1200, but I can't for the life of me find a incorrect component.  Impedance is fine at the line in.  I am using a new MR-Pro for the readings.  Before I start pulling capacitors out and testing them, is there any place in particular that I should be looking?  The sad part in all of this is that I built this unit years ago, I have used it a lot and love it.  It would be nice to at least know how I modded it, haha.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: StillNotWorking on June 09, 2017, 05:09:41 PM
R134 (5k1) effectively sets the bottom of the trim pot signal level....just imagine if it were zero ohms, then when the pot was fully counter-clockwise the wiper would be attached to ground (through the zero ohm link) and there would be no signal going into the stage 3 amplifier.... so for 30dB attenuation it would need to be somewhere between 0 Ohms and 5k1.... I'll let you calculate that !
...snip...

Colin
www.audiomaintenance.com

Reading this I’ve got the idea I could use a logarithmic scale pot for R149 so the Trim now function as a fader.

Not sure how good idea this is thought? As it looks to me R134 and R149, 15k1 in series also function as the load the passive HPF look into? If this is correct wouldn’t this also change the frequency response for the HPF when the Trim is altered?
Don’t own this preamp yet so wondering anyone are able to confirm or dismiss this?

thanks
Hans

Edit:  ahh, must include R135.  Then  trimmer variation on standard unit becomes 3k to 5k.  But still,  shorting R134/R135 and  replace R149 to 5k LOG how will that fare with the HPF?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on June 18, 2017, 10:58:34 AM
Hmm, just fired up my latest build of this and I'm having trouble with the +48V. It only goes to 19.6 V when measuring from J3 to J5.

https://www.dropbox.com/s/96gpd7dp9hu83ou/48vtoagnd.jpeg?dl=0

So I started to trace the problem and I find that I'm only getting 9 VAC from the toroidal transformer, and it should be 44 VAC according to the schematics when measuring from Agnd (J5) to the red cables coming from the toroidal transformer.

https://www.dropbox.com/s/1rb3ryy85kqocwm/redtoagnd.jpg?dl=0

When measuring from positive terminal of the voltage regulator (BR2), it increases to 21.6 VDC.

https://www.dropbox.com/s/mi5cjsn58qlawro/br2toagnd.jpg?dl=0

What have I done wrong? I'm on Norwegian power, so 220-240V from the outlet, probably closer to something like 235V. See under for a photo of my wiring from the fused and switched IEC to the toroidal transformer. Grey and purple are connected, and brown and blue goes to the iec. Earth goes to the chassis earth. Should be correct, right?

https://www.dropbox.com/s/6ymb582mimo8ni2/iecwiring.JPG?dl=0

Any help would be much appreciated!

Edit: can't get the photos to embed in the post, so you'll have to follow the urls, I guess.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on July 07, 2017, 04:04:59 PM
Humbly bumping this post. Can I safely assume that the toroidal transformer is bad if it gives voltage readings that are too low straight out of it's leads, or can the fault be later in the circuit?

Thanks :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on July 07, 2017, 11:13:09 PM
Pull the transformer and wire it directly to the the outlet (without injuring yourself) as it written on the transformer for your power and then measure the secondaries. If it's still reading too low then it's bad. Probably.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Harpo on July 08, 2017, 06:51:08 AM
Hmm, just fired up my latest build of this and I'm having trouble with the +48V. It only goes to 19.6 V when measuring from J3 to J5.
Double check resistor parts values, especially R12, R15, R18 and trimmer R10. One might be a decade off.

Quote
So I started to trace the problem and I find that I'm only getting 9 VAC from the toroidal transformer, and it should be 44 VAC according to the schematics when measuring from Agnd (J5) to the red cables coming from the toroidal transformer.
The cables coming from the toroid have no relation to Agnd (J5). Measure AC voltage across both red cables. These probably will measure fine (with a 9VAC feed you won't get 19.6VDC out).

Quote
When measuring from positive terminal of the voltage regulator (BR2), it increases to 21.6 VDC.
BR2 is a bridge rectifier, not a voltage regulator.
Keep in mind, both voltage regulators U1 and U2 are different parts and have a different pinout. Maybe look up their parts datasheet.
Good luck.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Gbracam on July 24, 2017, 11:14:59 PM
Hey guys,
The Mic pre and line input work nice and sound very clean, the problems I am having is with my EQ section.

1st, when I engage the EQ I get a slight buzz and hum. this is not that noticeable at first but as I increase the higher frequencies it become more noticeable.

2nd problem I have is with the high shelf EQ section. It seems to be turned down by default making everything sound muffled, as I increase the gain all the way to the right it almost sounds normal.

I never noticed this this problem before, any ideas why this is happening?

Thanks
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on July 27, 2017, 05:00:14 PM
Double check resistor parts values, especially R12, R15, R18 and trimmer R10. One might be a decade off.
The cables coming from the toroid have no relation to Agnd (J5). Measure AC voltage across both red cables. These probably will measure fine (with a 9VAC feed you won't get 19.6VDC out).
BR2 is a bridge rectifier, not a voltage regulator.
Keep in mind, both voltage regulators U1 and U2 are different parts and have a different pinout. Maybe look up their parts datasheet.
Good luck.

Thank you for the reply, and my apologies for not writing earlier. I got a last minute mixing gig for a record with a deadline, so I ended up spending a lot of my time of that, and then summer came and family obligations. But now! Finally, I've found the time to drag out this project again.

So, I've desoldered and checked  R11, R15 & R18, and they all measure correctly, alas. I soldered them back in, and I've double-checked that the correct trimmers are where they should be, and that the same goes for the voltage regulators. So far everything seems to be in order. Hmm.

I measured across the red wires from the toroidal transformer and I get around 17.2 VAC. When measuring across the white wires from the toroidal transformer I get 21 VAC. See the attached pictures.

The toroidal also gets quite hot to the touch shortly after I switch on the circuit.

Any ideas? I'm sort of thinking that the toroidal is the culprit, but I also know that there's high chances of me being incompetent is the culprit  as well! :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on July 27, 2017, 05:04:13 PM
...and when measuring across the white cables from the toroidal transformer

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bobtheninja on August 01, 2017, 11:44:32 AM
I swapped out the toroidal transformer from one of my previous builds and as I suspected all voltages is fine now, and the unit is passing gorgeous sound (well, as gorgeous as it can get with me grunting into a mic). Problem solved. Thanks for your help, everyone.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: ilfungo on August 01, 2017, 01:59:04 PM
Hi
I've bulit 2 AML 1073 kit.
GREAT GREAT SOUND!!!
GREAT KIT!!!
Only 2 questions:

I've noted that if I listen the eq at hight level when mid frequency is on  .36 and  .7 frequncy, there is hum  ( not at 1.6-3.2-4.8-7.2).
Same on hpf only at 50 and 80 ( less noise).
Have someone noticed the same problem?
I can't trim the phantom below 48.7 v
It's this on tollerance or can create some problem for the mic?
THANKS!!!


Thanks!!!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: samguaiana on August 07, 2017, 11:07:14 PM
This sounds like a dumb question, but how... do you get the knobs off of the ez1073-500?  ;D
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on August 08, 2017, 07:20:35 PM
This sounds like a dumb question, but how... do you get the knobs off of the ez1073-500?  ;D

Aren't they collet style knobs? You would remove the cap and unscrew it from the inside.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: untune on September 16, 2017, 06:33:06 PM
Hello all; I thought it might be better to ask here than start a new topic. I've built the ez1073 rack version and tested it. Everything seems to function just fine apart from one thing - the last five clicks of travel on the MIC GAIN pot do not pass any signal. The previous ones all gradually increase the gain, but then it goes silent. My first thought was that I put the stop pin in when the switch was in the wrong position (I didn't actually note the orientation before doing so but I believe it was unchanged.)  Given that there is only the one pin in the mic gain switch (12 positions), I'm guessing that this will actually make no difference, and the problem lies with the soldering somewhere - possibly the first gain stage.  Can anyone offer any insight?

Cheers
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on September 16, 2017, 07:06:26 PM
Bad solder joint on switch or gain resistors.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: untune on September 16, 2017, 07:19:15 PM
Thanks Paul - I remember the switch seemed to be fine when I did it but some resistors were a pain. I've isolated the likely suspects from the schematic and will take a closer look.

Cheers!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: untune on September 16, 2017, 10:49:51 PM
Getting on for 4am and I've tried everything I can think of - checked the area around the gain switch, resoldered anything that looked like it was a bit off and still the same problem persists.  Nothing for the last 5 positions of the mic gain switch. Still assuming it can't be the stop pin... duff component perhaps?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on September 17, 2017, 04:44:55 AM
You can take a multi meter and see if you get continuity between the pole and the positions in question on the switch. If they seem fine then we're back to the bad solder joint around the gain switch section. Keeping looking at the schematic and follow signal path.

It's unlikely it's the switch but not impossible.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on September 17, 2017, 08:04:52 AM

It's unlikely it's the switch but not impossible.

Thanks!

Paul
Absoluteley,I remember when I got my first Grayhill ages ago and fooled around with it.......had some hard times to get it back to work since there was nearly nothing to find in the internet about how to set it right.....and nothing to get it back to normal!
In case you want to check this here's how it works including removing a stop pin

https://www.dripelectronics.com/new-blog/2016/9/23/setting-stops-in-your-greyhill-71-series (https://www.dripelectronics.com/new-blog/2016/9/23/setting-stops-in-your-greyhill-71-series)


Best regards,


Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: untune on September 17, 2017, 08:42:16 AM
Thanks guys, I tried again this morning and rechecked all major solder joints around the 1st stage. The switch pins actually did seem a bit sketchy, I retouched them and they are conducting properly but still no joy. I checked the three BC550s and they seem ok. If I shout loud against a dynamic mic I do get a very small signal through, not sure if that demonstrates anything though.

With the pins, since only the 12 o clock is set I imagine that can't be the issue, ie 5 positions not working.

Maybe a dodgy cap or something, I'll see if I can have another look tonight, but any other ideas welcome.

Cheers!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadpoisoning on September 17, 2017, 11:46:16 PM
Thanks guys, I tried again this morning and rechecked all major solder joints around the 1st stage. The switch pins actually did seem a bit sketchy, I retouched them and they are conducting properly but still no joy. I checked the three BC550s and they seem ok. If I shout loud against a dynamic mic I do get a very small signal through, not sure if that demonstrates anything though.

With the pins, since only the 12 o clock is set I imagine that can't be the issue, ie 5 positions not working.

Maybe a dodgy cap or something, I'll see if I can have another look tonight, but any other ideas welcome.

Cheers!

Did you try following the circuit path through the attenuator resistor bank?? Could easily (most obviously) be something in there?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadpoisoning on September 18, 2017, 12:02:38 AM
Phew - i spent a few evenings reading nearly EVERY ONE of these posts and commisserate with some of you for some of the problems you had or are having. I feel blessed for everything to have gone relatively smoothly - but wanted to add a couple experiences I had as well. Most of which were RIDICULOUS  oversights on my part since they were almost as obvious as having forgotten to plug in the power cord. I was so focussed on the tiny details that I was overlooking the major ones and lost a few nights over them.

First one: I was having a HELL of a time trying to calibrate the 48v circuit. I could only get it up to 32 something volts and the trimmer seemed to have NO EFFECT whatsoever on the circuit. (a few of these posts rang familiar to me). Turned out I'd SOMEHOW soldered the red trafo leads into the white sockets and vice versa (!!) - NO idea how i did that - maybe i was working on it with the board inverted (from the bottom) .... live and learn. Maybe because i wasn't EXPECTING to be able to make a mistake there - it made me less than vigilant (?) After switching them back - it fired right up and calibrated to 48v nicely.

Second:  one one of my two units - I simply COUDLN'T get my mic amp working no matter what - SOMETIMES i was getting a signal (though faint-ish) even when 'dialed up' ... and other times not. So i disassembled everything, pulled the board and started going over solder joints (was driving me a bit nuts because I'm usually quite pleased with my attention to detail in soldering!) - thinking there must have been a poorly wetted or bonded joint SOMEWHERE ... - i resoldered about 40 odd joints and even did a number of not-so-necessary joints on the top of theboard - when i noticed something .... I had COMPLETELY FORGOTTEN to solder the pins on the Carnhill transformer to the daughtercard (!!!!!!!). So i soldered those and stitched everything back up and what do you know??? A monster mic pre!!

Third: Here's a silly trap. When i first tried test firing my two units I'd mis-soldered and switched the hot and screen leads for my output jack - since I'd forgotten what it might mean that I'd flipped that jack 180 degrees on the back of the enclosure (have all my jacks oriented sidways due to space constraints behind my rack). So luckily no messed up or blown components etc ... just me being my own worst enemy ...

I'm so relieved now that I've gotten through these issues ... it's surprising what one can overlook. I don't know - maybe it's only me that has these problems. But I thought I'd share my experiences. Now to start working on my front panel and start the final assembly (not to mention figuring out the knob situation -too short shafts).

thanks everyone for sharing and feel free to reach out if you have questions on your build.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: untune on September 18, 2017, 05:47:48 AM
Thanks again for the responses, lots of useful tips there from leadpoisoning.

The only error I made (which I spotted right after I'd done it) was that I was on autopilot doing the XLR connections and reversed the hot and screen on the output due to that one being male.  That, and I also missed the vias (which I thought could be the culprit but alas not!)

In terms of the resistor banks etc - going off the schematic it's probably no coincidence that the last 5 steps of the mic gain control go through gain stage 1, and nothing else does. SW2a (+50 to +70) all head that way, and then hit R92-95 attenuating +50 to +65 on the way out (SW2b). I'd expect some signal on at least one of those settings even if there was a funky resistor in that bank.

It's baffling because other than this, the rest of the unit is *perfect* - line in and gain are fine, EQ is all fine, switches and trim all fine, and the first steps of the mic gain are functioning as they should. I went over the resistors in gain stage 1 last night and they're all in the right places. I measured the resistances in circuit but that's not much use anyway. Electrolytics are all correct polarity, the transistors all tested ok.  I can't see it being a power issue, because stage 2 shares it. All I can do is inspect it all again and hope something stands out!

Cheers
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: untune on September 18, 2017, 02:56:15 PM
Solved this tonight... not entirely sure what did it exactly, but I retouched a couple more solder points and cleaned the whole area with IPA and a toothbrush - working perfectly now. Cheers for the help :)
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadpoisoning on September 18, 2017, 03:08:42 PM
Solved this tonight... not entirely sure what did it exactly, but I retouched a couple more solder points and cleaned the whole area with IPA and a toothbrush - working perfectly now. Cheers for the help :)

congratulations! just goes to show how important cautious work can be! I suspect that half the problems in this thread have the same solution....
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadpoisoning on September 24, 2017, 05:33:08 AM
the one other thing i would add - is DON'T BE CHEAP! Shell out for the prefabricated enclosures which a few are offering. I decided to do my own and probably spent even more than that for all the ancillary bits needed to do a decent job - but most importantly all the time lost trying to tweak this or that or having to order the wrong parts/supplies etc.  I underestimated also how difficult it was to get the drilling for the pot shafts JUST SO.  I ended up having to do quite a lot of remedial filing out of holes to get to where i needed to be. Not only that - but the lack of exactitude on my part (and I'm a PRETTY CAUTIOUS person) makes me worry about stress to the solder joints due to compression between the front plate holes and the pot shafts ... so ... just a word of caution from someone who's gone this way ... only do it if you absolutely need to for whatever reason ...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: miscend on September 25, 2017, 01:02:16 PM
Has anyone built the ez1081-500 yet?  :) :) :)

Looks like a fun build but where is the EQ.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: TillM on September 25, 2017, 03:18:07 PM
as you can see its just the preamp.
Maybe Colin can told us more about it.
I think he sell it not so long, last week I don't found it on his site.
But the price is a bang for the buck in my opinion.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: PeteC on October 16, 2017, 06:28:00 PM
Hi everyone.  Tonight I just completed my 1u ez1073 build and calibrated.  Everything works perfectly first time - so really pleased with that.   However when I come to fit the pcb  into the collective cases 1u rack I find that there is no way it's going to fit without the bolts on the underside of the pcb fouling the bottom plate of the case.   When I look even closer I find that the front panel mounting holes
Look to be drilled too far down the faceplate.  There simply won't be any space to use standoffs etc under the pcb.  This is very disappointing as I waited a long time for U.K. Customs to clear my order from Dan.   I think it's just a duff case where the tolerances weren't being met by Dans supplier and its slipped through QA.    So now my only option seems to be to jointly house the 1073 inside a 3 unit rack case I have spare and have it housed with some other preamps and my headphone amp.   My question is really this - will the pcb be ok self supporting from all the pots and switches on the faceplate and if not then what can people suggest I do to support it if it's housed with other stuff inside a larger rack case?   Bit frustrated as I want to track either the ez1073 as soon as possible having heard what it can do tonight.   All ideas greatly welcomed     Cheers Pete
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: TwentyTrees on October 17, 2017, 02:38:02 AM
Hi Pete,

That sounds frustrating! The ez1073 is definitely a snug fit even with a custom case so I can well imagine that a little tolerance slip would cause issues.

I would definitely not support the PCB just from the front panel pots & switches - even if you've not got the mains transformer mounted on-board, the audio transformers and inductors make it very heavy for a PCB so I'd expect the risk of damage would be high. Without knowing more about the 3U case you're considering I can't really suggest anything other than "long standoffs?", but even so with all that iron the ez1073 is going to be sensitive to things like other power transformers so you might not get optimal performance if you co-house it, even if you do solve the mounting issue.

Obvious question, but have you contacted Dan about sending out a replacement case / panel?

Andy
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on October 17, 2017, 03:16:44 AM
I've used Dan's case for an ez1073 and it is snug but should fit fine. One thing to keep in mind is that I had to use the standard hex nuts on the inside for the Grayhill switches as they aren't flush with the Omeg pots when you bolt them in, causing the PCB to warp if you just tighten down the nuts as is. I also only used standoffs for the rear of the PCB as that is where most of the weight is going to be. 1/4" or 6mm will fit.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: PeteC on October 17, 2017, 03:37:53 PM
Thanks for the thoughts guys.

I measured and test fitted everything again tonight and sadly there is no way the pcb is gonna fit without TX bolts and the output TX itself fouling/shorting the bottom of the case - it must be poor tolerances in the case machining.
The only solution appears to be to file out the faceplate mount holes so that the faceplate and pcb sit a couple of mm higher than they do at the moment - this might give me the clearance away from the bottom plate of the case that I need. I an do this by filing out the holes to lower them o the faceplate and thus raise the faceplate relative to the rest of the case.  Bit of a bind though to be honest. Shame after getting it running with no electronic bugs.    Not sure if Dan would send me a replacement over this side of the pond - I'll ask the question at least.
Cheers
Pete
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dandeurloo on October 17, 2017, 07:51:06 PM
Hey Peter, I just responded to your email as well.  But I thought it would be good to have the info in this thread again.  I am pretty sure it has been covered a few times here but these threads do get long, so it is good to have the info come up again.

The design of the AML ez1073 is a little different then most.  The front of the PCB has to sit lower then the back of the PCB.  There are a few reasons for this.  The height of a 1U case, the center placement of the Greyhill switches  and pots and the size of the output transformer (which just barely fits in a 1U) are all part of the issue.   Is your issue that the front of the PCB has to tip down compared to the back of the PCB?  If so, that is normal. 

The other issue you may be running into is if you fully installed your switches and pots to the PCB prior to lining them up to the front panel.  The panels always line up if the switches are fastened to the panels first, then the PCB is fitted to the switches.  Then you solder the switches to the PCB in place so they don’t move.  This makes for perfect alignment of the switches to the front panel.  This is a common method for projects with a lot of PCB mount switches.   

With all the PCB mounted switches and pots in the front and the angle of the PCB you don’t have use any standoffs toward the front of the PCB.  The switches are more then enough to secure the PCB in the front.  In fact, the couple that I built I only added 2 or 3 standoff's toward the back of the PCB.  The output transformer also helps to hold the PCB in place(up and down) so not much is really needed.  Just a few standoff's to help things from shifting around.

For extra comfort, I trimmed the solder pins of the switches and pots pretty close to the bottom of the PCB and then used electrical tape or vinyl tape under them and between the bottom of the enclosure.  Just to have a extra layer of protection from  any of the switches shorting out on the case.  It isn’t needed but I did do it just to be extra safe. 

Let me know if this addresses the issue or if you have any more questions.

BTW, I just looked at my old emails back and forth with Colin when he supplied me all the layout info.  This project started back in 2010.  Pretty amazing! 

Hi everyone.  Tonight I just completed my 1u ez1073 build and calibrated.  Everything works perfectly first time - so really pleased with that.   However when I come to fit the pcb  into the collective cases 1u rack I find that there is no way it's going to fit without the bolts on the underside of the pcb fouling the bottom plate of the case.   When I look even closer I find that the front panel mounting holes
Look to be drilled too far down the faceplate.  There simply won't be any space to use standoffs etc under the pcb.  This is very disappointing as I waited a long time for U.K. Customs to clear my order from Dan.   I think it's just a duff case where the tolerances weren't being met by Dans supplier and its slipped through QA.    So now my only option seems to be to jointly house the 1073 inside a 3 unit rack case I have spare and have it housed with some other preamps and my headphone amp.   My question is really this - will the pcb be ok self supporting from all the pots and switches on the faceplate and if not then what can people suggest I do to support it if it's housed with other stuff inside a larger rack case?   Bit frustrated as I want to track either the ez1073 as soon as possible having heard what it can do tonight.   All ideas greatly welcomed     Cheers Pete
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: PeteC on October 18, 2017, 07:16:22 AM
Hi Dan,

Thanks for the tips - you are right in thinking that I soldered in my switches to the pcb without the faceplate - so that could be the source of some of my issues.  Too difficult to re-do that now without a very good desoldering tool.

I guess with standoffs at the rear then its just the fact that there is less than  1mm or so clearance between pins and the bottom panel at the front  - but I will look to use a sheet of tough plastic to insulate everything.  I think at the rear of the pcb everything will be fine.  The mounting bolts for the output TX are probably a little tool long for the case height- but I can replace them with something a little shorter

I'll try everything you have suggested and see if I can get it to fit without any shorts.

The things sounds bloody amazing tracking DI'd Bass through the mic channel in conj with a Bo Hansen DI box  !

Cheers
Pete
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: PeteC on October 18, 2017, 02:49:34 PM
Just to add....
I will be using a 1mm rubber sheet on the inside base of the case just to be really sure everything is fully insulated from shorting out - especially where the switches and pots are.

one quick unrelated question - whats the correct orientation for the LED - positive leg into the right hand hole I am guessing looking at the pcb traces ?

Cheers
Pete
 
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: dandeurloo on October 18, 2017, 09:49:25 PM
Hi Dan,

Thanks for the tips - you are right in thinking that I soldered in my switches to the pcb without the faceplate - so that could be the source of some of my issues.  Too difficult to re-do that now without a very good desoldering tool.

I guess with standoffs at the rear then its just the fact that there is less than  1mm or so clearance between pins and the bottom panel at the front  - but I will look to use a sheet of tough plastic to insulate everything.  I think at the rear of the pcb everything will be fine.  The mounting bolts for the output TX are probably a little tool long for the case height- but I can replace them with something a little shorter

I'll try everything you have suggested and see if I can get it to fit without any shorts.

The things sounds bloody amazing tracking DI'd Bass through the mic channel in conj with a Bo Hansen DI box  !

Cheers
Pete

If one of the switches looks to be more off then another you can use QucikChip.  That stuff works like magic in situations like this.

I use it a lot for SMD part removals. 

Talk to you soon.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: PeteC on October 20, 2017, 06:57:57 PM
cheers Dan, and Colin,

all racked up tonight and sounding mighty fine !!

Think I might need more 1073s........ 8)

Rgds
Pete
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: miscend on December 17, 2017, 03:02:07 AM
I am struggling. The bias adjuster trimmer has no effect on DC voltage.  What are the necessary steps to troubleshooting the reason for this?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on December 17, 2017, 08:50:17 AM
Which voltage are you trying to adjust with the bias trimmer?

Thanks!

Paul

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: miscend on December 20, 2017, 07:25:15 AM
Which voltage are you trying to adjust with the bias trimmer?

Thanks!

Paul

Hi

I'm making the new 500 series build with just the pre. In the build document it says I should be getting DC voltage of 40-50 mV from the multimeter on theTP1 and TP2 test points. However I am only getting 26.8mV.

Theres 5k Bourns trimmer for adjusting the bias. The doc says I should turn that clockwise until the DC voltage measures 90mV from those same test points. However that has no effect.

I've checked the polarity of all the caps. And I've reflowed and resoldered some of the joints. At the moment I'm trying to isolate where on the board the issue will be. I'm a beginner level builder but I've built kits from JLM and Soundskulptor.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: IMUTHANT on January 06, 2018, 07:09:01 PM
Similar issues here. I just finished building 4 kits of the EZ1073pre, and I tried to calibrate them just now.

2 of the modules started between 40-50 mV at the bias test points, and the trimmer took that up to 90 mV, as the colourbook described. However, one has plenty of clean output, whereas the other has hardly any output, even when the output fader is way up there. Also sounded a bit highpassed possibly.

The other 2 modules are, just like the previous post, stuck in the mid to high 20s in mV, and no amount of turning the trimmer changes that.

Any input would be hugely appreciated. I've built several VP28s, JLM LA500s, hairball kits, and others. I also took over a week of slowly building these ez1073 modules, triple-checking every step and soldering well. 2 of the modules are for my buddy's professional studio, so I'm a bit bummed that I'm having these issues.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: IMUTHANT on January 11, 2018, 03:11:05 PM
Update: Colin suggested that the 2 modules not taking as much voltage would result from either an issue with the output stage PCB or the surge control PCB because "the 20mV suggests that the
output amp is not operating." I removed both of these boards, doubled checked all the components, and reflowed all the joints, even though they all looked good. Unfortunately, I still have the same issue...stuck around 26 or 27 mV. Any ideas how else I could trouble shoot this part of the circuit? Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: miscend on January 14, 2018, 11:11:46 PM
Update: Colin suggested that the 2 modules not taking as much voltage would result from either an issue with the output stage PCB or the surge control PCB because "the 20mV suggests that the
output amp is not operating." I removed both of these boards, doubled checked all the components, and reflowed all the joints, even though they all looked good. Unfortunately, I still have the same issue...stuck around 26 or 27 mV. Any ideas how else I could trouble shoot this part of the circuit? Thanks!

Okay I have followed exactly as you did above with limited success. Until I removed the connector on the output transformer and soldered  the wires directly to the board. I am now getting the correct 90 mV, when I adjust the trimmer.

But I now have a new  problem. I get no sound output at all when the front switch is set to 1200 ohms.  And I get a noisy output with hum when I set it to 300 ohms.

Any advice on how to proceed will be greatly appreciated.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: IMUTHANT on January 18, 2018, 10:28:40 AM
Okay I have followed exactly as you did above with limited success. Until I removed the connector on the output transformer and soldered  the wires directly to the board. I am now getting the correct 90 mV, when I adjust the trimmer.

But I now have a new  problem. I get no sound output at all when the front switch is set to 1200 ohms.  And I get a noisy output with hum when I set it to 300 ohms.

Any advice on how to proceed will be greatly appreciated.

Thanks! That fixed everything...what a relief. Makes sense now that the molex connection would be the issue. Everything else in the kit and build was perfect, except for the molex connector. The pictures from the colour book had the molex looking different (short legs where the pictures shows long legs, and long on the short side). I just heated up the legs and pushed them through so that they looked like the diagram in the colourbook. To fix it, instead of wiring it in directly, I just pushed the legs through an extra couple centimeters and reconnected the transformers, and that fixed the issues I had in each of the 4 modules (the working one had developed the same issues eventually)

I also learned that there are two types of loctite thread sealant  ::) the type I had lying around is apparently the stronger type, so after a few stripped screws (and one where the nut broke loose from the rear panel and started floating freely in the panel) I eventually managed to remove the transformers in order to troubleshoot.

My buddy just messaged me that the pres sounded great in his session yesterday.

Wish I could help with those issues you are having, but I wouldn't know where to start...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Slenderchap on January 18, 2018, 12:12:42 PM
I can now appreciate that is not a very clear drawing... I will correct the colourbooks.

Colin
www.audiomaintenance.com
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: IMUTHANT on January 19, 2018, 06:43:39 PM
I can now appreciate that is not a very clear drawing... I will correct the colourbooks.

Colin
www.audiomaintenance.com

Didn't mean to be rude. The kit and instructions were very clear, and lots of fun. I'm just a bit inexperienced with solid molex connections.
Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: bluespills on February 01, 2018, 08:59:12 PM
I just finished a pair of ez1073s,

One is working good, but there is a level drop when i flip the phase switch...?

The second one I have a very low output from the mic channel, and a lot of buzzing when i touch the mic gain knob... 

I have already gone over looking for bad joints and trying to clean up but no luck so far.

Any tips are appreciated!   ::)

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: leadpoisoning on February 13, 2018, 02:08:23 AM
I just finished a pair of ez1073s,

One is working good, but there is a level drop when i flip the phase switch...?

The second one I have a very low output from the mic channel, and a lot of buzzing when i touch the mic gain knob... 

I have already gone over looking for bad joints and trying to clean up but no luck so far.

Any tips are appreciated!   ::)

possible you stressed the gain pot when fitting the board and pots through the front panel openings? maybe cracked a solder joint? check around the pot for continuity maybe ...?  might be my first guess.

maybe something similar going on with the phase switch? it would be an easy fix were that the case anyway
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 02, 2018, 02:09:25 AM
Dear Everyone,

Hi! I am probably going to order 2 of these this weekend. The 1U rack version. They look & sound incredible from what I have gathered.

Just a quick question to those who have built one: I am a newcomer to DIY, but I have built 2 microphones and heavily modded 2 other microphones successfully. I repair small instrument parts for a living (sax mouthpieces, to be specific), so problem solving, following detailed instructions, and working with small parts doesn't bother me.

Based on that, do you guys think I could build a couple of these 1U rack version 1073 preamps succesffully? So far I'm very keen on DIY and I need two more preamps to fill out the last remaining spaces in my 16 channel analog i/o recording setup. Would love to make them a pair of these. I am choosing these over the SCA N72's and Sound Skulptor MP73's because of AML's reputation for having gotten this preamp right!

I read the whole build manual and nothing looks too outlandishly hard to understand.

Finally, other than the faceplate & case & knobs, is there anything else one must buy/order to finish one of these fine AML kits?

Cheers, and thank you for your patience!

EarthTone.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 08, 2018, 01:11:57 PM
OK really lively responses to my questions about this preamp above, thanks chaps! Sarcasm intended!

On a more related note, what is the best faceplate/case for this? Does the Collective Cases case fit well? I read where some people had a tough time fitting it into that unit, but it looks like the most complete faceplate/case available and it also has the power switch hole drilled which I would prefer. That one and the Don faceplate are the only ones I'm aware of. Are there more?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: kante1603 on March 08, 2018, 01:54:45 PM
Maybe this one,here in germany,you can ask Frank Röllen (owner of this company) if you need modifications,he is cool:


https://www.frontpanels.de/miscellaneous-frontpanels/ez1073/


Best regards,


Udo.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on March 08, 2018, 02:49:23 PM
I second Frank's work. He's done a number of mods to standard cases for me and is really great to deal with. One thing to consider is that his cases are deeper than Dan's at Collective Cases if that is a consideration for you. If you need you can have Frank make the front panel with drill holes for Dan's cases.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 08, 2018, 03:52:27 PM
Thanks for the info gents! Much appreciated.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 15, 2018, 01:31:59 AM
I just ordered two 1U rack mount version kits from AML! I am so phsyched for these builds. Here in NYC we have an electronics store called BH Photo where they have a demo room full of mics and preamps you can try. They had a Heritage 73'jr which I tried and loved. I tried it out with my sax. They had the preamps plugged straight into a converter so you could hear them. The Heritage preamp was sans-EQ, but it sounded amazing. I hope the ez1073 sounds like that! From everything I've heard, it should. Looking forward to these builds! I have read through the colourbook and have a friend who has built 4 of them I've already bugged a bunch so feel like I'm prepared, but I'm sure I'll have some questions along the way.

Cheers,
ET
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: sr1200 on March 15, 2018, 03:07:46 PM
I'm on LI, couple blocks from the LIRR if you wanna hear what they sound like.  I have a pair of the AML and i have 8 of Martins.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 15, 2018, 05:07:59 PM
I'm on LI, couple blocks from the LIRR if you wanna hear what they sound like.  I have a pair of the AML and i have 8 of Martins.

Oh, cool! Really nice studio website! What are Martin's preamps? I see on your site you've got listed 8 1290 clones, is that what you're referring to? I'd love to hear them.

I'll hit you up when they're built maybe we can have a little gear hang. I've been building some mics too...
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 15, 2018, 05:11:18 PM
Also, I'm wondering if anyone here has had the opportunity to compare the ez1073 w/EQ rack version to the new 500 series preamp-only kit? If so, how does it sound when compared to the preamp section of the rackmount version? Like if the EQ is all zeroed out on the rackmount, I wonder if the tone of the preamp is essentially the same.
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 16, 2018, 09:09:32 PM
Quick question for those who have built one using a Collective Cases 1u rack case: which sized standoffs did you use, 4mm or 5mm? Thanks!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on March 18, 2018, 05:41:49 PM
Sorry to bug, but anyone build the rackmount version with the Collective Cases case and know which size standoffs will work? 5mm? 6mm? Any preference on standoffs with threaded leads poking up through the PCB vs. female ends with mouthing screws coming in from the top of the PCB? Thanks.
Title: Potentiometer knobs fit?
Post by: EarthTone on April 24, 2018, 12:40:49 PM
Hi,

I ordered all my stuff for this project at the same time and I made the mistake of assuming that the CAPI Gear Neve style knobs would fit my potentiometers in the ez1073. I'm almost at the end of hte project (I built two) and just started assembling the knobs on the front panel when I noticed the trim and EQ pot knobs I bought do not fit. The shaft size of the pots is much larger than the shaft bore of the knobs. The macaronis for the preamp gain do fit, though. I am talking about this stuff: http://capi-gear.com/catalog/product_info.php?cPath=202_203&products_id=398

Is there anything I can do? Should I try to exchange the knobs for macaroni knobs, or is there a way I can easily and reliably bore them out with a drill?

I bought these which do not fit: http://capi-gear.com/catalog/product_info.php?cPath=202_203&products_id=398

Is there a way to change the shaft size of the pots?

Thanks,
ET
Title: Re: Potentiometer knobs fit?
Post by: Potato Cakes on April 24, 2018, 05:28:43 PM
Hi,

I ordered all my stuff for this project at the same time and I made the mistake of assuming that the CAPI Gear Neve style knobs would fit my potentiometers in the ez1073. I'm almost at the end of hte project (I built two) and just started assembling the knobs on the front panel when I noticed the trim and EQ pot knobs I bought do not fit. The shaft size of the pots is much larger than the shaft bore of the knobs. The macaronis for the preamp gain do fit, though. I am talking about this stuff: http://capi-gear.com/catalog/product_info.php?cPath=202_203&products_id=398

Is there anything I can do? Should I try to exchange the knobs for macaroni knobs, or is there a way I can easily and reliably bore them out with a drill?

I bought these which do not fit: http://capi-gear.com/catalog/product_info.php?cPath=202_203&products_id=398

Is there a way to change the shaft size of the pots?

Thanks,
ET

You can drill them out to 1/4" with a press and be fine.

As a note you ordered the inner concentric knobs, which are meant for 1/8". It is labeled as inner concentric on the website with the shaft diameter.

I believe you were looking for this: http://capi-gear.com/catalog/product_info.php?cPath=202_203&products_id=430.

I have done the same thing. I drilled out the hole for the knob and everything was fine.

Thanks!

Paul
Title: Re: Potentiometer knobs fit?
Post by: EarthTone on April 25, 2018, 04:37:33 AM
You can drill them out to 1/4" with a press and be fine.

As a note you ordered the inner concentric knobs, which are meant for 1/8". It is labeled as inner concentric on the website with the shaft diameter.

I believe you were looking for this: http://capi-gear.com/catalog/product_info.php?cPath=202_203&products_id=430.

I have done the same thing. I drilled out the hole for the knob and everything was fine.

Thanks!

Paul

Thanks Potato Cakes! Much appreciated. I have figured it out with the supplier of the knobs. Going to get replacements, thankfully! Almost done with these builds. I am so excited to turn them on and see what they sound like.

ET
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on April 29, 2018, 10:32:50 PM
I just built two of these. I decided to wire one of them up to power first to see if there were any trouble spots before I wire up the 2nd one to power.

I’m kind of amazed since this is my first DIY preamp, but almost everything works perfectly on the 1st one! Mic gain, EQ, trim, it sounds great.

The only thing not working is that even though I measure 48V correctly across the 48V power rails,  no condensers work. The mics do bot seem to be receiving phantom power. Dynamic mics sound fine.

Any ideas?

Thanks,
ET
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on April 30, 2018, 04:15:28 AM
There is a schematic of the PSU in the build guide. You'll have to look at it and follow it to find where the problem is. Somewhere in there you have a bad solder joint or misplaced component. It is very possible but unlikely you have a bad component unless it was destroyed in the build process.

Nice work on the rest of it. These things are pretty great.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 01, 2018, 03:29:38 AM
There is a schematic of the PSU in the build guide. You'll have to look at it and follow it to find where the problem is. Somewhere in there you have a bad solder joint or misplaced component. It is very possible but unlikely you have a bad component unless it was destroyed in the build process.

Nice work on the rest of it. These things are pretty great.

Thanks!

Paul

Hi Paul,

Man, thanks so much for the help, really appreciate it! So, I built two. I powered the other one up tonight and that whole thing works perfectly. I'm both thrilled and amazed that it works! I've never done this before. I guess that means the kits are very high quality. Man, it sounds great. Phantom works perfectly on that one.

Regarding the other one which has the phantom problem, I hear a loud "pop" when I engage phantom power. The 48V phantom test terminals are showing 48V. So I guess the 1st part of the 48V section is working up until at least the terminals. It must be after that. Could it be the switch? Probably not, right...

I think I understand the PSU schematic. I've reflowed solder on all those points. No luck. The components on the 48V line are in the exact same positions on both units and the same orientation on the polarized ones.

Thanks,
ET
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 01, 2018, 07:11:32 PM
OK! I found the problem. Sorry to make so much noise on here when it was my own fault. I took the ez1073 without phantom power outta the case and took a much closer look in the light. I had already racked it before testing. Overanxious to get going I guess. Anyway I found a solder bridge at the input transformer. I also reflowed solder over the entire 48V section and a bunch of other places again. Nowwwwww it works!

I now have 2 fully functional ez1073's on the first try. They sound amazing. I guess they really do live up to they're "EZ" name.

Thanks Colin! AML all the way. Might buy a few more of these suckers.

Cheers,
Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 02, 2018, 03:29:03 PM
What are the steps to properly ground this unit? There are two “mains safety earth” connections on the pcb. Do I need go connect both of them to star ground, or only one?

Also, on the XLR chassis connector jacks, do I connect the d-tabs to pin-1? Or do the d-tabs go to star ground? Or do I leave the XLR jack d-tabs open?

Thanks!

ET
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: fistman on May 03, 2018, 11:56:35 AM
Hey all -

So I’ve got two units.  One I just finished and the other just needs the mains hooked up to the transformer.  Couldn’t wait to try out the completed build... and... the fuse blows.  Immediately.  No light no power to the test points. 

I took the heat sink off in stage 3 to check that the lock washers hadn’t come off the pad.  All was good there.  Took the bottom of the case off and tried a new fuse to be sure I wasn’t grounding out somewhere there.  No dice.

Anyone have any recommendations where to look next?  I blew 3 fuses in a row so I’m doubtful of a bad fuse.  I’m assuming some sort of grounding issue, but if anyone has any advice I’d greatly appreciate the help. 

Feeling pretty bummed as I’ve built a few other diy kits previously with no issues and I’m generally very meticulous when putting these things together.

Thanks,
JF
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 04, 2018, 03:40:04 AM
Hey all -

So I’ve got two units.  One I just finished and the other just needs the mains hooked up to the transformer.  Couldn’t wait to try out the completed build... and... the fuse blows.  Immediately.  No light no power to the test points. 

I took the heat sink off in stage 3 to check that the lock washers hadn’t come off the pad.  All was good there.  Took the bottom of the case off and tried a new fuse to be sure I wasn’t grounding out somewhere there.  No dice.

Anyone have any recommendations where to look next?  I blew 3 fuses in a row so I’m doubtful of a bad fuse.  I’m assuming some sort of grounding issue, but if anyone has any advice I’d greatly appreciate the help. 

Feeling pretty bummed as I’ve built a few other diy kits previously with no issues and I’m generally very meticulous when putting these things together.

Thanks,
JF

Hey man ~ I'm sure you've been over it several times but I think you've just gotta keep checking for solder problems. I was sure I didn't have any on mine until I unhooked it from the case and looked really, really close. I caught 2 solder joint problems. In the end I'm not sure exactly what fixed my phantom power, but after I removed a solder bridge and redid some questionable joints, I reflowed solder on most of the joints on the board just to see if that would make a difference. Something I did fixed it.

So I would encourage you to do that too.

If you built two units, compare the two and see if you've got any misplaced parts anywhere. It's pretty easy to do this visually since the resistors are color coded.

There's always the chance you misplaced something on both units though. If it's a misplaced resistor, it's going to be pretty time consuming to find it. You are basically gonna have to go through the whole build again and measure resistors from step 1.

Look for shorts. Try a different power cable. Check your power transformer wiring, did you wire for the correct voltage? Look at the teeth on your input transformer pins. Anything bridged? Electrolytics placed the correct polarity? Transistors facing the right direction?

Could be a bunch of different things.

Check that your LED is orientated the correct way if it's not lighting up. If you're viewing the unit from the front, the positive leg goes to the right. It's the opposite of the Electrolytics polarity, if memory serves. That's not marked anywhere, I found it in this thread buried deep somewhere when I was trying to figure out which way it went, too.

Good luck. When you finally get it working, you will love the way it sounds.

Best,
Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 04, 2018, 04:16:32 AM
Are you guys connecting the XLR d-tabs to star ground? Or are you leaving that open on the connectors? I have seen pictures and replies about people doing it both ways. What yields better results?

Also, whatsup with there being two holes for Mains Safety Earth? I connected only one to star ground. I don't know what to do with the other one. I saw some pics where it looks like there was a screw in the 2nd one, but I can't tell what's going on there...

Sorry I'm new to this. Help?

Matt

Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on May 04, 2018, 08:41:05 AM
Search for Mixer Grounding 101 by Ian Thompson Bell. Use this for all of your rack gear builds.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 04, 2018, 05:55:49 PM
Search for Mixer Grounding 101 by Ian Thompson Bell. Use this for all of your rack gear builds.

Thanks!

Paul

Hi Paul, thank you so much for your advice. That is what I was actually trying to remember to search for, couldn't remember the title of it and had seen some folks suggest reading it on here... Very helpful thank you kindly.

Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 04, 2018, 10:05:27 PM
One more question: Are you guys terminating the output at 600ohms or are you leaving it at stock? What's the difference in the sound? I'm plugging it into an interface, UA Apollo to be specific. Should I be terminating to 600 or leaving SW1 open?

Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: Potato Cakes on May 05, 2018, 03:14:05 AM
One more question: Are you guys terminating the output at 600ohms or are you leaving it at stock? What's the difference in the sound? I'm plugging it into an interface, UA Apollo to be specific. Should I be terminating to 600 or leaving SW1 open?

Matt

The instructions say solder those pads together, so I just do that. You can experiment and let us know what you think.

Thanks!

Paul
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 05, 2018, 05:21:23 AM
The instructions say solder those pads together, so I just do that. You can experiment and let us know what you think.

Thanks!

Paul

Thanks Paul. I wish there was some more info than that for those of us less experienced, but thanks for your input!

Best,
Matt
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 10, 2018, 05:49:48 AM
Phew! I just finished casing up two of these units. I am very proud of the way they turned out. Cases from Dan at Collective Cases and the knobs I bought from CAPI-Gear.

EDIT: Scratch that! I don't know what was wrong when I tried it yesterday, must've been plugging something in wrong. The line gain is working perfectly on both units.

Everything works! I am incredibly stoked. Beautiful sounding units. I love running a 2-mix through them on the stereo bus! I used these to record a live piano concert last night. They sounded incredible.

Thanks AML!

Photo 1: https://flic.kr/p/25V1ZWm
Photo 2: https://flic.kr/p/271C2DP
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 11, 2018, 06:07:58 PM
I want to share some recordings I made of my sax through one of these puppies. I love the sound of these preamps! So warm and lovely.

First, flat EQ with no extra input drive: https://soundcloud.com/mattmarantz/ez1073-tryout-flat-eq

Some brighter EQ added from the ez1073: https://soundcloud.com/mattmarantz/zz1073-tryout-brighter-eq

Lastly, no EQ added, but some input transformer drive was used and the trim was backed off a bit: https://soundcloud.com/mattmarantz/ez1073-tryout-little-bit-of-input-drive

So cool that you can get so many sounds out of this box. This is the 1U rackmount version for anyone interested. Love it!
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: miscend on May 16, 2018, 04:49:41 PM
I just finished a pair of ez1073s,

One is working good, but there is a level drop when i flip the phase switch...?

The second one I have a very low output from the mic channel, and a lot of buzzing when i touch the mic gain knob... 

I have already gone over looking for bad joints and trying to clean up but no luck so far.

Any tips are appreciated!   ::)
Did you manage the solve the issue with the second unit?
Title: Re: Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500
Post by: EarthTone on May 28, 2018, 08:04:06 AM
Yes! Found a bad solder joint. Everything's finished & working awesomely now. Thanks,

Matt