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Old 1st May 2013, 03:24 PM   #111
RNMarsh is offline RNMarsh  United States
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Have you tried to paralleling ADC's for better performance? Either mulit-channel products or with the IC themselves.

Thx-RNMarsh
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Old 16th May 2013, 10:42 PM   #112
RNMarsh is offline RNMarsh  United States
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Default where is the How To part??

Hi dave... where is the mod description - the how too - pictures etc for the 0204? I see the schematics here but where did you place the How to part of it??

Thx
RNMarsh
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Old 16th May 2013, 11:13 PM   #113
davada is offline davada  Canada
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Originally Posted by RNMarsh View Post
Hi dave... where is the mod description - the how too - pictures etc for the 0204? I see the schematics here but where did you place the How to part of it??

Thx
RNMarsh
My camera crapped out so I can't take pics. You should be able to figure it out once you have the EMU0204 lid off. The part designator numbers for the EMU board are on the schematic. The op amps are dual standard pin out. I removed the pot on the from panel to open that part of the circuit. You'll need a magnifying glass. Glasses if you where them.

Cheers,
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Old 17th May 2013, 01:27 AM   #114
RNMarsh is offline RNMarsh  United States
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Rats! yes, I have a mag-glass. Thanks... I'll look at the schematic for the board numbers... didnt realize that's what they were. Just getting around to it. Thx - Richard
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Old 17th May 2013, 02:02 AM   #115
RNMarsh is offline RNMarsh  United States
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I've been looking all around with a magnifying eye piece... have not found all of them, yet. I think I'll just take a picture of the board and put it on my large PC screen and zoom in on it there.

-Richard
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Old 17th May 2013, 02:13 AM   #116
davada is offline davada  Canada
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I've been looking all around with a magnifying eye piece... have not found all of them, yet. I think I'll just take a picture of the board and put it on my large PC screen and zoom in on it there.

-Richard
Looking at the board from the front of the 0204, R53 is about half an inch left of U5.
With the pot for the right channel removed connect a 3k or 3.2k resistor from pin 7 to pin 2 of U5.
I think there was a 100 ohm resistor I had to remove beside the phone jack. I take a look and let you know.
That really about it.

I remember now. Remove R26 and solder a wire to the nearest ground and the non inverting pin 5 of U5. There is a ground on the board used for a test point just to the right and slightly below U5. Square pad. If you like you can leave R26 in but it has to be routed to ground. It was the non inverting input for the original configuration. R26 must be removed from the input jack. I found it easier to just remove it altogether.
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Last edited by davada; 17th May 2013 at 02:26 AM.
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Old 17th May 2013, 06:34 AM   #117
RNMarsh is offline RNMarsh  United States
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I looked for an hour... no R26. Did you mean R29 instead?
Or, give me a clue to where R26 is... near which IC? or other landmark.

-RM
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Old 17th May 2013, 02:17 PM   #118
davada is offline davada  Canada
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I looked for an hour... no R26. Did you mean R29 instead?
Or, give me a clue to where R26 is... near which IC? or other landmark.

-RM
Hi Rick,

The are two resistors on the left side of the 'right' input jack.
Take your multimeter and trace the one that connects to the jack on one side and U5 pin 5 on the other side. That's the resistor.
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Old 17th May 2013, 04:42 PM   #119
RNMarsh is offline RNMarsh  United States
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Thanks -- as you can tell, i am unlikely to redo from scratch what others already did without details... too time consuming. Too many projects and trying to sell a house as well. So, i'll get back to this mod when i have more time. meanwhile, i'll try the eMu-0404 that i did a mod and use ARTA with it. I want to see if either e-Mu model is better than the QA400 in accuracy at low distortion levels.

Thx-RNMarsh
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Old 17th May 2013, 06:26 PM   #120
davada is offline davada  Canada
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Originally Posted by RNMarsh View Post
Thanks -- as you can tell, i am unlikely to redo from scratch what others already did without details... too time consuming. Too many projects and trying to sell a house as well. So, i'll get back to this mod when i have more time. meanwhile, i'll try the eMu-0404 that i did a mod and use ARTA with it. I want to see if either e-Mu model is better than the QA400 in accuracy at low distortion levels.

Thx-RNMarsh
Just the front panel gain adjustment and cal I described in the PM and you'll get good results.
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