Ambika VC volume low

[Strange Tales]

Xpost between here and Muff.

I'm having a god damn whale of a time trying to get this one voicecard working. It's volume is a ton lower than the other voicecards, and the only things I can find from googling are check for shorts and try replacing the TL072. I tried replacing the 072 (and 074 for that matter cause why not) to no success. My eyes don't see any shorts, but a good possibility my eyes are just bad.

Anyone have any ideas? First response from Muff was to check my 4.7/47k and 2.2k resistors to make sure they were the right value, and they are (as long as my eyes can see, I have some trouble differentiating between red/brown with these things). I reflowed those as well to no success.

(Big pictures)
PCB pictures:
http://i.imgur.com/AQHl5Im.jpg
http://i.imgur.com/ir6puyJ.jpg

PCB Info:
http://mutable-instruments.net/ambika/build/smr4

[crochambeau]

You say you have a working circuit on hand to compare? I'd start with comparing voltages at all the pins and see if you can spot a discrepancy.

[Strange Tales]

That's a good idea. I've never actually had to use my DMM yet so this will be fun

Any hints on pins I should check out?

[crochambeau]

Power supply pins, then stage inputs, then outputs. Start at DC reading, if that passes read AC voltages while the unit is under operation and passing signal in the 60 hz range. You'll find a point that stuff drops off.. then it's just a matter of sorting why.

[eatyourguitar]

First response from Muff was to check my 4.7/47k and 2.2k resistors to make sure they were the right value, and they are (as long as my eyes can see, I have some trouble differentiating between red/brown with these things). I reflowed those as well to no success.

wow all that reflow and still never dusted off the multimeter to check the thing that they told you to check. you need to check resistance with your meter set to Ohms. you might find the problem is a resistor of the wrong value. if it is not that, then probe the circuit with an audio probe. find the loud parts and the quiet parts. that will get you closer to the problem. probably a solder bridge or something like that.