[cello]

one fine lookin mint you got there. The bright blue LED is the way to go (that's what I used on my Meta42).

 

[tangent]

That's rather high for an AD8620, but liveable. You don't have to fix it, but if you wanted to try, I'm not sure how you'd go about assigning blame. You could do it easily on a META42 because you could use sockets, but on a MINT you have to test it in the fully assembled state.

 

[was ist los?]

I believe three of my four buffers are damaged! The right channel always had 16mv and then i stacked it and it became 15mV. The left channel once had 6mV, but now has 20mV.

 

[tangent]

Hand-soldering SO-8 wihout overheating the chips is tricky. Stacking chips increases the chances of problems. Maybe your skills just aren't up to the challenge? I'm not saying that that's what happened, it's just a "maybe".

What resistor values are you using?

Measure the DC offset with headphones plugged in and the source plugged in, and without. Measure all four combinations.

 

[was ist los?]

It's not my soldering. After i stacked them, it was fine, but something happened to the chips when i took the amp out of the case and put it back in, which is quite mysterious. The side with 15mV of dc was probably already damaged because i just reused it from a dead MINT board.

 

[was ist los?]

Ok, i've replaced the opamp and buffers and still 19mV per channel! Arg i hate dc.
*Edit* Stacking appears to make dc lower. I've also replaced the ground buffer and tle. Anyone have any clue what else is messed up. Turns out the buffers were fine.