[ishtob]

I just finished populating a SOHA kit that I got from glass jar audio, I'm doing some test with the voltages, all the points checks out except for the 2 marked as +40v I know i have to adjust the pots to get it to 40v, but I cant seem to get the voltage pass 30V, then turning hte pot who have absolutely no effect after that.

 

[adamus]

what ccs setup did you use? lnd150's?

check the jumpers are right. Then check solder joints.

 

[ishtob]

found the problem! while i was checking the joints i noticed that I had the R7 and R8 reversed (and also their counter part for the other channel) after switching the resistors I was able to adjust the voltage to 40.

But i got a new problem. After trying the amp with a pair of cheap headphone i noticed that the signal was really really weak (the music is really soft even though I turned both my mp3 and the amp up. I double checked all the component and still can't find anything wrong.

 

[ishtob]

does haveing a 150ohm resistor at R6 and R16 causing the volume decrease? I still dont think it would causes such a drastic drop in volume though

Update:
I bypassed the R6 and R16, the music volume is louder now, but the bass remains at the same volume, very shallow and not what I expect a amp would do. What would cause this lack of the bass range?

oh, I am using the MOSFET ccs setup

 

[adamus]

sounds potentially like a phasing issue, although its quite hard to get wrong on the soha (I assume you have used the alps pot mounted in the pcb?).

check the jack wiring and check the inpuy wiring.

also, check the DC offset, if this is above 10mv or so then you have a problem.

 

[ishtob]

oooh!! thank you!! found the problem with the input joints... looks like I have overlooked the input and output connections

now i jus tneed to get everything cased up and it should be good to go!