What the heck have I done..!?

[lazyfly]

Hi forum.

I've wired up the + - rails on a BrianGT GC and all rail voltages are spot on (25+25 transformer - 36V rails on both modules).

Now, one channel produces 58mV at the output whereas the other channel is producing 35.5V!!!!! What the?

Please help

 

[lazyfly]

hmmm, don't know if this will help but measuring in Ohms across pins 3 & 8 (nfbr) I get 21.9k and the working channel is the same. When I measure across pins 3 & 7 I get 0k on the dodgey chan and 44.5k on the working channel.

 

[aHobbit]

If you get 0 ohm between pin3 and pin7, it looks like you have a short circuit between pin 3 and the V+ rail of your supply. Thus, you will have 35.5Vdc at your speaker output terminal.

check carefully that no stray wire or whatever connects your V+ and the pin3.

regards.

 

[Nuuk]

This is also a symptom of one 'broken' rail. So check that you have the correct voltages on each pin of the chip.