what are these? amp experts please help!

[admin_exported]

hi, last week i took my A400 apart for a clean and whilst doing so i noticed to adjustable trim pots(?) inside on PCB. i have included a pic of them (they are the things circled in red). could anyone please tell me what they are for? thanks, chris

 

[Anonymous]

They are biasing pots

 

[Andrew Everard]

Thanks for the clarification, Rev

 

[Thaiman]

Normally they are for biasing the voltage of the pair(s) of output transisters / fets etc. Unless you know what you are doing, best left WELL alone!!!!

 

[Anonymous]

Andrew, i was thinking the same thing ;-)
Thaiman you are the man! thanks for your info and advice. i thought they might have had something to do with the input levels and maybe by adjusting them i could do away with the attenuators i am using. i guess not, but i am glad i asked before just experimenting!