Biasing powerball II blackface

[just42dave]

Am I not seeing something here or is a powerball two fixed bias... This is the newer powerball. There is no whatsoever trim pot inside this amp which would make sense as it has the tube shut off system.....I even took it apart again to see if i missed something

 

[PrestoDone]

On The PC Board there is a trim pot to adjust the bias. Forgot where is saw a pic of it....but its in there on the pc board....kinda hard to see though.

 

[just42dave]

i didnt see anything resembling anything to bias there is a large siver plate attached with plactic anchors and has like a ground wire cobering it.. I shouldnt have to remove anything to bias correct??? And is this the newer powerball we are talking about cuz I know where the pot is on the silver face...I looked and i am thoroughly sure nothing was visible at all..

 

[bananaladonpcp]

Theres a hole in the board. The bias pot (along with almost all the other components) are on the other side of the board. Look for the hole and you will see a white plastic piece that you can put alittle screw driver in. its by the transformer. about 3 or 4 inches to the right of the transformer to be more precise.


-Alex

 

[just42dave]

got it it was hidden by the thick relay wires