Bias Adjustment SA/10e - SA/11m

[ADH]

Hello everybody,


I need some help with my SA/11m monos (similar to SA10/e). The amps show different temperatures to each other and also inside (left to right side). Measured from the outside between the heat sinks in the rear area between 52 and 58 °C.


Can someone describe the bias adjustment procedure (test/ adjustment point, additional hints)?


Thanks a lot


André

 

[Nelson Pass]

I have attached what schematics I have, which do not list the SA11m.

The bias is normally adjusted by a single pot on these, but I think this
may have occurred after my time there, and perhaps there are separate
adjustments.

Both sides of the amplifier would be controlled by the same bias
circuit, so if they are biased to different temperatures you would want
to look at why that would be. Any bias adjustment should alter the
current draw of both sides.

 

[ADH]

Hello Mr. Pass,


thanks a lot for your hint. Where can I find this Pot (located in the amp)? Can I take any measurements (with Multimeter) to verify the problem?

 

[Zen Mod]

carefully look for sole trimpot on small (FE) pcb

use heatsink figure , with lid on