ARC LS25 mkII adjustment

There are no voltage readings on the ARC schematic, but you could check the voltage drop across the 1 K source resistor; it should be approximately equal. Unless you know someone fooled with it, I would not worry.

Jazzgene, Did you change the adjustment?

I know someone did swap and adjust the amp. I was told it was John Rutan at Audio Connection.

I do want to confirm it is all good.

Gmuffley,

R10 and R11? Or the 1k trimmer itself? I guess I can measure the voltage drop at RV1 and see if the 2 channels are similar.

I think John probably knows better than to change those adjustments.

If it was my preamp and I suspected adjustments have been changed I would ship it to Audio Research, so I know it is working properly.

I think a lot of audiophiles try equipment that isn't working properly or not broken in and decide they don't like it. These hybrid preamps take a few days of warm up to start sounding their best.