ARC LS25 mkII 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.

I don't know John Rutan but have heard good things about his business. I don't think he's a tech though. All this is what I heard from the previous owner. Not that I don't trust him but I just want to make sure the amp is working properly.

Found a schematic for the LS25 mkII. I think I got it now so I will check the voltage tomorrow. Right now, I am going to enjoy the Yanks bash the Rangers again!

Did a full voltage check. Had to tweak one of the trimmers a very small amount.

The preamp sounds really great.