First watt B1 r2

[richmain]

I have just brought a used First watt b1 r2 pre i plan to replace the volume pots with a pair of Tribute autoformers which i use at the moment.Can anyone tell me what the blue adjustment pots are for and what is the difference between the B1 pre amps i see some with a lot of caps.

 

[Dennis Hui]

Are you talking about the blue pots in the first photo of this post?

https://www.diyaudio.com/community/threads/b1-r2-proto-or-prod.363274/#post-6418312
If so, they are used to trim the dc offset.

Edit: This should be the schematics: https://www.diyaudio.com/community/threads/b1-rev-2.301812/#post-4940993

 

[richmain]

Yes thats them thanks.