Rather than spending $$$ to rehab an older preamp, and especially since you’ve had this one so long, I’d consider taking the opportunity to try or go listen to some others. For example, if you’re open to tubes the Linear Tube Audio MicroZOTL preamp — among many others — could be a revelation and they may have some kind of trial or return policy to try it in your system (and yes, it has a HT bypass). Just another thought FWIW.
Bel Canto Pre2 mod/update?
I've had a Bel Canto Pre2P (purchased here) since ~2009 and it does everything I need in a combo 2 channel/HT system. And it still sounds quite good. I leave it powered on constantly. When it does power up it displays a version number with a 2004 date, so it is pushing 20 years old.
I'm wondering if I should get it "tuned up?", that is have some caps/resistors replaced, perform any biasing, etc. I also have no idea who I would send it to for this tuneup. I'd appreciate anyone chiming in with recommendations.
TIA,
Mike