How many of you upgrade your preamps and amps?

Samujohn.....I guess my point was that the factory tech doesn't have the descretion to make changes that would void a warranty. At this point for me that's not a issue.

As an example my tech called today about my P300 Accuphase...the Mundorf M-Lytic caps 47,000uf 80V will fit the cabinet...as he machined the sheet metal covers for clearence. These caps are expensive at 130 bucks a piece but they are exceptional. So my P300 upgrade should be magnitudes better than a factory spec amp. For $600 spent the amp should approach class A performance.

Pretty important difference between "non factory tech" and "my local tech was a trained Accuphase dealer".

I have a factory upgraded Accuphase C200 and a C200 that my local tech upgraded. The private upgrade is about 10X better....no comparison. The original used elna caps...I had Nichicon gold installed. I am lucky as my local tech was a trained Accuphase dealer. On the C200 there are about 22 caps that need to be changed out or bypassed in the sound path. Also the noise floor can be lowered significantly.

I urge you to contact the service dept. of Accuphase. I have installed many simple capacitor and other parts upgrades but I always contact the service techs for their advice. Often they know a bit more about their stuff than you can figure out for yourself.