I completely agree with all the above 95%... Any Adcom other than the GFP750 will never be made significantly better to the point of being worth the money for future resale... On the other hand. If you have some nice parts laying around and in general like the Adcom. A polystyrene or teflon bypass or replacing a cheap electrolytic with a poly cap or such with the same value, will make a difference. Minimal investment and an audible return. Outside of that, I would recommend to sell the Adcom, add the money you were going to spend on the mod and upgrade your preamp.
moding and the inexperienced
hi,i'm looking at adcom preamps and from reading alot of posts have begun to be curious about it better caps transformers etc.but i have no elelectrical experience to figure any of this out.does anyone know of some good firms thet do mods for you and are reasonably priced?