FYI Rick's mods are per Nelson Pass himself. That's right he told Rick what he would have designed had Adcom gave him the go ahead on a cost no object design meaning "make the best sounding, most reliable amps with the highest quality parts on the planet". I had him mod a pair of Adcom GFA-565, one GFA-555 MKII, and a GFA-535 MKII. All of them sound just as good and the Pass Labs X.5 and the 565’s will go toe to toe with the big XA series any day of the week. If you have him mod the GFA-565’s all you need is a Pass Labs X1 pre or newer pre-amp and you’re all good unless just want to say you spent more money just to brag. The sound won’t get any better, I know i’ve been there and done that. Never again. I have owned the McIntosh MC-601’s, Bryston 7bsst’s, Krell KSA-100’s, Parasound JC1’s, Threshold SA1’s. All of them have been sold off to friends that thought I was crazy. I now tri-amp using the Mini DSP 4X10HD & Pass Labs XVR-1 2-way crossover, the 565’s monos are feed via a Mini DSP 4X10HD powering a pair Acoustic Elegance TD12S woofers, the 555 MKII is feed via Pass Labs XVR-1 2-way crossover on a pair of Volt VM752 3" dome Mids and a the GFA-535 MKII pair of Raal XR70-20AM ribbon tweeters. Just for sub use only I use a pair of JL Audio F112 from 50Hz & down at 18db slope and in phase they just disappear. Cables are DH Labs silver sonic and Cardas Clear Reflection and i’m still trying to decide which sounds the best to me between the two and right now it’s too close to call. If you like a brighter more dynamic sound go DH Labs, if you want laid back 3 dimensional sound go Cardas Clear Reflection. I keep switching back and forth both are killer cables. Power Cables are my on custom DIY DH Labs Red Wave. This system has been 15 years in the making! I have friends that have $80K to over $170K systems and they are blown away by the synergy of this system. Now the same friends all want me to help them design a system with sound quality of mine. To be fair I have sound treated my listening room which honestly makes huge improvements over an untreated room, also the minidsp on the woofers is a must. Just saying it’s all about how you put it together!!!