Update! I am working on a new pcb layout for the psu of my Adcom. After looking and measuring a bit on the original board dimensions, I can actually use the original speaker connectors AND have room for 35mm snap in caps! This is going faster than ever before because now I have experience laying out boards. It has been much easier this time.
I am also laying out this proto to also permit the installation of ceramic smt caps to run from voltage rails to common in place of the mica caps specified.
I realize now in my current working board that I installed metal film resistors. Turns out that these are more inductive than metal oxide resistors. MOX resistors are used on the original board, so I will go back to that type. This board would be easier for someone to get up and running quickly and not have to mess with chassis mods to retrofit some other type of connector for their speakers.
Ok, so now to mire into a bit of muck.....
I don't have an opinion either way of someone wants to buck up their caps to 100,000 uF or buy Vishay nude resistors. Go all out!
But the reason anyone says not to do something is because maybe they have been down that road and really messed their amp up badly. In my comms with Anatech, he has owned a business dedicated to audio repair and as a mod on diyAudio, his advice is extremely sound. He has encountered several boxes bought off of ebay that folks purchased only to find some major fault. He has seen and corrected the mess that others have created.
Now, having said that, if you have the knowledge of what you are doing, understand the practical limits of your equipment, then proceed with your idea. My opinion is clearly in the camp that if you don't know what you're doing, then research the heck out of it and understand it. There are many times I wanted to try something with this amp and have taken a very slow approach to making certain changes to it. I'm on a journey just like everyone else.
I have even had my ideas put upside down and spun backwards after trying them. I have read too many times on the net that if you do this or that, you are overcoming some weak points in the original design. That may be true, and maybe not.
Finally, my point is (and others have hammered this too) is that if you are at a certain skill level, why not build a circuit from scratch and understand the principles. After all this time, I respect what the guys at Adcom have done. Nelson Pass and John Curl often speak nicely of the Adcom days when they were in New Jersey. I don't want to put a huge fingerprint of mine on this box. I am now just about ready to build a class AB amp from scratch and just be happy with what I have learned from the Adcom.
As far as boutique components, yes, I agree that some guys know what they are doing in modding equipment (and some guys not so much). My opinion is that some mods can be very good but others don't buy you much even though you spent $$$$. Soooo, YMMV. But what I enjoy so much is that I have better understanding on what is going on under the hood and I know that a $.65 cap may be just as good as that $7 cap. On a nudge from Uriah Dailey, I showed up at LSAF with my hybrid headphone amp, based on a Pete Millett design. I had guys come in and listen and they were shocked at how good it sounded, even with a 45 cent electrolytic right there at the output in the signal chain. One guy's jaw dropped and he said that he loves solid state but this head amp sounded like real analog.
So, if you guys are interested, keep following my journey here. If after I test my proto board, I will let you guys know how well it works and I know some have expressed interest in a copy. It will definitely add years to your Adcom 535 and all parts will be EASILY available.
For ALL who have posted here, thanks for your comments and input. If it makes even one person think, then that is a good thing!
Rega P25 and LFD Mistral phono (analog) or Oppo DVD Player (digital) > Aunt Corey's Buffered Pre > Adcom GFA 535 > Spica TC-50