Really? I had an original 535 and never considered it worth beans. I've had hundreds of basic amps, most of which I've made but plenty of commercial designs and I have to say that the Adcom 535 was utterly undistinguished.
The original preamps that they made, the GFP1 and 1a were both great for the time and the price. The 565 preamp was stellar for the time. The GFA-535? No so much.
The original preamps that they made, the GFP1 and 1a were both great for the time and the price. The 565 preamp was stellar for the time. The GFA-535? No so much.