I owned a 555 and a 555 type 11 many years ago and they were both solid amps. I never experienced problems of any kind with either of them. They had limitless headroom and I'm sorry I sold them. That was back before Dolby surround and I used them with a great Lexicon processor. I then decided to sell them and go with a Sony receiver. I've been sorry for that move ever since.
By the way, could it be that there are more Adcoms on eBay because more Adcoms are sold initially than most other brands? I honestly don't know if that's the case but that figure should be considered when trying to evaluate why folks are selling them.
Photodan
