I am in the process of modifying the ZR1600. Dave Garlett says that the ZR1000 actually sounds better, particularly if used in bridged mode. The nice thing about a modded amp versus one that you design yourself is that there are many protection and detection circuits that can be helpful and prevent damaging the amp and/or speakers. I believe that both the ZR1600 and 1000 have potential. There are a LOT of improvements that can be made to an already good-sounding amp. It has a massive transformer, it is very quiet and has reasonable protections - fuses, filtering and overvoltage protection. Pro audio gear tends to be made very bullet-proof. The main problem with these amps is they have way too many features and switches to use these features. It is also somewhat modular to allow different input and output boards etc.. This drives the parts count and the number of op-amps used to an unreasonable number. This add a lot of noise and sibilance. It also has protections in terms of bandwidth limiting. Most of this stuff is not necessary for audiophile use. Once these "extras" are removed, without compromising the protection mechanisms, I believe it will be a stellar amp, maybe even unbeatable, certainly at the price-point.
