I have a 686 build that I completed earlier this year. It's fed with a my own pre-amp build based around Tom's buffer modules. Having had many high-end amps over the years I can say with confidence that this is easily the match of any of them and I can't really ask for more from an amp. That said, as Si mentioned above, Tom's amps don't add any real signature so if your system needs a certain characteristic to balance the system it's part of they may not be for you.