I have been using an NJC Reference Headphone Amp for a while now and have recently purchased the Reference DAC.
I have had many conversations with Richard over the last couple of years and his help and advice has been above and beyond what I expected.
Both units are superb, not only in craftsmanship (NJC virtually hand make them) but the sound quality is beyond anything else I've heard.
I'm sure you will be impressed, please report back when you have had a chance to listen.
Chord Mojo / Sennheiser HD600