Hello James, I would wager a good deal of beer tokens on this sir. Going on the 555 effort, they would need to improve their dac by a serious amount to compare to the T/P unit. I believe there is a 556? planned with another 555 psu for each of the channel, plus a dac cost around the £25K mark. Thats a lot outlay for a Naim sound. Genuinely the twisted pair dac (diy kit from the US) is pretty good and with minimal work can be made to sound very good indeed. You really would appreciate its performance James. And no we do not sell them! Pretty sure a few guys on here have got the latest 90018 unit and have been 'tinkering' with it