Hi Jan,
If I'm wrongg, Dan or PJ will surely correct me, but as far as I know this was a very limited kit of parts with sparse documentation that was made available on an experimental basis some years ago. Therefore if you weren't in on that or didn't pick up the schematic before the folks at bottlehead decided to keep the IP under their hats, you're pretty much out of luck, unless somebody wants to sell theirs, which is pretty unlikely.
You'll have to wait for the next version, if there is a next version, and whatever it may turn out to be. See the SR-455 amp thread for the current back-and-forth on the preliminary design of this potential amp. You'll see that it's not even sure if it will be a product or not at this stage, just some ideas that PJ is kicking around.
If you see one for sale, grab it! :-)
-- Jim
Jim Rebman -- recovering audiophile
Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).
s.e.x. 2.1 under construction. Want list: Stereomour II
All ICs homemade (speaker and power next)