Original's listening room is extraordinary. The reference system when I was there was Thiel CS 2.2s, a pair of Mark Levinson No. 29s, an XLH preamp, and an Original A9.2 CD player.
The soundfield was vast, with depth out the wazoo. I asked Du how much time he actually got to use the room, "Oh several hours a day. We use measurements, but the final proof is the sound."
Across the hall from the listening room was a test bench and construction station for those spur of the moment parts changes.