What Bill is doing with the DR9s is to take out the 'balancing' circuitry at the inputs which is op amp based. Its only practical function is to allow XLR to reduce noise in long interconnect runs. Otherwise, that circuitry is of lower quality than the rest of the amp. We gain room for better (very good) caps. CSA / CMR / PURITY. He's upgrading some storage caps and some critical resistors too. He can optimize bias, etc, by committing to bridged-only operation. When bridged the DR9 delivers 400 / 800 / 1100 watts into 8/4/2 ohms. Bill can get the noise better than new. And so forth and so on. I ordered the relevant ClarityCaps with the recent sample order. The sample order so long in the making has finally been confirmed.