jafant - at Bill's shop, he must be able to drive all kinds of loads with both unbalanced and balanced inputs. CJ experimented wide and long about adding balanced operation and chose to not go there. The unbalanced circuit simplicity won the musicality race even though balanced is 6dB quieter. True balanced requires twice the part count, and fudged balanced often disappoints. My experience reflects his observations. RCA cables often perform better than their XLR counterparts, unless there are pro conditions such as long runs, high EMF environments, lighting interference, etc. In livingroom hi fi we often have very manageable environments where single-ended RCA outperforms balanced XLR.
On my personal front, Bill is removing the input balancing circuitry from my Classé DR9s. It is op-amp based and of lower quality than the actual single-ended unbalanced input stage. We'll use the extra space for larger, better caps and a cleaner layout for what Bill promises to be decisively better results.
Regarding the 3.5 equalizer, the top version will actually have two complete circuit boards with one running positive and the other inverted, requiring an EQ for each channel - powered by an outboard power supply big enough to power both channels. That fully balanced performance will be better than unbalanced RCA, but at double the component count and cost. In the case of a real balanced preamp and poweramp (such as Benchmark), the true-balanced EQ will maintain balanced topology throughout.
I didn't ask, but I bet Bill has CJ at home.
