Unlike in the BP1, in the BP2 signal ground looks to be "floating" - i.e., has no 0V/chassis reference (other than by way of 0.1 uF ceramic cap that I assume is to shunt high frequency noise to ground). Is this in fact the case, and if so, is the purpose of the floating scheme to prevent ground loops?
I have an at best fuzzy sense of the possible benefit of eliminating the middle signal house ground reference in, say, a DAC -> BP2 -> Kaiju chain. I'm guessing you go from 3 possible loops to just 1 -- with the 1 formed by the rca ground connection at the DAC at one end, and the rca ground connection at the Kaiju at the other, connected in between by the floating signal ground scheme of the BP2. In the unlikely circumstance that I'm right about the structure of this 1 loop, is there any "potential" (pardon the pun) for the notional signal "0V" of the DAC and the notional signal "0V" of the Kaiju to have different and varying voltage potentials relative to house ground, with the result that a small noise current runs through the signal ground of the BP2? I strongly assume not, and that any such differences are resolved by low impedance paths from signal ground to house ground in the DAC and Kaiju, but I thought I'd ask just to rule it out in light of a couple recent reports of hum. And apologies if I'm out to left field with this - please ignore if that's the case.
Independently of the considerations above, in cases of hum, I wonder whether it would be worth testing the effect of temporarily creating a chassis/house ground connection for each channel in the BP2 - e.g., by using clip leads to connect 4U (signal ground) to 3U (chassis connection) and 14U (signal ground) to 13U (chassis connection)? Just a shot in the dark. Same caveat/proviso as before: please ignore if this makes no sense.
cheers and thanks, Derek