Interesting discussion about the H/H360 setting at 63 vs a lower setting. There are several aspects to discuss here. But one piece of information I’d like to know is simply – what is the S/N spec is for the H360? It's important but I can't seem to find it anywhere.
The general rule is that ideally, one typically runs the highest gain in the device with the highest S/N ratio. In the case of the H360 this is somewhat confounded by the S/N in the tubes, which typically do not have S/N much greater (and often less) than 90dB. My preamp, the Soulution 727 has a S/N of 120dB. Therefore, ideally, most of my gain should come from the 727 and not the H. But unfortunately, things become complicated because of the sonic liability when you use the volume control of the H /H360 at anything below 63. IMO, the inclusion of the H preamp section unfortunately confers a slight but noticeable sonic hindrance when the VC is set lower than 63. However, if you're bypassing the VC by running at 63, then you are left with only 1 option, which is to use your preamp to provide the necessary and adjustable gain you need. In that case, even though your preamp is quieter, it may not be providing as much gain as the H set on 63. (Even though I don’t know the S/N of the H360, I’m assuming the 727 with a S/N of 120dB is certainly quieter than the H360). In other words, by running the H at 63, I am creating a suboptimal paradox whereby the most gain is not coming from the device with the highest S/N specification.
Furthermore, if you're running a H set at 63 into a preamp such that the volume control needs to be barely moved to get full volume, that could be another problem and one that does not have an easy answer. Either run the H at less than 63 (and take a sonic hit), or, as has been suggested, figure out how to attenuate the gain of your preamp so that the VC provides a greater range of adjustability when the H is set to 63.
The other issue that seems to be part of the discussion is the old “single ended vs balanced” interconnect issue since the lowered gain of single ended components might be helpful when running the H/H360 into one’s preamp. I use single ended inputs into my preamp from the H360 and from my Zanden 1200 MkIV phono but use balanced outputs of the 727 preamp because my interconnects are 25 ft. FWIW its worth, having been down this road before, I defer to Keith Johnson at Spectral. Keith Johnson, as good as recording engineer as God ever created, said that you have to remember that a balanced signal uses 2 discrete amplification paths for each leg of the balanced signal, so there are always infintesimal differences in transistor responses between the 2 legs that occur. Hence what comes out isn't necessarily what goes in. Even if the transistors are matched as well as possible, these differences are simply not an issue with single ended amplification. One way to reduce or resolve these disparities is to match the transistors with exquisite precision as Dan D'Agostino does in his Relentless Epic 1600 monoblocs. "The unique input stage achieves extraordinarily low noise and distortion by assuring that the positive and negative halves of the signal are perfect opposites of each other, even if the incoming signal is not perfectly balanced". The labor involved in matching those transistors so precisely contributes greatly as to why the amps cost 350K per pair!
In a nutshell, unless you have long cable runs, as say from mics to the mixing board in a recording studio, or from pre-amp to amp, there is pragmatically no advantage to balanced cables and in fact, there can be a sonic hindrance compared to single ended. However, with long cable runs, the lower noise due to common mode rejection of balanced cable might be advantageous. If that's a good enough rule of thumb for Keith Johnson, that's good enough for me. Bottom line, this is one of the forever popular "how many angels can fit on the head of a pin" issues that audiophiles waste a lot of unnecessary time on as the differences seem negligible at best unless long cable runs are involved. It therefore seems reasonable to do whatever works best for you but don't over-think it.
