Believe it or not, I'm still trying to figure that out. The other night I got astounding sound w/the Final D8000 (a planar). A couple weeks ago, astounding sound w/my other planar, the Ori.
Results with the Atrium have been a bit mixed: several days ago I got a very large, spacious sound with a bit more treble than expected (total level of treble, I mean--actual sound of the treble was terrific).
This amp is a real project. Mfr recommended 300 hrs burn-in, which I did. But it may prove to be one of those devices that keeps changing sonically until ~500 hrs' burn-in. I say that because I've gotten variable sonic results in the time I've had it in my main system (after 300 hrs' burn-in).
Part of the variability was because I tried 2 different tactics to knock down the excessive gain of the amp (external passive volume controller; or pair of high-quality 10 dB in-line RCA attenuators). The in-line attenuators work well and have been in the system for past week+. I'll try the VO & Atrium on this amp again soon, probably over the weekend.
As for output impedance of each jack, I really can't figure out this design at all:
- Thanks to a "pigtail" from ForzaAudioWorks, I can use my typical XLR/balanced FAW cable with either the THR-1s 4-pin XLR output or either of its 1/4" outputs. Here's the weird thing--the level doesn't change, no matter which output I use. That can't be correct; the high impedance output ought to put out lower volume. But it doesn't work that way.
- Compounding the weirdness is the fact that the volume from any of the 3 HP outputs is at least double that of the line-level outputs that go my amp & speakers. Comfortably loud on HP is ~9:30 on the dial, while comfortably loud on speakers can be 2:00+ on the dial. I can't figure that out at all
- At first I thought the passive controller or attenuators were somehow acting differently for HP outputs vs line level output (not possible, but still, I checked). Running the amp w/no attenuation at all, the same volume different exists, but now the volume is pinned counterclockwise for HPs, barely getting above 7:30 on the dial before becoming intolerably loud, while the preamp output is @~9:30 on the dial.
So to say the least, there are some operational oddities w/this amp. Some of this stuff wouldn't be noticeable to anyone using it only for headphones and not also for preamping, as I do.
But in general, the sound I've heard since putting it IMS is really high level SS sound done right--strong bass, big/rich midrange, and very extended treble that is also delicate and nuanced. The headphone sound is strikingly good on some headphones. I'm putting in all this time and effort w/the THR-1 mainly because its core sound seems so promising to me.
More to report in a few days re sound w/VO & Atrium...
(current rig is Chord Qutest -> Feliks Euforia -> Atrium, a demo unit) Apparently she got tricked, she took the headphones off to check if, or who was chatting outside. Turns out it was just in the recording haha! It's not even biaural, Jazz at the Pawnshop 30th Anniversary.
