Originally Posted by zilch0md
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I'm having no difficulty seeing your post as an absolutely sincere and credible testimony of your personal observations - your veracity is unquestioned, in my mind - but man, this has got to be one of the most amazing posts I've ever read in terms of its ability to elicit a "How can that be?" reaction.
It helps that I'm in the camp that believes jitter, or the lack of jitter, can do incredible things to the sound, all the while delivering a stream of 1's and 0's, and I "know," from personal experience, that USB cables can make a difference, believing it's because of the impact they can have on jitter, but I've never really worked out just exactly what the scope of impact is for jitter. Reading your post, if jitter is the variable in question, it can impact a lot of traits that I wouldn't think possible. Clarity, yes, but sound stage, for example, is a difficult trait for which to imagine an explanation.
Still, I have to reiterate, I respect and appreciate your observations. I use the Concero exclusively as an S/PDIF source, even though I consider it to be the best ESS9023 DAC available - way better than three other ESS9023 DACs I've spent a lot of time with. It doesn't even sound like an ESS9023 DAC - like the other three - but I have other DACs that I prefer to the Concero (including the ESS9018-equipped Oppo HA-1, and for a warmer sound, the Wolfson-based Beresford Bushmaster MkII (with which I use the Concero for Coaxial input), and for an even warmer sound - which has become my "cure" for the HD800 - the PCM1792A Line Out of the still bug-laden FiiO X5 DAP.
Some people have written, in this thread, that there are better USB-to-S/PDIF converters out there than the Concero, including the AP2. Having previously talked about, but having never done any comparisons myself, it's great to read that (for some types of music) you prefer the Concero to the AP2, in that role, but I had never imagined that it could add "a touch of musicality and a little bit mid bass and the expense of outright clarity."
Now, I'm thinking I should just get on with my previous thoughts of buying a "cheap" USB-to-S/PDIF converter, such as the 96kHz-capable HiFiMeDIY Sabre U2...
... but then I'd be comparing an optical cable to a coaxial cable, as well. To stick with Coaxial output, I could spend a little more money and go with the 96-kHz-capable Teralink X2, instead.
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I would be approaching the Concero comparison from the low side, instead of from above, as you did, but that might reveal even greater differences than what you've discerned with the AP2.
I've had the Teralink X1/X2 PSU for several months now (pictured below), and have found it to be a very, very clean-sounding power supply, providing 5VDC at 1A output (or an user-adjustable 9VDC, via a different jack - the brass screw head seen in the photo atop a little blue box allows the user to adjust the voltage at the barrel jack - up to 9VDC - but I have no audio gear that can make use of this feature.) The Teralink PSU works very well with the Concero, but I prefer battery power, as a rule. You might want to give it a try with your Concero, given that your AP2 PSU apparently doesn't provide enough current. It includes a very nice USB Power/Data splitter cable, that substitutes some very expensive alternative cables out there for segregating USB power from data:
OK, I just ordered the Teralink X2 USB-to-S/PDIF converter. "Estimated delivery Thursday, July 24 - Wednesday, Aug. 27" Ouch! - I guess it's a long way from Taipei, Taiwan to Texas!
Let's hope it helps me to appreciate something I've been taking for granted with the Concero. Otherwise, the Concero will go up for sale (as I don't have any PCM files at rates higher than 96kHz and I'm not really interested in paying for higher rates.)
May the better-sounding USB-to-S/PDIF converter win, regardless of price, build quality, chicness, and cosmetic appeal!
The TeraLink X2 arrived two days ago - much sooner than expected. After about 10 hours of A/B testing into both my OPPO HA-1 Coaxial input and my Beresford Bushmaster MkII Coaxial input - with these DACs feeding the HA-1 amp section's analog inputs and going balanced out to my HD800, I've concluded that the $75 TeraLink X2 sounds every bit as good as the $599 Resonessence Concero as a USB-to-S/PDIF converter. If anything, the TeraLink X2 actually has a smidgen more detail and separation in the treble, but I must be imagining this, perhaps only because I want the underdog to win. In any case, the $75 TeraLink is certainly not any worse than the Concero, as a USB-to-S/PDIF converter, using its Coaxial output.
And just to bolster my own sense of credibility, if not others' confidence in my findings, I'll add that I am surprised to discover that both the Concero and the TeraLink X2 are equally good at outperforming the OPPO HA-1's own USB receiver - which is ever so slightly diffuse (smoother and less detailed) in the treble, relative to these outboard USB receivers.
As a disclaimer, let me add that I'm still using an OPPO HA-1 prototype - I don't have the released version, yet.
The point I'm making here, is simply that I can't hear any significant difference between the TeraLink X2 and the Concero as S/PDIF converter, even though I can hear them both outperforming the HA-1's USB receiver - splitting hairs, using an HD800, and the HA-1's excellent amp section, with selected sections of good recordings. In the end, I'd be happy with any of the three USB receivers.
Update: For both the Teralink X2 and the Concero, 5V power was provided by the excellent Teradak PSU via their USB Y-cable. Only data was pulled from the laptop's USB port - using a Moon Audio Blue Dragon USB cable (which come to think of it, cost me more than the Teralink X2). I haven't tested it and it might not be fair to say this, but I seriously doubt the Teralink X2 could do as good a job of power management from a USB port as the Concero does - that's one of the Concero's greatest strengths.
Edited by zilch0md - 7/16/14 at 10:00pm