Lol, been shown not to have effects by whom? Are you seriously trying to argue that the entire high-end is essentially a scam, or waste of time, because most of what you pay for are components like better and better power supplies, more accurate clocks, better connectors, etc?
There are always going to be people who will try to eek out the last .001% of performance from a system, no matter the cost, and no matter whether there is a actually a discernable difference. Those people are free to muck about in the high end, but it is a game of rapidly diminishing returns and rapidly escalating costs.
Yes, I have - and have done abx testing to see if I could reliably tell the difference between them. I could not. I challenge you to do the same. There are certainly theoretical differences, but whether they fall within the realm of human audibility, seems to be up for legitimate question.
There are certainly degrees. Done well I take to mean quiet (shielded, and does not introduce much noise into the system) and stable. I don't think Westlake is a scam artist, but he may certainly be reacting more to the demands of the market, more than to audible improvements. Or he may just be after something as close to perfect on paper as it can get - I can respect that, but I'm sure not going to pay for it until it is demonstrated that I can hear it.
Almost all the respected magazines include measurements of clock jitter and any PSU related distortions. The HiFi world technical report on the TeddyDAC said something along the lines that it had better PSU and sounded better as a result.
Yes. But I don't believe any of them have demonstrated that jitter at the and distortion at the levels we see in the vast majority of kit is at all audible, or that improving it, actually improves the sound. The published works on Jitter indicate that human audibility actually requires quite shockingly bad jitter in order to detect. Performance even the worst of the consumer gear manages to stay below.
‘‘Theoretical and audible effects of jitter on digital audio quality,’’ Preprint of the 105th AES Convention, #4826 (1998).E. Benjamin and B. Gannon.
"Detection threshold for distortions due to jitter on digital audio" Kaoru Ashihara, Shogo Kiryu, Nobuo Koizumi, Akira Nishimura,
Juro Ohga, Masaki Sawaguchi and Shokichiro Yoshikawa. Acoust. Sci. & Tech. 26, 1 (2005)
Benjamin and Gannon using signal-correlated jitter place the thresholds at around 20ns. Ashihara et al using random jitter place the thresholds at around 250ns.
As for PSU distortions - once you get into mid-tier kit, designers and builders start paying better attention, and the majority of problems get mopped up pretty quickly. Certainly they can be a theoretical problem, and some designs may benefit from better isolated PSUs, but overall - not that big a deal, sound wise. At least not in my own ABX testing or any that I have seen.
I don't question the existence of cable reflections. I do question whether it has an audible effect - especially in a digital signal which is being clock matched, or otherwise processed from bit data, not analog frequencies. At worst, a mismatch would begin to introduce some level of cable induced jitter. Something either the async clock in the dac would compensate for, or would likely be below audibility (per above).
And there are many 75ohm bnc and coax connectors out there - it is an industry standard, and easy to find for much less than the boutique connectors you list. A package of 10 usually runs about $15 for basic 75ohm cable end bnc connectors. You can pay more - and there may even be good reasons to... but there is no reason to go nuts.
Edited by liamstrain - 5/17/12 at 1:27am