arnyk wrote: > I can't recall what you reported, but I can tell you that in general the > clocks of audio products are very accurate and very stable and fall > miles within the relatively poor human ability to perceive long-term or > short term changes in pitch. That's what changes in clock frequency show > up as, changes in pitch.
Morning Arny! I hear you & I don't disagree with your statements, but it could still be somewhat analogous to the analogue wow & flutter which you have yourself reported as finding particularly irritating: for myself I found that I was able to "suspend my disbelief" sufficiently once I got my LP12/Ittok LVII/Koetsu (first Black then Rosewood Signature) source. I had previously owned a Transcriptors (later Mitchell Engineering) Hydraulic Reference deck with an SME 3009 arm & a Shure V15 MkIII cartridge (I'm sure you remember the '70s too) & the difference was like night & day. The Koetsu's tracked at 2g (which would formerly have been regarded as excessive) but managed not to grind through my vinyl by virtue of a very sexy stylus tip shape despite the low compliance of the cartridge which I accommodated by fitting a (Linn supplied) additional counterweight to the Ittok. This arm has precision ball-bearings (how well these have survived my travels in the past 30 years remains to be seen) rather than the knife edge bearings of the 3009, & the Shure V15 was of course a high compliance cartridge (as I recall, it would track quite happily at around 0.8g), so the newer design was a complete sea-change. Although the extrovert made much of the revolutionary qualities of his kit, the LP12 is really a derivative from the original AR turntable design from at least 10 years earlier, & Linn contracted out their precision engineering work. I believe the more recent SME turntables & Mk.V arm would now be superior (but a little bit more expensive :D ) - they at least do their own production in-house & use the heavy isolated belt drive concept for their decks & have switched to the precision all-round bearing approach for their arms. I do intend to hook up my old kit again now that I have a moving coil cartridge preamplifier (included in the Brokkly DAC) just for old time's sake: however, I'm sure you'd still hate it if you heard it! :mad: , :rolleyes: ... I wondered if you had any direct comments on the research paper that I referenced (which may or may not prove to be good science depending on whether the claimed results are confirmed independently). The test results were intriguing if valid. Correct me if I'm wrong here but I believe Shannon's sampling theory proof based on Nyquist's earlier conjecture (which only concerned Morse code, a digital source) if the sampling frequency is not completely regular is dependent upon the noise components mixed with the signal being "i.i.d." (independent & identically distributed) & that if that is *-not-* the case there may be theoretical problems in the interpolation process necessary for the reconstruction of the original analogue signal (I think that the Cheung-Marks Theorem covers an extreme aspect of this, where they show the addition of an arbitrarily small amount of *-non--*i.i.d. noise, such as that arising from quantisation errors, may make the reconstruction process "ill-posed" which is maths jargon for saying it no longer has a unique solution), IOW -the precise job that the DAC is attempting-, and in particular that suggestions made by Shannon in attempting to generalise his results to irregular sampling intervals are not correct. Even small instabilities might have some effect following this line of thought. This is all rather heavy stuff, & I'm guessing that any audible differences would tend to arise in the quiet passages of source material with a high dynamic range where the difference between the signal amplitude & the noise floor is reduced. Just perhaps some people may be attuned to "digital jitter" in this wider sense of including clock drifting inaccuracies, in an analogous way to the fact that you found early CD's (which did have some problems of their own in terms of engineering quality of recording) preferable to analogue, whereas at that stage I definitely preferred my (mature technology) analogue set-up. It's just a thought. Obviously we don't capture the full concert hall dynamic range of an orchestra even with our digital recordings, & if we did either the quiet parts would be smothered by ambient noise or the loud parts would make our ears bleed in the context of domestic listening. It's a question of producing a subjectively satisfying illusion of the underlying musical performance ultimately which may leave -some- "wriggle-room" for individual preferences yet. Still staying open minded atm this side of the pond. Dave :) ------------------------------------------------------------------------ Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
