Friday, February 14, 2014

Analog preserves micro time

It hit me while listening to my Lenco L75 playing Rick Wakeman, which was virtually unlistenable on my Mitsubishi LT-30 because of wow (I think it's not working to spec, even, so lets not judge all LT-30's let alone all direct drives on that example).  But the Lenco has been a revelation of sorts, I really do hear far more from this analog source than anything else I've had…even if the source material is below spec (and I've been using my least well regarded records until I ensure everything is working ok).  Rick Wakeman plays with pitch a lot, but if you can't follow his play, it sounds all flat.  Did I hear him scratching?  Never heard that previously.

My idea is best stated like this: When two different instruments begin creating a sound at slightly different moments, what are the possible differences in the relative time they can start?  Well on an analog system, there are infinite possible time differences (perhaps down to some level of quantum time…or quantum something).  With the digital system, there is always a finite number (just as there are a finite number of different voltages, whereas an analog system can have infinite levels of voltages down to some quantum level).

(Not, eventually the instruments on parallel analog and digital systems catch up.  It's merely the first instant of information that is truncated.)

But unlike the different voltages, which may be to some extent (I've long accepted that we can hear at least 20dB into noise level, it may be far more in real life situations) affected by noise, so that we can't hear all possible differences in voltage, there is nothing (well except our own physiology again, but differently) to prevent us also from hearing infinite differences in time, or at least being able to detect and correlate them with other things…to create a different sonic experience (for example, in a spatial image).  And that being able to be influenced by such a difference, if not be aware of it as such, might get down to very small levels too, not exactly quantum levels, but very small, far smaller than digital systems.

Very high frequency delta sigma systems, like DSD, preserve time better because the time start rate is the bit rate, 2.88 Mhz for DSD (or the corresponding fraction of a second).  In that sense, these systems ARE far more like analog.  I had never thought of this before, and have been critical that DSD doesn't actually deliver high (voltage) resolution in upper frequencies.  Of course DSD is quite complex and may have other issues too…  But in preserving start time, it is far superior to PCM digital systems.

Conventional PCM can go to 96kHz or 192kHz in consumer, that's far higher temporal resolution then the 44.1 Khz of CD Quality digital, though not in the league of delta sigma systems.

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