Monday, June 27, 2011

Thoughts about vinyl records and advanced resolution digital

On a computer group, the subject of vinyl records came up...quite a few digital geeks are quite fond of vinyl records.  I was asked to comment, and came up with all this (never miss a chance to push my favorites either):

I think vinyl is fine.  However, I don't actually bother with it much anymore.  Sacrilegiously most spins of my turntable in the past 4 years have been to digitize recordings not available any other way.  My brother-in-law who is in the business (for 25 years now) of selling audio tweaks like CD dampers (I'm not interested) and is therefore a truly over-the-edge audiophile (yes, he has the ionizers and all that) often praises vinyl but, so far as I know, hasn't had a working turntable in past 5-10 years.  My working vinyl playback system burned out in power surge/brownout last November, I mean to get it fixed (in fact, I have acquired parts for a second system, just haven't gotten around to fiddling with it, top quality vinyl playback typically requires a lot of fiddling).

Of course all analog systems like vinyl are essentially "infinite resolution."  It is unfair to compare them to digital systems on the basis of S/N or similar specs.  Vinyl playback is typically much noisier than digital, if you really work hard you can get 75dB S/N, whereas even standard CD gives you a theoretic 98dB, but it's not really that simple.  The true resolution of a pure analog (vinyl or tape) system (which hardly anyone does anymore, even vinyl record sellers) would be limited by quantum physics alone, somewhere in the neighborhood of 400dB.  (This is echoing tweeks comment that you are hearing a literal echo of the original...yes you are.)  That isn't actually achieved because the "infinite" resolution is obscured by various noise and distortion mechanisms which digital systems can avoid.  However, it turns out we can hear through the analog noise (but not the digital noise).  Exactly how far we can hear through the noise depends on the person and many other factors, but 20dB or so can be demonstrated, and it might be more than that.  So you may well get better resolution from a vinyl listening experience than an uncompressed CD quality one.  And don't get me started about lossy compression systems like MP3, I can't stand any of them.  Lossless digital compression system like MLP are fine, but I've never heard MP3 etc. which didn't sound distorted.

And then there is the care and feeding of a vinyl system which some people enjoy, something like doing an I Ching divination the old fashioned way, with sticks.  That may work for some people, but it does nothing for me, I have enough stuff I need to do with my playback system already.

But possibly more applicable is that generally vinyl records are simply "mastered" differently than digital recordings.  That means they often add equalization and limiting and things like that.  Often, actually, the effect of these things results in a more enjoyable recording.  When digital recordings are made, sometimes the mastering engineers either leave it alone or--more likely--apply extreme amounts of compression to make it as continuously loud as possible, so that the loudness level varies from about 0dB (maximum) to -3dB.  That isn't done on analog systems because the 0dB spot is kind of bad, and distortion increases a lot right there, so they generally keep the level fairly low and just let it hit 0dB for the real super peaks where you don't notice the distortion so much anyway.  The totally annoying level of compression used in many digital recordings (because they can), especially pop ones, is something that audiophiles and the bettering mastering engineers are enraged about.

But digital systems need not be limited to the old 16 bits 44.1 kHz format pioneered by Phillips and Sony.  Nowadays, many digital recordings are originally made at 24 bits resolution and 96kHz if not 192kHz.  Can you hear the difference?  Maybe.  You may not actually need the high frequency response on a 96kHz sampling system (theoretic frequency response to 48kHz) but it seems to help playback if the super-steep brickwall filters at 21kHz are not needed.  And because the distortion in digital systems at very low levels, getting close to the least significant bit, is very nasty, you want to stay as far away from that as possible.  Just the small jump from 16/44.1 to 24/48 gives you most of the audible benefit.

Two audiophile formats appeared on the market around 2000, SACD and DVD-Audio.  Both of these give you something like 48kHz sampling rate or better, and approaching 24 bits of resolution.  Because SACD is a sampled but non-PCM format, it can't strictly be compared with ordinary PCM systems by the usual specs, but many audiophiles believe it is better.  (I have mixed feelings about SACD, long story, but when available, I get the SACD version if for no other reason than it is probably mastered better.)  The "advanced resolution" stereo formats available on DVD-Audio are a clear win, you can't argue that 24/96 isn't simply better than 16/44.1.  And then both of these formats offer a no-lossy-compression multichannel experience in many cases, but like many audiophiles I almost always use stereo which really provides all the spatiality you really need--multichannel for music is mostly distraction.

Unfortunately, the specs for DVD-Audio weren't fully worked out at the time DVD-Video was released, and when they were worked out there were extra licensing fees.  As a result, most DVD players will not play the advanced features in DVD-Audio discs.  And for that and other reasons, DVD-Audio has never hit the big time, and most people, even serious AV people, may never have heard of it.

As for me, I will not buy any disc player that does not support these formats.  For that reason, I did not buy a cheapie Blu Ray player, or any Blu player, until I could get the Oppo BDP-95 (a super machine).

King Crimson is in the process of releasing their early catalog in DVD-Audio.  You can enjoy up to 24/48 on any DVD player, higher levels of resolution require a DVD-Audio player, and I think they even include a bonus CD.  I very highly recommend these "40th anniversary edition" packages, especially the absolutely essential Court of the Crimson King.  Some of their other albums are just a bit hard to get into for most people.  There was absolutely nothing wrong with the 30IPS half track analog tape machines used to record such material originally (though it often suffered from lousy mixing procedures...that was especially true of Court, and the effect has been negated in the new edition with all new mixing).

You can now get digital downloads in 24/96 and 24/192 digital, for playback via computer or you can burn to DVD-Audio disc.  It sounds like a great idea, but I haven't done it yet.

So I stroke my "I want better than CD quality" feeling more by getting advanced digital recordings.  No, they do not have 400dB theoretic resolution, but they seem to have enough resolution, finally.  And generally audiophile editions of all recordings have less compression.  One of my biggest finds last year was Pink Floyd "Meddle" on Mobile Fidelity Gold disc.  It's just standard digital, but the straight-from-the-mastertape uncompressed recording is mind blowing, completely unlike any Floyd you've heard on regular CD's.  BTW, the going rate for these now collectable discs is $100-$300.

But if you find what you need in vinyl, that sounds fine to me.  I've heard lots of mind blowing audio on turntables and big reel tape machines.  One of the hottest sounds I heard at CES in 2009 was from a big reel tape machine (played back by the original recording engineer).

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