Future Tense: The Magic of Plastic

Posted 08/20/2010 at 12:31pm | by David Gerrold

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I’ll say it again.  There is genuine magic in a vinyl record.  

The grooves pressed into the vinyl are direct analogs of the sound waves that struck the microphone.  Because they’r analogs, the physical medium becomes part of the process of sonic reconstruction.  Every single factor in the signal chain—the physical characteristics of the stylus, the cantilever, the coils, the magnets, the tonearm, the turntable motor, the connecting wires, the preamplifier components, the equalization curve—everything affects the signal quality.  Every single component votes on the overall sound.  

That decades of engineering brilliance have made it possible for such stunning sound to come out of such an obstinate signal path is the triumph of passionate will power over the inordinate obstinacy of the physical universe.  During the seventies and eighties, I invested a small fortune into high-end stereo gear and a much larger fortune into an admirable collection of rock and classical and electronic music.  

Playing a vinyl record is an act of devotion for an audiophile.  You handle it lovingly, you use a special blower to bow excess dust off it, you give it a wipe with a clean micro-fiber cloth or maybe you run it through an expensive record-cleaning machine, you install a special brush on the end of the tonearm to remove errant dust from the grooves before the stylus gets there, you lower a dust cover over the whole affair so that dust doesn’t land on the record while it’s playing.  And you make sure you have the whole thing sonically isolated on so that even an errant foostep won’t be felt by the stylus and produce an audible thump in the music.  

In the late seventies and early eighties, there were several experiments with direct-to-disc recording.  There was no master tape.  The music went straight from the mixing board directly to the cutting head of the mastering machine.  The several direct-to-disc records I had demonstrated just how good vinyl could sound.  Astonishing presence, superior to any other recording process.  The bass had impact, the instruments had sharpness and clarity.  

At the same time, there were also several well-funded experiments with digitally mastered recordings.  Those discs were also superior to conventionally mastered records, with greater depth in the bass, terrific clarity, and greater presence throughout.  Removing the analog master tape from the signal path was like removing a veil from the music.  

But as good as the digitally mastered records were, they didn’t have quite the same impact as some of the direct-to-disc recordings.  It was an interesting comparison, but not one that was definitive—because the miking and mixing on a direct-to-disc jazz recording in a small studio is going to be much different than the miking and mixing on a large orchestra in a concert hall.  The sonic soundstage is a critical factor in the presence of a recording.  Engineers have debated microphone placement for as long as there have been microphones.  There may have been other factors at work too—psychological as well as acoustical.  

To understand digital sound, you have to understand binary arithmetic.  Most people don’t.  Only geeks, nerds, and technophiles take the time to find out.  

At the atomic level, a computer only knows two states.  A single bit is either on or off.  One or zero.  If you have two bits, you can measure four states.  00=zero, 01=1, 10=2, 11=3.  Add another bit and you double the number of states to eight.  100=4 and 111=7.  Add another bit and you double the number again.  1000=8 and 1110=14.  A byte is eight bits, and you have 2^8 combinations.  You can count from zero to 255.  Give yourself two bytes or 16 bits and you can go from 0 to 65,355 in only 22 microseconds.  

If you can sample a sound wave 44,056 times every second, charting the amplitude of each sample as a point on a scale from 0 to 65535, you can create a fairly accurate representation of that sound wave.  16 bits gives you a theoretical dynamic range of 96 decibels.  (For the record, the threshold of pain is about 120db.  The noise floor of even a quiet room can be as much as 35db.  So in practice, a 90db signal-to-noise ratio is more than you need for most music—even for heavy metal at 400 watts per channel—and nearly as much as you’ll want for watching Transformers 2.)  

Sony and Phillips began developing digital sound recording in the mid-seventies. Sony demonstrated its first optical audio disc in 1976.  It had the same specifications as the commercial compact disc they introduced in 1982, a 44,056 Hz sampling rate with 16-bit linear resolution cross-interleaved error correction codes.  Although the first prototype had a 150-minute playing time, the final form of the compact disc was 120 millimeters (4.72 inches) containing a maximum of 80 minutes playing time.  

The available playing time on a compact disc was actually an artistic decision as much as a commercial one.  The Japanese celebrate New Year’s by playing Beethoven’s joyous Ninth Symphony.  It’s a long symphony and can require three sides of two vinyl records.  Depending on the enthusiasm of the conductor, it usually runs between 65 and 70 minutes.  (Although I did hear a recording once so turgid, it came in at 77 minutes.  It was about as joyous as a state funeral.  <shudder>)  So when it came time to determine the maximum size of the compact disc, Sony executives decided it had to have enough playing time to hold Beethoven’s Ninth Symphony without interruption.   

On a compact disc, the 6.5 trillion ones and zeroes necessary to reconstruct a stereophonic recording of Beethoven’s Ninth are represented as a series of pits.  The laser is either reflected by the surface of the disc or not reflected when it hits a pit.  The pickup sensor sees the pattern of reflections and not-reflections as a string of ones and zeroes.  Error correction codes within the string allow the processor to correct the bit stream for inconsistencies—like when the surface of the CD is scratched.    

If the bitstream is accurately reconstructed by the CD player, and if the digital-to-analog conversion is accurate, the sound coming out of the CD player should be as clean and as clear as the sound waves that hit the recording microphones—or at least as clean and clear as the signals that came out of the engineers’ mixing boards.  

Audiophiles anticipated the introduction of the compact disc with enormous enthusiasm.  It promised a level of high-fidelity music reproduction hitherto unavailable.  The compact disc promised a truly flat frequency response of 20-22k, with a dynamic range of 90-95 db.  Wow and flutter and rumble would be effectively nonexistent.  Tracking error and pinch effect and tape hiss would no longer compromise the sound quality.  Other sources of distortion would also be eliminated from the signal path.  

Musically, this meant that bass notes would have physical impact.  High notes would be crisp and have ‘air’ around them.  Piano tones would be clear and solid, not watery and vague.  Tympani would shimmer.  Cellos would have a rich deep resonance, violins would shine with a delicate rasp of stroked vibrato, clarinets would have the mellow sense of stroked velvet, and the brass would blaze with a glistening sheen.  To a great degree, many of the first digitally-recorded CDs demonstrated the excellent sonic quality of digital recording—especially those from Telarc, which were meticulously recorded.  In fact, the Telarc discs all had warnings that the wide dynamic range of a CD could cause damage to your speakers if the disc was played too loud.  

But … something was missing.  

Some audiophiles admitted they missed the whole mystique of preparing a record for playing.  Playing a record was like choosing the right wine, opening it carefully, and letting it breathe, sniffing the cork, pouring a splash into the right shape glass and carefully savoring the ‘nose’ of the wine before tasting it  and rolling it around on the tongue, waiting for the various flavors to reveal themselves.  

Dropping a CD into a player and pressing start doesn’t have anywhere near the romance of carefully removing a vinyl disc from its sleeve, placing it on the turntable, and carefully lowering the tonearm into position.  There’s a rich relationship with vinyl, profoundly physical and emotional.  The CD never had that.  It has been an emotionally sterile technology from the beginning.  The little plastic disc was just too easy to disrespect.  

Yes, the CD is rugged and immune to noise and degradation and all that other stuff that plagued vinyl purists for so many years, but … very quickly, many audiophiles began to notice serious shortcomings in some of the early compact disc releases.  That early disaffection eventually created a meme that analog sound on vinyl records is inherently superior to digital sound.  

But is there any real truth in that belief?  I’m going to get into that next time, but right now, what do you think?  

David Gerrold is a Hugo and Nebula award-winning author. He has written more than 50 books, including "The Man Who Folded Himself" and "When HARLIE Was One," as well as hundreds of short stories and articles. His autobiographical story "The Martian Child" was the basis of the 2007 movie starring John Cusack and Amanda Peet. He has also written for television, including episodes of Star Trek, Babylon 5, Twilight Zone, and Land Of The Lost. He is best known for creating tribbles, sleestaks, and Chtorrans. In his spare time, he redesigns his website, www.gerrold.com