Before I continue to dig myself deeper into this controversial hole, though, I think a little background might be in order. Most self-proclaimed audio…
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In 1978, when I reviewed Sony's first audiophile-type PCM-1 converter, I earned the undying scorn of a large segment of audiophilia by reporting that, on the basis of a rather short testing period (which did however include some live recording), I was unable to hear anything the matter with its sound. Four years later, but after substantially more testing, I am obliged to report the same thing about the PCM-l's son, the PCM-Fl.
Dealing with digital criticisms
I shall deal now with a few other criticisms which have been directed at all digital recording systems:
I shall deal now with a few other criticisms which have been directed at all digital recording systems:
(1) "It changes the timbres of musical sounds." It doesn't. Accuracy of instrumental timbres is in fact one of its strongest points, for—unlike disc playback—the system is totally free from any mechanical resonances whatsoever. The sound is absolutely uncolored!
(2) "Digital fouls up massed-string tone." I did not get to record a large orchestra, but can vouch that massed-string tone from analog- (or direct-) mastered discs is reproduced…
Sidebar 1: Sines and Squares
A transient is nothing more than a (usually isolated) very steep rise or fall of energy, such as the lead-in to a squarewave. A half cycle of squarewave (fig.1, left) consists of an almost instantaneous rise above zero voltage (the base line) to a certain height, a period of unchanging level (the horizontal part) for a specified time, and an almost instantaneous fall back to zero. A half of a sinewave, au contraire, consists of the slowest rise and fall that the energy can have in order to reach maximum (peak) level and get back to zero again within the…
Sidebar 2: Specifications
Description: digital-audio converter for use with video recording systems. Inputs: stereo microphones (10k ohms unbalanced) or stereo line level (20k ohms). Outputs: Audio line level, PCM copy, video connections to videocassette recorder. Quantization: Switch-selectable 14 or 16 bits.
Dimensions: Converter 8.5" W × 3.125" H × 12" D; external power supply 4.25" W × 3.125" H × 12" D.
Price: $1800 (1982); no longer available (2021).
Manufacturer: Sony Corp. of America, Park Ridge, NJ 07656 (1982); Sony Electronics Inc., 16535 Via Esprillo, San Diego,…
As ALF would say, "There's more than one way to cook a cat." We've been so overwhelmed with linear pulse-code modulation (PCM) recording, we forget there are other ways to pass from the analog domain to the digital.
One of these is delta modulation. The Greek delta (which in its upper-case, block-letter form, looks like an equilateral triangle) is the mathematical symbol for the difference between two quantities; accordingly, in delta modulation, we record not the absolute value of a signal sample, but the difference between successive samples.
Delta modulation isn't new. It's…
The decoding process is identical to the coding. We simply use the logic highs and lows to switch the Ipos/Ineg charge pumps. The integrator output is then a kind of zigzag approximation of the original input. Of course, the zigs and zags are at 644kHz, so it's easy to filter them out. We're then left with (we hope!) the original waveform. Of course, the actual circuit is rather more complex. A different type of integrator, which produces less quantization noise, is used. The noise level still isn't low enough for critical use, so compression (similar to the system used in MTS) is placed…
Sidebar: Specifications
Description: Rack-mount digital audio processor using predictive delta modulation with compansion (CPDM). Output: conventional TV signal (North American standards) which can be recorded on any high-quality VCR. Power consumption: 60W. Dynamic range: 110dB (maximum 1kHz signal to A-weighted noise 20Hz–20kHz), 105dB (unweighted). Frequency response (sinewave 100mV input): 20Hz–20kHz ±0.5dB. THD (1V input, 1kHz): <0.05%. Wow & flutter: <l0.01% (unweighted), <0.006% (weighted RMS). Anti-aliasing filtration: –3dB at 37kHz. Sampling/bit rate: 644kHz.…
This is a speaker we've been fairly intimate with over quite a period of time. Designed by John Bau, the SC-50i started out three years ago as an inexpensive speaker system ($330/pair) not sold through dealers.
One of the factors allowing it to cost so little was the clever adaptation of cardboard tubes, normally used as forms for pouring concrete pillars, for use as speaker enclosures. They have a number of advantages, other than low cost: their circular form helps eliminate resonance of the back wave within the enclosure; the material is rigid because of its shape, and is non-resonant…
Sidebar 1: Specifications
Description: two-way acoustic suspension speaker system with 6.5" Audax paper-cone woofer and 1" Audax soft-dome tweeter. Impedance 4 ohms.
Dimensions: 13.5" H × 9" D (circular back).
Price: $460/pair (1982); no longer available (2021).
Manufacturer: Spica, 1570 Pacheco Street, Santa Fe, NM 87501 (1980–1983); 1601 Paseo de Peralta, Santa Fe, NM 87501 (1984–1988); Parasound/Spica, 3425 Bryn Mawr NE, Albuquerque, NM 87107 (1989–1996). Company no longer in existence (2021). Web (2021): spicaspeakers.com
It's been a long time coming, but it is finally happening. As I write these words, T.H.E. Show (aka The Home Entertainment Show), the successor to the late Richard Beers' original T.H.E. Show that began as an alternative high-end showplace to CES, is about to begin in the Long Beach Hilton. (That's Long Beach, California, for the uninitiated.) Dealers and exhibitors have set up in 20 or so rooms and numerous marketplace booths, said their prayers, enjoyed dinner in the hotel or in downtown Long Beach, and begun to burrow in for the night. As they do, components cook, cables settle, and the…