PL-570, a Luxury Turntable from Pioneer
The Equipment:
Pioneer PL-570, a two-speed (33 and 45 rpm) automated single-play turntable assembly, with tone arm, base, and dust cover.
Dimensions: 19 1/4 by 15 1/2 inches (top): 7 1/2 inches high with cover closed, 18 1/2 inches clearance required with cover fully open.
Price: $400. Warranty: "limited," two years parts and labor.
Manufacturer:
Pioneer Electronic Corp., Japan; U.S. distributor: U.S. Pioneer Electronic Corp., 75 Oxford Dr., Moonachie, N.J. 07074.
Comment: If there is any component in which efficient, no-fuss operation can inspire the user with a sense of security, it is a turntable. With the exception of a volume control set inadvertently to speaker-destroying levels, mismanagement of electronics is harmless and easily rectifiable.
Phonographic fumble-fingeredness, however, may be punished summarily by damage to a cherished record--or by a horrendous transient that can also put loudspeakers in danger. The Pioneer PL-570 seems to understand this. It almost seems to dare you to try to make a mistake with it.
Apart from initial setup, installation of the pickup, and balance and adjustment of the tone arm (which can be a trifle fussy), tie user who favors automatic operation has just one responsibility: to make sure that the controls are set correctly for the disc on the platter before touching START.
And a touch is all that any of the activating controls needs.
If you like to make manual starts, the unit will indulge you by setting the platter spinning as soon as you remove the arm from its rest. You then cue up the arm and release the cueing lever, which lowers the arm quickly but gently to the disc surface. Should you forget to raise the cue mechanism in the first place (in which case the arm is free), the balance and feel of the arm is such that a reasonably coordinated person will not find it difficult to lower by hand. Using the cueing lever to interrupt or "edit" a record is also rewarding. The negligible side drift makes it easy to return to the groove you left.
For no-hands record playing, the START automatically places the arm in the lead-in groove. If REPEAT is pushed before START, the arm recycles at the end of a side and be gins to play it anew. A light push on the STOP button cancels REPEAT: a second touch returns the arm and brings the action to a halt. The arm returns automatically at the end of a side in any mode of play: yet, gratifyingly unlike some automated turntables we've worked with, the PL-570 does not return the arm when you try to cue to a record's inner bands. Nor is there any speed/diameter interlock to inhibit playing 7-inch LPs or 12-inch 45s. In fact, we can think of only one operation that is possible on typical manual players but not on the PL-570: back-cueing.
It is noteworthy that throughout the machinations of the arm its position is monitored optically rather than mechanically, thus insuring minimal drag (CBS Technology Center found none to speak of.). Tripping of the automatic re turn requires a minimum stylus force of 3 milli-newtons (0.3 gram). Total cycle time is 11 seconds.
Despite its rather substantial appearance, the tone arm has a low effective mass. Used with the Shure V-15 III cartridge, it resonates at 8.5 Hz-lower than "ideal" but no cause for alarm: we found it would track moderately warped discs well. The relatively good damping holds the amplitude rise at resonance to a mere 2 1/2 dB. For all practical purposes, the stylus-force gauge measures exactly up to the setting equivalent to 20 milli-newtons (2 grams), going only negligibly over the indicated value at settings above that. Antiskating force is linear over the most-used part of the range. And. while we're talking about arm features, the headshell is interchangeable with other standardized models. The arm will therefore accept the pre-mounted pickups that are appearing from several companies.
Of course, a sophisticated tone arm is of little use unless the platter does its job well too. The Quartz Lock servo sys tem of the PL-570 keeps the speed of the platter exact at line voltages of 105 and 127 as well as at a normal 120, both at 33 and 45 rpm. It thus renders the easily read strobe redundant except for reassurance. With the Quartz Lock defeated, the speed can be varied by an amount equivalent to a bit more than a semitone up or down. Aver age weighted peak flutter (ANSI / IEEE) reads 0.04% at 33 rpm with a maximum instantaneous value of 0.07%, representing fine performance. Rumble is well suppressed, reading -64 dB with the CBS ARLL weighting. The isolation system prevents the turntable from being noticeably sensitive to footsteps or minor accidental jogs.
Considered in toto, the PL-570 offers a lot in the way of features and performance to justify its price. The tonearm, incidentally, is adjustable for height, and while we are unable to verify Pioneer's claim that this is unique in such an automatic, we can't recall seeing it elsewhere. Much of what the unit offers is in the realm of convenience and therefore not absolutely necessary, but all the basics are taken care of almost impeccably. To top things off cosmetically and operationally, the turntable projects a gratifying sense of refined elegance and attention to detail. The PL-570 is truly a fine job.
Milli-newtons? For some time, we have had to suppress a small wince every time we expressed a vertical tracking force in grams, regardless of the fact that the gram is a unit of mass.
This solecism has long since become convention in the industry; to correct it would surely have caused confusion. But the situation is different now. Some manufacturers are beginning to use the newton (named for Sir Isaac), which is a unit of force, and so will we from now on.
For a force of the magnitude applied to a phono pickup, the milli-newton (0.001 newton) is appropriate. The relationship between grams and milli-newtons is simple: A mass of 1 gram placed at sea level in the earth's gravitational field develops a downward thrust (weight) of 9.8 milli-newtons. Thus, "10 milli-newtons" (abbreviated mN) can be taken as equivalent-not equal-to "1 gram." with a negligible 2% error. We will continue to supply data in grams (in parentheses).
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(High Fidelity, Nov. 1977)
Also see:
Philips AH-572 stereo preamplifier (Equip. Report, Nov. 1977)
Hitachi SR-903 receiver (Equip. Report, Apr. 1977)
Empire 698 turntable (Equip. Profile, Apr. 1977)
Sony STR-5800SD stereo FM/AM receiver (Equip. Report, Nov. 1977)
ADC--Accutrac turntable (ad, Apr. 1977)