USEDSony PS-X7 Turntable Condition 9 out of a 10 For once, the rest of us got what the Japanese didn't get: the PS-X7 was export only. In Japan, the top end of this mid-end lineup was the PS-X6: same 'table, same BSL motor, same SBMC heavy cabinet, same functions, same feather-touch switches... But the PS-X7 had a carbon-fiber tonearm !
"Mid-end", however, is used to describe a turntable designed and made during what arguably was Sony's best period. So it may look like a flimsy piece of plastic but it really is NOT. The only "mid-end" part of the PS-X7 is the tonearm which is unfortunately fixed and isn't the PUA-1600S found on the PS-8750 ... The X7 is nevertheless a stunner which sold very well then and still astonishes those who -thinking they only get a cool-looking piece of outdated japanese junk- buy one for 50€ and, once properly hooked up, can't believe the sonics of this cool-looking piece of... enduring japanese engineering. Speed Monitoring Sony's speed monitoring uses a precise pulse signal recorded onto a magnetic coating at the extreme outer edge of the platter. This signal is received by Sony's unique 8-pole magnetic pick-up head. By averaging out the signals picked-up by the 8 poles rather than just one, extremely high precision speed monitoring is acheved.
The phase-lock circuitry of the PS-X7 compares the phase of the frequency supplied by the 8-pole magnetic monitoring head with the one produced by the quartz generator. Speed variations are detected instantly and then corrected by the servo motor's speed control circuitry. Drive System
The type of motor used in the drive system of any turntable will greatly determine that turntable's performance. And the most ideal system is the one with the fewest moving parts. The PS-X7 is built with Sony's unique BSL motor at the center of its smooth running servo system. The motor works without cogging or the friction generated by conventional DC motors, which are structured with brushes and magnetic pole slots. And since the motor's drive shaft is also the turntable's spindle, the need for any speed reduction devices such as idler wheels, belts or pulleys is also eliminated.All this results in a drive system with extremely smooth torque characteristics, fast start-up and greatly reduced mechanical vibration. The high stability operation of the PS-X7 allows it to achieve a wow and flutter figure of less than 0,025% and a rumble figure of 73dB. Eliminating Acoustic feedback The Sony PS-X7's cabinet is made from a special inorganic (non-plstic) molded compound which has very low "Q" (sharpness of resonance) characteristics. [...]
Sony has reduced harmful vibration caused by the platter itself by using a heavy die-cast aluminium material in its platter construction. To further deaden the platter, a special rubber mat has been developped. It is filled with with a viscous gel for the most effective vibration damping characteristics. It also minimizes the vertical vibration that warped records can cause. The same viscous gel is also used in the adjustable rubber feet of the PS-X7 to further isolate the turntable system from floor and shelf vibrations. These newly developped materials are so effective in reducing vibrations that the PS-X7 can even be placed on an operating speaker cabinet. FEATURES Quartz goverened X-tal lock servo system
Automatic lead-in, retrun, repeat and stop
Electronic touch switches with LED display
8-pole magnetic pick-up head + pulse-coated magnetic rim
Optical end-of-record sensing
Direct-reading stylus force gauge
Viscous damped tonearm cueing
AS compensation with direct-reading and lateral balance weight
Machine-finished die-cast aluminium platter
Quartz governed stroboscope
Strobe markings on platter rim
Heavy rubber, viscous gel filled platter mat
Height-adjustable, viscous gel filled feet
Items in the Worthopedia are obtained exclusively from licensors and partners solely for our members’ research needs.