David Price looks at the cheapest of Sony's legendary 'Biotracer' turntables, the PS-X600

There are no two ways about it -Sony were plain bonkers when they came up with the Biotracer tonearm back in 1979. Ridiculously complex and hard to build, they must have sweated blood trying to get the darn thing to work properly. But, to their eternal credit they did, and the PS-B80 was the result. A gut wrenchingly expensive product, its £800 selling price was far higher than a contemporary Linn. It simply couldnít compete with the best of British in sound quality terms, and duly got a panning in the hi-fi press.

Actually a very clever beastie, it offered fully automatic operation, intelligent repeat modes, record size and speed selection, plus forward and backward cueing at the touch of a button. This was all made possible by the Biotracer arm's electronic motion detectors, motors and microprocessor brain. Lateral and vertical sensors passed signals to tiny linear motors controlling the arm's motion, while tracking weight and side-thrust were continually monitored and corrected. As if this wasn't enough, the system also electronically controlled subsonic damping too!

The result was a supremely user-friendly disc player with great ergonomics. Placing a disc of any size on the deck's large platter, pressing 'Start' and watching the arm glide decorously across to the cue-in point, moving back a little to correct itself if need be, was a joy. The only trouble was that, in the case of Sony's new baby, the best things in life were most certainly not free. What was needed was a smaller, cheaper, second generation Biotracer deck - enter the PS -X600.

With a price of 'just' £180 it was a veritable bargain by the standards of its predecessor. Yet they hadn't skimped on the build, and the little deck was far heavier than its diminutive size suggested. Its composite plinth sported four adjustable, air damped feet which did the job of isolation far better than they had any right to.

At the front of the deck was a row of metallised, touch-sensitive controls offering power on-off, speed selection, repeat and cueing facilities. Little red legends lit up to denote speed, repeat and quartz lock operation. 

The 1.6kg alloy platter sported a decently supportive rubber mat with slats cut into it for the deck's photoelectric disc sensing mechanism. At the rear of the plinth was a raised pillar into which a light was set, which not only ensured reliable disc size selection, but gave some useful extra illumination for cueing.

The drive motor was Sony's superb brushless, slotless linear direct drive unit - not in one of its most torquey incarnations but nevertheless able to whip the platter up to speed in under half a revolution. It was quartz locked, naturally, and used a pulsed magnetic thread running around the inside of the platter, feeding a tape head. The head read the pulses, allowing the X-tal lock to know at exactly what.speed the platter was running all the time. This was a very clever system, but not strictly a Sony innovation - Denon had come up with the idea some five years earlier.

In use, the PS-X600 was a gem. The automatic tricks were smooth as silk and in a completely different league to rival 'fully auto' non-Biotracer designs. Tracking was impressively secure, and the deck worked well with a wide range of moving magnet and moving coil cartridges. Tracking force could be adjusted with complete safety while a record was playing. Bias was a function of the Biotracer system and thus set automatically anyway.

Even by today's standards this odd little Sony turntable is a capable performer. It's quite up to, say, Rega 3 standards and in many ways better. Speed stability is excellent, giving a solid, confident and musical sound, with remarkably few signs of any particular problem areas. Only when you put it against the big guns do you realise how light-weight its bass is, and how the midband is a touch splashy and vague.

These days there aren't many PS-X600s around, so pay between £50 and £100 for a minter. Parts availability isn't great so if the Biotracer arm goes wrong - unlike Steve Austin - we cannot rebuild it. The good news is that build quality is exceptionally high - so thereís no reason why you shouldnít get many more years use out of a well preserved specimen. If youíre looking for a classy automatic to take the load off your high end belt drive, then this is the one.