The 'small and square' turntables that appeared in the early 1980s were arguably the last important development in vinyl playback before CD arrived. Begun by Technics in 1979 with its SL-10 [HFN Apr '19], Japan's hi-fi industry rushed to produce something similar, with varying degrees of success.

It is odd that Sony, masters of cramming quarts of technology into pint-sized boxes, chose to excuse itself from this particular craze. Its 'very small and square' PS-Q7 [HFN Apr '21] was certainly neat, but it could not compete with the SL-10 and its imitators on performance. Meanwhile, a slew of drawer-loading models, such as the Sony PS-FL7 [HFN Mar '20], were niche products largely confined in appeal to the stack systems they matched.

Baby Bio
The closest Sony came to addressing 'small and square' head-on was with its PS-X800 Linear Biotracer turntable, launched in 1982 and seen here. Despite not being especially small, the PS-X800 did include other key features of the genre, such as a quartz-locked direct-drive motor, fully automatic operation and linear tracking. What's more, Sony's electronically damped Biotracer arm was also employed for the first time in a linear-tracker. The Biotracer system has been seen in these pages before as part of the PS-B80 [HFN Jul '12], the first Sony model to employ the technology.

To assist its tracking over warped records and through eccentric grooves, the Biotracer arm uses electromagnetic sensors to detect movement at the pivot in both the vertical and horizontal planes. Magnetic actuators gently assist the arm, maintaining a constant tracking force, without interrupting the slower movement of the stylus across the record. Resonances are damped, but higher, musical frequencies are unaffected. The effect can be appreciated by trying to move the headshell while the system is active: it feels like it's moving through a viscous liquid!

In theory this provides an ideal platform on which to mount the cartridge and extract the maximum information from the record groove. Furthermore, as Sony's Biotracer arm applies downforce electromagnetically, rather than by conventional static weights or springs, the tracking weight may be adjusted and optimised 'on the fly' between 0.5-3.0g, even as a record is being played.

A Cut Above
The linear-tracking aspects of the arm appeared conventional, but as ever with Sony there were refinements just beneath the surface. The arm was driven along a precision-ground bar by a tensioned cord, the same method used by Technics in the SL-10. The arm itself was supported on resin bearings which were said to be less noisy than conventional metal ball types. The motive power for moving the arm came from a pair of miniature BSL (Brushless and Slotless) motors that worked in much the same way as the larger motor that drove – directly – the diecast aluminium alloy platter.

In practice these tonearm motors were the same as those used to drive the capstans of Sony's top cassette decks (such as the TC-K81). Two were employed and linked by a clever epicyclic gear drive that allowed either one of them to drive the tonearm without anything having to be disengaged. One motor was used for fast actions, such as cueing and returning the arm at the end of a record, while the other moved it during playback.

One intriguing feature of the PS-X800 was that the tracking motor ran at a continuous minimum speed while the record played, rather than in the small jumps normally observed with linear-tracking decks. The speed was calculated as the arm progressed and Sony claimed that this more closely mirrored the movement of the cutter head when the record was being made.

Other aspects of the PS-X800 followed the traditional Sony practice of the era. The plinth was made from SBMC (Sony Bulk Moulding Compound) resin to which all the parts were rigidly mounted. Adjustable feet with elastomeric inserts were the only form of isolation offered, other than the near 12kg weight of the machine as a whole. The BSL spindle motor was quartz-locked and ran at two speeds, neither of which could be varied by the user. Finally, a Sony 'Magnadisc' servo pick-up measured the platter's speed. This had a strip of iron-loaded paint around the inside of its edge, which was printed in the factory with a magnetic pattern, much like a recording on a piece of tape. This was then read by a pick-up head in close proximity, clearance being maintained to eliminate the possibility of wear.

Zip Drive
Despite being largely made from synthetic materials, the finish of the PS-X800 is immaculate. True, it doesn't quite have the solidity of a Technics SL-10, but the detailing is superb. As was the fashion at the time, the lid falls short of the front of the plinth leaving the controls exposed. This allows a record to be played in a largely dust-proof atmosphere, and with power cueing there is no need to open the cover until all the listening on that particular side of the disc is concluded.

Like all the PS-X800's functions the cuing works smoothly and silently. The arm moves slowly if just the direction keys are pressed but zips along more smartly if you push the 'fast' key as well. An odd omission, given the level of automation present in the machine, is that speed selection is fully manual, despite it being logic-controlled. A beam of light that shines from the rear of the arm housing and down through slots in the platter will recognise a 7in single, otherwise the turntable will play at 33rpm. To automate this function would surely have been trivial.

The arm does not require special cartridges (unlike the PS-X800's Technics and B&O rivals) but I would suggest a pick-up with high-ish compliance to give the servos a fighting chance. Our example was fitted with a classic XL-45 moving magnet produced by Sony's specialist Sound Tec division, which only produced cartridges and microphones. Although not strictly 'period' it is nevertheless a reasonable match, and I've yet to hear a cartridge that gives the Linear Biotracer a more even tonal balance – although I've not yet given up hope that such a thing exists.

Tim Listens
The sound of the PS-X800 is best described as 'engineered'. Just as with the Kenwood DP-1100SG CD player [HFN May '22], it is only really appropriate to critique this design on the grounds of personal taste, there being no obvious signs of corner cutting, production economy or unresolved loose ends in its construction. While some other turntables seem to have been optimised by following a 'try it and see' approach, the PS-X800 feels like the result of genuine and methodical research.

Smooth Talk
The predictable aspects of the sound are beyond reproach. The motor runs silently and consistently and, as a result, subjective speed stability is as good as you are likely to ever get from a record, the limiting factor being how accurately the hole has been punched in the middle. What is odd is the lack of bass, and the two-dimensional soundstage that the PS-X800 projects. These observations are based not only on the beautifully preserved example used for this review but the many others that have passed through my hands over the years.

The opening guitar chords of 'Talkin' 'Bout A Revolution' by Tracy Chapman, taken from her eponymous first album [Elektra 960 774-1], sound thin and jangly on the PS-X800 – as they do on many turntables – but the situation is usually redeemed as the bass rolls in after the first few bars of the song. This does not quite come off as planned with the PS-X800, as the weight and the warmth simply aren't there. Set that aside, however, and what is revealed is pinpoint detail and an unusual sense of smoothness, which isn't just the result of a soft top end. The delicate strumming of the guitar on 'Fast Car' is crystal clear, while there's a sense of texture many conventional turntables miss, although you'd only know that once you'd heard what Sony's creation can do.

Fiddling with the downforce dial as the record played confirmed what everyone knows already – that cartridges perform better the more firmly the stylus is held in the groove. Secure tracking keeps record and stylus wear to a minimum too. How much is too much? When the cartridge body scrapes along the disc is my preferred answer!

Sade's 'Paradise' [Stronger Than Pride; Epic 460497 1] gave another insight into the strengths and weakness of this fascinating design. Vocal clarity was exceptional and the tempo rock solid, but the presentation lacked the embracing ambience that makes this recording special. Repositioning the loudspeakers closer to the rear wall of my listening room cured much of the low-end roll-off, but it could not make up for the lack of front-to-back projection. This was a disappointment because the rest of the performance was of an undeniably very high standard.

The PS-X800 is something of an enigma. In simple terms it is outperformed by quite some margin by the best of its contemporary linear-tracking rivals, such as the cheaper Technics SL-10 and slightly more expensive B&O Beogram 8000. However, there is always something about the PS-X800 that hints at greatness, waiting to be revealed by a synergetic cartridge choice and/or some inspired selection of partnering equipment. On the other hand, it may be best to simply enjoy this turntable for the masterpiece that it is. It's certainly a deck I'm going to find difficult to let go.

Buying Secondhand
The PS-X800 is dauntingly complex and repairs are not straightforward. Wear in the two tiny belts that link the tracking motors to the arm mechanism is the most common concern. There is a lot to remove even to reach them, and doing so will inevitably result in the tension of the driving cord becoming loosened, so this has to be carefully re-laced afterwards. The tension of the belts is critical and in practice many of the sets offered as replacements are not suitable for the purpose. Sometimes the only suitable approach is to buy a larger selection of belts and see which ones work the best.

Resist Temptation
Careless removal of the platter can damage the magnetic paint, meaning the quartz-lock servo will operate erratically. There is little that can be done about this so the utmost care must be taken when working in this area. Where other faults are present the first thing to do is to check that all the supply rails are of the correct voltage and free from hum and noise. The temptation to try and adjust any of the multitude of pre-set resistors must be strongly resisted, as it just makes matters worse without solving the problem.

Finally, the SBMC plinth material is relatively soft so if you remove and replace the various screws seated in it too many times, or over-tighten them, you run the risk that their threads will strip. Similarly, the turntable's lid is not especially strong and can crack around the hinges if not treated carefully.

Hi-Fi News Verdict
Apart from the PS-B80, this was the most complex turntable Sony (and possibly any company) made. While it does some things exceptionally well, it could be better in other areas, but that does not mean it is not a very desirable object. Present day values make the costs of upkeep seem sensible in context, so the PS-X800 need not be feared as it once was, making it a good buy for the serious vintage enthusiast.

Sony PS-X800 Turntable Lab Report

Sony's quartz-locked brushless/slotless direct-drive motor brings the alloy platter up to 33.3rpm in a little over one second and holds it to an absolute speed accuracy of +0.005%. Peak wow is very low at 0.02% [main signal, Graph 1] and while there's some slight broadening of the 3150Hz signal the peak-wtd flutter – with discrete sidebands at ±9Hz, ±18Hz, etc – is just 0.05%. Not only is the PS-X800 very pitch-stable but it is quiet too with a through-bearing/motor rumble of just –69.0dB (DIN-B wtd), reducing still further to –72.0dB (re. 1kHz/5cm/sec) when measured through-the-groove. Clearly, the combination of diecast alloy platter and rubber mat is effective in further reducing any motor-borne noise in the PS-X800.

The 'Biotracer' arm, meanwhile, has a pivot/stylus length of 180mm although the stubby square-section tube is just 80mm (3.2in) in length, hence the higher-than-average 165Hz main bending resonance [see CSD waterfall, Graph 2]. The limited harmonic and headshell flexing modes at 255Hz and 475Hz are further indications of the simplicity of a structure that hides relatively complex, miniature electromechanical engineering within. The latter is effective in applying downforce, albeit 10% light (so a setting of 2g yields 1.8g), and without the incremental 20Hz-80Hz 'bump/thump' we saw with the Technics SL-10 [HFN Apr '19]. Instead, the impact of Sony's 'continuous' adjustment of arm position may well explain the progressive increase in unwtd rumble from 20Hz down to near-DC. This lies below the –60.0dB hum and noise (unweighted), and also outside the DIN-B rumble weighting, but could it explain our reviewer's subjective bass experience...? PM

• Turntable speed error at 33.33rpm33.33rpm (+0.005%)
• Time to audible stabilisation1-2sec
• Peak Wow/Flutter0.02% / 0.05%
• Rumble (silent groove, DIN B wtd)–72.0dB
• Rumble (through bearing, DIN B wtd)–69.0dB
• Hum & Noise (unwtd, rel. to 5cm/sec)–60.0dB
• Power Consumption17-36W
• Dimensions (WHD) / Weight440x120x445mm / 11.6kg

Review: Tim Jarman, Lab: Paul Miller

Source: www.hifinews.com