
Turntable design has seen little real innovation since the 1980s, with development fastening instead on the refinement of existing approaches – refinement that has followed two basic paths: increasing simplicity and increasing mass. Indeed, the vast majority of record players now offered to the public constitute subtle variations on an extremely basic theme; rigidly coupled plinth systems support heavy platters, belt driven from standalone motors. The more you pay the more you get: more belts, more motors, more mass. Okay, so I’m exaggerating slightly, but the only really innovative turntables I’ve seen since the original AR-XA, are the Versa Dynamics 2.0 air-bearing design and its spiritual descendents, the Rockport record players, culminating in the impressive and vastly expensive Sirius III, complete with a dual-axis air-bearing, zero-contact direct-drive system and vacuum platter, all contained in a massive, active air-suspended and constrained layer plinth. No wonder the purchase price was astronomical.
For us mere mortals such exotic creations are largely irrelevant, leaving us with a choice of variations on the belt-driven theme – variations that have, in fairness, achieved a high level of performance, given the inherent shortcomings of the approach. Shortcomings? Well – yes. I’m afraid that given the essential dichotomy at the heart of turntable design, a stretchy belt isn’t exactly a high-tech response. The problem facing any turntable designer is to create a player that revolves at accurate, stable speed and does so quietly (meaning, without excessive mechanical vibration). The trouble is that accurate, stable speed control demands a closecoupled drive system and the motor just happens to be the biggest single source of vibration in the unit. Hence the use of belt-drive, which doesn’t just decouple the motor noise, it also helps solve the far thornier issue of real-time variations in speed, through the twin devices of elasticity and slippage. So, far from subtle changes in motor speed are evened out by the belt into less jagged and intrusive variations. Like I said, it may not be sophisticated, but it is surprisingly effective. So much so that it drove off the commercial threat of direct-drive with comparative ease, despite the latter’s clear theoretical benefits. You see, even if you coupled a decent, quiet directdrive motor to a well-engineered bearing (which actually isn’t that difficult) the Achilles heel was the speed control system, which used servos to hunt the correct speed. The end result was arguably a platter that turned constantly too fast or too slow, but most damagingly of all, was constantly changing speed, a subtle distortion the ear detected all too readily. The advantage of a belt drive is that those fluctuations in speed are far more gradual and thus less intrusive.
Turntable designers have responded to these issues by applying inertia: ever-heavier platters or auxiliary fly-wheels. They’ve also built better and more accurate motor control systems. The problem is that the heavier the platter the more powerful (and thus noisier) the motor has to be and the less capable it is of controlling the system’s speed accurately. In fact, if you are not careful the platter starts to drive the motor, a highly undesirable situation! Of course, designers have worked long, hard and with varying levels of success to deal with these problems, but every solution applied has one thing in common; it is trying to ameliorate the effects rather than eliminate the cause – which is the belt itself.
It was against this background of turntable development that Grand Prix Audio set out to apply their proven engineering and materials expertise to the creation of a clean sheet design. Eschewing conventional wisdom and design approaches, they embarked on a fundamental re-examination of the problems of record replay and arrived at a simple (but staggering) conclusion. The single most important aspect of turntable performance should be speed stability, as this defines the accuracy of the pitch information embedded in the record. Yet existing standards of measurement were wholly inadequate when it came to defining both absolute accuracy and stability. With a background in the hightech world of car racing, where each design project is very much a team effort and results are measured against an empirical standard, their response was entirely predictable: they assembled a team of engineering partners with the necessary skills, and set out to devise a measurement protocol capable of revealing the effects of the various engineering solutions applied. Having done that they could finally set to work on product development – and what a product they produced.
GPA’s Monaco turntable breaks all the analogue rules: it’s small where the competition is big, it’s direct rather than belt driven and in a world where mass and quality are seemingly indivisible, it’s positively svelte. It’s also superbly finished, beautifully executed and reassuringly expensive (should you need the price of your equipment to reassure you as to its quality). To dyed in the wool vinyl addicts of the sort who might consider dropping £12K on a turntable, that presents quite a challenge. After all, real men don’t listen to record players they might actually be able to lift up! But look at the engineering that’s gone into the Monaco and it’s awfully hard not to be impressed, both by the attention to detail and the thinking behind it.
Comments
Dear Roy,
Analog tape machines of the "Golden Age" created mastertapes with app. 1% speed variations ( also audible in CDs of the old maestros ) which, added to the effect of eccentric holes punched "somewhere near the centre of many LPs", probably make speed & pitch variations interesting audiophile food for thought, but are you serious about audible speed resp.pitch differences between the Grand Prix Monaco and, say, the SME 30/2?
I use a 22 year old Basis Debut TT with a brandnew SME V and fail to hear stylus drag which, according to famous MC designer AJ van den Hul might rip the stylus out of the cartridge's body if it were as serious a problem as many reviewers pretend. Playing a special version of a v.d.Hul Colibri at 0,7 Gr. VTF, the resistance in the groove at 10% amounts to 0,07 Grs.
According to Basis Debut's designer AJ Conti and forementioned AJ van den Hul this kind of resistance can simply not cause a well designed and -builtTT to slow down as per a simple law of physics and, finally, I attend up to 3 classical concerts p.m. but I fail to hear the pitch variations which are apparently caused by a psycho-acoustic phenomenon as stylus drag....
Sorry if I do believe my ears and not the voodoo stories which simply defy the laws of physics as described by forementioned designers and now we get the new rage of idler wheels! Money makes the world go round, apparently.
Sincerely,
Ronald Dunki