Whereas the top plate for the G model is machined from 10mm solid sheet, the GR uses a more traditional cast aluminium design, which appears fairly similar to the chassis / top plate of the older decks. This design difference, along with the one-piece, cast platter, goes a long way to explaining the overall weight difference between the G / GAE (18KG) and the GR – which appears to be around 6KG lighter (and a similar weight to the discontinued SL1200 models).
In contrast to the analogue drive systems of their predecessors, the G and GR use digital circuitry for motor control – and both use what is essentially the same 9-pole motor. Whereas the G has twin rotors, the GR has a single rotor, giving it less torque. Although the GR has less torque, it achieves the same 0.7s start up time as the G on account of having a lighter platter (all previous SL1200 series used a 12-pole motor, with magnet and stator armature built into the platter – as opposed to the motor used in G and GR, which is effectively a standalone unit).
Technics claim in their literature that, as with the G model, the GR motor eliminates the troublesome phenomenon of ‘cogging’. Whilst cogging as a concept is well understood, objective proof of its effects in turntables that cannot be attributed to other elements in the chain is thin on the ground. With this in mind, a cynic could wonder if the inclusion of this claim is to appease industry figures who’ve postulated over the decades that cogging is the DD turntable’s Achilles Heel.
The GR differs from the G in its use of a feedback generator coil system (as used in the original SL1200) instead of an optical encoder. Although the optical system should give greater feedback resolution, it’s worth noting that the original SL1200 models were proven in tests to have exemplary speed accuracy, so it would be interesting to see lab measurements comparing turntable generations.
With the G having a hybrid brass / aluminium sandwich platter, weighing 3.5KG, the GR has a more traditional design of Technics platter, made from a single aluminium casting, damped with rubber and weighing 2.5KG (original SL1200 platter inc. earlier rubber mat = 1.7KG).
At the launch, Technics’ representative showed a waveform comparing the GR platter’s resonant decay to that of an SL1200Mk5. Although a quick tap of the knuckles on the platter at a press launch isn’t exactly forensic, its ringing, or lack of, appeared to confirm what the waveform showed. With its better-damped platter / mat combination, the GR should be substantially less prone to feedback in clubs than the original SL1200/10 – if maybe not quite as immune as its more expensive G sibling.
The SL1200G is fitted with a magnesium alloy tube, whereas the GR has an aluminium tube. The G’s arm also has a different finish to the GR, which Technics claim prevents resonance. The GR’s tube, being a different material and having different surface treatment, is likely to have very different acoustic properties to that of the G. Aside from the obvious differences in tube material and finish, both arms appear to be of a design that’s extremely similar to the original arm fitted to the first series of SL1200/10.
One added feature of note is the RCA sockets fitted to the GR. This will be to the considerable relief of anyone who’s experience cable fatigue in the old series of SL1200MK2/3 etc.
Technics claim that the design of foot used on the G and GR is optimised to each turntable, utilising a construction based around silicone rubber and ‘microcell polymers’. The feet were regarded by many as a weak point on the older SL1200 series, so this would appear to be a positive improvement.