[Listening Test] 60 mm Platter TPA for Michell Orbe and Gyrodec

Product: Machined acrylic 60mm platter for Michell Gyro/Orbe
Manufacturer: True Point Audio Ltd. - UK
Contact: Charles Melling info@truepointaudio.com (+44)78 40 377 019
Prices: TPA 60mm acrylic platter UKP850
Author: Mark Wheeler - TNT-Audio UK
Reviewed: Autumn 2024 to Summer 2025

Regular readers will already have read about the 40mm True Point Audio acrylic platter for Michell turntables. True Point Audio offer these attractive clear alternative platters for Michell turntables and many people may find that the TPA aesthetic is a better match for Gyrodecs with a silver subchassis. Your taste may differ.

When your Old Scribe ordered and paid for the platter it was for the 60mm version. This was based of the saying, “Never mind the quality, feel the width”. There tends to be an automatic audiophool assumption that heavier equals better when it comes to turntable platters. But being open minded and able to tolerate safe uncertainty, your Old Scribe simultaneously took delivery of a loan 40mm True Point Audio solid acrylic platter for Michell turntables. An original Orbe platter was tried alternately with the 40mm TPA platter and the 60mm TPA platter and the findings noted. The 60mm platter was later returned to TPA for some machining converting to Stage II (further review when it comes back) after notes were taken about the sound quality differences. Your Old Scribe then left 40mm version on the resident silver modified Orbe. Given that both 60mm and 40mm versions were assessed against an original Michell Orbe platter, your Old Scribe's contentment with the 40mm platter speaks volumes when it would have been a 15minute job to put the Orbe platter in place.

The TPA 40mm and 60mm platters look brighter and prettier than the black platter alternatives. The only aesthetic criticism made over the 6 months of the 40mm platter in residence was from someone who felt that it looked like a food container. The True Point Audio 60mm platter is exactly what you would expect. It is a 20mm deeper version of the previously reviewed TPA 40mm acrylic platter for Michell Gyrodec and Orbe turntables. While the 40mm version looks perfect on a Michell Gyrodec and Gyro SE, the additional height of the 60mm version is identical to the Orbe platter height creating a similar visual sense of bulk as Michell's Orbe platter. Compared with the Michell Gorbe platter kit, the TPA platter does not include the Michell Orbe screw down platter clamp kit.

“What? We've already had one review of the TPA acrylic platter for Michells” Challenge plebs, stage left, “What else is there to say?”

Platter Masses

The table shows that the TPA 40mm platter is close to the static mass of the Michell Orbe platter. The Michell Orbe platter has more of its mass concentrated around the outer xxmm rim so will have greater rotational intertia/momentum. The TPA 60mm platter is nearly 1kg heavier than the genuine Orbe platter but this extra mass is nearer the axis of rotation so will have less extra rotational inertia than we might imply from the figures. The extra mass will have proportionately more vibration damping effect, all other factors being equal.

Technology

The deeper TPA platter is also 950g heavier than the Michell Orbe platter. However the Orbe's loaded acrylic mixture platter has a hollowed out central volume, so the rotational momentum of the TPA 60mm acrylic platter is more similar to the slightly lighter Orbe original than the different masses imply. This is a perfect opportunity to investigate differences in platter mass, and platter mass distribution when all other things are equal. The 40mm TPA acrylic platter has similar static mass to the Michell Orbe platter, but the Michell has its mass distributed closer to the periphery of the platter, increasing its rotational inertia (and a slightly different type of acrylic). The 60mm TPA acrylic platter has higher static mass than the Michell Orbe platter but a remarkably similar rotational inertia to it.

Aesthetics and Theory

The 60mm TPA clear acrylic platter superficially looks like a clear version of Michell's own. It certainly suits a silver coloured Michell subchassis visually and is quite a contrast with the black; both are resident here side-by-side. The matt finish clear platter is reminiscent of the original Pink Triangle, and TPA also make aftermarket parts for PT too (see what I did there). Again, Wow & Flutter measures very similarly with two belts and the Pete's Pylons with all three platters.

Sound Quality

Swapping the 60mm True Point Audio platter for the 40mm True Point Audio platter brought immediate and obvious differences. The subjective differences were as we might expect. A greater sense of control, a bigger soundstage and what seems like more bass depth rather than more bass weight.

Regardless of the material played, from scratchy old dub plates to premium audiophile pressings, the results were consistent. Interestingly, the results were also consistent with the differences between a genuine Michell Gyrodec platter and a genuine Michell Orbe platter, assuming both have the same bearing and clamp assembly. Marcus Miller's bass parts on Miles Davis' albums Tutu and Siesta get that extra throb with the deeper platter.

“Fnarr Fnarr,” quoth plebs, stage left, “The Old Scribe wrote THROB”.

Cartridge relationships

Past experience with Linn LP12s and Garrard 401s has led to observations that the platter mat interface can be differently affected by different cartridges. So the Dynavector DV XX2mkii, the Stanley bodied rebuilt Decca London and an Audio Technica VM95ML were all tried on all three platters. Results are absolutely consistent.

The genuine Michell Orbe platter upgrade kit includes a screw down clamp adapter, domed washer, retaining nut, ring and sachet of Densodamp. The screw down clamp adapter is not the same as the full Orbe bearing. It costs UKP825 and is therefore head to head with the TPA60mm platter. In a double blind test I doubt whether I could reliably identify the 60mm TPA platter from a genuine Orbe platter. With heavy audiophile vinyl (180g or 200g pressings) the difference is beyond the 15minutes of audio memory as the platters are swapped and arm height adjusted. Having said that, with thinner vinyl the extra 950g mass of the TPA brings benefits especially with the proper Orbe bearing/clamp rather than that clamp adapter.

The Decca London cartridge has very low vertical compliance. Hence, with such a cartridge potentially creating a livelier interface between stylus tip and vinyl surface it might show up more differences. Choosing some old ultra thin 'oil crisis' pressings, the difference is more noticeable. Predictably it is ambience and soundstage retrieval most affected because they're carried by the vertical vector. Ambience and soundstage are better on the 60mm True Point Audio platter, when both it and the Michell Orbe platter are riding on a low mileage Orbe bearing.

The 40mm platter is slightly more Regary/Linny/Pinky, seeming upbeat (speeds identical) than either the 60mm TPA or the Michell Orbe platter. This might well be simply because those turntables choose lower mass for less energy storage and the n40mm platter is lower mass. The look of the TPA platters is reminiscent of the Pink Triangle; just as chefs claim “We eat with our eyes”, perhaps we listen with our eyes too.

There is also slightly more difference between the 40mm TPA platter and the Gyrodec platter. In musical terms the 60mm TPA platter is my personal preference, the genuine Orbe second, the TPA 40mm platter third and the Gyrodec a close but different fourth. In aesthetic terms the genuine Gyrodec platter wins every time. In sound quality terms I'd rather have an Orbe with a Gyrodec platter than a basic power supply Gyrodec with an Orbe platter. The two TPA platter options widen the possibilities greatly when considering how to upgrade one's Gyrodec.

Conclusion

The first upgrade for any Gyrodec is the big power supply for whatever motor you have.

The next upgrade can now be to any of three platter choices. There is so little sound quality difference between the genuine Michel Orbe platter (with its supplied screw down clamp bearing) and the TPA 60mm platter that it could just come down to appearance. The TPA 60mm platter does seems to terminate slightly better stylus-vinyl interface in extremis, but this is only really obvious with the Decca London riding very thin 1970s pressings.

At classic car and motorcycle events there are those judges who dismiss any vehicle that is not 100% original as it left the factory. Your Old Scribe tends to prefer bikes and cars that have been modified to make them more usable or beautiful.
“Have nothing in your house that you do not know to be useful, or believe to be beautiful.” William Morris

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Michell Gyrodec platter mass	3.3-3.5kg depending on vintage
Michell Orbe platter mass	4kg - 60mm thick
TPA 40mm platter	3.985kg - 40mm thick
TPA 60mm platter	4.953kg - 60mm thick

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