Direct Drive vs. Idler Drive vs. Belt drive

When I got my Pioneer PL-70L II DD turntable a few years ago I was planning to use a CU-180 copper mat, which had worked wonders on my Micro belt drive tables. I inquired at HiFiDo where I bought the table and they forwarded the question to Pioneer, who had serviced the table prior to the sale (Pioneer still operates a service shop for their Exclusive range and a select few other units, including this table).

The reply was firm: please refrain from after market mats exceeding the weight of the standard mat (made of thick soft rubber) as this will interfere with the PLL feedback circuitry and could compromise speed stability. Just as lewm suggested. Apparently Pioneer also adopted a very tight control. I refrained from trying out the CU-180 (which took some discipline), but did try alternatives within the same weight range, like hard rubber, cork and leather (even a sandwich of the two). This was no improvement. Quite the opposite in fact, so I decided to stick to the standard mat.

@noromance please check your system page

WRT to platter mats, the concept that materials cannot absorb/attenuate vibration is not correct.

@antinn I suspect you misread my post, as you and I are on the same page w.r.t this statement; it is the same point I was making (or at least was attempting...)

Thanks for your thoughts, Ralph. About air bearings, I think that a very heavy platter on an amorphous carbon thrust bushing is virtually immovable - at least, mine is. You need a lot of force to raise it - and more to lower it - 87N per micron, plus the inertia. Compare that to a fragile cantilever. For radial stiffness, see above. The New Way figure is 34N/u.

@terry9 If the platter is unable to move up and down or in any other plane when subjected to vibration, such that whatever vibration might be present in the plinth is the same as that at the base of the arm and the surface of the platter, then the needed mechanical engineering principle is satisfied and the pickup will be immune to that vibration.

Agreed.

Apparently Pioneer also adopted a very tight control. I refrained from trying out the CU-180 (which took some discipline), but did try alternatives within the same weight range, like hard rubber, cork and leather (even a sandwich of the two). This was no improvement. Quite the opposite in fact, so I decided to stick to the standard mat.

Did you try Boston Audio or The Mat ? This is a lightweight mat (454g) if your turntable drive suffering from heavy gunmetal mats like Micro @edgewear

When i’m looking at my Denon DP-80 or Victor TT-101 i think it would be better with lightweight mats like SAEC or The Mat. Because the platter is lightweight.

When i look at my Luxman (made by Micro Seiki for Luxman) i know that i can use Micro Seiki CU-180 on it and this is what i do. The platter is thick and heavy. But CU-500 mat is definitely too heavy.