Turntable speed accuracy

Albert - excellent, thoughtful response. You may now don your asbestos suit! ; - )

I think you make a couple of excellent points; namely that speed precision AND accuracy are both important. IME, individuals vary in their sensitivity to one versus the other. I also agree that while speed parameters are obviously important to turntable performance, other characteristics contribute to the overall turntable quality including immunity from internally and externally generated noise/vibration.

Dear Henry, I guess I have been too lazy to check the Kenwood L07D with Timeline so far. However, my neighbor's Timeline is still sitting around my listening room, and I will do it today, sans LP and sans stylus drag. If there is a consistent error up or down, that would not concern me, because speed is adjustable within the outboard PS. (The L07D does not provide user accessible fine tuning, as does the Technics Mk3 and the Denon DP80,) I had two L07D's until recently and was using one heavily whilst the other was being "refreshed" by Howard Stearn (the L07D guru who is also an orthopedic surgeon, not the shock jock on radio). Howard did a fabulous job on my first one, so I trust him to have done similar work on my second. (I bought the second so as to get the original Kenwood accessory record weight and platter ring that go with the L07D and because it was in mint condition.) Anyway, I sold the first one and have not yet got the arm mounted on the second one, because I want to re-wire it. This is why I am in between L07Ds. With the Lenco and the Mk3 in full service, I hardly feel the screaming need for a 3rd table. The L07D was far and away my favorite table before I had the Mk3 up and running.

Albert, EMI picked up by the cartridge from the L07D motor was rumored to be an issue. It seemed improbable to me, because the platter and mat constitute two solid slabs of stainless steel which ought to afford some decent shielding. Nevertheless, I made an LP-size shield out of "TI Shield" (Texas Instruments), the best shield around for a combo of EMI and RFI, and I inserted it over the spindle and in between the platter and platter mat. This actually did result in a noticeable but small increase in transparency even though I heard no "noise" per se prior to installing it. The Mk3 ought not to have any issues in this area, because its thick brass and SS platter is an even better natural shield than is that of the L07D.

Was invited to have a listen to 2 audio systems and did bring the Timeline with me just to see how other tables faired. The first was a modified Technics SP10 MKII (I believe) with the plinth from Albert Porter and the Timeline did not waiver one bit. The other was an SME10 and here the Timeline showed the table running fast, unfortunatelty we the SME does not have pots to adjust the speed. Could we hear this effect on the SME? There were 4 of us listening and to be honest no but it would have been nice if we could have adjusted the speed to be dead on and then hear what we thought.
Just some more data points for all to think about.

Unoear ask:

why do you think that the NVS was not up to task? ... It appears that is not an issue with the quality of the mains being presented to the motor controller; otherwise, I guess that Technics Mk3 would also have an issue...what do you think could be the issue with the NVS?

So far no turntable has passed the test as I conducted it, except the MK3. The NVS was up to the task as the rest.

Have you checked your DD Rockport?

I have a huge bias in favor of that table. I wish to know if it's as rock solid as I imagine it to be.

Lewm posted:

Albert, EMI picked up by the cartridge from the L07D motor was rumored to be an issue. It seemed improbable to me, because the platter and mat constitute two solid slabs of stainless steel which ought to afford some decent shielding. Nevertheless, I made an LP-size shield out of "TI Shield" (Texas Instruments), the best shield around for a combo of EMI and RFI, and I inserted it over the spindle and in between the platter and platter mat. This actually did result in a noticeable but small increase in transparency even though I heard no "noise" per se prior to installing it. The Mk3 ought not to have any issues in this area, because its thick brass and SS platter is an even better natural shield than is that of the L07D.

I use the TI FerriShield too, although it had no affect in tests with the MK3. With the MK2 the results were astounding, I imagine the holes in the aluminum MK2 platter looked like a strobe light to the phono cartridge.

When I say FerriShield was effective with MK2, this assumes the stock rubber mat, the Funk Firm mat, Boston Carbon Fiber or other mat that offers no blocking from RF and EMI.

Looking back I now realize some of the amazement of the Micro Seiki Cu-180 was the hard surface and superior design, but also the total blocking it provided, equal to the Texas Instruments in my tests.

My current mat is the TTM from Japan and is the highest performance mat so far on my MK3. I suspect it's mass is too much for the MK2 but the MK2 does well with the Micro Seiki Cu-180 and negates the need for FerriShield.

I have not gotten into this much in forums, but the center weight or clamp, plus mat is almost as much affect on sound as tonearm cable (and in some cases) the cartridge itself.

Maybe I'll make up a list of combinations of mats and clamps and what I heard. I sometime wonder if this variable plays a role in cartridge preference among members.

If any of you have tested same, I would love to read your results. I've been doing this for several years, it's a tedious process since one must be VERY careful to insure VTA and other variables are not more result than the parts in play.