What is an acceptable rpm variation?

sunnydaze · « **Reply #20 on:** 18 Apr 2016, 09:14 pm »

A touch fast is better than a touch slow. More likely to hear things dragging a bit than a bit of extra giddyup. The latter, if not extreme, can actually make the music more exciting,

rbbert · « **Reply #21 on:** 18 Apr 2016, 09:23 pm »

Sensitivity to pitch aberrations varies from person to person as well as musical frequency and type of music. In general, for frequencies in the range of the human voice fundamental and first harmonic (roughly 100-500 Hz), a pitch (speed) difference of 0.3% will be noticeable. So if your table is more off-speed than that, you should strongly consider making a change of some kind. Even if it is less than that, some people will notice it on some kinds of music.

Letitroll98 · « **Reply #22 on:** 18 Apr 2016, 09:50 pm »

Quote from: sunnydaze on 18 Apr 2016, 09:14 pm

A touch fast is better than a touch slow. More likely to hear things dragging a bit than a bit of extra giddyup. The latter, if not extreme, can actually make the music more exciting,

And I have the opposite viewpoint, slightly slower, and thus lower in pitch, can sound more natural and pleasing. Everyone may look at things differently.

sunnydaze · « **Reply #23 on:** 19 Apr 2016, 01:47 am »

Quote from: Letitroll98 on 18 Apr 2016, 09:50 pm

And I have the opposite viewpoint, slightly slower, and thus lower in pitch, can sound more natural and pleasing. Everyone may look at things differently.

That's interesting. On my table I have a fine speed adjuster, so I can play around with speeds. And I have. When I play slow ballads and mellow piano based jazz, it is sooooo obviously "off" and draggy when I set it a hair slow. Basically, unlistenable. When I set it a touch fast for the same music, it sounds absolutely fine, like nothing is amiss.

Maybe it just depends on the type of music being played?

S Clark · « **Reply #24 on:** 23 Apr 2016, 08:33 pm »

Well, this thread was started because I got a new belt drive TT and the RPM Calculator app on my phone was bouncing from 33.5 to 33.2 rpms. Being a little slow on the uptake, I finally took my wife's identical phone, placed it opposite my phone to counterbalance, and took readings again. Nearly all the variation went away, of course

+- .05 rpm now.

Moral of the story. If you use a phone app with the phone on the platter, counterbalance.

a.wayne · « **Reply #25 on:** 23 Apr 2016, 08:48 pm »

Piano's die on TT 's with bad speed and flutter ......

SteveRB · « **Reply #26 on:** 25 Apr 2016, 05:33 pm »

Quote from: S Clark on 23 Apr 2016, 08:33 pm

Well, this thread was started because I got a new belt drive TT and the RPM Calculator app on my phone was bouncing from 33.5 to 33.2 rpms. Being a little slow on the uptake, I finally took my wife's identical phone, placed it opposite my phone to counterbalance, and took readings again. Nearly all the variation went away, of course +- .05 rpm now.

Moral of the story. If you use a phone app with the phone on the platter, counterbalance.

That's a good recommendation -- I never considered it before. I wonder how it would be effect by DD or idle drive motors that have more torque...?

S Clark · « **Reply #27 on:** 25 Apr 2016, 08:58 pm »

Quote from: SteveRB on 25 Apr 2016, 05:33 pm

That's a good recommendation -- I never considered it before. I wonder how it would be effect by DD or idle drive motors that have more torque...?

I tried it on two DD tables just to see how it would read, a JVC QL F6 and a Technics SP-10 MKII. In both cases the rpm reading stayed constant, even without a counterbalance. The JVC is actually a pretty stout little motor, and the SP-10 could be used as a starter for a truck- so in both cases it's no real surprise that there was no measurable variation.