Speed Control


I've had a Classic 3 for about 1 1/2 years. When I first bought it, I used the KAB strobe to determine it was running spot on 33 1/3 RPM.

Recently I added an SDS. At 60hz it was running fast. With the SDS adjusted to 59.81hz, it runs at 33 1/3 RPM. Any ideas on the impact of -.19hz difference in speed?

At the correct speed it has a much wider soundstage. It sounds like it is playing in a room much larger than my actual room. I have a lot of acoustical room treatment (absorption and diffusion) so that my contribute to the difference.

My system is Benz LP (re-tipped) > Classic 3 > Sutherland Hubble > VK32SE > VK75SE > Eggleston Rosa. I use the record clamp and ring.
bigby
There is also a new speed controller by Phoenix called the Falcon that can also incorporate an optional RPM sensor called the Roadrunner. Sells for a good deal less than the SDS. $612 for both, and $378 for just the Falcon
You can also place it under a clear record album and play on top of it. Lucinda Williams' West and Blessed are both clear enough for this trick. I did not notice any difference in speed with needle in or out of groove.
I could not believe my strobe was that far off until I used the Sutherland Timeline. In combination with my SDS to adjust the speed everything now sounds correct. Best of Luck
The KAB is smaller than a 12" LP, so you can just run the test with the KAB on top of a playing LP.
Interesting points, under subheading #5, here: (http://tf.nist.gov/timefreq/general/pdf/2125.pdf) How they accomplish it? A decent analogy, in the third post, here: (http://boards.straightdope.com/sdmb/showthread.php?t=446800)
AC motors are sync to the line frequency not the voltage. Line frequency in the US is highly regulated and controlled and does not deviate as much as line voltage.

If you use the Platter Speed test record and associated mobile app, you can set you table's speed compensated for stylus drag.
06-09-14: Brf
A SDS is a great unit for equalizing the variances in pulley, platter and belt machine tolerances.

Not to mention variances in household voltages too.

I thought the speed was supposed to be slightly faster than 33 1/3 when setting the speed using the KAB though, to offset the slight drag from the stylus. Not much for sure, but just so the dots appear to be ever so slightly moving fast under no load so that it would be spot on under load. Is this incorrect or misinformation?

I have tried it both ways and can't really say that I hear much of a difference. Nothing like the differences I hear in overhang, VTA, VTF or azimuth. I'm surprised to read that you are hearing that much of a difference.
A SDS is a great unit for equalizing the variances in pulley, platter and belt machine tolerances. Very few people who run SDS have them set for exact 60 hz and achieve exact 33 1/3 speed. You situation is completely normal.