Do you use variable speed on your turntable?

One of my tables is an older Rek-o-Kut CVS-12 circa 1950s, mounted in solid ply base. The only way to engage the motor to the idler and platter is through a variable speed lever. Sometimes, I adjust the speed slightly to match the pitch of the instrument in the recording (music in key of A should match my tone generator tuner set to A. There is some variablilty in LPs--especially with older recordings. Of course, we don't always know if the musicians were perfectly tuned to a stable reference or if they used a cold brasswind horn-- but many classical musicians have perfect pitch, or at least good relative pitch and would want accurate tuning. This is a better method than a visual strobe representation of 33.3, in my opinion.

Cocoabaroque, I'm not sure I understand you clearly when you say

This is a better method than a visual strobe representation of 33.3, in my opinion.

If I DO understand you, you are saying to adjust the TT speed until an "A" on the recording matches a tone generated "A", which makes perfect sense to me. But then I have a few questions:
Do I need a tone generator? (Suggestions for a cheapie?) Or even better, is there a website that provides accurate tones through your PC's speakers? (wouldn't that be great?!)
Second, finding a sustained "A" in most recorded material doesn't seem all that easy. Any tips?

thx
.

Nsgarch, any inexpensive tone generator used for musical instruments would be fine-- also I googled and found a few free online websites under "free tone generator" or audio frequency generator".

With most generators, you can choose the pitch, so if the music is in key of D, then you can select your generator to D. It may take a bit getting used to (musicians are more familiar with pitch recognition), but with a little practice, you can match the pitch of the tone generator (any frequency) to the key or pitch of the recording. It really only takes a few seconds when you get used to it. When your skills improve, you can tune to a tone generated "A" even though the music is in key of D. Most of the notes in a musical passage are "centered" around the key. Hope this helps!

Here's a perfect example of HYPE and GOUGE, praying on those of us, concerned with TT speed accuracy: (http://www.musicdirect.com/p-4838-digistrobo-turntable-strobe.aspx) This is NOT a, "strobe" at all, but- a simple LASER tachometer, that has been rebranded. They act as though it were something new. LASER tachs have been around for DECADES. Tell me the difference between it and any of these(outside of PRICE and appearance): (http://www.amazon.com/Digital-Photo-Laser-Tachometer-Contact/dp/B000EUT9ZS) (http://www.ebay.com/itm/LCD-Digital-Laser-Photo-Tachometer-Non-Contact-Counter-/110703270848?pt=AU_Car_Parts_Accessories&hash=item19c66ddbc0) (http://www.grainger.com/Grainger/Tachometer-5URH0?Pid=search) I own the last one, as it resolves out to hundred thousands, and is a tad bit more accurate(+/- .04%). The ONLY thing you DON'T get with these, is the small disc, with the reflective strip already on it. HARDLY worth $100.00, for something I can make for free(and completely non-essential). The reflective strip, on my record clamp, works just fine(as would a strip on the platter edge). The great thing about this method, is one can measure speed, with the record playing.

Something that got me thinking more about speed accuracy lately, as both of my tables are equipped with AC synchronous motors: (http://wattsupwiththat.com/2011/06/25/it-hertz-when-you-do-that-power-grid-to-stop-regulating-60-hz-frequency/) (http://radiomagonline.com/infrastructure/power/60hz-stability-going-away-0627/) If you are using a strobe disc, that depends on your house lighting's 60Hz flicker, or your table has a motor, dependent on your AC's 60Hz for speed regulation; take note. This may soon become a concern.