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TT drive belt comparison

Hi folks,

Last night and today we A/B'd the two drive belts that came with our new Teres 265. One is the standard silk string as explained on the Teres web site. The other is a 1/2" wide length of spliced magnetic tape. Chris Brady is now supplying a 1/2" high motor pulley, at least on some models, and is testing a variety of belt materials.

SUMMARY: the magnetic tape beats the silk string very handily

Why? Because the tape provides better speed stability. The audible differences are at the micro-detail and instrumental/voice timbre levels, but they are clear and entirely in favor of the tape. The tape significantly reduces the time-smearing of notes, making the whole system sound faster and cleaner.

Soprano soloists and choruses are notably clearer, cleaner, better differentiated, less shrill, less sibilant. Very high-pitched organ notes are far less smeared or distorted, as is every note and overtone on that notoriously difficult beast, the harpsichord. The voice of a bowed cello or bass is weightier and more authentic because each vibration of the string is now clear. Individual voices in the orchestra are more individual, less mushed together. Nearly all attacks are quicker and weightier.

I could go on but you get the idea. If your Teres (or other TT) will accomodate a tape rather than a string or rubber belt, I recommend you try it. It's fussier to set up. The motor and platter must be levelled exactly the same or the tape will crawl off the pulley. I shimmed the cups beneath our motor spikes with varous thicknesses of paper and now the tape stays in the center of the pulley.

Good job Chris!
dougdeacon
sean
6,231 posts
 
A wider tape or drive material should:

1) spread out the vibrational load introduced to the platter that originated with the motor in a more consistent manner

2) help to damp air or platter-borne vibrations due to the increased contact area of the tape with platter

3) offer a greater contact area for improved power transfer with less slippage

4) cause less "walking" of the spindle within the shaft resulting in greater pitch stability

5) reduce eratic bearing wear

Sounds like a "win/win" situation in "theory".

How does one go about sizing the tape / mylar and attaching it to itself once cut to size ? Sean
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dougdeacon OP
3,338 posts
 
Sean, sounds like I should get some 70mm film stock and a really tall pulley!

My tape was spliced just like the leader on a VHS tape would be.
dmailer's avatar
dmailer
235 posts
 
I picked up a TAC 1/2" video tape splicer from B&G Sales in Canada. It was around $50 and does an excellent job splicing. I would think it would be hard to get the tape lined up correctly without a splicer.
dougdeacon OP
3,338 posts
 
Here's another source for a 1/2" videotape splicer:

http://www.mvipro.com/splicingblock.html

$32.95US for a splicing block and some splicing tabs.
dmailer's avatar
dmailer
235 posts
 
Thought I would give you some of my observations on the mylar tape. I have been using a 1/2" mag tape shiny out on a Redpoint/Galibier battery powered moter controller and Testa Rosa TT with drilled aluminum platter, teflon top, and anvil weight. I ordered several colors of the mylar tape from the source that Chris suggested. I ordered the silver, gold, and holographic and felt if the tape sounded better than my mag tape then I would have a color selection to choose from. I noticed that the holographic was much thicker and stiffer than the silver and gold. First I tried the silver and compared with my 1/2" mag tape. I have been running the mag tape shiny side out. After listening to about 5 changeovers on familiar music I came to the conclusion that images were much better focused with much tighter bass and more detail. I pretty much heard the differences that Dougdeacon heard going from silk thread to mag tape. It is possible that mag tape shiny in could sound close to the silver but the mylar tape looks alot better than mag tape dull side out. Next I tried the holographic mylar and compared with the silver. Believe it or not I saw the same type improvements that I had seen going from mag tape to silver. It seemed better yet with further improvements in image focus and clarity. I think the differences have something to do with the finish as well as the thickness of the tapes. I took my caliper to them and the mag tape I was using was .001 thick while the silver mylar was .0015 and holographic was .0025. The only problem I had with the holographic was that my splicing machine had trouble getting a real even splice. I think this was due to the thickness of the tape. It took several tries before I could come up with an acceptable splice. Overall IMHO the holographic mylar seems like a winner. The side benefit is that it looks very cool spinning around my polished aluminum platter with colors changing with various angles. I would like to hear from others that may have tried the mylar tapes to get their impressions as well.
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