Multiple Belts?

Re: Multiple Belts?

Postby Brf » Tue Sep 20, 2016 9:43 am

jaragaki wrote:I measured the speed of my Prime with the Feickert and it's "faster" but no steadier with two belts instead of one. I attribute this to overcoming drag from the needle.

The noticeable difference is the transmission of hum from the motor to the platter. It's very audible from the listening position with two belts and not audible with one. So I'm sticking with one, despite losing the advantages of having two. I'll likely keep it this way until there's a different solution for the hum.


Hum or motor vibration? If the later, users forget that by adding more belts, you are effectively putting more tension on the pulley shaft as you are reducing the elastic deformation by the sum of the belts. You can equalize the decreased belt compliance by reducing tension i.e moving the motor pod closer to the platter which will result in less motor noise being transferred to the platter
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Re: Multiple Belts?

Postby Brf » Tue Sep 20, 2016 10:02 am

rateourmover wrote:I
I too have audible hum which I too believe to be transmitted motor noise. However, I pay that price because it’s only audible between tracks. However, I’m convinced by you alI here and elsewhere in this Forum, I’d immediately realise the benefits of no hum during playback.


See above post

rateourmover wrote:I
The cheap one is to replace rubber belts with silk thread.

Questions:
1) One silk thread ? If more, how do you manage to tie them off at exactly equal lengths ?
2) Doesn’t the knot cause a micro-blip of some sort ?
3) Why doesn’t VPI offer non-rubber belts as an alternative – similar to their different centre weights/clamps and footers ?
4) Best specification of thread if I have to source it myself ?
Any cautionary tales ?


1) 1 thread is all you need
2) No, you can tie either a blood knot of a micro seiki knot which both have a flat spot
3) Not all VPI tables have a movable motor pods. It take more effort and time to set up a table using silk drive. Perhaps VPI does not think that it offers that much of an improvement over a rubber O-ring
4) Surgical 4-0 silk from any medical supply store
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Re: Multiple Belts?

Postby Orchids1 » Tue Sep 20, 2016 10:19 am

Rate, Did you initially attempt the rim drive and later 3 belts because of platter speed fluctuations. If so, it would seem that the first thing you should try is a speed controller, definitely one made by a company that is civil and conciliatory. If you have a different reason (e.g., motor noise transmission) for wanting to try silk thread, there are finished silk and nylon belts in different sizes made by a couple of different people that are for sale on the internet. No knots involved.

Stillpoints are impressive, although I have not found the need to step up to their prices. I don't recall seeing a bad, or even a tepid, review of their footers or platforms. On the other hand, as you've probably read here, Harry recommends a mouse pad under the motor, which I suppose you'd put on top of your platform and seems somewhat like surplusage, although it would help to further separate the motor from the table, and it's a hell of a lot cheaper than Stillpoints. You could, at least, give it a try. I did, along with Terrastone footers under my previous table, and liked the result. Rich
Avenger (w/mods)+SS Paua, Phoenix Eagle psu/tach, Sutherland 20/20, Audionet Pre1G3, Benchmark AHB2 monos, YG Carmel 2 spkrs, JL e112 subs, Nordost/Audio Sensibilty ic, Kubla-Sonsa spkr cbl; Auralic Aries renderer, Auralic Vega dac; dedic. 20A circuits.
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Re: Multiple Belts?

Postby rateourmover » Tue Sep 20, 2016 11:35 am

Firstly - thanks Brf.

If I’m going to take silk I should be able to judge both sides of an argument.

What is your view of silk vs rubber belts ? You may be brief. I’m thinking of slippage, transmission of motor noise, speed variation due to stretching and.. and.. can’t think of anything else.

( I’m aware this is expert knowledge given freely and am suitably grateful ).

Meanwhile, I’m stillpointedly hoping for input on those footers. ( John Tverdik ?)


[[ Secondly – thanks Rich.

My rim drive troubles were primarily huge and audible vibration. ( Wife in doorway – “what’s that awful noise” ) SDS, motor, powercords vibrating – the lot. Believe me I tried everything VPI and I could think of over a period of many weeks and many emails (and one or two phonecalls).

Reading all similar since, I’m guessing there were a few intolerances stood in a line. One being the superplatter not being as round as the ali classic. That doesn’t explain a vibrating powercord to the SDS and a few other things. I gave up and moved to three belts. (When in hole stop digging.)

Speed variation was probably an issue but I never got that close. From day to day the rim drive decided to behave or slip badly (and Yes, I spent the requisite time getting the two platter-rotations before it stopped).

I’d be fascinated to know the likely causes. I know VPI had at least one Name who couldn’t set it up either. ]]
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Re: Multiple Belts?

Postby Orchids1 » Tue Sep 20, 2016 12:00 pm

Rate, Just out of curiosity, what kind of floor and stand/cabinet/shelf is the table and motor sitting on. A vibrating SDS power chord sounds a tad eerie, especially out in the remote countryside. I would arrange for an exorcism. Rich
Avenger (w/mods)+SS Paua, Phoenix Eagle psu/tach, Sutherland 20/20, Audionet Pre1G3, Benchmark AHB2 monos, YG Carmel 2 spkrs, JL e112 subs, Nordost/Audio Sensibilty ic, Kubla-Sonsa spkr cbl; Auralic Aries renderer, Auralic Vega dac; dedic. 20A circuits.
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Re: Multiple Belts?

Postby Orchids1 » Tue Sep 20, 2016 4:41 pm

Rate, Do I understand correctly that you've taken the rim drive out of your system, and are still experiencing motor vibrarations and transmitted noise. If so, you might take a look at " Scout 1.1 Motor Noise" in Harry's Corner to see his responses. According to him, some Hearst motors (I don't know if they are used in the rim drive) are commonly prone to vibration, which can be significant. He didn't characterize this as a design or manufacturing defect, although I'd say it is certainly one of the two. He recommended using a computer mouse pad, as I mentioned. He also recommended using "new" rubber Scout feet under the motor. I couldn't figure out whether he was referring to new feet designed specifically for the motor or new feet designed for the table's plinth. I think he meant the latter, though it sounds a bit odd, because he then got into talking about having to put holes in his platform to accommodate some other sort of vibration control device that would raise the level of the motor. If one were to use the Scout table's feet on the motor, I would assume it would be necessary to lower the motor by removing it from the platform (which could be very touchy with a rim drive) or creating recesses in the platform for the feet (which could also be difficult, but probably not quite so touchy). I'd say, sell the damn rim drive, unless you've already gotten rid of it (I might have beat it to death), get an Avenger motor (it's solid, heavy and stable, and costs less than the Stillpoints) and use it with the three supplied VPI belts. This works fine for me, although it's more pedestrian than a rim drive. Tinkering with a turntable or classic Morgan can be fun, but it's time to stop when things turn frustrating and hard to correct. I, for one, have gotten too old for that kind of thing. Good luck. Rich
Avenger (w/mods)+SS Paua, Phoenix Eagle psu/tach, Sutherland 20/20, Audionet Pre1G3, Benchmark AHB2 monos, YG Carmel 2 spkrs, JL e112 subs, Nordost/Audio Sensibilty ic, Kubla-Sonsa spkr cbl; Auralic Aries renderer, Auralic Vega dac; dedic. 20A circuits.
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Re: Multiple Belts?

Postby Ayre Conditioned » Tue Sep 20, 2016 6:18 pm

I find this thread fascinating.
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Re: Multiple Belts?

Postby rateourmover » Tue Sep 20, 2016 6:34 pm

The Rim Drive has long gone (solid gone) and the poltergeist with it (probably - since I've not had any spooky feedback on Agon).

My background noise is nothing at all like that now, no vibrating powercords or SDS, and I suspect Brf has the most likely solution for the likely unrelated problem, which I'll try. [ Brf is right to query 'motor vibration' vs 'hum'. I believe it is 'motor vibration'. If he'd said 'rumble' I'd agree with that even more. ]

As above, he says:
Hum or motor vibration? If the latter, users forget that by adding more belts, you are effectively putting more tension on the pulley shaft as you are reducing the elastic deformation by the sum of the belts. You can equalize the decreased belt compliance by reducing tension i.e moving the motor pod closer to the platter which will result in less motor noise being transferred to the platter


I think I'm in danger of hyjacking this thread - which I don't want to do. Back to silk thread &or Stillpoints which I hope makes it relevant again.
SuperScoutMstrRef. Terracone feet onto Symposium Ultra. Mystic Mat, 3belts, Lyra Skala, Dorian mono, MusicMaker III Moving Iron. HRX & Stillpoints LP1 wts. Hovland HP200P & Radia. (HP100 & Sapphire in their boxes. Interested ?)
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Re: Multiple Belts?

Postby rateourmover » Tue Sep 20, 2016 7:15 pm

Sorry Orchids1, there's an earlier question of yours I see I failed to answer.

My racks are punching through carpet to a solid concrete floor. They are well-reviewed (but UK-only-ish I think) Audiophile Base & StarBase racks with Audiophile Base and StrataBase removable platforms. I've put Symposium Svelte, Svelte Plus and Ultra on top of these - which is very comfortably overkill.

With eyes closed and air guitar at manic whack, sax in dangerous contortions or baton at Harry Potter Angry, I think I've a good chance of not noticing an earthquake - or thinking I'm hearing the latest improvement thanks to Brf.
SuperScoutMstrRef. Terracone feet onto Symposium Ultra. Mystic Mat, 3belts, Lyra Skala, Dorian mono, MusicMaker III Moving Iron. HRX & Stillpoints LP1 wts. Hovland HP200P & Radia. (HP100 & Sapphire in their boxes. Interested ?)
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Re: Multiple Belts?

Postby Johnny » Tue Sep 20, 2016 8:06 pm

rateourmover wrote:
With eyes closed and air guitar at manic whack, sax in dangerous contortions or baton at Harry Potter Angry, I think I've a good chance of not noticing an earthquake - or thinking I'm hearing the latest improvement thanks to Brf.


What "improvements" did you make which resulted in your quite visual and eloquent above description?
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