AR Turntable Drive Belts

[tysontom]

On eBay there are several sellers of AR turntable parts, particularly drive belts and related parts. Typically, a seller might say that the belt being offered is an exact “AR Replacement” belt in that it is the correct ¼-inch width as with the original, rather than 3/8-inch width offered by some sellers. This is misleading.

One of the reasons that the AR Turntable won such high acclaim had to do with the design of the drive belt. Any production AR turntable, be it the original two-motor AR-TA or the newer single-motor XA, would meet or exceed NAB broadcast specifications for wow and flutter. Ed Villchur designed the turntable (after a consultant spent much time and effort without results) to be simple, reliable and accurate. The belt was an integral part of the turntable’s performance, and it was “machined” to accurate tolerances by using a frozen method, and thus the dimensional accuracy of the belt was assured.

Belts being offered on eBay, as well as nearly all drive belts of this sort, are made from a casting process, and the thickness is not necessarily uniform. Therefore, unless the belt was an original version sold by AR or an AR reseller, the chances of getting that original performance might be questionable. If old belts were cleaned and then stored in talcum powder, they will last for decades without degradation.

--Tom Tyson

[genek]

On eBay there are several sellers of AR turntable parts, particularly drive belts and related parts. Typically, a seller might say that the belt being offered is an exact “AR Replacement” belt in that it is the correct ¼-inch width as with the original, rather than 3/8-inch width offered by some sellers.

1/4-inch is too wide. The correct belt for all AR tables from the TT through XB77 and most of the 80's models is the FRY23.6, which spec's a maximum width of .135 inches. Any belt wider that that may not fit correctly in the two-speed pulley and will not have enough "give" for the lower-torque two motor models even if they have the wider single-speed pulley.

Dave Archambault of Vinyl Nirvana has set his son up with a college side business selling the correct belt for AR tables on eBay as seller "dmbnh101."

[rl1856]

Belts being offered on eBay, as well as nearly all drive belts of this sort, are made from a casting process, and the thickness is not necessarily uniform. Therefore, unless the belt was an original version sold by AR or an AR reseller, the chances of getting that original performance might be questionable. If old belts were cleaned and then stored in talcum powder, they will last for decades without degradation.

--Tom Tyson

Indeed. One of the manf of an extreme high end TT goes so far to make their own drive belts to ensure uniform thickness. They claim uniformity levels better than the width of a human hair.

Once again we find that Vilchur and co. were several decades ahead of their time.

Best,

Ross

[tysontom]

1/4-inch is too wide. The correct belt for all AR tables from the TT through XB77 and most of the 80's models is the FRY23.6, which spec's a maximum width of .135 inches. Any belt wider that that may not fit correctly in the two-speed pulley and will not have enough "give" for the lower-torque two motor models even if they have the wider single-speed pulley.

Dave Archambault of Vinyl Nirvana has set his son up with a college side business selling the correct belt for AR tables on eBay as seller "dmbnh101."

I may have mispoken regarding the precise width of the belt; in any event, the important issue is the uniformity of the thickness of the belt, something that is rarely mentioned at the AR-Belt Resellers Conventions. I suspect that Nirvana leads this convention.

The original AR belt, which cost $2.00 new way back when, was precisely ground to an exact thickness. Other belts that were not machined in this manner simply would not perform as well. Also, these belts almost always need to be "dusted" with talc to work properly on the AR turntable. First they need to be cleaned in denatured alcohol, dried and then lightly powdered. The belt won't ride on the pully exactly right without the talc.

--Tom Tyson

[genek]

I may have mispoken regarding the precise width of the belt; in any event, the important issue is the uniformity of the thickness of the belt, something that is rarely mentioned at the AR-Belt Resellers Conventions. I suspect that Nirvana leads this convention.

The original AR belt, which cost $2.00 new way back when, was precisely ground to an exact thickness. Other belts that were not machined in this manner simply would not perform as well. Also, these belts almost always need to be "dusted" with talc to work properly on the AR turntable. First they need to be cleaned in denatured alcohol, dried and then lightly powdered. The belt won't ride on the pully exactly right without the talc.

I've used belts from a variety of different sources over the years. I've never had a problem with any belt that conformed to the FRY23.6 PRB spec (which specifies thickness as well as width). And yes, they all have to be talc'd.

All rubber belts are ground on at least one side. PRB-spec belts are ground on both sides. Latex belts may not be ground at all and should be avoided. In the days when AR tables were new, virtually all belts manufactured in the US were PRB-spec rubber. Today, if a belt isn't specifically labeled as PRB it probably isn't.

The biggest problem with replacement belts for AR tables comes from the fact that many sellers are substituting other 23.6 belts, some of which may be thicker as well as wider than they should be.