Grace 707 Tonearm parts, information

[inspiredsports]

I recently purchased a turntable with a wonderful Grace 707 tonearm. It is missing a small (perhaps 4 or 5 gram) anti-skate (bias) weight. It works well without, but I think the right channel would sound even more dynamic with it.

Does anyone happen to know the exact weight of this missing piece so tht I might fabricate one, or better yet, have an original I might purchase?

[SCompRacer]

Not sure of the exact weight you would need. Maybe ask at Audiogon, Audiokarma, etc. if you can't find the weight of the original missing piece. You could use small scale calibration weights or fishing line sinkers. They are available in various weights, like 100 grams on up.

[SCompRacer]

My bad, I meant to say I've seen calibration weights from 1 gram on up, not 100 grams on up.

Like these.
http://www.oldwillknottscales.com/1-...on-weight.aspx
http://www.oldwillknottscales.com/5-...on-weight.aspx

Sinkers could be cut down in weight.

[inspiredsports]

Thanks! The problem I'm up against is that I do not know the actual weight of the original Grace hunk of steel that goes on the anti-skate rod.

The original weight delivers .75 grams of anti-skate bias in position #1, and then adds +.25 grams for each incremental position. However without knowing the exact weight of the original piece, it is impossible to know what force is being generated in the various positions as it is relative (and leveraged) to the starting weight.

As best as I can determine from measuring the rod (2mm), and then comparing proportions from photos, the original weight dimensions are 6mm in diameter by 4mm in length with a 2mm bore through the center and a 2mm set screw coming in from the side.

I have a precise 3 gram SME weight here that measures 8mm dia. X 10mm length with a 2mm bore so I'm calculating by ratio that the missing Grace part weighed .75 grams if they were constructed out of a similar metal.

[inspiredsports]

I've been researching this for about a month now and have determined there are very few sources out there for Grace parts and information.

By trial and error (and matching my guess from extrapolating weight versus size prom a photo), I've determined the 707 tonearm functions best with an anti-skate weight weighing .75 grams.

I cut various small pieces of aluminum tubing, weighed them with a stylus gauge, and then did countless listening tests until the sound quality of the right channel matched the left with the weight in an appropriate spot on the anti-skate mechanism lever. I'm having a nice little .75 gram piece of stainless steel (6mm dia. X approx. 4mm long with 2mm bore through the center and 2mm set screw) fabricated until I can find an original on the vintage market.

My next project is refurbing a table with an Infinity Black Widow

[inspiredsports]

Updating my search for a Grace 707 bias weight,

I located the exact original part from a man I found in California who had an extra. He mailed it to me in a plain white letter sized envelope for $20.

When it arrived the envelope had a nice hole in it. When the envelope hit the automated rollers used to process letter mail, the weight must have been ejected like a watermelon seed squeezed between your teeth.

I then tracked down a guy in Australia who manufactures them and sells them on eBay. . .

http://shop.ebay.com/tempo*5/m.html?...1&_from=&_ipg=

It's perfect.

The Grace 707 is one of the lowest mass, best tracking, best sounding vintage tonearms I've ever owned.

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I've also just finished up rewiring an even lower mass carbon fiber arm Infinity Black Widow.

These arms join my SME 3009 Series III with nitrogen hardened titanium "S" armtube giving a triumvirate of 3 of the lowest mass tonearms ever produced. With fastidious setup, it is simply amazing what these arms are capable of retrieving from a spinning piece of vinyl.

All three require high compliance cartridges with 20 x 10-6cm/Dyne or greater compliance (25 to 35 even better) and I've amassed quite a collection of high compliance cartridges to outfit the arms.

All three are mounted on restored/tweaked Thorens TD-160 BC Mk II's.

I can finally concentrate on listening.

Vinyl life is sweet around here now :)

[paulszakal]

Where can I purchase a new cable for my 707?
Its the one that connects the bias weight arm with the back of the arm underneath--maybe 1&1/2" looped on both ends.

[inspiredsports]

Where can I purchase a new cable for my 707?
Its the one that connects the bias weight arm with the back of the arm underneath--maybe 1&1/2" looped on both ends.

You might be confusing the Grace 707 with another brand tonearm. I've never seen a Grace 707 with the part you are describing

[inspiredsports]

Where can I purchase a new cable for my 707?
Its the one that connects the bias weight arm with the back of the arm underneath--maybe 1&1/2" looped on both ends.

Grace parts seem nearly impossible to find.

SME uses a similar line with their weights and I have seen some weights with line listed on eBay by a company called squareheadtubes. You might be able to modify the line to the proper length needed on the Grace.

[doctorcilantro]

Here's the Vinyl Engine database page.


Interesting to hear about such low mass from this arm. My MG1 I thin kI had estimated at about effective mass of 4g at one point but I could be wrong.

I always use the Grados on it.

[inspiredsports]

You might be confusing the Grace 707 with another brand tonearm. I've never seen a Grace 707 with the part you are describing

paulszakal, I misunderstood your original post thinking you were looking for an electrical cable.

You are correct there is an extremely small gauge nylon or plastic line with a loop at each end that attaches between a pin on the bottom of the back end of the tonearm shaft to another pin on the hinged lever that holds the bias weight.

When I first purchased and was restoring this tonearm about a year ago, I read every article on the Internet I could find about the Grace 707. I found virtually no parts available, just the occasional broken arm offered for parts.

The loops on this line are engineered such that they spread open to allow you to slide them over the pins, and then pinch back closed so they don't fall off of the pins. It would be extremely difficult to fabricate a direct replacement unless you have fly fishing fly tying equipment.

It is worth pursuing though as the 707 is a stellar performer when set up correctly.

[Polkersince85]

The vintage arms just have that twinkle to them that the newer arms can only hope for. They came from the period when vinyl was king.

My Micro Seiki arms are hard to find parts for also, especially the Max-282. Thankfully mine is complete at the moment and hopefully for a long time. My MA-505 and MA-701 are a little more common albeit expensive to replace.