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Cartridge Mounting Hardware

I recently upgraded my tonearm to the Clearaudio Universal. This is a great arm and worth tweaking and experimenting a bit to get the best out of it. My cartridge – Concerto V2 (7 gr.) – came with several sets of cartridge mounting bolts: 5 mm nylon and aluminum flathead screws, and 8 mm stainless hex bolts. No nuts since my cartridge is tapped for the bolt threads. For years I've been using stainless bolts. With those I use a 49 gr. stainless counterweight and it sits nearly as close as it can go to the fulcrum when VTA is dialed in. When I play the Hi Fi News test record the resonant frequency of the arm is more or less at ~10 Hz as far as I can tell.

Conventional wisdom – AFAIK – says that's all good. 

I recently saw a Clearaudio photo of my arm with another one of their cartridges in the line (also 7 gr.) and it's mounted with the nylon screws. That got me to thinking about trying it, and maybe trying the aluminum ones too. With the nylon screws I can no longer use the 49 gr. stainless counterweight, and have to change to the aluminum 31.5 gr. counterweight, but that sits farther out away from the tonearm fulcrum (although it looks cooler, IMO). I'm trying that now. With the test record the tonearm resonant frequency is still right around 10 Hz. I'm playing music now and don't notice a difference, but my aural memory for such things sucks, so I have to live with it for a bit, and then revert to see how I feel. This weekend I'll play some records I use to test out setup changes and see if I hear anything for better or worse.

So that makes me wonder what others know and experience about cartridge mounting hardware (and techniques). What's your wisdom on the matter?
dwette

Showing 6 responses by terry9

terry9
2,243 posts
 
Second the torque screwdriver for cartridge bolts and nuts. I use a premium Stahlwille tool (as in Mercedes shops), and it made a significant difference. Not only was the torque made to be consistent, it could be optimized as a set-up parameter. Easily the difference between two high end MC - for $500!!! And the Stahlville will never need a retip!

YMMV
terry9
2,243 posts
 
As for Fremer’s trust for the wrench - internet "bargain"? I’ll bet it wasn’t a high end industrial version, like Stahlwille. I mean, what kind of sucker would pay all that money for a tool he could trust?

I remember, at a track day, one of the Porsche drivers waving around a box store torque wrench. A $50 wrench for a $150,000 car. Riiiiight. Had a nice looking case for it, though.

Look up the Linn engineer who discusses cartridge torques and the level of precision required for an optimal setup. Maybe some hands can reliably sense a 5% difference, but for the rest of us, a quality torque screwdriver is an important setup tool.
terry9
2,243 posts
 
Sleepwalker, thanks for the correction. I'm a little anal-retentive about tools since I saw a VP vaporize a prototype because of faulty instrumentation.
terry9
2,243 posts
 
Fremer trusted it enough to use it, whatever his initial impression.

Do you really think that the force holding two mating surfaces together has no impact on their dynamic behaviour? Really? Do you not think that variables such as material (plastic or wood or metal), mating surface, lubrication, and human habits of tool use, might make a difference? And that posted values are for guidance, but that ultimately experimentation is definitive?

As I said, the torque values suggested came from a post by a Linn engineer who had studied the matter in some detail. You declare that he is "full of it". What is your evidence, please?

You also seem to be saying that all tools are equally reliable, accurate, and repeatable. But remember Fremer.
terry9
2,243 posts
 
At 11:54, "Torque values have nothing to do with sound."

At 3:23, "Of course these things matter. Of course they affect the sound."

Yeah, sure, whatever, Mr. Miller. Goodbye.
terry9
2,243 posts
 
It's not hard to identify the material of nut and bolt. Identifying the exact alloy is very hard, but perhaps not essential. Best to assume industry standard alloys and published tables, and then take care not to exceed.

Also (at the risk of ribald levity), if the mating surfaces are very lightly lubed the required torques are lower and more easily adjusted. I always start low and increase until the sound begins to deteriorate, then back off to the previous setting.

Most of the improvement seems to come from equalizing torque, but there is still more to be had by optimizing.

IMO. YMMV.
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