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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
slaw's avatar
slaw
5,785 posts
 
I always joke with my prosthodontist when I see her regarding the use of her "torque wrench".

Newton meters....?
millercarbon's avatar
millercarbon
324 posts
 
Listen to Michael Fremers story about destroying a many thousand dollar cartridge with a torque wrench. He has never overtightened and only did so because he was told to trust the wrench. My hands and his are far more reliable. YTMV.

I've swapped parts out like this before. Stainless usually sounds the best.
dwette OP
77 posts
 
I ended up not liking the vinyl screws. I think they softened the high end and dynamics a bit. At the moment I am using stainless bolts, but 5mm instead of the 8mm I had before. That brings the stainless 49gr counterweight about as close to the arm's fulcrum as possible. It sounds great and when I run the test record the resonant frequency is at or near 10 Hz, as far as I can tell. The whole system tracks beautifully and sounds great, with very well focused bass (I use Confidence C2 Platinum with a pair of REL R-328 subs). 

When I changed the cartridge bolts I realized a torque wrench is probably not necessary. With my Concerto V2 and the Universal headshell it's very easy to tell when the bolts are snug enough without over tightening. It's a very solid fit when somewhat thumbtight using the long oreientation of the small hex 
terry9
931 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.
dwette OP
77 posts
 
How does one determine the correct torque for headshell bolts? If I get one it would be the analogmagik mentioned above.
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