2. analog
  3. 142837-9330

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 7 responses by dwette

dwette OP
288 posts
 
Thanks for the tips about over-tightening. I don't think that's ever been a problem for me in the 4+ decades I've been playing records. However, that analogmagik torque-wrench is intriguing. Given that my TT/arm/cartridge are close to $15k it may be a small price to pay for getting things as dialed in as possible. There's always Valentine's Day coming up. :)

FWIW: I use the Clearaudio protractor (essentially Löfgren A and B). I have used B in the past but am using A now, mostly because I play a lot of classical music. I would love to have a table with two arms: for jazz and classical. 
dwette OP
288 posts
 
@vasaudio Thanks but not this time. I don't know how I would even audition such a change, but I also want to leave the warranty intact. I will probably upgrade my cartridge this year.
dwette OP
288 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 
dwette OP
288 posts
 
How does one determine the correct torque for headshell bolts? If I get one it would be the analogmagik mentioned above.
dwette OP
288 posts
 
I used a Sears Craftsman Torque wrench (maybe $100?) on my M3 at the track. Never had an issue with it.
dwette OP
288 posts
 
The correct way to tighten something is according to the manufacturer’s specifications. They know more about their products than anyone else does.


These are the manufacturer specs for fixing the bolts on my Clearaudio Concerto V2, given in the installation manual...

"Please take care to not overtight them by force"

How many cartridge/tonearm manufacturers provide this spec?
dwette OP
288 posts
 
@spatialking

That torque chart is qualified with the following statement, and therein lies the rub, as far as I’m concerned.

Keep in mind that this is only an estimated value. It may provide satisfactory performance. Every application needs to be evaluated on its own to determine the optimum torque for each application

I don’t think I want to trust a torque value for a specific bolt unless it comes from the cartridge manufacturer. I for one don’t want to destroy my $3K cartridge and rather err on the side of the bolts being maybe a bit too lose and/or slightly inconsistent between the two. I tighten mine very gingerly, just enough for the cartridge to stay put.

More to discover