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 3 responses by sleepwalker65

Accuracy of torque wrenches is relatively unimportant compared to getting consistency of torque when it comes to tightening lug nuts (or wheel bolts if we’re talking German cars). There, a Harbor Freight torque wrench will suffice. On the other hand, if you are assembling an engine, you need a much more accurate torque wrench for nuts on bearing caps on connecting rods, bolts on main bearing caps and head bolts. 

Jumping back to thr topic, yes, a high precision torque screwdriver is required to properly tighten the mounting screws of a cartridge to headshell, especially when we’re talking about a $500+ cartridge. 
The correct way to tighten something is according to the manufacturer’s specifications. They know more about their products than anyone else does. 
While I don’t have the spec for my cartridge’s (Audio-Technica VM540ML) mounting screw torque, I’ve requested that of the manufacturer just recently. If I get an answer back, I’ll share it here.