Lyra and OMA

@o_holter 

Experimenting with adding mass to a tonearm (presumably to the headshell) may help dynamics and low-frequency weight and extension, but doing so will also push the counterweight farther away from the tonearm pivot, which may trigger adverse side-effects such as reduced maximum tracking ability.

Pragmatically this may not be such a great concern, as on most LPs you may not notice any difference in tracking performance.

Nonetheless, the overall results will likely be better if it is also possible to add mass to the counterweight, so that the distance between the counterweight and vertical bearing can remain the same as with the unmodified tonearm, or be reduced.

hth, jonathan

There is another solution to the tracking problem along with graded counterweights and that is a flat record. One can rig almost any turntable with a reflex clamp, vacuum clamping is the best. The records that are beyond the capability of reflex and vacuum clamping should be returned as defective. Aside from not upsetting the tonearm and cartridge the pitch stability of a flat record greatly helps the sensation of a live performance.

@lewm , that is definitely my experience bass being better with higher effective masses. I always push the resonance frequency down to 8 Hz and sometimes a little below. Having a suspended turntable helps avoid the problems associated with a very low resonance frequency. I always measure the resonance frequency and never depend on equations. There are too many variables to depend on equations. Cartridge compliance and tonearm EF tolerances are not that tight. Test records will not break the bank and they help greatly with other issues. 

@ jcarr recommended observing the cantilevers angle for adjusting anti skate. With his cartridges, cantilevers hanging out in the breeze, it is very easy to observe using the tonearm lift to raise and lower the cartridge watching which direction the cantilevers deflection goes when the suspension compresses. For fun I used that technique then checked skating with the WallySkater. It landed right on 11%! Unfortunately, this technique is difficult with many cartridges, but if you have a Lyra or Clearaudio cartridge it works very well.

A key role of a tonearm is to function as a mechanical high-pass filter for the cartridge.

Roughly speaking, above the resonance frequency the tonearm stays still and allows the cartridge to follow the LP groove, below the resonance frequency the tonearm moves to alleviate the cartridge cantilever and suspension from having to reproduce non-music inputs. These include off-center LPs (horizontal perturbations at 0.55Hz), warped LPs (largely vertical perturbations, generally considered to occur around 5~6Hz, although the affected frequencies may be higher if the warps are steep), plus the act of cuing a cartridge onto an LP (mainly vertical perturbations, with affected frequencies depending on whether an elevator mechanism is used or not, how much damping is applied to the elevator, and how quickly / slowly the cartridge is lowered if the cuing is done by hand).

Therefore, choosing a cartridge / tonearm resonance frequency that is on the high side may be good for tracking performance, but not so great for sound, as the tonearm will move to cushion the cartridge from LP groove signals that it should be tracking.

If there are no issues with the turntable suspension, including the stand structure and floorboards, and the motor(s) are quiet, like @mijostyn I tend to prefer the sound of a cartridge / tonearm resonance frequency in the lower 8Hz ~ upper 7Hz range.

However tracking performance (as well as pop / click noise levels) are also impacted by bearing design, counterweight design, and bending / twisting resonances of the headshell and armtube (a completely separate issue from the cartridge / tonearm resonance), with less rigid / more resonant tonearms more likely to benefit from setting the cartridge / tonearm resonance to a higher frequency.

Conversely, super-rigid tonearms like the SATs or Kuzma SAFIR-9 are likely to sound better with cartridge / tonearm resonance frequencies that are lower than would be prudent with most other tonearms.

hope this will be useful to someone, jonathan

I’m still here and I’m still listening. Thanks Jonathan.

@jcarr , Way to go Johnathan. You have designed what is to my ear the finest cartridge I have ever listened to in my system. My other cartridges are fine units but one does not match with my phono stage well and the other while having more gain rounds over the details just enough to lessen the frisson. The Altas SL has a way of sounding very detailed without any edge whatsoever. The ascending violin of Vaughn Williams The Lark Ascending brings tears to eyes. I have never heard it reproduced this accurately without any pain. The same holds true for female voices. I have no words to describe the reproduction of #21 "In Trutina" of Orff's Carmina Burana. 

Thank You, 

Mike