Removable headshells 101

Wood VS the rest,..tests done by Reed tonearms in the research section of their web site have illustrations of acoustic vibration traveling through a table you may find helpful.

Orsonic, there seems to be an endless supply of this rare and short lived brand coming from somewhere, including a brand new box with it.

Regards, Dlaloum: TA = ToneArm. Vibration analysis is such a complicated branch of physics there may be a few professionals who can understand all of it, you can be assured I'm not one. Perhaps not a "black art" but it is a subject prone to generalizations. Building on your comments and Henry's most recent post, permit me a few?

My rudimentary understanding is that a vibration, emitted from a source point, “propagates” and follows the path of least resistance, somewhat like the ring of waves seen when a rock is tossed into a puddle. When these vibrations meet a border between two surfaces, they split, part reflected back and the rest continuing along the second body. How much goes where depends on the acoustical impedance of these materials.

Resonances are characterized by selection of materials, geometry or various devices attached to this body. These resonances may be reflected, amplified and reflected again until the source of the excitation ceases. Mass, materials, wether hollow or solid, holes, stress, associated materials this body is in contact with, texture or coating of the surface (skin effect) and physical configuration (straight/curve/taper/length) all have a consequence in frequency, amplitude, or transient behaviors. From my layman's perspective (read poorly supported opinion), if I intentionally selected a questionable design it would incorporate a removable headshell, and I did.

All this is so very complicated some simplifications are, for me, a neccessity. There are three means of address or correction available in my limited tool kit: Vibrations can be damped, reduced, or tuned. Selection of headshell material and mass are means of addressing these concerns, the choice of wether to retain the o-ring at the coupling is another. Cartridge isolation is also an influence long recognized. I'm reminded of the dimpled triangular alu. plate Grado offered as an option in the late '70's. There are some who are now exploring hard-points between the cartridge and headshell, "tip-toes" for your cart.

Although some of the above statements are probably accurate, I hope you'll correct me where wrong. None the less, a trial and error approach still seems sensible. Was it Voltaire who said, IIRC, "Best" is the enemy of "Better"?

Peace,

Well my experiments with resonance damping on arm & headshell have failed miserably...

Not because it doesn't work, but because my current test track/measurement method has accuracy that is around +/- 0.25db....

That results in variations of up to 0.5db between two readings of the same setup....

My gut feeling looking at the plotted results is that I can see a shift, but it is small (less than 0.5db) and not demonstrably repeatable...

Bye for now

David

I'd really like to revitalize this thread (minus the verbose theories) and share experiences to see if ant predictable combinations become clear.
I will confine my comments to my Sumiko Premier MMT with Cards rewire. I had been researching a possible replacement arm for my Oracle Alex MK III; but I am abandoning that for now, as the only affordable options seem to involve fixed headshells. So I'm looking to tweak the Sumiko. If anyone knows of any good tweak for the MMT, feel free to share.

The cartridges/headshell I use:
Hana SL/Sumiko with Cardas Rhoduim wires the rubber collar washer is lost. 19.26 g/lowish? compliance
I've ordered a Yammamoto HS-4 (carbon) intended for this one because I just can't leave well enough alone and I think I thought I may have heard something I slightly didn't like on one LP the other night.

Denon DL-301 II/LP gear Supreme 18.52 g/22 uN
Dynavector 10X3/TT-N 19.63 g/12 uN (I use damping)
Shure V15 RS SAS/Ortofon SH-4 16.24 g/25 uN and Stabilizer

I listened to the Shure, Hana, and Dynvector with and without collar washers today. No earthshaking differences; I think I prefer the Hana without and the Shure with. The Dyno sounded the same.

As I said, I plan on mating the HS-4, which is about 0.7 g lighter than the Sumiko, with the Hana.
I am thinking I'll move the Dyno to the Sumiko to lighten the load there. But maybe the DL-301.....?

Regarding leads, I am not sure I buy the idea of silver or rhodium having much effect unless the entire arm is wired the same way. Kind of seems like a 4" pipe connected to a 2" one. The 2" controls the flow rate. That being said, I'll probably try switching the Cardas leads to the HS-4 if I haven't bent a cantilever by that point.

Comments? Advice? Similar experiences?