Eminent Technology ET-2 Tonearm Owners

Richardkrebs

para 1 - not obvious to everyone.
You are testing the effect of magnetic damping with an ET2 with rigid counterweight and high mass. Chris has been testing magnetic damping with partially decoupled counterweight and no added mass as has Frogman.

I have not said that mass, mag damping and fluid damping are the same other than that they all resist motion and that this resistance increass with frequency.

This simplistic view fails to differentiate between inertia and damping of motion.
During the course of this debate over the last few weeks you dont seem to comprehend the difference between inertia and damping of motion.

Inertia is the resistance to a change in its state of motion or rest. When you add lead to your ET tonearm you increase inertia. By increasing inertia the cantilever will flex more on eccentric records.
Damping is the retardation of motion once the movement has commenced. This means the cartridge can move straight away with an eccentric record, which results in minimal flex in the cantilever, and less distortion, but eddy currents generated by the motion of the arm relative to the magnet retards the oscillation of the arm and cartridge.

Adding lead mass creates higher inertia but does NOT retard motion.
Magnetic dampening has lower inertia and dampens motion.

I repeat again that the lead mass that you have added puts more load on the cantilever when the arm tries to move to accommodate an eccentric record.

Furthermore, with the higher mass of the added lead, when the arm moves there is more momentum, there is no control over this mass, and there is no damping of motion to minimize overshoot as the arm tries to correct.

As viewed by the cantilever this is no different to me adding mass in the linear plane to the ET.

Again - a very simplistic view of the world. Pivoted arms have tracking error and offset angle. The physics is quite different to that of a linear arm.

Adding mass

but Morch with their flywheel do not appear to have reached that point nor have I with my arm.

This is an assumption and speculative.
I could just as easily surmise that the Morch arm is so thin and lacking in structural integrity that it needs added mass and fluid dampening to control energy and resonances in the arm generated by a good moving coil cartridge.
Conventional mathematics says that adding mass to a flywheel, not only increases inertia, but it is harder to slow down. You are making the problem of navigating an eccentric record bigger than it needs to be.

Hi Chris - Yes I have a good memory. When we first imported a pile of ET2's we had in the shop an ET1. There was a big debate at the time that the ET2 had less bottom end than the ET1. The ET1 has a fixed counterweight. My business partner preferred the counterweight bolted up as per the ET1, but I found that gave a one note bottom end, lacking speed and articulation.
I experimented with the counterweight coupling and other ET2 mods quite extensively not only with a variety of TT's including Sota Star Vacuum, Townsend Rock, Roksan, Oracle and Final Audio TT, but also a variety of speakers including Martin Logan CLS, Apogees, Proac EBS, Proac Tablettes, Duntech's, vintage Tannoy Monitor Golds and many others - over the last 30 years.
Also have run the ET2 specifically with a wide variety of cartridges including Madrigal Carnegie, various Koetsu's, Van den hul Grashopper, Shinnon Red, Sumiko Talismans/Virtuoso's, Shure V15VMR, Denon 103 Garrott, Benz Reference and many others I've long forgotten.
I have also seen enough off centre cantilevers to last a lifetime from the misapplication of both tangential and pivoted arms.

Dover
As you said we will never agree on this.

The difference is that I have tried both light and heavy ETs. As far as I can tell, I am the only one who has done that. If so, I am the only person here who can speak with any authority on the subject.

People are free to try, it is entirely their choice. Install an alternate cheap cartridge, play a record you don't like, if you are that worried about damage to same. Your scaremongering may have dissuaded people from trying a simple reversible mod, which is a pity since we could have advanced the collective knowledge of this diverse group. And isn't that exactly what these forums are for?

“para 1 - not obvious to everyone.”

Why not, there are only 2 words to understand: ‘modified ET2.’

“Adding lead mass creates higher inertia but does NOT retard motion.”

Yes it does, more energy is required to activate the system.

You’re banging on about lead mass and inertia as though it is a random activity.

Required mass (and its related inertia) will be cartridge specific, so isn’t it simplistic to state or imply that no mass should be added to an ET.

Thank you Chris, Dover, Richard, and all for the fascinating data, opinions, and food for thought. I continue to enjoy the, admittedly, subtle effects of using a single weak magnet with my ET.

I can't claim to understand the physics involved well enough to give a thorough explanation of what happened in my particular case, but I have to concur with Dover about the concerns over added mass. In my case, it was not mass in the spindle, but a case of too much mass at the "headshell" and cartridge itself. A few years ago I managed to destroy the suspension on one of my VDH cartridges by applying too many bits of Blu-tac to a "naked" MC1, and to the top of the headshell in an attempt to dampen a cartridge that sounded overly aggressive in the highs. It worked to smooth out the ragged highs, but within days, experienced a collapsed suspension. The cartridge was properly balanced and setup at the appropriate VTF.

****Does damping not mean - reduce, diminish, dull - to a point that reduces some of “vinyl’s nasties”, caused mostly in this case with the ET2 tonearm – the off center hole - but we want to do this without taking away too much from the music itself ?**** -Chris

In the endless debate about wether footers, pads, etc. have a beneficial effect on music playback accuracy, I have always contended that, in absolute terms, it is not possible to overdamp a component's resonances by adding mass. Added mass can only be a good thing; in theory. While it may be possible to tweak the resonances to suit a particular system or listener's tastes, eliminating/controlling resonances can only be a good thing for a component's electrical performance, if not it's role in a given "system" (including the listener's ears) which is functioning in the electrical domain. But, it seems to me that in the case of a tonearm, we are not talking about simple resonances, but how added or removed mass affects the movement and stability-in-motion of the arm/cantilever "system". Sorry for possibly stating the obvious, but it helps me to make better sense of all this. Thanks again for a most interesting discussion.