Perimeter Ring Clamps: Yay?, Nay?, Sources??

Correct; I do not get your “sense of humor”. But I gather you followed Halcro’s advice, if that is what he wrote.  As far as I know, he is very happy with his TT101.

I don’t understand.

First, JP never suggested dumping Victor DD turntables. Second, in my experience the TT101 has been 100% reliable since JP repaired it. Or do you advocate dumping them because you may not be able to fit a ring?

Elliott, I was looking at my TT101 with your quest in mind. As you know, the two platters present the same problem for fitting a perimeter ring. There is very little margin for error. In fact I can think of no “off the shelf” ring that would fit. Certainly my Kenwood ring is not even close. So, if you do invite someone to bring his ring to fit your TT81, I’d advise you to be sure in advance that his ring has a hope of fitting.

mulveling, I am surprised to learn that the Benz cartridges you named would have such strong magnets, because they also have high-ish internal resistance for an LOMC, which suggests that the coils have many windings, yet the output is "low". Thus you’d think the cartridges could get by with a weaker magnetic field. On the other hand, my Ortofon MC2000, with an internal R of only 2 ohms and a vanishingly low output is probably dangerous for anyone with a pacemaker; its magnets are scary. The MC2000 inadvertently revealed to me that the Kenwood L07D platter sheet (made of stainless steel) is mildly ferrous; the MC2000 nearly committed suicide by squashing against the sheet. Since then, I had a copper platter sheet made for the L07D; better shielding of the cartridge from the motor EMI and totally nonmagnetic.

Elliott, Not that I want to talk you into using a peripheral ring, but what was it about Twoleftears' reference that turned you off so thoroughly to the whole idea of a peripheral ring?  It turned me off to "Wayne's Audio", more than anything else. Anyway, good decision even if for puzzling reasons.

To add a highly specific experience of my own, I have a Kenwood L07D. Kenwood made an accessory outer ring for the L07D, the DS20, which goes to show how old the idea is. When you install the DS20, you are also supposed to activate a switch on the outboard PS which allows the servo to compensate for the added mass; I have not weighed the ring, but it cannot weigh more than a pound or two or three. Because of my own fear of damaging a cartridge, I generally mount the ring on the platter so it sits UNDER the lip of the LP, not acting as a clamp. I have consistently found that I actually prefer the sound of the L07D without the ring. Just an anecdote and not proof of any general principle, except do be thoughtful about the effect of a heavy ring on speed regulation of a DD turntable. Because Kenwood was.

Have you actually placed the ring on yourTT81? Because I am otherwise dubious of the fit. Also, many have reported a danger to the stylus and cantilever when placing the cartridge at the rim of an LP. Finally, what is the mass? I would not automatically assume the TT81 motor and servo will like it.