Periphery Record Rings

That's my initial thought Spence. The primary issue with my rig is nasty subsonic effects. I think a periphery ring would help with that more than a heavier platter, as much as it would be a PITA (not the bread).

I'm mostly wondering about the quality of this new brass ring.
- Has anyone seen it yet or is it brand new?
- Is there any slippage on the LP edge to worry about?
- Should that be damped where they come into contact or just leave it as metal to vinyl?
- Is the concentricity (is that a word?) good enough to ensure that there is no out of balance issues that would affect speed stability?

Bob

Here's some thoughts from another source that I have queried on this topic:

"I think the only way to go is with a matched fit with 3 point engagement on the outside diameter of the platter so you don't give up concentricity and minimize resonance transfer. If you locate the ring on the O.D. of the vinyl record, you're depending on the record being pressed dead on concentric and this rarely happens. The ring then rotates about the same eccentric axis as the record and destroys balance."

An interesting thought for sure about a non-concentric record's problems being emphasized by the ring. I like the thought of there being some kind of centering mechanism for the ring, to ensure concentricity, but implementing something that is also user friendly (given that a ring is generally NOT user friendly to begin with) could certainly pose a design challenge.

As for the brass platter plate, my mind is still uncertain on this one. I like the design of my black VPI platter, where the record and the platter are similar and rather effectively coupled via the VPI clamp. I may wait to see how that one fares on your rig Dave :-)

Bob

I've had some correspondence with Larry, the seller of the rings in the link I posted originally. He does address the possibility of the ring being non-concentric as follows (I hope he doesn't mind my posting this information, but it does help explain how to best use this ring and remove buyer concverns, and as such I would think it is helpful to him and his sales effort):

(begin quote) "Big issue records vary in size .100 so lots fit without setting but the exceptions must be considered, lots of tweaking now, we actually made 14 different shapes and sizes for testing.

1 - If the ring runs out less than .015 no issue with speed etc. No affect
2 - If the record is a small old A&M pressing the outer ring setting disk tool must be used that set the disk with .005 concentricity
3 - If the Record is on top limit on diameter we have enough room to make the ring concentric with the disk
4 - some albums are not concentric and I use them successfully because they are out no more than .015 and that really does not affect playback

The Disk is simple it is a recessed (counter bored disk, same diameter as the ring, with a spindle hole bored in it). Place the record in the disk and put it on the TT and remove. It also stores the outer ring nicely, it is machined with ) run out form the diameter to the spindle hole and you can get the album concentric with a few
thousands if you are careful. I have tested every LP size/manufacturer and condition and thus far it is flawless." (end of quote)

I guess time will tell. I would be anxious to hear impressions from anyone who purchases one of these new rings and their listening and usage impressions.

Bob

I saw his sale for the rings posted a couple of weeks ago, but nothing since. Is he selling these somewhere else or is he still doing some tweaking of the final product before he offers them for sale on a regular basis?

I'd love to hear more impressions from purchasers.