Hi Bob, we seem to think along the same lines... I may try their brass mat, based upon my recent positive experiences with brass clamps and bearing housings. At 3.5 lbs. the brass mat should contribute both to flywheel effect and to resonance control. But IMO a periphery ring is a PITA. |
The VPI ring hasn't been a PITA for me. Agree w/Dgarretson about the benefits, not to mention that warped LPs will never be a trouble again. Cheers,
Spencer |
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 |
When all said, the only way to determine if the ttouter will work for you is to try it. All different TT's will react differently. TTouter offers a full refund, with no restocking fee. You are out the in and out bound shipping. It's worth the try so you can be put to rest your doubting and wondering. |
Bob, I also have the VPI black delrin & lead platter. The thing that got me interested in the brass mat is how much better brass sounds than stock delrin in the feet of my TNT. Who knows how brass will sound coupled to vinyl-- though there are a few high end TTs out there with heroically heavy brass platters. |
The VPI weighs (about 5 lbs total weight) much more than the brass one in the above link. It fits snuggly to the outside edge of the VPI platter, so it is very centered. It helps warped LP's only a bit (in my experience). I don't feel it is a PITA, but that's me. A couple LP's I own circumference is too small to allow you to use the PRC (2 out of 4-500 approx). I have no experience with the TT brand PRC above, though I am considering a TT brand center weight.
I realize this did not answer your questions, but I still hope it is helpful... |
I checked the weight of the VPI PRC-4lbs 11 oz, or 2130 grams. |
In my system, Scout, JMW9 Signature arm, SuperPlatter, SDS, Benz Ruby3 I had mixed results with the VPI periphery clamp. Older vinyl sounded better in every way. The newer records and 180-200 records sounded worse. It was though all of the life was sucked out of the vinyl. YMMV depending on your system. I would try it in your system before you commit to buying it.
Good Luck! |
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 |
The physics of a slightly off-center ring flywheel are complex. Even with the inner & outer ring perimeters shifting slightly, the majority of the ring's mass remains concentric. The net flywheel effect may still be superior relative to no flywheel at all. However, like an unbalanced auto wheel, there may be odd resonances at particular speeds of rotation-- but probably not a problem with a flywheel running a slow 33.3RPM. |
I have emailed Larry and he is working on a slightly lighter weight version for suspended tables about 400 grams hopefully it will work on my Oracle turntable. He should have it tested sometime this week |
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. |
Hi guys, have a look at the video it shoould answer your questions,
http://www.youtube.com/watch?v=XnzDGGAmtDo
Thanks
Larry |
Outer Ring RUNOUT Near perfect
Check out the runout when installed less than .010 Total Indicator Reading
http://www.youtube.com/watch?v=XnzDGGAmtDo
Cheers
Larry |
Hi guys, we have a newLight Outer Ring version now, just making three weights, 250 - 350 and 400
Diameter will be aprox. 12.0 to 12.5 inches.
Also engineering a super light clamp for the Oracles so we can use an outer ring and our clamp, stay tuned.......
Please email if interested or you have any comments or ideas
Cheers
Larry
larryd@ljtmfg.com
Thanks
Larry |
|
Quite keen to experiment with this periphery ring. However is wondering what is the risk of dropping catridge needle on the ring? |
I have used the VPI HRX outer ring for 6 years.
As ong as you are careful and use the cueing device you will have no problems. After all how many times to you miss the platter completely??
You have a lot more potential issues when setting up a cartridge. |
I would love an outer ring designed to focus the weight along the depth of the platter. This would allow me to easily integrate it w. some 9 inch arms and not interfere w. the arm rest or lift or any other part of the arm that is in the way. Instead of the outer ring being lets say 12 inches in diameter, it would be 11 inches but there would be additional rings under the top outer ring to add to the weight. You could add or remove rings at will. I was thinking of making this but don't have the time. This way you can adjust the weight of an outer ring. Obviously this would only work w. platters that are fairly deep and that are fully vertical in height rather than angled or fairly thin. Obviously I am referring to my Raven A/C or an Acoustic Solid, Brinkman or many of the belt drive non suspended turntables. |
