Who's used a periphery ring on their TT?

[Rob S.]

I'm considering buying a VPI periphery ring for my VPI TT.   Has anyone used one and what were your thoughts on the changes to the sound.  Seems there are several different kinds of them.

Rob S.

[BobM]

I've been toying with that idea myself for several years now. The only thing holding me back is that they are damned expensive. But everyone who has one or tried one says they have liked it, from what I've read on the forums. It can be a bit of a pain to use and you do have to worry about dropping the cartridge on the lead-in groove and not on the ring itself.

[Rob S.]

I'm still trying to wrap my head around $700 for VPI's ring.   Seems the TTweights has some that are a bit less.  But likely less weight and different material so not sure if I should try one of those or just go with the brand I already have.

Rob

[bacobits]

I had one standard on my Merrill Heirloom a ways back and it was nice for warps.
I don't remember what the sound was like without it. Kind of a pain when changing sides too.
DON"T DROP IT! It was pretty heavy.


Den

[rollo]

I'm still trying to wrap my head around $700 for VPI's ring.  Seems the TTweights has some that are a bit less.  But likely less weight and different material so not sure if I should try one of those or just go with the brand I already have.

Rob

Rob if you do not have the dedicated power supply than by all means try the ring. If not buy the power supply from VPI. IMO the most bang for the buck even at $1000. One of our members has one and to my ears was NOT a big improvement worth the $700. Where as the power supply was night and day difference.


charles

[tmazz]

Rob if you do not have the dedicated power supply than by all means try the ring. If not buy the power supply from VPI. IMO the most bang for the buck even at $1000. One of our members has one and to my ears was NOT a big improvement worth the $700. Where as the power supply was night and day difference.

charles

Has anyone out there compared the VPI SDS to the old PLC. I have a PLCand always thought it made a significant difference. You can get a PLC on A'gon for around $200 and I am wondering how much better the SDS is given the going price of $800 on the used market ($1200 new.) I know the SDS puts out a cleaner sine wave where the output of the PLC looks more like a square wave, but I am not sure how much of an audible difference this makes.

[BobM]

The PLC is really not much more than a power conditioner. The SDS fully allows you to control the speed stability of the turntable. I don't have an SDS, but I do have a speed controller designed by Mark Kelly which performs a similar function.

Bottom line, this is probably one of the biggest improvements you can make to your turntable. It will make a very noticeable improvement on its own, but it will also let you get rid of that crappy rubber band of an O ring that drives your platter and conveys all sorts of vibrations and distortions to your stylus. Replace it with a silk string, dial in the speed, and gain the PRAT and clarity that you have been missing all these years.

Bob

[tmazz]

The VPI PLC is actually a full AC regenerator. It takes the incoming commercial AC rectifies it down to DC and uses that DC to drive an oscillator stage to rebuild an AC wave at a user specified frequency (since VPI TTs use AC Synchronous motors the frequency of the AC wave controls the speed of the motor. So functionally the PLC and the SDS do essentially the same thing. However the SDS is a more "refined" unit in a couple of ways. First off, the PLC is a more basic and crude device and the AC wave it produces is much closer to a square wave than to a sine wave. Back when the PLC was a current model VPI's take on this was that the improvements obtained from the frequency stability of the square wave was greater than any problems that might be caused by the fact that it was not a sine wave so it ended up making a net positive improvement and from my experiences with the unit I wholeheartedly agree. It is my understanding that the SDS improves on the PLC in two ways. First the circuitry used to regenerate the AC output is more complex (which of course means more expensive ) and is able to produce an actual sine wave. Secondly, when speaking with Mike in the VPI service department, he recommended that I change some resistors in my PLC to lower the output voltage. It seems that the motors on the VPI TTs run better and quieter at 72VAC. The only time you need the full 120v is to get the platter started from a dead stop. VPI recommended lowering the voltage and giving the platter a hand spin to get it moving before turning on the power to the motor. The SDS incorporates this concept by allowing you to select a lower "steady state" output voltage. The SDS will then know enough to put out 120v while the platter is spinning up and lower it to the chosen steady state voltage once the platter has reached full operational speed (I don't think there is any kind of speed feedback used, I'm sure the voltage just drops after a certain amount of time.)
The SDS also has a built in run time counter which I guess is good for someone who want to track the amount of usage on their cartridge.

While I understand the differences between the two units and can see where the SDS is definitely a "better" unit on paper, what I am wondering about is how much of this "better" translates in to sonically significant differences. The PLC was an outstanding purchase at its full retail price of $300 in 1989 and I am curious how the SDS compares to it sonically given that its list price is about 3X greater.

Of course for those looking to purchase a new unit there is n o choice since the PLC has been out of production for many years now. In fact the company that made the logic chips in the PLC is no longer in business so getting repair parts for one is also out of the question.  But for those of us who currently own a PLC there is always the question of what would be the gain in making the jump to an SDS and I was wondering if there was anyone out there who had done so and could shed some light of the subject.

[Rob S.]

Great guys, now I have to spend more on this TT setup.  I'm now keeping my eyes peeled for a SDS to go along with the periphery ring.  Shoot me a note if you see one for sale used.   

Rob S.

[tmazz]

Great guys, now I have to spend more on this TT setup.  I'm now keeping my eyes peeled for a SDS to go along with the periphery ring.  Shoot me a note if you see one for sale used.   

Rob S.

Used SDS units can be found on a regular basis on A'gon for aboud $750 to $1K. Keep in mind that the PLC, while little tougher to find can be picked up for somewhere in the area of $200. Hopefully someone will respond to the last post and we can get an idea of what the sonic difference is between the two.

Tom

[BobM]

Does the PLC allow you to adjust the speed? I thought it didn't, but I could be wrong since I never had one. I think the biggest bang is to be able to adjust the speed significantly enough to replace the O ring with silk thread.

[tmazz]

Does the PLC allow you to adjust the speed? I thought it didn't, but I could be wrong since I never had one. I think the biggest bang is to be able to adjust the speed significantly enough to replace the O ring with silk thread.

Absolutely. There are two versions of the PLC. The guts are the same but they offer different user interfaces. The original version (which is what I have) has thumbwheels that allow you to dial in the output frequency  down to the tenths. In theory 60.0 Hz = 33 1/3 RPM and 88.1 Hz = 45 RPM allthough individual tables will vary and you should dial in the exact frequency you need with a strobe disc. (FYI - Mine is dead on with the standard settings). The second version that came out has two dials to set frequencies for 33 & 45 and a toggle switch to flip between them.  I guess it is a little easier to flip the single switch as opposed to moving 3 thumbwheels, allthough I never found it to be that big of a deal.
I originally bought the unit so I could play my 45 RPM Reference Recordings LPs without moving the belt and was absolutely shocked to hear the sonic improvement it made to the table.

[BobM]

Get some of that silk thread Tom and give it a shot. You may be pleasantly surprised for very little money. And you can get the color of your choice too 

[tmazz]

one of the reasons i like my oracle deck is that its ever-so-slightly convex platter, combined w/its screw-down spindle clamp
doug s.

VPI does the same thing with their platters. The stock VPI clamp and platter will flatten most records but the ring will pretty much do them all. A little more money, a little more inconvenient and a little better sound. Pick you poison.

[richidoo]

Do you mean concave, so the rim of the platter is higher than the center? Then a clamp at the center would tension the whole record with pressure on the rim, similar to a rim clamp. If the platter is convex with a hump in the center, then the outer edges flap loose? Thanks for clarifying