Eyeing the Prime Signature but...
 

Hello,

I am really wanting to pull the trigger on the Prime Signature but I have also been considering the Clearaudio tables. The one sticking point with Clearaudio is their OSC, optical speed control. In my mind, as the record plays, there must be sections of the record that the records slows or speeds up. In the case of a Clearaudio table these adjustments would be made by the OSC - how does VPI compensate for this?

I prefer the look of the VPI and their reputation precedes them and would love to go VPI. Any input would be appreciated.

I tried to send you a PM, but it appears you are not a member.
You should sign up, as the conversation about this alone will be well worth the annual fee.


B

I have a big Clearaudio table (Innovation Master). And to be fair, the massive platters on both the Prime Signature and any of the upper-range Clearaudios will make groove drag a non-factor. The OSC won't be able to react quick enough for "draggier" passages, anyways (because of belt compliance and the huge mass of the platter).

really, why ?


I own a VPI Aries III, the speed is locked in via an 'SDS'

http://www.audiophilia.com/reviews/2...s-drive-system

Will do, I just signed up on the board a couple of days ago.
Seems there are two memberships, I look at both and get back with you.
Thanks

Thanks for the input.

In my mind, as the needle drags over the record the speed can change b/c the grooves are different as it goes. You have an SDS to maintain the speed, isn't this the whole reason for the SDS?

Im not sure, but the variation is speed must be b/c of the mechanical nature of vinyl.

I'm not sure what you mean when you say "the grooves are different" or why that would affect platter speed. Frankly, it's very difficult to imagine that a diamond stylus with a tiny footprint tracking an album at a couple of grams on a 22-pound platter can be subject to groove-induced speed variation.

The role of the SDS is to filter the AC power - actually, it regenerates it - and allow the turntable speed to be set precisely. That's how it maintains speed - it doesn't use a servo to correct for any speed deviation.

I have not used any of the Clearaudio tables. I do love my VPI Prime Signature. It pairs well with the Ortofon Cadenza Bronze I am using. I would certainly buy it again if I was starting over.

Both the VPI SDS and Clearaudio DC/OSC are just different approaches to guaranteeing a constant 33 1/3rd (or 45, 78) RPM platter speed when fed an AC line that either deviates from the an exact 60.0 Hz frequency and/or drifts in frequency over time.

Variable drag at the groove/stylus level would not be accounted for in either case. And even if this variability mattered, it's not really possible for any servo/drive system to react fast enough. Again, a massive platter is a very practical and effective solution here.

The Clearaudio OSC actually also requires you to fine-adjust the "absolute reference" speeds (33.3, 45, 78) via 3 trimpots and speed-strobe/disk, btw . And it's kinda tedious to do. It doesn't maintain an absolute reference in its controller. It's extremely stable once adjusted for your setup, though -- 2 years with no drift on my old Innovation Wood (I didn't check for 2 years, and it was still dead-on in the end). Maybe the OSC is slightly more adaptable than SDS to certain conditions that change slowly over time or permanently (e.g. more weight on the platter, higher friction from degrading bearing lubrication), but the you REALLY should re-adjust and lubricate in those cases, for optimal performance.