VPI Analogue Drive System

I'm considering getting the VPI Analogue Drive System for my Scoutmaster Signature turntable with JMW-9 tonearm.  What is your opinion especially as to sound improvement?
can anyone hear a difference between the SDS, and the ADS??  Just wondering.....
I just got through reading the whole thread on the VPI forum about this unit...the one that closed down May 5.  All I can say is WOW.  Such invective! 
I missed out on the Eagle/Roadrunner units because I wasn't really interested in this until now.  I would only get the ADS if it made a difference in sound quality and there seems to be surprisingly little comment about this.  I'm also concerned about the on/off switch on the motor eventually giving out.
I may have to take a leap of faith and purchase one from MusicDirect with a 60 day right of return if the unit makes noise in my system.
Its very rare that a speed control doesn't enhance sound quality. It should be a nice upgrade. If you don't want to spend $1000, Sutherland makes a really good one for $400. Cable Company is a Sutherland dealer, They'll send send you a demo unit to try in your system.


If you want to know the difference between the sds and the and the ads, call Hollywood Sound in Hollywood Florida. 90 percent of his business is TT related. I can't think of anyone more qualified. He's also known for good deals.
Thank you for your responses.  Using the Platterspeed Feickert phone app I know my unit runs a little fast, about 33.5 rpm.  It seems fairly consistent.  It seems to me the Sutherland unit will tell me the same, but how does it slow it down to 33.3 or maybe I would want 33.2 for some recordings that sound too bright?

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Keeping the speed at 33.3 is an important function of a speed controller, but it is not the most important thing. Maintaining that speed without micro-speed changes is even ore important and is heard in better, smoother, sound. I can vouch for the ability of the SDS and the Eagle to achieve these goals--and the Eagle (or Falcon)/RR combo is a particularly elegant and simple way to do both.

The VPI ADS can do it, but it is a machine that has been plagued by problems traceable IMO to a less than the best design and the use of very cheap parts. Do you watch "Shark Tank?" Do you know what margins are? I, personally, would not buy one of these things.

At the same time Bill Carlin (Phoenix) has published DIY material for people to make their own speed controllers and it looks like some people may be getting together to turn these out--either as kits or built. If I had to decide now, I would get something I could sell easily (like an old SDS or VPI PLC) and wait to see what happens.

For a tech view of all this have a look at http://turntablepsu.com/vpi.html Though unsigned, it’s probably written by Bill Carlin; nobody knows as much as he does about this stuff.

The Southerland device referred to above, by the way, is NOT a speed controller. It’s just a very expensive strobe.

melm is correct about the Sutherland.  It's a record weight with a strobe built into it.  The only commercially available add-on device that can really "control" the speed of a belt- or idler-drive turntable is/was the Phoenix Engineering Falcon or Eagle power supply combined with the RoadRunner tachometer.  When the RR is attached to the Falcon or Eagle, speed is held as close to constant as the workings of the turntable permit, to the speed 33.333 rpm, because the RR gives constant feedback to the Eagle or Falcon based on real time data streaming from the platter.  Sadly, PE is out of business, but Bill Carlin and some others on DIY Audio are making and selling parts that enable the DIY approach, and for much less money.  The SDS, the Walker Audio Precision Motor Controller, and many other similar devices allow you to set the speed precisely, but they cannot correct for variations in line voltage or current or stylus drag or bearing friction, all of which might cause at least momentary loss of speed stability, once you start listening to music.
... The SDS, the Walker Audio Precision Motor Controller, and many other similar devices allow you to set the speed precisely, but they cannot correct for variations in line voltage or current or stylus drag or bearing friction ...
This is not really accurate. The devices you describe work with AC synchronous motors; line voltage and current have no affect on speed, which is governed by the AC line frequency. (That's the "synchronous" in "synchronous motor.") AC line frequency is very tightly controlled by electric utilities, because deviations in frequency can unbalance power distribution systems. It's unlike voltage, which can vary widely without causing disruption in power delivery.

As for bearing friction and stylus drag - these are really only factors with lightweight turntables and platters.  Once the platter has sufficient mass, these variables have little to no influence on platter speed.
So it's kind of as I thought.  If the unit is left on all the time there should be little variation in speed from that point of view.  Stylus drag and bearing friction should also be constant.  Apparently the speed can be controlled with minimal turns of a dial. 
I was thinking along the lines of ramping the speed up or down in tiny increments to see how it might affect individual recordings which may too "bright" or too "dull".  I listen to classical music exclusively and many digital recordings sound "digital", just like CD's. 
Has anyone experimented along these lines, to make these recordings sound "better"?  Or am I way off kilter?

... I was thinking along the lines of ramping the speed up or down in tiny increments to see how it might affect individual recordings which may too "bright" or too "dull". I listen to classical music exclusively and many digital recordings sound "digital", just like CD's.
Has anyone experimented along these lines, to make these recordings sound "better"?
I don't think adjusting turntable playback speed is a remedy to treat bright or dull sound.
cleeds,  Do you dispute what I actually wrote, in essence, that you can set platter speed with the SDS or the Walker?  I did neglect to mention that the motor should be of the AC synchronous type, but that wasn't really the question.  Most turntable motors fit this category, to one degree or another. Also, I don't know how you can say that current has no effect on platter speed, but frequency does.  "Current" has the property of frequency, which as you say does determine the speed of an AC synchronous motor.  I have read conflicting statements about the degree to which AC line frequency is tightly or not tightly controlled by power companies. Most sources say it's "pretty good" with small variations over short time that average out to 60 Hz over longer time periods.  Is that good enough for most audiophiles? I don't think so.

Jerry, Stylus drag is definitely NOT constant, by the way.  It's constantly varying across the surface of an LP.
I moved my motor drive belt up to the top slot on the motor drive pulley which effectively lowered my 3150 test tone from 3160 to 3149 on my PlatterSpeed app.  There was a significant improvement in sound quality with all my MC cartridges (I have 4 of them).  This obviously didn't cost me anything and I should probably have done it awhile ago, but I've just started paying attention to this tweak.  So far I'm not running out to buy anything yet.
Running your TT at the right speed (or nearly so) is not a tweak.  It's just a very basic thing everyone should do, like leveling the platter.

Sorry.  Wrong word.  At this point I'm almost ready to take your advice not to buy anything and maybe the DIY components that Phoenix Engineering used to make will be available again.
So far no one who has bought the ADS has responded as to how great it is.

All the "speed control" fanatics are completely missing the point and the REAL issue.  Speed control is NOT the issue.  It is VOLTAGE control.  At wall voltages, the motor will generate pulses that are carried to the table through the belt (or drive).  Reducing the voltage will reduce the magnitude of the pulses and fix the noise issue.  THAT is the reason to get one of these units.  A variostat will do the job at a fraction of the price of a "speed control."  Start the table at full voltage then reduce to 70 volts or so when it's time to drop the needle.
Doesn't my SDS that drives my turntable do what the ADS does??  What's the difference - is one better than the other, etc.
stringreen, Having compared the SDS to the ADS with a friends Classic 3 signature. One thing the ADA absolutely did was wipe out noise that I didn't really notice until we switched it in. It's an immediate  and noticeable improvement with his table. He purchased it on that alone, not sure what the sonic improvements are, I'll ask now that he has had more time to compare the two units.  
Thanks tom....  I just listened again to mine, and find it dead silent....I guess I have to get one to test out in my system
Tom:  eagerly awaiting your report re sonic improvements with ADS unit.  This was my original question.
I used an SDS for many years.  A bullet-proof device.  As for noise from it; there wasn't any at all.  I replaced it with an Eagle/Roadrunner,  Performance, as far as I can tell, is identical--but for issues that RR addresses.  Odd to hear about any noise issue with the SDS.  
A rare occasion where stringreen isn't a vocal proponent of a VPI product!

I can only assume the ADS is better based soley on the fact VPI has discounted their stock of SDSs and heavily promoted the ADS.

They sent me one after my complaints. I have still not inserted it w/ my Classic3 into my main system to listen.

The question remains..Why does a customer have to purchase a speed controller when they have just spent thousands on a TT?
I had forgotten about his thread.  MusicDirect discounts the ADS to $850 so I bought one.  It does seem to improve my vinyl playback system with wider soundstage, better instrument separation, better dynamics, overall musicality, etc.  The factory setting is a little off so I'm using the KAB strobe system to set it exact.
I know I'm echoing the VPI endorsement, but I'm pleased with it.
There was never a question for me whether or not the SDS improved the performance of my TTs.

( VPI had fairly recently hiked the price of the SDS to $1499. At the same time they were advertising the ADS at $999.00, as a better solution.) It was news to us, but they were aware of it. This is a problem with me. I don't know about the rest of you? I'm SO glad I had the sense to sell my brand new SDS that came with my Classic 3 package deal before they, once again, disinflated the value of one of their components to their unsuspecting/loyal customers.

A forty year old company with ongoing issues that should not be. Look at the roll-out of the Shinola TT. A big disgrace, IMO, as reported by MF.