VPI ADS Versus SDS

The effects of less than perfectly consistent speed screw up the music way before they occur at the level at which they are perceived as pitch problems.  At these lower, less obvious levels, the music looses rhythmic impetus and excitement; lessened feeling of the music’s groove.  My SDS made a very significant improvement to my TNT6’s playback.  I would not consider being without it.

My Opinion is that speed stability is about off-center holes, not A/C frequency.

If you have a a/c sycro motor Any change in frequency with result in a change in speed.  Voltage drop only reduces the power and sometimes the vibration.

If you can not hear the improvements that  some controllers can make you can save some money.  If you want to state most are over priced that's a economic debate.

If you can build electronics there is a on going diy project on the diy forum.  It all started with a guy who wanted to 2 phase drive a Hurst motor on his VPI. Then Bill, the designer of Phoenix products, jumped in and you can have a unit that can run 1,2 and 3 phases.  It also automatically reduces voltage and many other features.

Enjoy the ride
Tom

The controllers clean up or reconstruct the AC signal, regulate it as to frequency and lower the voltage.  My experience is that they provide a degree of improvement and clarity to the sound much as does the addition of a flywheel or a heavier platter (providing more flywheel).  If you have a revealing system and a discerning listener, the improvements are obvious.

Having said all that, the speed of a belt driven TT may still drift from 33 1/3 because of aging bearing lubricant, an aging belt and/or needle drag.  Other factors?  Hence, many users welcomed the Roadrunner tachometer which measured average platter speed over a period of about 3 revolutions.  When brilliantly mated to the electronic drive as was done with the Falcon and later the Eagle, the frequency would be adjusted slowly, but quickly enough as to be done right and not noticed by the listener.   It is a "set it and forget it" system.  (This differs from the instantaneous correction, as in Asian direct drives with relatively light platters, which, according to many people results in a deterioration of the sound.)

IMO nothing has approached the Roadrunner-Falcon/Eagle system which, unfortunately, is no longer available, and not even on the used market--for no one is parting with them.  And just for the record, these were sold at a much lower total price than the competing VPI systems and IMO were built to a much higher engineering and physical standard.  VPI has literally spent years trying to come up with something comparable, but with no apparent success.

As for this new Australian device noted above, despite the pretty page filled with hype, very little information is actually given regarding its actual use, particularly about its "tacho" or "strobe" system, nor about any incremental cost for them.

I don't miss the point, and you didn't READ my comment.   MY OPINION is that speed stability is about off-centered spindle holes, not A/C frequency.  I am very sensitive to pitch fluctuations and only experience them with off-center spindle holes.  

The reason for many controllers,  A/C sycro motors, is to stabilize frequency.  The reason some have voltage drops is to lower the vibration of the motor.  Also a big plus is to vary the frequency to get the right rpm.  Lots of things vary the rpm.  A two phase unit would be nice for the hurst motor Vpi uses.  Get rid of the cap and dial in the phase.  

To believe that speed stability is not critical is to Completely miss the point!!!  

Enjoy the ride
Tom

bpoletti

I have never really understood the need for an SDS or other similar type of device. The only REAL reason for such a device is to reduce the voltage to the motor during record play.

That may be true for you. But for anyone who sometimes plays 45s or <shudder> 78 rpm discs, an SDS can offer a convenient way to set exact speed.

In my experienced opinion....

I have never really understood the need for an SDS or other similar type of device.    The only REAL reason for such a device is to reduce the voltage to the motor during record play.  That can be easily achieved using a Variostat.  The VERY minor fluctuations in frequency is insignificant compared to typical off-center spindle holes/  I have no trouble with pitch on my 20+ year old VPI Aries.  I use a Variostat to start the table at 120V and during "dust-off" and reduce the voltage to around 75V during playback.  I reduce the voltage to zero to stop the table rotation.  I don't use ANY on/off switch except to turn on/off the Variostat.

Yes, it is a very little bit more involved, but hardly worth mentioning.  It just becomes a habit.

The results speak for themselves.  Not picking a fight or comment war, just stating my OPINION.

gbanderhoos

This is an interesting alternative for little more money than the original ADS:

http://www.9tci.com/

Some VPI motors consume more than the 7-watt limit of that controller, so some caution is warranted.

The last number I saw bantered about for the upgraded ADS was ~$2K.

This is an interesting alternative for little more money than the original ADS:

http://www.9tci.com/

~$1200.  Crystal controlled, dual phase, 2 motors, tachometer feedback...

IIRC those pages are written by Bill Carlin who designed and used to manufacture the Falcon/Eagle/Roadrunner.

There is an on-line review here that covers some of the differences:

http://www.turntablepsu.com/vpi.html

That is too bad.  I have a Falcon and a Walker and I ended up using the Falcon.  

A movement from an SDS to an ADS is not an "upgrade." They both are designed to do about the same thing and with the same level of quality. Unfortunately the ADS has been found by many users to be noisy, that is, to produce a vibration that can be heard if it is near the listening position. Best guess offered over on the VPI site is that VPI has used a very cheap transformer inside that simply vibrates. Seems that it needed, but did not get, a redesign upon its launch. That’s why many people are looking for SDSs and the used price is holding up.

Too bad no one has picked up on the Falcon/Eagle/Roadrunner designs.

Dodgealum - 

I have not heard the ADS, but "reports" from those I trust indicate the best thing you can do is to keep your SDS.  Give VPI some serious time to work out the bugs.  I'm seriously softening the comments I've heard.

   VPI is working in conjunction with Mark Levinson on an upgraded version of the sds. It has been a long time coming.

   I am waiting for that version.