2. analog
  3. 135398-81

VPI ADS Versus SDS

Gents:

Has anyone "upgraded" from the SDS to the ADS? I've had a two VPI tables over the past decade and have always thought about but never tried one of their speed controllers. I'd be interested in hearing from folks who have used both models and can share comparisons. I've noticed that despite the introduction of the ADS there has not been a significant price drop of the SDS on the used market, which leads me to wonder whether the ADS offers a significant increase in performance. Also, I had heard that VPI was going to launch several ADS models but it seems there is only one currently available. Anyone know about plans for other cheaper or more expensive versions?

In general, what can you expect when you add a speed controller (either model) to your analogue playback system?

Thanks!
dodgealum
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cleeds
5,912 posts
 
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.
bpoletti
1,547 posts
 
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.


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cleeds
5,912 posts
 
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.
tomwh
150 posts
 
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
1,547 posts
 
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.  
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