VPI Single Motor Flywheel / SDS / Aries 3

I just purchased a new VPI Single Motor flywheel for my Aries 3. I have an SDS. It seems like I get answers a little quicker from this forum than VPI, although I have a call in to them.

Here is my dilemma: When I have the Single Motor Flywheel plugged in to the SDS or the wall outlet, the motor turns the flywheel too slowly and I am several HZ below the 60Hz/33RPM on my SDS. The sound is very slow and clearly under 33 rpm on the platter. The flywheel seems we lubricated and turns easily. The motor is quiet. It's just slow. So slow, I have to turn the SDS up to 65-66 HZ to approach strobe disc accuracy and acceptable sound for 33 rpm. Haven't even tried 45 rpm yet.

The motor is placed within proper distance to the flywheel. It came with two small brown belts for the motor to spin the flywheel and one larger black belt which appears to be the same size as the belt used on the Aries 3 regular 300 rpm motor.

Is this normal? Anyone with VPI single motor flywheels or experience with them that could give me advice would be greatly appreciated.
My SDS is set at 72 for my Single Motor Flywheel with my Aries Extended. I think I set it using the center weight and ring but it has been a while. I have the other 2 tables set up now but I will check as soon as I put it back. I just took it down for photos so that should be soon.
Stan, thanks so much for your response. So this is 72 for 33 rpm speed? That would seem to make sense as I would guess at 72 this is where I would have to be to get accurate speed for 33 rpm.

Any more info I can gleem from you would be great. Your sure know your VPI stuff!
Stan here are my settings with the original Aries 3 motor using center weight and peripheral ring: 33RPM - 60 Hz, 45 RPM- 81 Hz.

I'll try the flywheel with strobe disc more tonight and see what I get. If you had to set it at 72 Hz to get 33 RPM with flywheel and center weight and peripheral ring, it would make sense from what I'm seeing.
I have the same stuff (aries 3 with the flywheel and 2 belts) 33 is 72 volts. Then using the strobe and the disc adjust the (mine is 60.22) until you achieve the speed. There is no one perfect setting for everyone. The trick is to set it and let it run and recheck. It takes a while for the thing to lock in on 33 rpm So take your time and have a couple beers and adjust slowly to get the proper result. (Read Harry's instructions-they are very clear!)
I just had an interesting experience. As I said my voltage is usually 72 at right on 60 Hz. I decided to connect the SDS to my Scoutmaster, I had to lower the setting to slightly below 60 to get the exact speed. When I went back to my listening seat I noticed the voltage read 84. I was puzzled until I realized that I had plugged the SDS into one for the regular lines rather than one of the two dedicated ones. When I plugged it into one of them the voltage went back to 72.
So there is a 12 volt difference between my dedicated and non dedicated lines on the SDS, no wonder they sound different.
Hi Philb,

I have the same setup with a single flywheel, SDS, and VPI ring and clamp.

The SDS voltage and frequency really should not matter, as long as both 33 & 45 speeds are perfect with your KAB strobe.

I learned a good tip on Audiogon for the SDS and VPI setup.

When you are fine tuning the SDS, put an LP record on the turntable with the ring and the KAB disc over it.
Now, before putting the clamp on, take a 45rpm single with the center plastic in it, and place it on top of the KAB disc, then put the clamp on top. (you will still be able to see the speeds on the KAB)

When you go to set your speeds, place the stylus in the center of the 45 track and actually play the 45. (you can leave the volume off of course) Now set your speeds. This gives you the speed of the fully loaded platter including the average stylus drag..

Absolutely the best way to do it..

Have Fun,
Buy two more belts. One from the motor to the flywheel and one from the flywheel to the platter.
Thanks for the feedback everyone. The Flywheel seems a little more finicky than the simple 300 rpm motor, but I'm still at work at it. One thing interesting is it does seem like it takes the flywheel a good 5 minutes or so to get to a stable speed. If I work on adjustments on speed using the strobe disc immediately, I wind up chasing my own tail! After five minutes, its seems like it has reached a stable speed and I can start adjusting.

I ordered some VPI magic lube for the bearing of the platter and flywheel and applied them last night. It seems to make the flywheel run smoother and quieter, but i have seen no real improvement in stability of speed or being able to lower the Hz on the SDS back to where the single 300 rpm motor was set.

I did get a response from Mike at VPI and he suggested the Magic lube and he is also sending me an HRX pulley. My flywheel has the dual sized pulley for playing 33 and 45 rpm without the SDS. He said since I had an SDS, the HRX pulley should be much more stable and I may be able to use only one belt from the flywheel motor pulley to the flywheel.

The saga continues....
By the way, anyone replaced the black plastic/delrin motor pulley on a 300 rom motor or single motor flywheel before? How do you do it? It hasn't arrived from VPI yet, but I'm just trying to be prepared. Thanks....
Hi Stan,
I've noticed that the voltage on my SDS will sometimes read 72, and at other times will read 84. And this happens without making any changes to my system. I've often wondered why this happens.


Tom, the same thing is happening to mine. After I did my last post I went back downstairs and, still plugged into the dedicated line, it read 84 again. Now it reads 72 but switches to 84 when I turn the motor on. I have had it on the Scoutmaster, I am going to put the Aries back up this afternoon and see what happens. I earlier tried it with the Scout and the pulley didn't rotate, just vibrated, I don't know what to make of that at all.
Guys, mine does the same thing: 84v to start and then quickly to 72v in 33 rpm and up to 115v to start and down to 102v in 45 rpm. I think this is normal activity and its the way the SDS 'kick starts' the spinning to get things moving then back to the optimal operating voltage once spinning start equilibrating.

Repeating a quick question: has anyone out there replaced or changed out the black delrin motor pulley on a VPI 300 rpm motor or single motor flywheel? Just wondering how you do it. Thanks.
Hi Again,
The SDS is made to jump start the platter and then reduce voltage after a few seconds on both 33 & 45 speeds..

That is normal operation..

However this is only when you use the switch on the SDS as your on and off switch. I do not. Mine works fine at the reduced voltage using the motor switch as the on and off..

Here is the Correct Pulley for the setup. Mine works very well with this.


Joe, I agree about the SDS. My Single Motor Flywheel was sent with a different pulley (I think made for people without SDS).

Here is a pic of it and my current setup:


Mike from VPI sent me the HRX pulley that is shown in your pic from your previous post.

I wanting to replace it, but no instructions were sent on how to. Of course I could wait until Monday and shoot Mike another email, but I'm hoping someone out there has replaced a pulley on a VPI motor and can give me some advice.
Sorry, link doesn't work. Its the pulley that has two circumferences, with a little larger on bottom for 45 rpm play.
Here is a pic of my current set up with a link that works:

Philb7777, I haven't got your pulley but I think you'll find 2 hex grub screws on either side of the pulley near the bottom.

Simply loosen the hex screws and the pulley will slide off. Put in the replacement pulley and evenly tighten up the grub screws on the new pulley.

Regarding the SDS voltage.
I use the original 20lb(?) acrylic/lead TNT platter with the single motor/flywheel. I also used two belts between the motor and flywheel and 2 belts between the flywheel and platter - because it sounds better IMO. However, turning that heavy flywheel, platter and 4 belts is perhaps too much for the single motor used at 72V (which no doubt reduces the torque of the motor). The motor will do it, but some bass impact and speed appears to be lost. This may be why Harry went to the dual motor setup with the Scoutmaster/TNT-6/HRX.

In any case, I use the SDS set to 115V with my single motor/flywheel setup and find the sound much 'snappier'. I can't detect any increase in noise - if anything the the motor appears to be running smoother (to the finger test).
It may be worthwhile trying the higher voltage settings on the SDS to see if you derive any benefits.

System Details
Thanks for the info Tobes. It is a 2mm allen wrench. The screws have a green nylon tip. I replaced my dual sized pulley with the HRX one and it now works perfectly. My Hz required for 33 rpm is 60 with two belts and 45 rpm is 80.75 with two belts. I may experiment with one belt as Mike from VPI said it would be less noisy. That said, my speed is rock solid and dead on, and the music to my ears is back to the original sound of the regular 300 rpm motor, yet more air, more dynamics and slightly lower noise floor. Images are more rock solid. Subtle improvements over what was already fantastic, but you know us audiophiles, always looking for more....

Thanks a bunch for everyone's feedback, responses and help. This is a great community and I'm thankful for it.