Scoutmaster runs very slow

I have a Scoutmaster and the SDS. When I plug the Scoutmaster directly into the wall and measure speed with the KAB Speed Strobe 10 numbers drift by, moving right, in about 5 seconds. KAB states 10 numbers in one minute represents .3% accuraccy, so I'm really slow. Using the VPS, turned up to 66 frequency, 10 numbers drift by in around 15 seconds, better but still very slow. The voltage number reads 84. I would appreciate any suggestions
Things to check, would be the Platter first. Have you ever re-lubed the Platter Bearing? Removing Belt, and rotating, can you feel any drag?

Belt Slippage. When was the last time you replaced the Belt? Try cleaning the Belt, and Platter.

Try plugging directly to wall outlet, and measure speed again, still running slow?

66hz is quite a bit to try compensating for any anomalies, with either Platter-Bearing-Belt-etc. I'm running my SDS with VPI MK-IV Platter at 60.17hz, and achieve dead on speed, which I can look at the KAB Strobe for countless minutes on end, and cannot detect even the slightest of drift one way, or another.

One other possibility, is your Ramp Down Voltage is too low. I have my SDS set to Ramp Down to 72 vac with no problems, but it is possible your motor, or something else is not permitting it to work at such a low voltage.

You can go into the Calibration Mode, the instructions are on VPI's website on how to accomplish this, and you can select a higher Ramp Down Voltage, and see how this works? If no success, I think a call, or email to Mike at VPI is in order. Hope this helps, Mark
It sounds like your motor has a problem. Can you swing by your VPI dealer and have it looked at?
Which motor do you have? If it's the standard 300 rpm motor that fits into the cutout section of the Scoutmaster plinth, make sure it is about 1/4 inch (check manual to be sure) from the plinth. If it already is that far, try moving it out just a tad more. If that still doesn't help, have VPI send you a new belt. How old is your current belt? Also, make sure the belt loops around the center of the pulley. If I remember correctly, the pulley has a couple of varying diameters to allow speed adjustment.
I found that, during the summer months, my SDS was set to 59.85 to achieve solid 33.3 rpm. During the winter, I had to dial it almost to 61 because my rig is in a room that gets cold (lots of windows).
If none of this works, I would suspect the motor itself.

Hope this helps.

I suggest you not worry,... bring the speed to 33 1/3, and relax. If the sound is steady all is fine, if the sound wavers...ah, then it has to be looked at.
Put a power conditioner aka/power regenerator before the sds. Typical voltage variation where I live is +/- 15 volts (Fla) try a premier audio 300 etc. or better and you will be happy.
I read the last two posts. Two things:

1) Yes, you can dial the SDS up until you get to 33 1/3, but something is still wrong for the speed to be off by that much. I think it's worth getting to the bottom of. However, while you're debugging the problem, by all means ramp it up and get your records spinning!

2) If power delivery was the issue, I think your speed would be all over the map, rather than just slow. (Unless you live in a permanent "brown out" zone.)

Check the items mentioned in the previous posts, if platter, bearing, belts, etc. all check out fine then give VPI a call. They are very helpful.


I sent Mike at VPI an email. He said it sounded like a loose pulley and sure enough that was it. Speed is spot on now. Thanks for all your ideas.
I had a similar issue, but more like what Tom stated. My speed was all over the map and I figured it was a power delivery issue. I thought the motor was probably going bad. So I opened up the unit to find there was Hurst motor. Checked it out online. The motor I had was a 300 RPM 7.5 amp motor. They had the exact same motor and another one that was 9.5 amp and higher torque. Well, of course I had to go for the 9.5 amp version. What a difference. Speed is very stable now.