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VPI SDS 45 RPM malfunction

I have a brand new SDS unit that I've used for about a month now and it's been working fine at 33 rpm, but last weekend I tried to put on a 45 rpm record and the unit malfunctioned. I was able to adjust the frequency up to 80.80 Hz, which the strobe indicated resulted in correct speed, but the voltage would flicker between 72 and 115 V for several seconds and settle at 72. It seemed the turntable was holding speed at 72, but when I put the record on and the periphery ring, the SDS kept going back and forth in frequency between 33 and 45 (up and down between approx. 60 to 80 Hz and the motor would audibly "slip" when the SDS got to 80.80 Hz and then started going back down).

Is this a matter of adjusting the unit or is the unit broken? I sent an email to VPI, but I know they are very busy so I thought in the meantime I'd ask here. Any ideas or suggestions?
actusreus
philb7777
401 posts
 
definitely sounds like a malfunction of the SDS. I don't currently own one, but did for several years and it shouldn't be acting like this. Your voltage should set automatically based on the speed / Hz yoy dial in. For it to fluctuate means an internal problem only VPI is likely to fix.
brf
1,715 posts
 
Go to VPI's website and download the SDS calibration manual. In the manual are detailed instruction on how to adjust the SDS "steady state" voltage (run mode). For 45rpm, the factory default should be either 90 or 102 depending on the software version. If your SDS is dropping from 115v to 72 v after startup when in the 45rpm setting, it needs to be adjusted higher. You cannot hurt your table by trying a higher steady state voltage. I hope this corrects your problem
philb7777
401 posts
 
Brf is right - definitely worth a try.
wntrmute2's avatar
wntrmute2
188 posts
 
It is easy to set the voltage drop. Just read the manual, 72 volts is too low to reliably run 45 RPM on my SDS as well. Try a higher setting , it worked well for me.
stringreen's avatar
stringreen
6,380 posts
 
You said it is a new unit?? Send it back to VPI for proper performance.
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