VPI PLC question


I just purchased from here, I believe one of the original PLC's, i.e., the one with 2 round knobs on the front 33/45rpm, and a front toggle switch 33/45.

I have called VPI, and emailed them, and Ian, seemed to be a newer employee and wasn't familiar with the older PLC. He was to pass on my question to another person whom I haven't heard back from.

My question, I plugged my TNT JR into this thing.

On the PLC, using it toggled to the 33 RPM section, the platter spins,
On the TNT motor, if the belt is on the top part of the pulley, it will spin 33. If I put the belt on the lower wider pulley, its 45 tmp, just as it is w/o the PLC.

However when i switch the PLC switch to 45 rpm, the platter just stops at either pulley position. the pulley seems to be oscillating a bit, but not moving the belt.

I also found out, on the PLC 33 setting, I can use the 33 PLC round knob to adjust the speed of the platter dependent on the pulley position on 33 or 45rpm.
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My question is, is this normal? Why would there be a 45 switch and knob on the PLC if it doesn't do anything?

did i get a bum PLC?

thanks !
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The PLC must be started in at 33 rpm and switched to 45 on the fly. The motor doesn't have the torque to ramp up to 45 from a dead stop. The motor will just quiver.

Bill
This sounds like the problem I had with my PLC. It eventually got worse and actually made the sound worse. I would expect yours to get worse too. Hopefully you didn't spend a lot for yours.

The PLC was discontinued well over a decade ago when the SDS came out. The SDS is a huge improvement over the PLC. You should ditch the PLC and get an SDS.
The threaded stud on the back of the PLC chassis controls voltage. See if turning that full clockwise improves things.

The PLC was the worst audio purchase I ever made and the only item that went to trash. Mine never worked properly, and after two factory replacements VPI ceased support.
I was considering but Mike from VPI said it wasnt worth much. I did purchase a Music Hall unit for about $300.00 thst made a nice improvement in my HW-19. Claimed that it works up to 2 watts snd the vpi is 3 watt draw. Mr Hall said it would work fine and it has worked flawlessly for a year now. Doesn't even get warm.
The PLC was the worst audio purchase I ever made and the only item that went to trash. Mine never worked properly, and after two factory replacements VPI ceased support.

+1 - on being a bad purchase.

As a goodwill gesture - VPI should consider putting an announcement on their website that anyone bringing in a PLC will be given a credit of $$$ ? toward another current VPI product. Like the SDS. It think it would be good for VPI business.

Mat W are you reading?
Chris, FWIW I'll add that I threw all the electronics from the PLC in the trash and recycled the enclosure to host a Mark Kelly AC-1 drive controller kit. Waste not want not.