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Vintage turntable running fast, any ideas?

I got a Pioneer Pl-12 turntable from a friend who had it stored away for years. I cleaned it up but have found that some voices have a higher pitch compared to the CD version. I tried the free strobe disks and they verified my fears about the platter turning (I assume) too fast. I also measured similar songs from CDs and albums, and the albums always finish sooner. From some rough time estimates, the turntable is running about 3% too fast.

Looking from the bottom side up on the turntable, there are no adjustments and very little electronics at all. The only electronics are: the motor with a few wires running to it; an enclosed switch to select 115/230 voltable, and a somewhat large capacitor (I think). The "capacitor" has a rating of 0.1 uF and some serial numbers.

I suspect the "capacitor" is old or burnt or whatever. I doubt the voltage switch is the prolem, nor the motor, but who knows?

Any ideas? I have a voltage meter so I can measure the usual volts, ohms, or ampere, but I don't have an oscilloscope to measure frequency.

Thanks for any ideas,
rrick

Showing 2 responses by tmcroy

tmcroy
25 posts
 
You could try wiring an ordinary light bulb in series with the motor - be aware that it needs to be in a safe place as they are reasonably easy to break and of course a broken light bulb is an electric shock hazard - also remember they give off heat.
The smaller the wattage of the bulb you use, the more it will slow things down and vice versa.
This is in fact simply a current limiting resistor. Used it on my old garrard 401 as the speed control on those is a magnetic brake, which does the sound no good at all. Eventually I got round to machining up a smaller motor drive spindle - didn't sound any better than the lightbulb!
tmcroy
25 posts
 
Hi fi is usually a bottomless pit - but have you ever noticed that most musicains listen to things with the sonic elegance of a mice powered turntable using a 4" nail hooked up to an old tin can with a bit of string?
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