Vintage turntable running fast, any ideas?

There is an arm that moves the belt between two different diameters on the pulley. My theory was if it was getting in the way, it would slow down the turntable. Right now, it doesn't look like it affects the belt much.

If I want to physically change the dimensions of the turntable, I have two choices. Make the platter larger or the pulley smaller. Since the pulley is so much smaller, I probably sand it down.

What's weird to me is that the thing runs fast. I didn't expect to run into an old turntable with a hot to trot motor. I'll make sure is has lots of oil and let it run for a day or two. Maybe that will cool its heels.

The turntable is belt driven where the pulley is connected to the shaft of the motor. I have cleaned the area where the belt rides on the pulley. I don't think the pulley is worn because this would cause the table to turn slower or possibly erratically.

I went back and took a closer look at the belt fit and it looked liked the belt was riding high against a wider shaft. I refitted the belt and made sure it is in the middle of its allotted region, and alas, no change.

You did give me an idea. If all else fails I can sand the pulley/belt area down a bit. This will cause the table to turn slower. Right now, the table runs faster for both speeds (33 1/3 and 45 rpm).

I am close to positively sure the table is running fast. I checked the table with the strobe disk, and the strobe pattern is moving in the same direction the platter is turning. In my book, this means the table is moving a little faster than expected by the strobe disk.

It's funny how these threads have a life of their own and don't go in the direction you expect. My initial thought that it was some electrical problem within the turntable, but, most of the talk has been with mechanical issues.

Of all the suggestions, I think the thick belt suggestion is the one I plan to try next. I compared the current belt with a previous worn out one and sure enough it was much thicker. Once I get the speed correct, and get a stable disk strobe pattern, I'll check out if the motor has fast/slow problems. After that, its time to enjoy the thing or drop it off at the nearest thrift shop.

One thing I have learned here is the importance of a second source to compare things. (Now reread the above sentence until you understand it.) I only found the speed problem by comparing the record to a CD copy. After a couple of albums and CDs, something didn't sound right, and that helped me find the problem. In the process of switching the turntable between my main stereo system and the TV surround system, I've found that my much more expensive stereo system has a severe bass problem! Ah yes, this never ends, does it.

I have a theory on why musicians have such crappy stereo systems. From watching my violin playing brother-in-law, he uses a stereo like someone would use a hammer. All he wants from a stereo is the pace and tone of the music; mainly so he can play it himself. As such, he sees no need for an expensive system with great imaging and timbre, fast attack, etc. What's funny is that these are the same qualities he expects out of his violin!

It's wierd, I thought a percent or two change in speed wouldn't make much of a difference, but it does. With the speed-up you get an increase in frequency and also a change in timing. Not only are voices pitched higher, but the music has lots of extra snap to it. If you have a recording that seems dull and lifeless, just speed it up a bit, and man, it'll gain a new life.

Since we like to compare and grade our cables, power cords, and what not, I'll go out on a limb and say the tonal changes from the speed-up is a lot bigger than a cable change. At first I didn't notice the difference so much, but now that I'm keyed onto it, and I notice it immediately.

The turntable is not perfect but it is much better. From several internet searches I found that the original belt was possibly too thick and a tad long. I had great hopes for a new thinner belt and it did slow down the turntable, but not nearly enough.

The next fix was to get out the emery cloth and start sanding down the brass pulley. The pulley is only 3/8" in diameter, so I didn't have to sand it much, but I did manage to sand it down just a tad too much. (Don't ask me how I managed that, cause I was watching and checking like crazy.)

Luckily, the original belt was still handy and now I have a turntable with two options. I can run it a tad slow or a tad fast. Personally, I like the faster option and don't plan to tempt fate any more.

Cheers,