I have an old Dual 721 turntable and it turns fast... It has a strobe and pitch adjustment. The strobe has not worked well for quite a while. The pitch adjustment was working until yesterday but now that does not work either. The are some adjustable screw (resisters ?) on the circuit board under the platter. I can adjust the speed faster by turning a couple of these but I can not slow the turntable down to 33. I have cleaned things with alcohol but still no help. Suggestions?
I have just bought a Dual 721 as well. Mine is working fine so far. I have found an instruction manual on the internet. I haven't yet read it, but maybe there is some info about your problem in it. You can find it at:
If the table cannot be brought to correct speed, it will require some service - more involved service than you can manage with achohol. Try this page; if this doesn't get the table working properly, then you'll have to find a technician to do the repairs.
I have a Dual 721 which was not used when I bought it. It was remained in a shop that was closed for more than 15 years. Inside the box was a Shure V15 Type III with its manual. The complete assabling guide of the turntable. It works great, and does not have any problem so far...