In 2005, I dug my Dual out of the basement. After three attempts at a belt, I settled on a FS13.0 from Turntable Basics because that's what they recommended. It was too thick, so I had to build up the platter pulley to get it to run at 45rpm instead of 50, there was a lot of noise, and motor and platter lube jobs didn't seem to last long.

Fast forward to three weeks ago. I found somewhere online how to measure properly for a belt with a string. Measure the string around the pulleys, subtract 3-5%, and there's your belt length. My, my... turns out that my 1257 has the same belt dimensions as a 1258... an FM14.4. So I put in my order, and waited. Besides, after relubing my motor, I didn't want to risk damaging bearings made of unobtainium.

The three week wait was well worth it. As soon as I put the belt on, I knew I'd gotten a perfect fit.

No more rumble. No more motor noise. No more stretching the belt so tightly that I thought I'd snap it. I played a few garden variety LPs. I was shocked when I was actually able to hear tape hiss on Sade's Promise, which cost me all of $3 used. Noise between tracks? Of course not!

All this yakking goes to prove that the exact and proper size replacement belt is VITAL to your TT working up to snuff. Anything less and you WILL be able to hear the difference, and trying to work around it will bother you until you fix it properly.

Goes back to the old saying,"If its worth doing its worth doing right".
Glad you could find the correct belt.

Tanx for sharing this value info.