Don't know if you figured out which belt you need, but I believe that it is a FBM9.6. I just got a DT-30 off of ebay and should get it tomorrow. Pics showed two broken belts that were flat belts. Don't know if they are the same. Also, I scored both the original service manual and owner's manual in a different auction and should get them pretty soon. Media mail. Probably only have time to take the cover off and decide whether or not I want to take on the belts. Gotta a vacation coming up. I understand that parts are unobtainable so that might be an issue. I have been looking for a DT-30 for years because I have the matching amp, pre-amp, tuner and meters. Might try to score an LT-30 too. Mentioned the DT-30 to the guy that fixed my Yamaha M-70 amp and he claimed that he could fix one regardless. Hopefully just the belts.