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Hatman
02-05-2011, 07:00 PM
Greeting Denon Tapeheads. Being an old dude I have an aged appreciation for the cassette medium and continue to enjoy my cassettes and vinyl. I have spent some time at AudioKarma and have enjoyed the tenor of its members and much appreciate the expert help with my vintage solid state receiver collection.
With my receivers recapped and attended to, I decided to back up my 1976-79 cassette collection, I felt that my two headed decks may not give me the best transfer results. Also, it gave me an excuse to get a new piece of gear. I researched 3-head decks and ended up with a Denon DN-790R. It is in excellent cosmetic condition. It reportedly was not 'on the road', but in a home theater system and had minimal use.

Although I have not opened it up yet the exterior build quality is impressive. I like its looks and feel. It sounds great, but my old ears are not that demanding. I have the Service Manual, but your opinion and insight about the belt replacement procedure and other considerations would be appreciated. I know from changing belts on my vintage Sony 2-headed decks, that belts need to be replaced. Although no problems are apparent I would consider replacing the two belts in this 790R.

My main question is; does anyone know the belts sizes and or a recommended vendor. The Service manual shows (capstan belt) #9DF F16M 31 Main Belt; 9DF F18R 11 Belt. NLA at Denon and they could not provide the dimensions. My usual sources vintage elec etc.... does not have any info / cross index for this model's belts. The unit is working OK, but want to include the belts in my next parts order so they are on-hand for replacement and eliminate the disassemble, measure and order route.

Hatman
03-04-2011, 09:51 PM
Hi, Despite a lot of searching I could not find out the belt size for this Denon DN-790R Cassette deck. So, I pulled and measured the two old belts. DN-790R owners, if your belts are original (1995) this is good time to save this information and add 'belt replacement service' to your list.

I determined the original sizes of the Main (capstan) Flat belt at; 9.0"IC x .023" thick x .130" wide. I used an MCM #42-3220 (9.0"x.024"x .150") @ $2.11. The Square (mode) belt measured 2.6"IC x .060 x.060 and a SCQ2.5 (2.5" IC x.060"x .060"), also at MCM @ $2.92, will match nicely. You could also get SL2.6, (2.6" x .059") square belt at ceitron.com (Consolidated Elec.) if you prefer @ $2.10, but there is a minimum order $.

Pretty easy replacement, not much dis-assembly and the erratic 'Mode' problem was cured. Contact me if you want more info on the procedure.

Naknut
03-05-2011, 09:14 AM
Thanks for the information and update Hatman. Although I don't currently own a Denon deck you never know when one will show up.
*bigthumbup*

Hatman
03-06-2011, 12:54 PM
Yes, sharing has really helped me refurbish, mod and keep my vintage gear running. So in that spirit, I put the original Service Manual into pdf (5.65MB), also three color pages (3.72MB). I do not think Tapeheads has a database, or I would put it there. I have sent both B&W and Color pages to AudioKarma and they should put it in their database. If that does not work for you, contact me.