Anybody familiar with Denon DR-M20 cassette decks?

dromunds

I have a buddy who bought this deck new and says he's had it worked on recently by a local shop and they got it working but it just doesn't sound right. He's de-magged and cleaned the heads but still not the sound quality it was. I appreciate that this is not a whole lot of detail but if there's somebody with familiarity with this unit, please let me know and perhaps I can pinpoint some more information. How good is this unit in the scheme of things? He may be looking to replace it with something better but I thought it would be worth it to pick some brains first. Thanks in advance for any help.

skrol

These were nice decks. I have a few of the more recent model Denons. That unit is a 3 head. Any idea what the service guy did?
http://www.vintagecassette.com/denon/dr_m20

erniejade

Tape head might not be aligned right are you using a prerecorded tape or homemade?

dromunds

Thanks skrol and ernie, he used TDK metal tapes mostly, but others also, mostly compiliation tapes he's put together but some prerecorded also. I don't know much about what the service guy did, all he said was after a long period of non-use the deck "locked up". He said the play, FF and reverse function "would stop." He said he took it to a local shop in Santa Fe and the got it working but now the sound is muddy. I think the service work was done awhile ago. I'll mention to him about the heads not being correctly aligned, I wonder if the tech messed with those?

[Deleted User]

Hello,
Sometimes when someone says the sound is "muddy" they are referring to a lack of treble information. While this could be caused by a misalignment of the playback head, it also could be a dirty head. Your friend should try a very thorough cleaning with a good quality tape head cleaner. In a pinch he could use Ronsonol lighter fluid and a q-tip to clean the heads.
Cheers, Ken

skrol

I recently picked up another Denon DRM-800, which is a little newer than yours (~1990). I gave it a good cleaning and demagnetized the heads and capstans and it sounds fantastic. Using a test tape I checked the speed and head alignment. The speed was checked using a frequency counter and it was spot on. The head azimuth alignment was checked using an oscilloscope Lissajous (XY mode) to view the left vs right phasing and it was very well aligned so I didn't have to touch anything. The belt looks to be in good condition too. I did find a couple broken solder joints where the RCA jacks solder to the PC board which I repaired. I played the deck for several hours and it works flawlessly.

I have always had good results with TDK, Maxell and Denon tapes in the Denon units. These were the chrome and metal formulations.

If you are looking for a nice Denon deck, I will be selling this one or I also have a DRM-700A that I should sell. The DR-M20 should also be a very nice deck if you can get it in shape.

dromunds

Thanks Kenneth. I PM'd you Skrol.

skrol

Ronsonol lighter fluid? I had not heard of that for cleaning heads before but internet search shows that it was a common practice. I used to have access to lab grade 100% isopropyl alcohol and freon. I still have a small supply of the alcohol that I use.

Something that I wonder about though is that around 2010 Ronsonol lighter fluid was bought by Zippo and is now the same as the original formula Zippo fluid. I am not sure if it make a difference but Ronsonol lighter fluid no longer contains naphtha.