Got into the DAT world, last week.

rca2000

Super Member
I have acquired a Sony dtc-670 DAT deck. Now, I t does NOTwork, but I did have it working for a bit. Durinng that short time, I was IMPRESSSED, with the sound.

I got it to work, by "finger cleaning" the heads, and that worked for a short time, but they soon were clogged again. So, I did this a couple of more times, and after about the fourth session of cleaning(with swabs and alcohol, the other times), it now refuses to read at all anymore. SO-- is the head drum shot? and, can I use the drum from a DATA DAT deck, (I may have one somewhere), will they be the same, or am I going to have to "find" another one, of the same model, or similar?

I was using a 90m data DAT tape I got (a box of 5) and it looks like I can get at least 3 hours of time with those, and over 6 hours in the LP mode--- so, needless to say, i would like to get it "going" again....


Oh, and it is great to see the site back again... for about a week, I was unable to get n here... BAD times indeed!!
 
rca,

The drum assy' of the 670 is still is available as a spare part and common to these models:
DTC-57ES/59ES/60ES, DTC-A6/A7, DTC690/750 and the pro PCM-2300.
The original DATM-100 mechanism used in the 670 can be upgraded to DATM-102 (used in the 2300 as well), both still available, too.

I've never had problems like yours, but the fault may not necessarily lie in the drums: DAT decks are finicky and a service manual + somebody who knows how to is necessary to service them... finger-cleaning isn't the way to go :D

I strongly recommend the use audio grade tapes (ie. Maxell, TDK and mostly Maxell Pro) and verrrry strongly to avoid the 180" tapes - NOT reliable.
The LP mode is ok with tapes no longer than or 74" or 90" but that mode gets you down to 32kHz sampling anyway so, not sure it really is worthwhile...

I believe that dr*audio here has proper DAT experience.
You can also see Eddie Ciletti's website.
 
In the first place you should never use q tips on any rotating head; DAT or VHS. The fibers can get caught in the head, or catch on the pole pieces and break them. Here's what you should do:
Go to your nearest autoparts store and buy a chamois; the real stuff not the fake stuff. Get some isopropyl alcohol. Now, put the chamois over your finger and wet the end with alcohol. Turn the head clockwise only, holding the chamois gently against the side and clean the head until nothing comes off. For this next part you can use a q tip. You need to clean the tape path on the head; the stationary part that doesn't turn but the tape wraps around. Clean it with q tips and alcohol, but position the head (as you do it) so the 2 little rectangular slots are not near the q tip. Those are where the pole pieces are. Next, clean all the tape guides with q tips and alcohol. Gently pull up on the guides that wrap the tape around the head. They sometimes come loose on Sony decks. These 2 guides have rotating bushings on them where the tape contacts them. Make sure you clean the bushings' complete surface. Clean the capstan. Clean the pinchroller with ethanol; Vodka works fine.
Now you have to examine the head. You need a magnifying glass. Look carefully at the pole pieces and make sure they are not damaged. Here's a link to a photo from Eddie's website showing a DAT head.
http://www.tangible-technology.com/helical/88head_1a.JPG
The arrow points to the slot labelled "head" is actually pointing to the pole piece. The pole piece should, under a magnifying glass, look like a very thin, flat piece of metal. You may see some wire wrapped around it. The pole piece should not look broken, it should be one piece, not 2. If it looks ok, the head is probably ok.
Here's a link to Eddie's page on cleaning:
http://www.tangible-technology.com/helical/swabbing.html
Allow it to dry for 1 hour before you load a tape!
 
I have to add one other warning to Warren's perfect advice: don't ever use a regular analog tape head demagnetizer on rotating video or digital audio heads! These smaller-than-normal heads have a glass piece that separates the gap in the coils, and the induced vibrations from the demagnetizer can shatter the glass and render the heads destroyed.
Tom
 
OvenMaster said:
I have to add one other warning to Warren's perfect advice: don't ever use a regular analog tape head demagnetizer on rotating video or digital audio heads! These smaller-than-normal heads have a glass piece that separates the gap in the coils, and the induced vibrations from the demagnetizer can shatter the glass and render the heads destroyed.
Tom
I didn't know that! I have never tried to demag DAT heads or VHS heads because I didn't think they needed it. Now I never will!
 
Hello, experienced tech here, with a pair of pictures and points on manual head cleaning. The common tools are 99% (low moisture/anhydrous) Isopropyl alcohol and a lint-free cloth. Both are available at your local audio support center. Moisten the cloth with alcohol, place it against the head and — this part is highly recommended — rotate the head in the counter-clockwise direction. Some heads are more forgiving than others, but on a DA-38 / -88 / -98, rotation is critical — absolutely counter-clockwise only — because the head surface is asymmetrical, one edge being particularly sharp.

Cw or ccw dr. Audio?
Looking from above drum?
 
I was always taught the head should be turned clockwise (looking from above); the same direction it turns during operation. I was told that if you turn it in reverse you can break the pole pieces. I believe this same information is in one of my service manuals; either Sony or Panasonic, I forget which.
 
Balthazarr said:
So why does he say ccw...twice, in fact?
The DA-38,-88,-98 being critical in this regard. :dunno:

I dunno. I'll try to find the page in my manual then post a link to it.
 
Well, I checked my manuals and the only one that says anything about cleaning is the Panasonic service manual, and it says rotate the head in both directions?! Anyway, now that I think about it, I realized I do turn the head counter-clockwise, NOT clockwise. Sometimes it's better to describe something when you're actually doing it. And I remembered who told me to do it that way. When I used to work for Fretter, doing their audio repairs, sometimes I would work on VCRs. One guy told me to rotate the head back and forth while cleaning it. The head VCR tech saw me doing that and said "What the heck are you doing?" I said this other tech told me to do it that way and he said, "Well, he's full of @$%#. Always turn it counter clockwise."
 
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