Teac X-10 - rec head problem after playing sticky tape

[fbaratto]

Hello to everyone (in particular to Skywave TDR),
I am the proud owner of a few Teac/Tascam RTR recorders...among which 35/2, X10, X3 Mk II etc..
This time the trouble is the recording head of an X-10 4-track.

After playing a few tapes to test them, I tried a Revox one (metal reel), 10.5". Tape type is not known but the seller assured me that it was ok....I played it once and then I tried recording some music on it at 7.5" speed...there were no high frequencies recorded....the sound was dull and muffled...ohmygosh!!!

I removed the tape and saw the tell tale traces of oxyde all over the transport on the capstans, the guides and the heads...I cleaned everything accurately with isopropyl alcohol on a cotton swab, removing just about all that it was there...
Then I changed the tape and placed an Emtec I know that works perfectly...One channel was much lower than the other... I then cleaned again the rec head (the playbak head is fine and plays tapes recorded earlier in a perfect way)...however the recording is still muffled, albeit better than before...

So at this point I don't know what to do...bear in mind that the dbx I circuit is off...

PLEAS HELP!!!! I am about to panic....Other than bringing it for service what can I do?

Thanks a lot!
Fabio

 

[Laszlo]

hello fabio,
did you demagnetize the head block? It might helps. Also, it may be worth to have a look at the head alignment with a test tape. Once you performed both you can investigate further..
Cheers,
laszlo

 

[fbaratto]

Well no...I don't have a demag unit...I was thinking of buying a teac E-1 or E-3 unit...Before that stupid tape all was well...Maybe I should use something stronger that IPA...like pure Acetone or denatured alcohol....what do you think?
Thanks!
Fab

 

[fbaratto]

By test tape do you mean a Dolby level cal tape? Because that only has a 400 Hz test tone on it...

 

[fbaratto]

Laszlo, I found an Acetone (a fingernail polish remover) product in a drug store made of pure Acetone and water...that should clean the heads in a more thorough way than the typical Isoprpyl alcohol....what do you think?
Thanks,
Fab

 

[Laszlo]

Hi Fab,

again, I do not think that cleaning the heads with different agents would make a big difference, if after the first cleaning the problem still persists. Aceton can be good for the heads only, however it is a strong solvant of certain plastics, therefore it is not recommended by the books.
Test tape: I mean the standard test tape which is mentioned in the respective section of the service manual. But certainly you dont want to buy all those different tapes because you are not a service man, so I suggest to use a generic test tape. You can buy one eg. from Gennlab.com. You need it if you want to set the levels on your own..But for a basic repro test a Dolby test tapes will do the trick, at least to see if all the channels have the same level.

Cheers,
Laszlo

 

[Mark Richards]

Fab, before you go down rabbit holes: correct use of a test tape requires careful handling of the tape and preparation of the recorder; knowledge of which test tape is appropriate for your recorder, and accurate test equipment. You don't just slap it on and hit the play button. Do you know how to prep your recorder to protect the test tape's integrity? Do you have an X/Y o'scope? Do you have an accurate multi-meter? If not, pass on the test tape for now.

Since the HF loss occurred after you had a tape shed problem, you most likely still have magnetic particles embedded in the record head gaps, particularly if there's some head wear.

I suggest soaking a thin cotton cloth in 98% isopropyl alcohol, and holding the cloth against the head while applying a head demagnetizer using the proper method for doing so. The combination of alcohol and the demag's pull on the embeded magnetic particles usually gets the head completely clean. And please don't rub the head with the cloth; just remove when you've completed the demag procedure.

By the way, you should be using 98% or higher alcohol (available at pharmacies). The alcohol available in most stores is 92% - the other 8% is water, and you know what happens when you leave water to evaporate on metal - the metal rusts.

 

[fbaratto]

Thank you Mark for your suggestions. I am currently using a type of IPA purchased from a pharmacy and it's 100% pure. Also, I finally got rid of the Rec head problem by using a cotton swab soaked in pure Acetone (not a diluted solution) and my X-10 frequency response on the treble is now back!