Tascam 38 playback troubles

[Deaaaath]

Hi,
Last night I recorded onto tracks 1, 2, 3 and 4 of my Tascam 38. All went smoothly. Everything played back and sounded great. Today I went to record on the remaining tracks and track 3 would not play back. When I turn the playback volume for track 3 to 10 I can just faintly hear what I had recorded there. Does anyone know how this problem can be fixed?
Thanks a lot!!!

Oh, by the way, I am using a Teac Model 3 mixer, which is essentially the same thing as the Tascam M-30 mixer.

[analogkid]

First off, clean the heads and demagnetize them again. What kind of tape were you using? It sounds just like the trouble I had with an old roll of Ampex 456, the dreaded sticky shed.



AK

[Deaaaath]

I'm using a brand new reel of RMGI SM911 1/2" tape.

[cjacek]

I'm with AK here in that you may have a troublesome tape. Unfortunately a small # of early batches of RMGI tape had problems. Prior to doing anything else, clean the heads one more time [use those cotton make up remover pads + 90% or higher alcohol] and play the tape back. Are you getting signal now? Check for any oxide deposits. Call one of the sales managers, explain the situation [you may have to answer a few questions] and they'll replace the tape free of charge: http://www.rmgi-usa.com/sales_manager.html

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[Deaaaath]

Hey,
Just for reference, how much, if any, oxide buildup should I see after about three hours of use with a lot of overdubbing?

[Deaaaath]

OK, so I cleaned my heads. They had a visible, though, in my non-professional opinion, not unreasonable amount of oxide buildup. Anyways, the track started working during playback again. Is my tape screwed or was this a natural order of events?
I put probably about 2 1/2 to 3 hours of recording over the past day or so. I also tend to fuck up a lot and get into this sort of overdubbing trance where I record, deem in unworthy, rewind, record, deem unworthy, record, etc.
Also, if my tape is shedding oxide at an unnatural pace, can I still try to salvage my session so far by overcautious maintence? It kills to ditch a somethin halfway through!

[cjacek]

OK, this confirms that in fact you're either not cleaning often enough or there is an abnormal shed from this tape, which is affecting the performance of the heads.

It's hard to put it into hours but if you see significant oxide on the heads / rubber pinch roller, after one pass or about 30 min of actual recording, then look into tape replacement. The good rule of thumb is to clean before and after each session and even in the middle of a session, especially if it's a long one.

Actually, do you recall how long it takes for audio to degrade, after you clean the heads and start recording?

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[analogkid]

IF I recall correctly TASCAM recommended cleaning the heads and tape path every 8 hours of operation. This was on new decks, I would imagine that any wear on the lifters or tape guides could accelerate the sticky shed issue. To have to clean every 4 hours of operation is probably not the end of the world.
As cjacek said, clean before and after each and every session, and if you take a break every couple hours you can do a quick clean before you start recording again.


AK

[Deaaaath]

I'm not so sure this is a problem with the tape.
When I take the tape off the heads I still can't get any sound to come off of Track 3 (when nothing is being played the tracks make a soft buzzing noise... track 3 doesnt)
During playback the track is reading at a healthy level on the meters, but still no sound. Occasionally the track will work, I'll move on, only to rewind and find the track has disappeard again.
Does this mean it's an Output problem?

[analogkid]

It might be - but couple of things more to try:
Have you tried playing the tape back in Sync as Well as Repro?

Have you thoroughly demagnetized the tape path and the heads?

It's my personal theory (and someone correct me or feel free to offer up another opinion/explanation) that when you get sticky on the heads, you are getting oxide as well, which, since you are recording/have recorded, is magnetized. So when this stuff sticks, you in effect have a magnet sitting on your heads! Granted, a VERY weak magnet, but I think it can leave the head partially magnetized even after a good cleaning. Before you panic, I would go back and clean those heads again - Q-tips and alcohol are cheap after all - and then demagnetize the heads.

If you have already done this and still have trouble, it could be a bad card on that channel. I believe the 38 has a record/repro card for each channel, so you could try removing and reseating the card, or even swapping it with another card from a working channel. I suspect calibration will be off if you swap cards, but it will tell you if the card is the trouble.

It has been nearly 20 years since I've worked with a 38, and longer since I've had one open so I am sure there are others here who can offer further suggestions.


AK

[Deaaaath]

Thanks so much! I'll look into that.
Just a dumb beginner's aside- when I'm mixing down my songs, do I want to use Sync or Repro? Or does it not matter?

[cjacek]

The sync and repro heads have the same frequency response on the 38 so it really doesn't matter which one you use for mix-downs. I tend to record, overdub and mix-down using the sync head.

You may want a tech to look over your machine as you may have other problems like cold solder joints, which may be causing intermittent channels.

I also would use those cotton makeup remover pads instead of q-tips. They're much more effective, especially for larger head machines, like your 38. In fact I'd use those on any machine 1/4" and up. Q-tips are great on cassette decks tho.

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[Deaaaath]

Well, I cleaned and demagged the heads, still no Track 3.
Over the course of the past few days it has appeared and disappeared about three times now.
Is looking at the record/repro cards something I can handle on my own... or should I just bite the bullet and bring it in to a tech?

[cjacek]

Try to remove and reinsert the channel 3 card and see what happens. If nothing comes of it then you may have solder points which may need to be retouched and unless you're familiar with this procedure then it'd be best to take it to a tech, rather than chasing 'gremlins', cause it may be a bunch of things.

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