Head re-lapping or replace?

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MagnumPI

MagnumPI

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I just got my Tascam 388 back from recalibration/refurbishment and noticed that track #1 was not recording to tape.
I never had any indication of a problem with it before it was taken in for unrelated work.
The tech said I need to either re-lapping or a head replacement.
Why would the head suddenly go bad after calibration etc?
Is it because they were running through it a lot for tests and it was about to go anyway?
Again track #1 was working perfectly before I brought it to them.

Re-lapping costs $200 and a new head would cost $300.
any thoughts?
 
If he gave you a specific reason why it might need relapped/replaced then fair enough, but without that I'd be skeptical.

Make sure the heads and tape path are clean then play some tape.
Have a look at the tape path across the heads and make sure everything's lined up as it should be.

I spent a few hours yesterday rectifying an intermitted channel 1 on a fostex R8.
It was completely down to the supply tension arm just ever so slightly guiding the tape off path.

My best guess is maybe the guy has adjusted or 'calibrated' something that's had a knock on effect.

Of course check all your cables and i/o first to rule out any problem before the machine.
These things can happen when gear gets unplugged and moved around.
 
Thanks Steenamaroo. Do you think I would have noticed a little diminishing of the signal before it went in to the shop, or could track #1/the head just go out all at once like he is suggesting?
 
MagnumPI said:
Do you think I would have noticed a little diminishing of the signal before it went in to the shop, or could track #1/the head just go out all at once like he is suggesting?
Click to expand...

It won't go out all at once if its from head wear. You would experience diminished performance that would be obvious. Are you able to playback old tapes that already have recording on track one?
 
Weird!

This is not first time I have heard of Tascam Service inducing problems in the course of servicing something unrelated. It happened to me once, years ago. I don't know why this would be happening, but it gives me pause to think.

For me, it was a 564 I took in for mechanism repair/replacement, and in the course of replacing the mechanism, somehow they knackered one of the REC FUNCT switches,... it became intermittent. A totally unrelated part of the machine. At the time, I wrote it off and made note to go in there myself to attempt to fix. Years ago and still TBA. Not good.

For you, I sympathize, but it simply doesn't make sense. It may be in your best interest to carefully troubleshoot the issue yourself at this point. I'll agree that the head won't go "poof" all at once from a worn head in possible need of relapping.

I'm wondering if the headphone problem was fixed, and what else they found that indicated needing servicing at the time? Obviously something's amiss that they won't fess up to. How does the post-Cal record/repro response of the other channels look?

I'm starting to think the most experienced analog engineers there may have retired or moved on. I used to have unwavering faith in their ability to service their older units. There was a guy there named Jimmy who was a real wiz. It's been many years since I've taken anything there, for better or worse. I don't have the budget.

:spank::eek:;)
 
Does it PLAY from a known good tape?

If so then it may be a record relay. Try swapping amp cards to see if the problem follows the card.

I'm assuming you have already done a similar test wth cabling connections to rule that out as the culprit.

If it doesn't PLAY *or* RECORD, are you using the same tape after the service as you were prior to service?

The reason I ask is if you were running Ampex/Quantegy before and are using something else now the wear path from the Ampex/Quantegy tape will be slightly more narrow causing the non-Ampex/Quantegy tape to ride up at track 1 or track 8. It takes very little deflection for signal to diminish to non-audible levels. Try reproducing a known good tape with signal on tracks 1 and 8 and *gently* deflect the tape ever so slightly toward the transport face and then away from the transport face and see if you get signal on track 1.

As suggested make sure the head hasn't a speck on it, and you can try fast forwarding or rewinding some of your current tape over the heads with the lifters defeated for a bit an then clean-clean-clean and see if that helps if indeed this is the issue.
 
MagnumPI said:
Thanks Steenamaroo. Do you think I would have noticed a little diminishing of the signal before it went in to the shop, or could track #1/the head just go out all at once like he is suggesting?
Click to expand...

Already answered but I agree with the other guys.
I expect you'd have noticed gradual degradation or intermittent signal.

+1 for troubleshooting this thing on your own first.
I'm not saying these guys set you up or anything, but I don't like the coincidence here...

Gently guiding the tape to make sure it passes channel 1 on the head is a good troubleshooting tip there, assuming everything's clean and there's definitely audio on track 1 of your test tape.
You could do the same whilst recording a test signal. If you do both you'll isolate this to an input, output or alignment issue.
 
The 388 head does not have relief cuts.as the head wears it creates a notch the width of the tape.Once it gets to a certain point the tape can skew in and out of the notch.Level/hi end freq. fluctuations on the edge tracks are a symptom.AFAIK there haven't been new 388 heads available for years.Reel person-most of the "prosumer" recorders including the 564 used "tact",(about .10 ), switches on their faceplate PCB assy.They are notorious for going intermittent and failing with no warning.Usually the PLAY,RECORD,and REWIND,(most used),get flaky first,and the REC function switches are used extensively too.
 
Agreed

The Rec Funct switch I'm referring to is a 3 position slider. I had not used the deck except for testing, and the switch "failed" over the course of servicing the unit for the minidisc mechanism, which is on the base of the unit and not the mixer top panel, where the switch is located. I'd generally had positive experiences with TEAC service in LA, but that one was one that was less than satisfactory.

My case is anecdotal & should be taken as such. An unfortunate turn that doesn't add up to much or go anywhere. I didn't lose any sleep over it, as I recall. Fixing it is still on my list of things "to do".
:spank::eek:;)
 
I could be there is a cracked solder joint on that switch-flow soldered circuit boards are prone to that.
 
I talked to the Tascam repair guy today about all possibilities and he said that he looked with a microscope at the head and did find a crack.
I was using the same tape when playing back and could hear pre-recorded takes that were recorded on track #1. They sounded perfect.
About the initial crackle, it was fixed when I got the machine back. No more crackle but he would not tell me exactly what was fixed.
Because of a timing issue for a job, I gave him the go ahead to do a relapping. At this point Tascam repair has had the machine since Jan 28. and I don't have much time (or patience) left.
The tech checked today and as most expected there are no new heads available. Don't know why he thought there might be. Well nothing to do now but wait, learn the lesson, and hope for the best.
 
wkrbee said:
I could be there is a cracked solder joint on that switch-flow soldered circuit boards are prone to that.
Click to expand...
Yep. That's what I thought & is what it seems like. It's intermittent and touch sensitive. I'd not taken any time to address it, as I got tired of taking things apart for a while & had other issues elsewhere. Just another fixit project. Things like that go in phases for me. The only thing that irritated me at the time is it came back from being serviced that way, when it was solidly working before. I didn't break it through normal use or having touched or used it in any way, but I do know it was working perfectly when I left it off for repair, as I'd been testing the unit just previously. Thanks for the tips.
:spank::eek:;)
 
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It won't go out all at once if its from head wear. You would experience diminished performance that would be obvious. Are you able to playback old tapes that already have recording on track one?
Click to expand...
Im getting the feeling that the guys at Tascam know less about whats going on than you guys do. They are a company called Digitron Electronics who from what I heard only recently became the Tascam factory service guys. He did say he found a crack in the head but why did it happen so suddenly without any prior indication? I dread the though that I might get this head relapped and it not fix the problem because its actually something completely different? Ay Caramba!
Anyone know another repair guy/place in Los Angeles that is a master with a 388?
 
I can't speak from personal experience, but...

there's "Adrian" audio service in Canoga Park, on Sherman Way,... who is well reputed and has been there probably 40 years doing audio service of all sorts. It's a small shop, not corporate.
 
The guys that USED to be the bomb at Tascam for analog gear service are long gone. I know this for fact. Makes me sad.
 
Yea thats what I heard too. Too bad. They must be in their garages somewhere building something amazing.
I'll bookmark "Adrian audio service". Thanks guys.
 
That"found a crack" statement is pure BS unless the head gap has broken,and no amount of relapping will fix that.Yep we are-in the garage.PM me Mag.
 
Yep we are-in the garage.PM me Mag.
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Ha! Will do. Thanks.
p.s. I just did a bit of research on relapping and found this very helpful page http://www.analogrules.com/badheads.html
So I'm really wondering why the Tascam guy is telling me he found a crack and then sending the head across the country to the East Coast to get relapped. It doesn't even make sense to attempt to go for a relapping if there is a visible crack in the head, or am I wrong?
here is a question: if the head is cracked so track #1 is not recording, would I still be able to hear a previous recording that was done on track #1?
I wonder if this guy ripping me off, simply making mistakes, or trying something that could possibly work?
 
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