need help on troubleshooting a tascam 48

[funkytonk]

Hey folks,

I have a tascam 48ob 8 track machine. I am recording just fine to tracks 1 & 2. When I try and record to any of the other tracks (3 thru 8) I can get the needle to show good levels (+3 red) prior to recording and during recording, but when I go to playback the needle is showing a way lower level than what it was recording at. Like way in the black (-). Listening to playback the signal is low and breaking up or scratchy.

This happens with both rca and xlr inputs.

I think I can eliminate shedding since I have cleaned the heads thouroughly and the tape I use does not shed.

Does this sound like a bad head?

I have only owned this machine about a month, so I don't have any history on it.

 

[The Ghost of FM]

Do the guide posts and tape lifter arms show even wear from top to bottom? I ask this because uneven wear on these parts could mean mechanical misalignment.

There is also the possibility that the previous owner made a failed attempt at calibrating the machine.

Do you have a qualified service shop in your area that can give you an estimate? Perhaps seeking one out is your next logical step.

Cheers!

 

[funkytonk]

The guide posts and lifter arms look great. There's no repair shop here in town. I could drive 3 hours to get to a shop though. I would like to try and narrow down the cause of this before I make that trip.

Somebody has definitely messed around with the bottom cover because it was incorrectly installed. So there is a good chance that the previous owner messed something up.

Does the scratchy/fuzzy sound on tracks point to anything?

 

[The Ghost of FM]

Does the scratchy/fuzzy sound on tracks point to anything?

It could point to a number of things such as intermittent internal connections on circuit boards with oxidized contacts. You might get really lucky by re-seating the channel amp cards from their connection sockets but I can't see that alone fixing the level drop problems.

Obviously this machine subjected to some kind of abnormal trauma...it might have gotten wet or dropped or badly overloaded or god knows what else?!

This is the joy of buying stuff second hand without testing it in person before you hand over the dough.

Put some gas in the car, man. Or do what everyone else does these days; re-sell it to some other poor sap on ebay.

Cheers!

 

[funkytonk]

Thanks for the help man. I definitely want to try and fix it, rather than getting rid of it. I bought it pretty cheap.

Cosmetically the machine looks great.

It doesn't have any signs of being dropped. There is no rust or any signs of it having been wet. No bad spots on the circuit boards. No obvious signs of trauma that I can see.

I do see a road trip in my future.

 

[funkytonk]

Hey folks, just wanted to update everyone on this machine.

I decided to purchase everything needed to do a full calibration and alignment on it, hoping that would solve most of the problems with it. I just completed the process last night and have done some test recordings on it with guitar, bass, drums, and vocals. It sounds awesome, and virtually every problem I noticed before is gone.

I have another 48 that was working fine and this unit sounds better than that now.

I bought the machine for $100 locally, and paid another $200 for all of the following:

Fostex TT-15 - tone generator w/ db pads. The pads are very handy

48 Manual direct from Tascam

Radio Shack 42 Range Multimeter - following Beck's suggestion on a different post I went out and bought this. My other meter only had one decimal point, but this has 3 which is a must have. After going back and re-checking with the Radio Shack meter I discovered my other meter was way way off. Had to start all over on the whole process.[/B][/B]

Teac Test Tape

New reel clampers direct from Tascam - $26 for the pair, why are people buying these for $35 on ebay?

+ I adjusted the reel table height and bent the tension arm rollers back to 'dead straight'

Oh yeah and I would have been lost without this calculator link
http://www.sengpielaudio.com/calculator-db-volt.htm

Anyways the resources on this board were the biggest help. I spent alot of time digging up old posts on here. Thanks to all who go out of their way to help newbies like myself learn the calibration process. Especially Beck, some of the info he has posted on here over the past years is great. He should write a book or something.

 

[cjacek]

Hey funkytonk, great post! Thanks for updating us and leaving some uplifting (and informative) information, especially for those who have yet to align their recorder.

If you think the reel clampers are overpriced (on eBay), did you see several of the poor bastards bidding up, 2, 3 or 4 times more for a 38 / 48 pinch roller? The one from TASCAM is like $32 and the winner, in that auction (actually in more than one), ended up paying like $120, with a couple others (who didn't win), close to that amount! Now that's insane? Are these people of this earth??

Hey, so you did bend the tension arms back to 'dead straight'? Great! Was it easy to straighten these out? How did you find the tape travel now? On mine, it's much better.

Yeah, I agree, the resources on this board are absolutely awesome and that Tim Beck, especially, should indeed write a book or at least charge for his invaluable advice over the years.

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[funkytonk]

A couple of other notes I thought I should make.

I followed the Tascam manual as closely as possible and made sure I did things in the order they were listed in the manual.

I also took my time and made sure I understood the whole process and the theory behind it. I wanted to know why I was making the adjustments I was and not just following directions out of a manual or off a message board. This helped me problem solve and answer some questions myself.

The tension arms were easy to straighten out. Hopefully it is something I have to do just this one time. If it turns out to be a reoccuring problem than I will probably take the repair to the next level and it won't be such a quick fix. The tape travel is definitely better though so it looks like we may have lucked out this time.

Ebay can be ridiculous. The worst part about it is there's no guarantee that the parts on ebay (pinch roller, reel clampers etc..) are even 'new'. They could be in worse shape than then ones you are trying to replace. Did you see the latest Tascam 48 on ebay? The guy wants $1300 buy it now and he has no photos whatsoever, barely even a description, no buyers protection, and sub par feedback, and only takes a money order. Hurry up and buy it though, he's only gonna be a registered user for another week!!!;

 

[cjacek]

Good follow-up post. [Thumbs up!].

Your post reminds that, IMHO, it's essential, in today's analogue, to do one's own servicing / maintenance, as long as it's within the limits of one's own skills and, of course, willing to learn and put in the time. Again, good post.

funkytonk, you should post more often.

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