38: wobbly sounding and no FF @ mid-reel point

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morte sicura

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Hi everyone...

This is also posted over at the tascam.com forum, in case it seems familiar ....
and please bear with me :-) as I try and get my goods together recording-wise.


As some of you know, I got my 38 a week or so ago and the manual came on Monday - one of the reel tables (right-hand side) was below operating level and I've fixed that. However, a new and perplexing problem has arisen, and though the manual is pretty thorough in describing adjustments, there isn't a "troubleshooting" section to help diagnose problems and point to the proper solution / adjustment.

I tracked a song or two off CD onto a couple tracks and I also set up some drum mics and began experimenting with drum sounds. Also tracked a bit of electric piano at the front of the reel. Everything sounds fine so far.

But - at about 2500 on my counter (with the counter zeroed where I started near the front of my reel), FF has seriously slowed down! It isn't running much faster than Play, and will eventually crawl to a stop, maybe around 3000 or so. Rewind works fine.

Also, although the material I recorded at the front of the reel sounded fine, by this point on the reel, there is noticable "wow" on the tracks. Playback speed is inconsistent and "warbly" sounding. I didn't really notice it with the drum tests, but when I tracked some electric piano in this mid-reel area, the pitch was moving around, almost as if someone was lightly twisting the pitch control. It sounded like an old cassette player when the batteries start to go bad.

Okay, so I have looked through the manual, but as I said, there's no real troubleshooting section. Does anybody have any idea what to look for or where to start in solving this problem? Seems like something isn't right with the right-hand side of the deck.....

Thanks,
Andrew
 
There are different tensions applied on the reels during FF and REW, and adjusting these could help with that problem. But both that problem and the wobblyness could come from oil gooing up and getting sticky. In that case cleaning will help (and using it may actually help too).

What I did with my A-8 after getting it and getting the service manual is that I went through it from first page to last and checked every single adjustment (except the ones that require oscilloscopes, because I didn't have one, and they were too expensive). I didn't have to change any of the mechanical adjustments, just the electricals (like bias and such), but since your machine was sligthly out of whack you may need to look over all the mechanical adjustments.

It will probably take you a couple of days, and you need to buy tension meters, and probably some more stuff, but it might very well be worth it.
 
Good thing you have the manual. Even thought the trouble shooting leaves something to be desired, it's better than nothing.

Other possibilities include a brake that's dragging, but not noticable until the reel has some tape on it. The brake selenoid may not be adjusted correctly

Is your right reel table square with the shaft? If not, it could be dragging on the brake once every revolution.

Could be worn belt. Or like Regebro said, it just could be full of gunk.

Take it apart again and dig in. If you can't find the problem, it's time for a tech.
 
What is the age/condition ot the tape you're using? I've seen the symptoms you describe, when I've tried to use tape that is very old, and hasn't been kept in ideal conditions. The binder used to glue the oxide to the tape-backing has absorbed moisture and has become soft. This can result in the oxide "shedding" on to the tape-guides and heads. The symptoms are as you describe; the tape-speed becomes erratic; in the worst cases the fast-forward/rewind starts malfunctioning as you describe - this might be caused by the tape-heads and tape-guides becoming gummed-up with a gooey mixture of oxide and binder. Another very noticeable symptom is that the all the highs on the tape will suddenly disappear. There is a (fairly) simple solution to this problem. Clean the tape recorder; bake the tape (see other threads in the analogue forum on this BBS - use the "search function"). Hope this helps!

Good Luck!

- Wil
 
tape is new

Just to let you all know, the tape is factory-fresh Quantegy 456 from the Tape Warehouse in Atlanta. I'll be cracking the deck open again this evening and fussing with it over the weekend. I guess I also need to look for spring scales and whatever other mechanical tools I'll need (I'll check the manual). I'll let everyone know what I find and whether I can figure it out.

ar
 
going in...

Just an update - the machine's going in to my local tech, who has a really good rep and works reasonably - "fair" in pricing. He keeps David Barbe's stuff running at Chase Park Transduction and I believe he also keeps John Keane's deck. I've spoken with him and talked rates, warranty, and evaluation et al. I spent some time trying to track down tools locally with no luck. By the time I got everything here I could have paid for the repair, and who's to say I could even do the work w/o someone to consult with? I plan to ask many questions. If I can pull and service a Porsche 911 engine and transmission, I can do this eventually. Just takes some comfort and assistance the first time around.

ar
 
Hope he doesn't charge more if you watch.:D

Good luck, let us know how it turns out.
 
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