tape deck speed problems

For the Yamaha, look on the back of the drive motor itself, speed adjustment pot may be there.

For the Technics...lots of thing can slip or bind causing these symptoms, try a different cassette if you haven't already

Thanks Michael - I'll look into the Yamaha. As for the Technics, I've had this problem with a few tapes, so I assume that it's not the tape itself.

semitone

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By now many tape decks are experiancing motor wear out . Try the speed adjustement first .

tempus fugit ha escrito:

the yamaha sounds like a case of adjustment. How old is the technics? that sounds like the motor, or more precisely the small controller chip inside it. I had to replace the motor on a technics (forget the model) which had about 7 years heavy use on it in a radio station (that was running too fast and varying). Recently saw an early 80s sanyo where the motor would either slow down to about half speed (again, varying) all of a sudden , or simply stop. In both cases the motor was at fault but you never know - I suggest you clean, check braking and gearing and replace belts first. good luck

-B

-B.

Great, thanks for all the suggestions guys.

Michael, the speed adjustment inside the motor did the trick - quick and easy repair (for a change). JR - plastic screwdriver? oops I already uses a jewellers screwdriver that was metal. Could that cause some problems?

The technics is a good 25 years old, but hasn't seen a lot of use in the past 10 or 15. I'll look into these things that have been suggested here. I wonder if maybe the belts are getting a bit worn and stretched too. I should also say (to add to the other anwers given here), that I once repaired a different Yamaha deck with similar problems as the Technics by replacing a few high ESR caps. Took a while to get to that conclusion, but as far as I know it did the trick.

Thanks again

semitone

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This is how I calibrate a deck once the speed regulator is found

Requirements: a 1KHz test tape or a recording of an accurate

1KHz tone made on a known good tape unit and played back on that machine to check, and an audio signal generator with a fully floating output ie no dc reference if not then de-couple the output with a couple of capacitors. Parallel together one channel of the phones output of the tape and the output of the sig.gen. and a set of headphones in mono (L and R connected). With approximately equal sound levels you should get unmistakeable beat note .Reduce the beat to a minimum by changing the speed regulation of the cassette unit motor.

The other tape deck - can be due to anything that moves

-- Diverse Devices, Southampton, England other electronic hints and repair briefs , schematics/manuals list on

That's very novel - I've never heard it done like that. I've got a strobe tape that I bought from CPC I think it was, years ago. It has a little window in it, and a stobe disc with two rings, one for normal speed and one for high speed dub. Very effective. I also have " Clint Eastwood " by The Gorillaz recorded on my workshop test tape. This has a very ' natural ' beat speed, and I find that I can set tape speed perfectly by ear, just using this piece of music. I always check afterwards with the strobe tape, but it's uncanny just how accurate the body's sense of timing is.

Another way I've seen of doing it with a 1kHz test tape, is to just put a frequency counter on the end of the deck. Too fast, freq too high. Vice versa for too slow.

Arfa

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You don't even have to have both headphone sound sources anywhere near equal level and the beats are still extremely noticable. Putting one source to one ear and the other to the other ear to produce beats in your head is not so straightforward.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

That's a good idea for setting tape speed. Since I'm a musician, I just get my guitar in tune to A440, pop in a known good tape, and play along with the tape, setting the speed to make sure the pitch is correct.

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Thought experiment. Is it possible with my technique to make a test tape using frequency counter cross-checked sig gen and one good tape deck. If the deck is actually out a bit it will still play back on itself correctly methinks. Do I require 2 good decks and make a tape on each and try in the other , then unless both are out by the same amount and both up or down by that amout then they should all be close to zero beats in all 4 permutations ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

"n cook" wrote in news:e7brdd$jnj$ snipped-for-privacy@inews.gazeta.pl:

You're right, if you record on a slow deck, and it plays back at the same slow speed, the tone it plays back will be the correct fequency but you won't have a valid test tape. Your analysis of two tape decks is correct.

Yes, I think that the way to do it would be as you say, with the 4 permutation cross-check. However, these tapes are readily available still, I think, already recorded on a known correct speed deck. I have a full set of test tones, torque measure, tape path mirror, 0dB record level etc

Arfa

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It begs the question , how do the manufacturers check the goodness of their test tapes? I seem to remember a picture in a manual or publication showing via some magnetic ink or similar, contrasting bands along a piece of magnetic tape carying a constant tone , perhaps they can use that process to physically count and measure the visualised bands on a sample of their tapes.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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I remember the standard rate of tape travel over the heads is 2 inches/second or something. Maybe they check a 'master' deck, mechanically, then use it to make master tapes.

I actually went looking on the net for the Konig tapes that I have to see if they were still available, and the only reference I could find was in New Zealand, so I reckon that I'd better start taking more care of mine ... !!

Arfa

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I tried that one time making a length of tape in a cassette, length of tape from head read position at start to end an exact length for 1 7/8 inches/sec , so counting seconds but results did not agree with my commercially produced 3.2KHz test tape (stretched?) and didn't explore any more.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on