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source for cassette speed test tape?

Lavane

Lavane

Lunatic Member
I finished cleaning, lubing and changing the belts in my Marantz 5220 cassette deck. Now I need to adjust the tape speed. Its running a bit slow. anyone know where to find a test tape or a file I can record to tape? I've adjusted it pretty close by ear but I would like to adjust it right.
 
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Calibration tapes are not cheap. $50'ish. Screw that unless you need it to repair several decks.

Do you have a deck with known good speed to record your own?
If so - you can find plenty of files on youtube or whatever site that play just the frequency you want. Maybe record 5 minutes worth of 3,000 hz.

After I made my test tape, I play it and have a wire I "engineered" so I can hook an output to a multimeter capable of measuring frequency.

If you do not have a reliable deck for recording your test tape, there is a "hard way" to make one but it can take up to a couple hours cause it's tedious...

First, make sure you know which direction to turn the speed adjusters to slow or speed the motor.

Pick one of your tapes with a song you choose that has a very distinct sound about 5 to 10 seconds into the song (more won't hurt but you need about 3 1/2 minutes worth of song). THEN on your phone or computer, pull the song on youtube.
In my case the song I chose was Megadeth's "Into the lungs of hell". A few seconds into the song the electric guitar blasts in abruptly, which was the "distinct" sound I chose.
So on the youtube video, I got to the point RIGHT at that blast and paused. I then played the song on my tape deck (make sure your receiver input is set to tape). As soon as the electric guitar kicked in, I un-paused the youtube song. Switching between aux and tape inputs, I listened to make sure the gap in note timing didn't change. If the youtube video got too far ahead of the deck, I increased the tape speed. You have to adjust in very small increments. As an added bonus, you will end up hating the song you used by the time you are satisfied.

Though this is the hard way, it can get very close but maybe not precise. Analog equipment is never precise anyways.

EDIT - If you do end up making a calibration tape, now would be the time to open up a brand new QUALITY blank tape like a Maxell, Fuji, TDK... Type 1 or 2 will work but JUST to make sure it is the best it can be, go with a type 2.
 
MetalFisher. Is the speed adjustment only available on high end, post 198x machines? Would I have this kind of internal "trim pot" in 1974 models?

I'm very much a novice to CP rejuvenation, but I have several that will need some attention when I find the time.

Of the decks I have opened up to find a belt issue, I've seen a belt spool that has more than one belt position of a different diameter. The part looks like a nylon gear with two (perhaps three?) grooves of different diameter. Without manuals, I haven't had confidence moving forward with belt ordering.

Can someone please shed some light?
 
bhundu said:
MetalFisher. Is the speed adjustment only available on high end, post 198x machines? Would I have this kind of internal "trim pot" in 1974 models?
Click to expand...

Pretty likely, but unless it is indicated on the circuit board somehow, it is hard to know what you are adjusting. Plus, you may not even have to mess with the speed. Unless something else is going on, it should be the same as it always was.
All the decks I have messed with are from the 1980's. Only one of them was "high end". Pioneer decks typically mark the speed pot with 1X or 2X (at least from what i have seen.)
A short version of something is - do NOT just guess which pots are for speed.

bhundu said:
I'm very much a novice to CP rejuvenation, but I have several that will need some attention when I find the time.

Of the decks I have opened up to find a belt issue, I've seen a belt spool that has more than one belt position of a different diameter. The part looks like a nylon gear with two (perhaps three?) grooves of different diameter. Without manuals, I haven't had confidence moving forward with belt ordering.

Can someone please shed some light?
Click to expand...

With being a true novice, just maybe pick up a deck or two cheap from a thrift store to mess around with to get an idea. If you ruin it, no loss.

Now assuming the belts are completely missing on those decks with several diameter grooves -
Just use a tight rubber band as a temporary belt, switching between grooves, and see which one comes closest to playing the tape at what sounds like a reasonable playback speed. Then measure it and order the belt. turntableneedles.com has them and may even have one listed for your deck without having to measure or guess.

Another option is to order all size belts and try each one but that is kind of a waste of money.
 
Thanks guys! I've tried the comparison trick already and that's how I got it close. Then I compared it against my 5020. I do have a signal generator and a scope. I just need a tape to record a 3000hz tone on. :thmbsp:
 
My method for checking whether both decks in a dual cassette machine play the same speed is to get out my Johnny Rivers cassette, time "Secret Agent Man" playing in deck A with my stop watch, and then time it again playing it on deck B. If I get the same time, I don't worry about dubbing changing the speed on the copy tape. I had a Denon deck on which the difference between the two halves, over that one song, was several seconds--very BAD.
 
I have a recording of the Atomic clock on short wave radio on cassette and R to R to test speed
 
It is kind of funny how we are SO particular about our decks.
Whenever i buy one, I automatically assume it needs calibration testing.
Gotta make it yours.
 
I think I read this idea on this forum but I can't find it to link, so credit goes to that person. I adjusted my Marantz SD30 speed by playing a cd of an album I had also on cassette and moving back and forth from SOURCE to TAPE to adjust the speed to what I hear is spot on., good luck.
 
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