Problem with a tape...

X-Electric

I discovered something funny this night, while I was looking for some old recordings from 1990. (Well, to be honest, I discovered this few years ago, but I never wanted to sample any material this badly to be asking anyone for help Wink

) One of the tapes I used to record radio auditions that time, started to act funny - when I push the play button, it starts to play at a decent volume, everything is ok, but during next 2 seconds it gradually goes to ~10% of the original volume. When I start it again it does the same - in a place where it played so silently just a second ago it performs just like a new tape, but after a second it does this low volume thing again. Anyone had a similar experiences with old tapes ? What could be the solution to this problem ? (and the source of course, since I'm studying 4-th year of Electronics it should interest me). If this thread was not supposed to be here - please move it - I wasn't sure where to put it.

elektro80 · Posted: Thu Apr 13, 2006 6:07 pm Post subject:

Did you ever try other tapes? Which type of tape? Philips C cassette stuff or reel-to-reel? The make and model of the playback unit?

YOu could be looking ta tapes that hsould be baked in an oven, but still.. such tapes shouldn´t quite behave like that anyway.

X-Electric · Posted: Thu Apr 13, 2006 6:44 pm Post subject:

Well, it's an old polish tape, "Bruce Springsteen - Tunnel of Love" - during 80's and 90's my father bought plenty of those, and other theoretically "original" tapes, because they were cheaper than new - empty tapes here in Poland at those times. All I can see on the package is "MX PRO B NR STEREO CK 817" - no other technical data printed Wink

Sorry for 3 times editing - but first I thought it was CK 817, than 847, and finally I can see it is 817 - those tapes are really old Wink

elektro80 · Posted: Thu Apr 13, 2006 6:50 pm Post subject:

Tat would be a cassette then? Does it play plan music tapes OK? Does it only make a mess of your own recordings?

I have no idea yet what this is about. Did you test these tapes on another deck ?

DrJustice · Posted: Thu Apr 13, 2006 7:11 pm Post subject:

X-Electric, from what you say, it sounds like it could be the player. But you have probably tried it with other tapes...(?)

DJ
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X-Electric · Posted: Thu Apr 13, 2006 7:16 pm Post subject:

Yup, it works with other "fresh" tapes perfectly, just some of the late 80's - early 90's don't wan't to cooperate. (And I don't think it was the recorder back then - because I was listening to them for some time then regularly- it just happened instantly, after laying in the closet for couple of years).

DrJustice · Posted: Thu Apr 13, 2006 7:23 pm Post subject:

OK - a strange phenomenon. Could it be something mechanical with certain cassettes then, like the tape getting an increased distance or other misalignment relative to the playback head as soon as it gets tension? Just speculating wildly now Smile

DJ
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elektro80 · Posted: Thu Apr 13, 2006 7:25 pm Post subject:

Isn´t there a "spring" and a pad .. are those there still?

elektro80 · Posted: Thu Apr 13, 2006 7:26 pm Post subject:

X-Electric · Posted: Thu Apr 13, 2006 7:37 pm Post subject:

http://xelectric2.republika.pl/1990_tape.mp3

This is a direct recording from few seconds ago - as some say - a mp3 is a 316.72 words Wink

Those 2 pauses are my pressing the "Stop" button commands, and there is no LP filter used - this is what this tape is doing and this topic is all about...

Elektro: Everething is 100% ok in my player - it's a kind of new AIWA lo-fi stereo system.

DrJustice · Posted: Thu Apr 13, 2006 7:54 pm Post subject:

If I'm not mistaken, elektro80 is referring to the spring and pad inside the cassettes. Since their function is to make sure the tape has contact with the playback head, any problems there could be a part a "Tape misaligned when under tension" theory...

The suspense... You have to find out and tell us what it is now Laughing

DJ
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X-Electric · Posted: Thu Apr 13, 2006 7:55 pm Post subject:

I think (I THINK) it could be something with the pressure of the head... In most tape players it was common to squezee the tape in the beginning of the playing sequence and then release it while playing, and I guess this is what my player is doing with some old - poor-readible signal right now.

X-Electric · Posted: Thu Apr 13, 2006 8:07 pm Post subject:

And the prize goes to... both of You - Elektro80 for giving the idea of making the tape being the subject of poor sound, and DrJustice for reminding me to look first into the tapes "hardware" :> That's right guys - It was this little spring in the cassette and my knwoledge that head goes lower (higher - depends on the player) a little bit more at the beginning of the playing process.

After some pretty simple repairing process it sounds decently.
Thanks, and see You till next problem Wink

jksuperstar · Posted: Thu Apr 13, 2006 9:59 pm Post subject:

Sometimes tapes that have been sitting for a few years will stretch or tighten by themselves, just due to humidity and tempurature. Fast forwarding & rewinding (maybe a few times) will re-seat those tapes properly & allow the tape player to get the head-tape interface right.

In the old days of computer backup & tapes, there were kids hired to come in at night, and do this exact thing to tapes in a library...they were called tape jockeys.