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Fix the tape-distortion?

category: music [glöplog]
 
Can someone please fix or help me with the cassette-tape distortion of this demo-scene tune that I like a lot?
"Firefox - Animotion-remix" (it's a remix of the MOD-music from the Amiga-demo 'Animotion' by Tip&Mantronix),
https://www27.zippyshare.com/v/IS3qtQyn/file.html
Jimmy "Firefox" Fredriksson recorded it for me in the 1990s from his Ensoniq VFX-synthesizer, but the cassette-tape got damaged over the years.
The beginning of the tune is the most damaged part, since one of the two channels is silenced the first ~5 seconds.

Thanks
added on the 2018-07-31 15:10:53 by Waffemann Waffemann
Already asked Jimmy if he still has a better recording and/or a midi file ?
added on the 2018-07-31 16:03:35 by Virgill Virgill
@Virgill. Yeah, I thought about that, but I've not been in touch with him for a long time :) But still, you're right, it's the best thing to do if I want the tune to be as good as possible. Thanks.
added on the 2018-07-31 16:11:45 by Waffemann Waffemann
I had a listen, but unfortunately there's no real way to fix that without basically re-creating the whole song. There's no magic "anti-tape" filter you can apply that would fill in the missing data. I suppose someone could go through and rigorously time-correct it in thousands of tiny steps, carefully adjusting pitch and stereo balance at the same time, but that would take hundreds of hours of work & probably still sound wrong.

Best to see if Firefox still has the original.
added on the 2018-07-31 21:22:44 by jmph jmph
@jmph. Thanks. I'd also hoped that someone else here that knew Firefox would have it too, but I guess not.
added on the 2018-07-31 21:31:43 by Waffemann Waffemann
In case everything else fails, it *might* be possible to semi-automatically correct at least the pitch of your recording.

The reason is that proper tape decks add a high frequency (30 kHz or higher) sine wave (AC bias) to the signal to be recorded to improve signal fidelity, and that AC bias signal often remains on the tape. You'll of course need a sound card that supports recording at high frequencies without applying a low cutoff.

Similarly, radio recordings often contain remnants of the 19 kHz stereo pilot.

These signals, even though typically very weak, allow the original pitch to be recovered. I've already done so with a tape recording of a concert, the result was marginally better (ABX-testable but you really needed to listen carefully to spot a difference in that case).

If there's a suitable remant you'll clearly see it in a spectrogram (FFT size large enough, 512 should do the trick), just check that it does disappear when playing a different / blank tape to ensure it's not an artefact.
added on the 2018-08-02 12:06:58 by Kabuto Kabuto
The phase errors can be corrected, hissing removed and bands balanced. But anything else is a lot of work case by case.
added on the 2018-08-02 17:28:05 by Salinga Salinga
@Kabuto. Thanks, but I don't think that I have a sound card that supports recording at high frequencies without applying a low cutoff, I just have a simple laptop right now, and I don't think that I have that ~25 years old cassette tape left, I don't even have a cassette tape-recorder.
@Salinga. Thanks, I need it to be little amount of work, since I got eight other tunes that Firefox recorded for me (like his "Chinese dreams"-remix that he also made on his Ensoniq VFX-synth, not his MOD-version), but they don't have as bad distortions as this one.
added on the 2018-08-02 18:52:11 by Waffemann Waffemann
And this is yet another awesome tune by from Firefox that got some small tape-distortions,
https://www23.zippyshare.com/v/l2f1IQBa/file.html

Nice if someone could to fix the distortion a bit, I need to buy better headphones before I can fix it slightly myself.
added on the 2018-08-04 21:06:27 by Waffemann Waffemann
And this is yet another awesome tune by Jimmy 'Firefox' Fredriksson that got some small tape-distortions that someone might fix for me :)
"Full Contact Remix" (From the menu-music in the Amiga-game),
https://www30.zippyshare.com/v/O0bEZSW8/file.html

BTW, R.I.P. C64-composer B.Daglish!
added on the 2018-10-04 19:28:50 by Waffemann Waffemann
^Sorry the tune-name should be "Chinese dream Remix".
I didn't even add "Remix" to the FLAC-filename or its container-ID =(
added on the 2018-10-04 20:24:36 by Waffemann Waffemann
And does anyone have a FULL version of Firefox's "Enigma"-demo tune "Hyperbased" ("Hyperbased"-remix, not the MOD-version) that he made the year 2002?
I don't know if he ever made a full version though.
I only got the short version,
"Firefox - Hyperbased.mp3"
https://www2.zippyshare.com/v/hRyj70Ng/file.html

A late Christmas present :)
added on the 2019-01-30 12:52:33 by Waffemann Waffemann
Correction: "Hyperbased"-remix that Firefox made the year 2003.
added on the 2019-01-30 14:19:53 by Waffemann Waffemann

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