Audio fading in and out on radio recording from cassette tape - UK Vintage Radio Repair and Restoration Discussion Forum

Nic-15fl · 6th Feb 2017, 3:16 pm

Hey there evreyone!
i have this wondering question, can the signal be decoded in a way so that the audio can be pulled out clean enough to listen on? im pretty sure it is possibel, but i cant do it, so would somebody be willing on trying that? and its audio that are oddly enough cleanest on the b side of the tape, if i attatch the file, would there perhaps be interest in trying?

ricard · 6th Feb 2017, 4:46 pm

If the sound is fading in and out, either there is a problem with the tape transport, or the actual recording has been damaged somehow (for instance by holding a magnet near part of the reel of tape in the cassette. Either way, no subsequent post processing will ever be able to recover the lost signal. If it just the level that fades up and down, a dynamic range compressor might be able to flatten the signal level but that would also have other effects on the sound (i.e. loss of the original dynamics of the recording).

dseymo1 · 9th Feb 2017, 9:36 pm

Yes, as long as there's enough difference between the signal and the noise floor, it should be fairly easy to normalise the level using something like Audacity. A bit of fiddling with time constants might be needed to avoid 'breathing', but any tricky bits could be adjusted manually.

Grubhead · 10th Feb 2017, 4:45 pm

I'm wondering if it is a tape head has slipped out of alinement?
If you have the software called Audio Cleaning Lab by Magix, that will make a massive difference to the quality of the recording. Unlike Audacity it has pre-sets for tape conversion and is much more controllable than Audacity. It has booster options and will get rid of noise and tape hiss better.

Peter.N. · 10th Feb 2017, 4:59 pm

I had this problem with some reel to reel tapes I recorded in '59-60 and thought the tapes were beyond redemption, a friend brought another recorder for me to look at and they played perfectly on that, so yes, it sounds like a tape transport problem, either the alignment is out or the tension incorrect.

Peter

Sideband · 10th Feb 2017, 7:54 pm

so many things can cause this. If the tape is not being pulled evenly across the head, the audio will vary. Worn pinch roller, worn capstan, worn head....all of these things need to checked along with any back-tension that is applied by a soft brake

6th Feb 2017, 3:16 pm	#1
Nic-15fl Hexode Join Date: Jun 2012 Location: Aabenraa, Denmark. Posts: 262	Audio fading in and out on radio recording from cassette tape Hey there evreyone! i have this wondering question, can the signal be decoded in a way so that the audio can be pulled out clean enough to listen on? im pretty sure it is possibel, but i cant do it, so would somebody be willing on trying that? and its audio that are oddly enough cleanest on the b side of the tape, if i attatch the file, would there perhaps be interest in trying?

6th Feb 2017, 4:46 pm	#2
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Audio fading in and out on radio recording from cassette tape If the sound is fading in and out, either there is a problem with the tape transport, or the actual recording has been damaged somehow (for instance by holding a magnet near part of the reel of tape in the cassette. Either way, no subsequent post processing will ever be able to recover the lost signal. If it just the level that fades up and down, a dynamic range compressor might be able to flatten the signal level but that would also have other effects on the sound (i.e. loss of the original dynamics of the recording).

9th Feb 2017, 9:36 pm	#3
dseymo1 Retired Dormant Member Join Date: Dec 2007 Location: Shropshire, UK. Posts: 3,051	Re: Audio fading in and out on radio recording from cassette tape Yes, as long as there's enough difference between the signal and the noise floor, it should be fairly easy to normalise the level using something like Audacity. A bit of fiddling with time constants might be needed to avoid 'breathing', but any tricky bits could be adjusted manually.

10th Feb 2017, 4:45 pm	#4
Grubhead Heptode Join Date: Dec 2016 Location: Sheffield, South Yorkshire, UK. Posts: 539	Re: Audio fading in and out on radio recording from cassette tape I'm wondering if it is a tape head has slipped out of alinement? If you have the software called Audio Cleaning Lab by Magix, that will make a massive difference to the quality of the recording. Unlike Audacity it has pre-sets for tape conversion and is much more controllable than Audacity. It has booster options and will get rid of noise and tape hiss better.

10th Feb 2017, 4:59 pm	#5
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: Audio fading in and out on radio recording from cassette tape I had this problem with some reel to reel tapes I recorded in '59-60 and thought the tapes were beyond redemption, a friend brought another recorder for me to look at and they played perfectly on that, so yes, it sounds like a tape transport problem, either the alignment is out or the tension incorrect. Peter

10th Feb 2017, 7:54 pm	#6
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,571	Re: Audio fading in and out on radio recording from cassette tape so many things can cause this. If the tape is not being pulled evenly across the head, the audio will vary. Worn pinch roller, worn capstan, worn head....all of these things need to checked along with any back-tension that is applied by a soft brake __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....