I like this discussion from 2007 about how to manipulate a tape recorder. Look at the difference in attitude. On one side, there’s the sound engineer who has very fixed ideas on how things should be done. And on the other, there’s someone who wants to experiment to see what’s possible.
I would like to be able to disconnect the eraser-head of my (now) old Sony WM-D6C cassette recorder. Anybody knows the process ? Thanks.
What exactly are you trying to do?.
…i would like to use this cassette recorder in a different way than usual : to re-record and re-record (…) without erasing the previous recording(s). It seems that the only way to do that is to disconnect the eraser-head ?
There are many problems with this – to record you need bias on the record head (to prevent huge distortion), this commonly comes from the erase oscillator – and the erase head is usually an integral part of the oscillator.
The bias on the record head will also tend to erase the existing audio on the tape anyway.
I’m presuming you’re wanting to multi-track?, this isn’t the way to do it!.
of course I know this isn’t the proper way to do multi-track – my idea is to do something really different, as mentioned in “Cities of the Red Night” By WsB, for example. link
He gets more advice. This time, from an electrical engineer,
If you try to record new audio over existing audio, the bias on the record head will partially erase the previous track. You will lose the high frequencies. If you still want to try this experiment, I suggest that you move the erase head out of the tape path. Do not disconnect the erase head as it is required to provide the proper load for the bias ocsillator.
He eventually gets the advice he needs, from someone who does not specify his qualifications in his profile,
put a piece of blue masking tape over the erase head gap
This goes to illustrate the enormous worth of questioning the assumptions you make based upon what you have learned. Or, as one of Brian Eno’s Oblique Strategy cards has it,
This track was recorded in much the same way as described above. It’s from 1988 and I think it is made up of four or five tracks recorded on top of each other.
Photo of the insides of a tape recorder taken from here.