How do you wire up these tape heads?

August 14, 2008 4:04 PM

Audio experimentation: How do I wire up these tape heads?

I've been reading this wonderful book and carrying out some of the recommended hacks.

So I've ripped the tape heads out of an old dictaphone and an answering machine and I've got ideas about moving them around in different ways over magnetic tape (and other magnetized objects) to make weird sounds.

Trouble is, I can't work out how to wire them into an amp. The heads I've ended up with both have 4 wires coming out the back, but they're mono heads. Judging by the fact that one pair of wires is shielded, while the other is a black and a red wire, I was assuming that the head was supposed to take some power, and then produce the audio signal on the shielded pair. But a great deal of fiddling with different arrangements has produced no results.

So how should I be doing this? Also, another possibility, might my amp have insufficient gain to actually hear anything? This is the one I'm using.

Thanks a bundle!

posted by godawful to sports, hobbies, & recreation (2 comments total)

I expect you'll find that the shielded pair is the signal pair, and the plain black and red wires drive the erase coil. Tape heads don't need a power supply to generate a signal - the interaction between the fluctuating magnetic field from the tape and the coil in the head does that. Because the magnetic fields involved are very weak, so is the signal from the head. You'll need a tape head preamp between the head and your amplifier to get a usable signal. Here's a stereo circuit; just use one channel of that for each mono head.
posted by flabdablet at 5:21 PM on August 14, 2008

When I've done this I've run the wires from the tape head back into the dictaphone for amplification. That works & lets you play tape canvases, etc.

That said, I don't really think it's worth it.
posted by Joseph Gurl at 8:28 AM on August 15, 2008