Analog tape echo

[Limhes]

Hi,

Just started wondering about making an analog tape echo machine. Mainly for fun, to be honest, I don't expect a premium quality machine . I assume most people know how these things work - endless tape with an erase, write and read head after eachother and a varying motor speed to control the delay time.

My question now is, what are typical specifications for these heads? It is, ofcourse, fairly easy to open up an old tape deck and salvage the heads, but I have no real idea what levels and methods are used to 'interface' with the heads. I found out all about biasing the write head to write (almost) without hysteresis, but don't know about what the coils want to see. Since it's a coil, I would suspect the magnetic flux they give to the tape is proportional to the current supplied, but what currents should I think of? mA, uA?

Further, does any of you have some basic read/write methods for tape heads to experiment with?

For those of you who want some info on cassette tapes:
http://hyperphysics.phy-astr.gsu.edu...o/tapecon.html

[Sega CD]

I'm a noob but, couldn't u mod an 8-track player to do that?

[pinkmouse]

cassette tape echo / delay

[Limhes]

Thanks!

But, as stated (might be not very clear though) I am quite aware of the techniques employed. The general sense of it, I mean. I am just a bit confused about the electronics. But, what the heck, I might just take some tests one day, starting from very small currents and then upwards...

A fun thing I was just thinking about is a rather big wheel (no loop whatsoever!) with the heads next to it. I am going, ofcourse, for the most straightforward option to start from. Could always expand it into some ultra advanced hi-fiddling aparatus...

Basics attached. But, it might be better (just realised) to put the adder in front of the write head to obtain multiple echoes (is that the term?)