How about a DIY tape echo/delay?

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Concretebadger
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How about a DIY tape echo/delay?

Post by Concretebadger »

Yeah, building one. In a proper mad bastard in the garden shed, MANLAND sort of way. I was noodling around on my RE-20 and decided that I love the lo-fi sound, and I'm at a bit of a loose end for my next home DIY project. I've repaired guitars, built a guitar, built a BMP clone and plan to do another, but I've only got as far as the general theory of how the industry standard tape delays work.

First thoughts are, it's doable but is probably hellishly difficult in practice. I'm not fussed about using valves, so the buffer/amp bits of the circuitry should be fine with ICs or transistors. I'm thinking more along the lines of a Roland Space Echo than a Maestro Echoplex.

My basic outline is one 'read' head and one 'record' head, with a loop of tape...at least for now. A two-head arrangement should give some cool slapback sounds, but it'll need some sort of feedback loop to get multiple repeats and allow self-oscillation stuff. I dunno about motors - I'd *like* to have the motor and the circuitry running at 9V DC for simplicity's sake, since I could power it off a PSA adapter or a one-spot. My grandad's into building powered model boats, and he often talks about the new electric motors that hobbyists use these days, so I'm wondering whether there's more choice over a quiet, reliable motor to drive the tape and modulate the speed than there was back in the old days.

Although this example is a bit Heath Robinson, it proved to me that it can at least be done, and the sound is kinda cool:
[youtube][/youtube]
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NickS
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Post by NickS »

You'll also need an erase; the Watkins (WEM) Copicat used a permanent magnet erase (at least my Mk. 1 does).
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Post by Concretebadger »

Ah, I get it. Yeah...some seem to have a dual erase/record head. Something to check as I go along. Cheers for pointing that out.

I've done a bit more reading around, and immediately discounted an Echorec design purely on the grounds of construction (the drum arrangement is clever, but very difficult to build). One cool design I stumbled on was a disc instead of a tape or drum: someone's used a 3.5" floppy drive, which is quite cool. The parts are readily available, it's compact and the flat disc won't tangle, jam or snap like a tape can. There won't be any of the 'quirks' of tape delay either, but it's an interesting alternative.

I'm starting to think that picking up a broken unit, be it a Space Echo, Copycat, Korg or Hiwatt, and restoring it would be better than plunging in and doing one from scratch. Thoughts?
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Doog
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Post by Doog »

That'd be a superfun project/learning experience, for shuuuuuuuure. Probably also maddening.

Only half related, but it reminded me of this Walkman Mellotron; so dope:

[youtube][/youtube]