Audio Delay Circuit

mikerbot · 2005-10-10T21:29:18+00:00

Hello, I'm attempting to design an audio delay circuit. Whileelectronic engineering is not my specialty, I can solder like a mad manand I have a general idea of what's going on. I was wondering if anyonewould be willing to help me along. The thing needs to have audio in(rca and 1/8" mini) and audio out. Adjustable delay from 0-12 seconds(more the better, but 15 would be over kill). .5 second steps would befine, infinite would be better. Both battery and adapter powered wouldbe nice. It should be small (walkman sized). On/off/bypass switch (ofcourse) and it should be as cheap as possible (of course). I explainedthis to a guy I know in Ohio, he gave me this:"If I understand what you're looking to do, this could be done with anADC, some memory to act as a buffer, and back to analog via DAC. Notreally all that complicated. Small pause on startup to fill thebuffer. Use an encoder (or even a pot) to set the delay value in thePIC that would be shifting the data out of memory to the DAC. Theremight be an even easier approach using some analog circuit, but itwould be pretty easy to do it via digital/analog converter ICs."I understand the very basic theory behind most of that paragraph (andcould figure out the rest.) The biggest conceptual problem I have withit is "some memory to act as a buffer." Thanks for your time.-Mike.

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John Fields 20 years ago

_And_ the transports have to be aligned properly so that the tape won\'t try to run off the capstans, and on and on, I think. Seems to me like the long way \'round when it can be easily done with probably substantially less than $10 worth of parts the other way(s).

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John Fields 20 years ago

And adequate tensioning mechanisms on both machines and God knows what-all else, including a reason why to do it that way. Seems a little bizarre for the OP\'s needs when for less than $10 worth of parts he can easily build it out of silicon.

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John Fields 20 years ago

If you\'ve got pressure pads holding the tape against the heads, perhaps. If you don\'t, and you\'re using a tensioning arrangement to do it, all of a sudden it doesn\'t look like such a good idea.

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John Fields 20 years ago

Good luck finding tape with oxide on both sides...

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John Fields 20 years ago

Ergo it _is_ goofy?

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John Fields 20 years ago

The link to it\'s been posted twice already. Get off your lazy ass and find it if you\'re interested.

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Rich Grise 20 years ago

Yeah, that must be it.

Thanks, Rich

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Rich Grise 20 years ago

I'd be interested in seeing this circuit.

Thanks! Rich

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John Woodgate 20 years ago

I read in sci.electronics.design that John Fields wrote (in ) about 'Audio Delay Circuit', on Fri, 14 Oct 2005:

Yes, it can NOW; those techniques were used when it couldn't be done digitally.

Regards, John Woodgate, OOO - Own Opinions Only. If everything has been designed, a god designed evolution by natural selection. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

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Jim Thompson 20 years ago

3.75ips, for 5 second delay, would only be ~6 inches in diameter, rotating at 12rpm ;-)

Maybe you could slow down a hard-drive ?:-)

...Jim Thompson

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Clive Tobin 20 years ago

I am surprised that nobody has suggested an analog bucket brigade delay. These used to be made by Reticon and I think Panasonic still has them, the last time I looked in the Digi-Key catalog. Fidelity is not wonderful and biasing can be touchy. I don't know how many stages are still available.

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Rich Grise 20 years ago

Heaven sakes, Jim! I had to go back and check the thread to see what in the world you were talking about! :-)

But, yes, a drum would work too - see "G-15 drum memory":

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Obviously, it would have to spin verrrrry sloooooowwwwwly... :-)

Cheers! Rich

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Rich Grise 20 years ago

This one?

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Thanks, but Mouser, Digi-key, and Newark come up 0, and the one source that lists the chip (MX609P) is one of those "Register and give us your personal information before we'll tell you how much it is" sites.

Where do you buy yours?

Thanks, Rich

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Pooh Bear 20 years ago

There were indeed proper drum based echo units.

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Graham

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John Fields 20 years ago

I don\'t, but if I did I\'d start with TI and Freescale.

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Rich Grise 20 years ago

That's two more zeros.

Apparently you can get them from surplus dealers, if you submit a(an?) RFQ.

Glad I'm not trying to build this thing.

Thanks, Rich

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Jim Thompson 20 years ago

[snip]

In fact, couldn't you do this with a hard-drive? Isn't this the same thing as TIVO (DVR) but just audio?

...Jim Thompson

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| 1962 | I love to cook with wine. Sometimes I even put it in the food.

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Michael A. Terrell 20 years ago

The "Echoplex" was a tube based echo unit for musicians in the '60s:

? Michael A. Terrell Central Florida

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Pooh Bear 20 years ago

ISTR getting one of those to service once. And a Binson Echorec too.

Graham

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Michael A. Terrell 20 years ago

I repaired a bunch of them in the '70s, both tube and solid state.

? Michael A. Terrell Central Florida

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Audio Delay Circuit

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