IC for a Click Track?

[jabney]

I would like to build a device capable of discriminating between an audio signal consisting of two different pitches (i.e. beeps with a musical pitch) and then translating each of those to a distinct non-pitched sound e.g. a square wave and a triangle wave. I/O should be at line-level, and it should be capable of being powered by one or two AA cells. Ideally, it would fit in an Altoid tin (empty, of course :-)

Does a single chip exist that would combine these functions and if it does, would it be reasonably cheap (i.e. quite a bit less than the $119 Yamaha wants for their rather cool click track device). It wouldn't need any output level control, merely a way of 'training' it to recognize the two tones that the existing electronic metronome puts out.

I write songs with a co-writer, and this is to help the writing and recording process. A pre-recorded tempo wouldn't work since we don't know how fast the song should be until we actually create it (and sometimes, not even then :-) - at least not right away). The metronome we have is OK, but I don't want its tones influencing any pitch decisions my co-writer makes.

Any help would be appreciated.

Thanks

[tINY]

Not sure what you mean here.

If you want a device that turns a fixed beep from a cheap metronome into a click, that should be pretty easy. You could build a high Q filter, feed the output into a integrator (set up a variable bleed-off on it), and use the output to trigger a one-shot. You can use an active filter on the one-shot to slow the edge rate and provide variable gain.

This can all be done analog.

If you need some sort of discriminator that will find a particular sound already in a recording and derive a tempo from it, it gets considerably more difficult....




-tINY