oscillators and looping a sound

[Tokyo Witch]

Hi,

  I've only just started my first project last night and it seems to be going quite well.  The project I'm working on is a toy electric guitar with buttons that produce sounds.  I'm managed to change the sound with two pots one to speed it up and one slows it down. It sounds great.

I have a question about an aditional bend I'm trying out.  at the moment when I push the button it plays the sound once and then I can alter it.  What I want it to do is loop the sound.  I don't mind if the actual loop isn't from the begining of the sample I just think it would sound better if I could get a sustained sound and then speed it up and slow it down.

What I did do was replace the push button with a switch however I think I will need some form of oscillating ciruit connected to the switch so it would turn it on and off continuously.  Does anyone know how I can do that?

There is nothing in reed ghazala's book on oscillators and whether they would fry a circuit.  I suppose I could just buy one and see what happens but I don't want to buy one and have nothing happen

Thanks,

[the_zombiest]

You can use a simple astable 555 circuit such as this one to trigger switches: http://www.mikmo.dk/cblfo.html
mad easy.

[untune]

Can this LFO circuit be used on a keyboard to vary the sound a little?

[wiredtoygeek]

hmmmmm...The stuff I'm bening doesn't seem to have a 555 on the board. Can I add one to the circuit board?

[computer at sea]

hmmmmm...The stuff I'm bening doesn't seem to have a 555 on the board. Can I add one to the circuit board?

Yeah.  Follow the link given above to build your own oscillator with a 555 chip and a small handful of other parts. 

[goldenbaby]

Does a 555 circuit like this also work to sample a sound....well, not really sample, but so that while a circuit is glitching out, I can lock it into a trance with the flick of a switch or turn of a pot?

[computer at sea]

Hmmm.... kind of.  It can loop some glitches, particularly ones that connect to the ground of the circuit.