Is there a way to clear (instantaneously) a delay line?

Is there a way to simulate Larsen effect (audio feedback) with PD?

Try with fiddle~
You should find it in the "extra" directory.

Many thanks, zac.

Zac, if you could post an example, I'll appreciate very much.

The point from which I started this topic was just that I had to wait 20 seconds to have the delay line cleared, and I wonder if there is something similar to MAX/MSP "clear" message to the "tapin~" object. It could be a feature request...

thanks giair,
however there's another little problem.
I'm using a 20 seconds delay.
Multiplying by zero the output, I hear no sound from the delay, and that's OK. But when I multiply by one again, I hear the previous 20 seconds recorded !
My necessity is to clear those "dirty" 20 seconds, so to restart cleanly, and hear the output only after the delay time.

Anyone ever had the same problem?

But "delay" object is only for messages, not for audio (unless I'm
missing something).

I am using "delwrite~"-"delread~" pairs, and I wasn't able to clear the delay buffer with a "stop" message.

Any suggestions are welcome.

Thank you for the suggestions.
I was trying to re-create with PD the environment of "Pendulum Music" by Steve Reich; it's just an exercise for my computer music course.

Thanks.
But, I'm not sure this is a good simulation of Larsen effect
(i.e. the howl you hear when you move a microphone too close to a loudspeaker).
There should be something more than a delay with feedback, I guess.
If you have any idea, please let me know.