7660 charge pump - laser gun sound when power removed?!

[Harry_Monk]

Hi,

I'm using a 7660 charge pump in my circuit. Since it's already in there for other purposes, I figured I'd use it to power a preamp stage I'm using in the same circuit - therefore I've a TL074 arranged with dual rail.

What I'm finding is that when I remove power from the circuit, I hear what can be best described as a laser gun effect!

I know it's the 7660, becuase if I hold power to it, while removing power from everything else in the cct, then I don't hear the laser gun.

I'm figuring it's something to do with the 7660's internal oscillator winding down when its power is removed - this is somehow getting through my TL074 & in turn into my guitar signal chain




Any ideas how I can work around this problem?

[anchovie]

Use a power switch with an extra pole so that you can disconnect or mute the audio output.

[slacker]

Personally I wouldn't worry about it, loads of pedals make similar noises if you pull the power. Just turn off your amp before your pedals and you won't hear it. Same goes for powering up.