Muting Mutations

[MoltenVoltage]

I am thinking about different ways to mute a signal using a control voltage.

I want to mute the signal coming out of a preamp and going into an amplifier, and I don't want to use a mechanical relay.  I want the simplest possible solid-state solution.

I know optocouplers work, but they are expensive.

I am wondering whether it would damage either the amp or preamp if I simply use a 4066 to short the signal to ground while leaving everything else connected.

Thanks!

[R.G.]

Either open a series element or close a shunt element - or both.

The cheapest muting is an NPN bipolar to ground. This requires a series resistance with the signal, and either a signal with guaranteed 0V DC level or a BFC in series with the NPN and  pulldown resistor parallel with the NPN. Offset voltages are a continuing problem with bipolar shunt muting.

Maybe the best compromise way is with a series JFET. Boss and Ibanez don't use that JFET switching thing for no reason at all. It's quiet, can be easily slowed down so it doesn't thump or click. It only suffers from awkward lapses when handling big signals.

Even better and only slightly more expensive is to use a series JFET and a shunt JFET (or NPN). This gives much better attenuation.

On the other hand, an H11F3 does an absolutely great job, with no possibility of feedthrough.