Z3ta: Muting Oscillators ??

Is there an easy way to mute an oscillator ?
Currently I have to set the level to zero, which loses the original level or turn the wave off.
DimLE and others have an enable switch which is much nicer and easier.

Thanks. That's what I was afraid of, but hoping I'd missed something.
 
I've used the Osc off setting, but its actually easier to remember the level than find a custom oscillator again. Z3ta is for toying with the osc shapes though apparently one at a time. Too old to update, but something to keep in mind going forward.