In article ,
Phil Allison wrote:
** The simple solution is to add a DPDT relay to mute both inputs of the
405 whenever there is no AC power.

Ideally, a miniature sealed type with gold contacts powered by rectified
AC from the secondary of the transformer - plus a suitable series
resistor.

You can use the contacts to either ground the two signals or open
circuit them.

Snag is this squawk happens immediately at switch off. So the relay would
have to operate extremely quickly.
But I was curious why some do it and some don't.

The DC in the Quad drops off pretty slowly after switching off. The panel
LED takes ages to extinguish. Just why the crossover goes unstable so
quickly, I don't know. The DC from the Quad PS is regulated down to 30v
for the crossover.

--
*If vegetable oil comes from vegetables, where does baby oil come from? *

Dave Plowman London SW
To e-mail, change noise into sound.