On 31/05/2016 9:13 PM, Dave Plowman (News) wrote:
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.

**Phil's idea is a good one. I used exactly that solution a short time
back with a Sony integrated amp. The preamp section was going unstable
at switch-off. The job was rapidly becoming unviable, so, after
consultation with the client, he agreed that a fast operating relay
would be acceptable. I used it to short the output of the preamp to
earth at switch-off. Perfect solution. Not ideal, but it does work well.

Try it.

--
Trevor Wilson
www.rageaudio.com.au

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