[sdiy] Power supply spike

[Mike]

> Sorry, I think I didn't explain myself clearly.  The spike is coming
> through the mains power supply into my active monitors.  It is produced
> even when the modular is connected to nothing else...  it is NOT coming
> through the audio path.
>
Ah! Different problem. You may need a 'soft start' for your power supply.
This is either a resistor in series with the primary, sorted out by a relay
after a suitable delay, or more simply, a suitable thermistor is series.

The thermistor will run hot, so needs to be in a suitably ventilated space.
You'll need to work out the value from the VA rating of the transformer. I
you give me some details, I may be able to help.

Usual Caveats apply, this is mains voltgae and can be very dangerous.

BTW. Is the transformer a toroidal? Thye are notorious for having a bigger
switch on surge that a conventional one. Some of the Peavey 400 watt amps
would pull the 10Amp breaker on my test bench. I went to a 16Amp 'motor
rated' one, on a seperate socket, to avoid nuisance tripping on switch on.
They wouldn't often blow the 5Amp fuse in the mains lead though....

HTH

Mike