[sdiy] Power supply idea found, need a bit of advice..........

[John L Marshall]

I prefer to use linear power supplies with audio circuits. As you mention
switching power supplies are noisy but the switching frequency us usually
high; 100 KHz to 1 MHz. High power amplifiers used in automobiles use
switching power supplies. I have used these amplifiers to drive monitor
speakers in my lab.

If you use two of the power supplies together in tandem, you will have only
one usable output on the negative supply if the ground return line  for 5
volts and 12 volts is common. The plus 12 volt lead from the negative supply
will be connected to your system ground and the ground lead will become
negative 12 volts. Okay, I suppose that you could use the 5 volt output as
negative 7 volts.

> www.allelectronics.com
>
> item number CAT# PS-9505
>
> it's a switching power supply (so that's more noisy than linear, right?)
>
> Would it be feasible to connect two of these, and tap one backwards to
> obtain -12v and -5v?
>
> at $2.50 each, I'd be willing to give it a shot and see just how noisy is
> noisy..............
>
>
> Rob
>
>