Noisy PSU? Ground issue?

[simon111]

I have built a unit that has the effect (distortion) being powered off one pp3 and the switching system (remote relay system) and LED off another. No pops at all, completely separate grounds etc. Works exactly how it should.

So i built 2 PSU's. 2 of the ultra clean circuits of GGG. Both of these circuits are being powered from the same transformer. My transformer has only one secondary so both the Ultra clean circuits are connected to the same secondary (is this the cause...) When I connect them up to my circuit, it is very noisy (hum).

I have a few ideas that I need to experiment with, but before I do that , does anyone know why and how I can make it sound like it is being powered from batteries? Any help would be gratefully received as I am putting the soldering iron till after Easter! so will start on it next week.

Cheers guys

Simon.

[simon111]

Update-

1st Observation.

Running the effect + control circuit off two separate PSU the hum is a lot lot less (not quite as good as with a battery but more of that later).
So my question is, why is this hum being caused by running two Ultra Clean PSU circuits as described on GGG from ONE secondary? Is there a work around using just one secondary as I would like to use the existing?


2nd Observation.

Why is there more background noise (white noise) when using PSU's over battery power? Not a lot but is noticeable when the distortion effect is active (By this I mean that when engaged the difference between powering off batteries and PSU is easy to spot) When I  disconnect the PSU plugs on the effect the noise is markedly reduced even though the measured voltage is just about the same. Is this something to do with a batteries impedance? And again is there any work around on this?

Would appreciate any insight into this.