Hello again - Ok, so I have a toroidal power supply powering 2x 25W Class A Amps as well as about 2A of other things. Total power consupmption = about 4A - fine for the toroid.

My question is, that with the smoothing caps I have in parallel with the power supply, adding more in parallel seem to be creating a buzz in my ground supply. This is audible through the amplifiers when the inputs are grounded.

Yes- thats right - more caps = more buzz in ground supply.

WHY? I thought it was meant to improve the filetering, not ruin it. Is there an explanation or does my power supply just suck?

thanks all

As in your other post, you're probably connecting something wrong.