Wife immediately heard the difference from another room

[anthonyTD]

Battery supplies are the lowest noise, no two ways about it If you can't get the voltage you are looking for then try a bank of NiCd or NiMh which have different volts per cell than lead/acid.

I agree to a point,
However,
batteries tend to have a similar problem as capacitors ie; they dont have a low enough impedance at all required frequency, although the higher the current capability of the battery, the better.
Anthony,TD...

[Reid Malenfant]

I was actually thinking noise wise Anthony, though someone (Trichord) manufactures a PSU advertised as NCPS (never connected power supply) where i believe the normal main storage capacitor is connected to a second one but only when the rectified secondary voltage is lower than that stored on the first capacitor. Thus avoiding mains born noise being injected into the regulator.

I acually haven't investigated battery impedance at high frequencies, so i'll defer to your better knowledge.

[anthonyTD]

I was actually thinking noise wise Anthony, though someone (Trichord) manufactures a PSU advertised as NCPS (never connected power supply) where i believe the normal main storage capacitor is connected to a second one but only when the rectified secondary voltage is lower than that stored on the first capacitor. Thus avoiding mains born noise being injected into the regulator.

I acually haven't investigated battery impedance at high frequencies, so i'll defer to your better knowledge.

hi Mark,
yes Trichord has been producing this type of supply for some years now,
and its a very interesting aproach, although i believe that Graham has fine tuned the design since its first incarnation.
Anthony,TD...