Power Supplies for effects ?

[petemoore]

  GEO Page is so  hard to find !
  Say I'm trying to power a Stage Center Reverb using a power tranny with CT'd secondary, and I'm reading 14/0/14 VDC with a FWR bridge and a 68uf cap across the _/+ of the bridge.
  Running that into the Reverb circuit seems noisey, not sure if it's the PS or all the wirings/condenser etc.
  Should I put a 100ohm resistor between the diodes and the first filter cap? then run another resistor to a second filter cap?
  Any schematics available from which to work from ?

[mojo_hand]

If you're doing a dual polarity supply, I'd recommend using two filter caps, one between + and the center tap, and the other between - and the center tap.  And I would make them bigger than 68 uF, unless space is at such a premium that a larger cap is just too big.  But if a couple of 68s are what you have to work with, a resistance of 100 ohms would drop the hum by several dB, which might be enough to make you happy.  Doing so would also drop the load regulation of the power supply...  op amps are good at ignoring such things, but you might want to consider what the load is going to be on this power supply.  I don't know what chips you're using, or what the tank's input impedance is, but the more current it draws, the stronger the arguments are in favor of using capacitance instead of resistance.