pt2399 reverb from electro-music.com/analog-custom

[deathfaces]

is he using two power supplies on this board? would it be possible to add a voltage regulator off the +15 to power the delay modules?

http://sites.google.com/site/analogcustomkits/config/pagetemplates/archivos/DigitalReverbProjectPT2399.pdf

[Mark Hammer]

Yes.  In fact that is probably what he did.

[deathfaces]

you mean using a regulator?

[Mark Hammer]

Yes.  It is a common practice to use an additional regulator as a means of stepping down a higher voltage.  That is true, even in the case of batteries.  For example, many pedals that use one of the MN32xx series BBDs will provide 9v to the remainder of the circuit, but use a 5v regulator to step the battery power down to a stable 5vdc.

[PRR]

Yes, you can extract +5V for the digi-stuff from the +15V for the analog stuff.

Problems:

The digi-stuff kicks spikes into its power rails, which may bleed into the analog rails, and thus into the audio output. The regulator may not supress this high frequency, and the big thing is ground-crap which will leak right into analog ground and signal. You "usually" like to give your digital stuff a completely separate power feed.

Dropping 15V to 5V wastes 2/3 of your power, which appears as heat in the regulator. I do not know how much current six(!) of those digi-reverb modules sucks, if this would be a problem (though in that size and the intended application, they can't be real hogs). Or if the modules suck digital spikes (again, the intended application would dislike digital noise or added complication).

I shovel-out excess 5V wall-warts (from USB hubs etc), so I'd probably start with a separate supply just for certain isolation. But sure, it will probably work with a regulator. Use all the caps the regulator data-sheet calls for. Keep the reg's ground pin nearer the digi-chips than the analog ground.

[cloudscapes]

shouldn't be a problem. I often use 5v parts inb my designs (microcontrollers, 2399, etc) but keep opamps and others at 9v. a regulator always works