multiple power supplies in a modular

[The Dark force of dance]

Y-ellow Eric 'n' y'all.
        Sounds like you've been working too hard. Put yur feet up. Tell all
them Audiophiles to shut the hell up and grow a brain. One brain between the
lot of them should suffice. :) 

My favorite statement by an Audiophile. "My system's so clear you can
actually hear the DC."

On the Innovative thinking network list, it was decided that there is no
such thing as a dumb question. My revised statement reads. "There's no such
thing as a dumb question except for ones repeatedly asked by Audiophiles."
The exception that proves the rule. But I understand. Dealing with
audiophiles all day must grind you down. 

I also believe that the thing about this list, and indeed the internet as a
whole is that we should all share our experiences. It saves a lot of time
and I can only hope that by sharing my experiences with *say* the 723
regulators for example, may serve to save someone a lot of time and slightly
costly experimentation when deciding on a regulator to use for a specific
purpose.

That said, I'd like to offer this. There's probably no real advantage or
disadvantage to either approach. But you might like to consider some
interesting observations made by people on this, and other synth related
lists previously. That LFOs and in particular, VCOs have been observed
syncing up due to PSU coupling. Slight dips and spikes propagated along the
PSU causing VCOs to somehow sync. At least if memory serves this was the
mechanism.

I have observed audio mixers which use a set of three terminal regulators on
each input channel to reduce PSU coupling but in these cases it is helpful
if a Star topology is observed for earthing. That is to say, that all earth
returns originate from a physically central point in the system. I would
assume that this would be hard to achieve in a modular synth. However along
those lines, a better approach might be to provide a central, pre-regulated
PSU. Say +/- 20 to 25 volts. Then for sensitive modules such as VCOs and
LFOs, one could provide local regulation. This may help prevent any PSU
coupling due to the relatively long feed lines one would encounter in such a
system.

So technically you'd have one PSU but 2 sources. One would be the regulated
+/-15 volts that feeds most of the system. The other would be a
pre-regulated higher source which would feed self regulated modules. Of
course there's nothing to stop you here having two independent supplies or
even more. Just try to keep all the earth returns to some central point as
best you can.

Hope this helps.

Be absolutely Icebox.
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