[sdiy] Power supply Xfmrs

[Tavys Ashcroft]

I just happened upon a large number (like 8 or so) power supply 
transformers.  They're nice Stancor ones with 120V primary and 28V 
center tapped secondaries.  My best bet with these would be a +/- 12V 
DC right?  I'd do about +/-14 volts and with the bridge and 
regulators I'd get safely down to 12V.  But I've heard that I should 
be a few volts above my regulators, so should I go down to 10V on the 
regulators to be safe?  I'm planning on using these for most of my 
future projects at least for a while since I've got a bunch of them 
and they were all free.  If it were +/-10V, would that be enough for 
a modular synth project?

-Tavys