How about this BiPolar power supply

What do you think of this bipolar power supply to use as as an 15vlt +- supply for preamp? Thanks

http://www.generalguitargadgets.com/index.php?%20option=content&task=view&id=191&Itemid=216

Simple, basic and works MOST of the time.

...but not ALL of the time.

The 79xx are known for latchup if the +Ve rail wakes up first, which happens some of the time with this non-center-tapped-secondary approach.

I prefer the center-tapped version.

Alternative quick-fix is to put a diode in the ground-sensing leg of each regulator, to raise the output by a diode-drop (about 0.6V) and compensate for the other two diode which you stick inseries with the +VE and -VE outputs respectively... one in each.

Keith

So basically a N4004 coming off the ground and the output of each regulator. Which direction would the diode be going?
thanks for your help.

I like this guy. Have order boards from him before. Great service.