power supply

[Maarten Halmans]

Hi all,

I want to build a power supply for my first modular synthesizer. I need
4 voltages;+/-5V  +/-15V respectively. Maximum current will be
approximately 800mA for each voltage. I want to use a toroidal
transformer.(lower induced noise, hum)
Questions:

1. Can I use 78xx and 79xx regulators or should  I use other (better?)
regulators?
2. Because I can't find a transformer with 4 separate secondary
windings,  I have to use each winding twice. When I use 78xx or 79xx
regulators the whole thing oscillates. Any suggestions?

Thanks,

Maarten Halmans