[sdiy] DC wallwart +/- on-board V Reg ?

[Scott Gravenhorst]

A DC wallwart gives only one voltage.  It may or may not be regulated, 
but still, just one voltage.

An AC wallwart can give multiple voltages, such as +12 and -12.  This is 
done with a half-wave rectifier for each voltage which feed into 
regulators for the required voltages.

The PAiA Fatman employs this method to get +8, -12 and +5.

 >On 5 Mar 2015, at 16:35, Justin Owen <juzowen at gmail.com> wrote:
 >
 > Hello,
 >
 > I was hoping to get some advice on the potential
 >advantages/disadvantages/benefits/costs of circuits that use a DC
 >wall wart adapter (e.g. 9V boss-style adapters) to power a
 >voltage regulator (e.g. LM317) which then powers the circuit -
 >versus designs where the circuit is powered directly from the
 >wall wart (e.g. guitar pedals)?
 >
 > Or, perhaps to rephrase that
 >slightly - what are the main variables involved in making a
 >decision on what way to go?
 >
 > Thanks,
 >
 > - J