Wall wart psu replacement: should I use regs?

My dac comes with an external 15V small and cheap wall wart psu. A friend of mine measured it and it produces a lot of noise... not hifi at all as expected.

I'd like to replace it with a more serious linear psu. The Dac has onboard regulators for all voltage lines (12, 5, 3, etc) including the analog section.

What is the best approach:

A) a simple linear psu giving 15vdc that uses just rectifiers and smoothing caps

B) a regulated psu using something like LM317, or LT1086, or even with dual regulators

I'm pretty sure that A) should be better than the cheap wall wart, but not so sure about the apparently better option B) is really problem-free. I remember that once I read somewhere (I can't locate the source unfortunately) that putting in series psu regulated with 3-terminal regs can create more than one problem.

I hope somebody can help!
One tip.

Very often also in expensive gear the regs have no capacitance between their legs.

If 78xx regulators in the dac are used. It's written in the dstasheet that kerkos (ceramic condensers 0,33 mfd) are important for stability. Putting them in makes impulse response much better.


  • Screenshot_20230910_065105_org.mozilla.firefox.jpg
    53.6 KB · Views: 28