Tweakers' Asylum: Re: Power Supplies for the TDA1541 DAC-Thorsten, anyone by Elso Kwak

Hi Ryan,
One of the problems that is often overlooked is the non-synergistic effect of having two or more regulators in series or series/parallel regulators combined. Also there is the effect of the on chip regulator of the DAC reacting to the regulator; most of the time not mentioned or specified by the manufacturer.
With Jung type regulators I found that pregulation is NOT benificial. The effect being worse with LM317/337 type preregulation. The 78xx/79xx were better for this purpose.
If I understand it right from your post you derive the +5 from +15V ( two regulators in series) I presume it is better to obtain the +5V from the raw supply, with sufficient cooling because of the larger voltage drop.
How the TDA1541 responds to different kind of regulators is something one has to determine experimentally. The datasheet is silent on this subject.
A 300 Watt toroid seems a factor 10 x overkill. I would use a 30 watt two chamber transformer . Large Hipot reading, low interwinding capacitance; to prevent high frequency garbage feedthrough. I tried it out and it makes a difference even with line filters in the primary's of the transformers. Most people think the garbage on the mains is coming from nabors but it are your own CDplayer and DAC polluting your mains supply!
Thorsten has a working solution for the supply and Lesha also. I used Jung superregulators for this DAC. Just experiment with these or Thorsten's or Lesha's . 78xx is nothing special.
Hope this helps and does not confuse you.
ELSO