[c12mech]

I'm in the process of putting together a new amp based on the TPA6120 chip. I'm basically using the info from an article from the 6-2008 issue of Nuts and Volts magazine. The power supply in the article is, as stated by the author, way overbuilt. This I do not mind as I am planning to add an ipod dock and a dac based on the DSD1792 chip. What I want to know is can I just tap into the +12v reulated line and add an L7805 to bring it down to 5v for the ipod and dac.

 

[joe_cool]

Yes, but looking at commercial DACs I find that the 7805 regulator more often has it's own diodes and filter caps even when it shares the transformer winding with the 7815 regulator. One DAC I know uses 16VAC (20-24 VDC) to supply both the 7805 and 7815 regulators. Another DAC uses 9VAC (11-13 VDC) for the 7805 and uses a voltage doubler on the same winding (to supply 22-24 VDC) for the 7815.

Actually there are transformers made for this purpose. They usually have two 15VAC windings (or 30VAC center-tapped) and one or more 9VAC windings.

Can you give us a link to the article?

 

[c12mech]

This is the original PS schematic.

I plan to put it on its own board as with each of the other components. I know that may be more work but space is not an issue as this will be on my desk. I also like the fact that if I want to change something I just have to pull out that particular board.

The original article did not dwell on the PS much as it was more about the 6120 amp and the gold point step attenuator.

Nuts and Volts - June 2008

The only link I can give to the article just shows the first 2 pages. For more you have to subscribe. The online subscription is great since you get access to all the back issues back to 2004.