Sigma11 Power Supply for Dummies


This article is about the Sigma11 Power supply, I built it for my Gamma2 DAC to see if a dedicated power supply would bring any improvement over USB power or a simple wallwart psu.

First thing to solder on is the lower profile components:
  • D5
  • CR1, CR2, CR3
  • R1, R8, R16, R3, R4, R5
Since this particular PSU was built for the Gamma2 DAC "R10" is not populated! (if you are not entirely sure, go back and double check that you ordered the correct components for your project).
Another thing to note is that at 5V the standard value of 10kOhm for R16 may result in the LED barely emitting any light, so I changed R16 to a resistor woth a resistance of 2kOhm resulting in a nice light output!

Continue with the slightly higher components:
  • C1, C2, C3, C4, C16
  • R12, R13
  • Q1, Q3, Q4
  • Q7, Q8, Q11
  • C14
  • C7, C18

You are making good progress now, and should continue with the higher components:
  • C9, C13
  • D1, D2, D3, D4
  • C11
  • C5

Almost there, mount the remaining components
  • Q13, Q14 with heatsinks
  • Whatever terminals you might need, I chose to only mount the "transformer" and a single "V+/V-" terminal
I did not populate the "LED" at this point since the LED will be wired to the case front when all is installed.