Whistle Rock Audio ML12 PSU

Projects > Whistle Rock Audio ML12 PSU

The ML12 is a four-rail power supply that provides +/- voltage, +48 for phantom power, and an extra + rail for LEDs, etc. The PSU was originally designed for an API 312-like preamp project, but the multiple rails and adjustable voltages could be put to many uses.

Images courtesy of Whistle Rock Audio

Notable Features:

  • Based on 337/317 regulators
  • Can supply up to 1.5A on the +/- voltage rails
  • Up to 200mA~700mA¬†of current on the +48 rail
  • Custom kits for selected voltages available
  • Transformer and heatsinks not included in kits


  • $15 for PCB only
  • $60 for 4-rail kit
  • $52 for 3-rail kit
  • $45 for 2-rail kit

More info:

  • Orders taken here.
  • View the manual. (PDF download)
  • Lots more pictures.