DG300B Power Supply — Rev. 2.01

The amplifier design below deals with high voltages — LETHAL voltages. If you are not comfortable or qualified to deal with these potentially deadly voltages, please do not attempt to build this circuit. Proceed at your own risk, expense, and responsibility. 

The power supply board for the DG300B features:

  • Soft Start Circuit
  • International Mains Voltage (120, 230, 240 V @ 50 – 60 Hz) Supported by Jumper Options
  • Unregulated B+ Supply: 525 V @ 330 mA
  • Regulated Bias Supply: -220 V @ 20 mA
  • Two Unregulated Low-Voltage Supplies: +20 V @ 1.4 A
  • Output for LED (Power-ON Indicator)
  • Board Dimensions: 4.0 × 6.0 inches (10 × 15 cm).

The board is intended to be powered by the Classic Tone 40-18069 power transformer. It is available from Triode USA and other Classic Tone distributors.

Unpopulated circuit boards for this 300B SET Power Supply are available for purchase. Prices are in US Dollars and payment is handled via Paypal.


Below is shown an example of such a board when fully assembled.