Frequently Asked Questions

Proven performance, used in many different brand tube amplifiers around the world.

Photo below shown this board installed in the Sophia Electric High End tube amplifiers.

This board would permit to warm up vacuum tube filament first, and then switch to high plate voltage in about 20 - 30 seconds later. To protect your expensive output vacuum tubes such as 300B/2A3/845, KT88/El34 ... to achieve longer lifespan, you need to get this delay action board (assembled, ready for use). Buy it today!

Price: $25 each + $5 shipping by Priority mail.

• Green wires with LED are for pilot display.
• Braid green wires are for 6.3V AC (from tube filament supply).
• Red/Black wires (2 pairs) are being used to switch up to two (2) sets of power supply.

  Instruction: When turn on main power switch, let the tube filament on first, 30 seconds later this delay action board is going to switch on (control two sets of plate voltage supplies).

  The board gets 6.3 AC voltage for its own power use. Once 6.3V AC (from filament winding) is being applied to the board, the red/black pairs are going to be connected in about 30 seconds. So you may use one pair of black/red as one set of switch. There are two sets of switch in this board for turn on the plate voltages with a delay.

  Warning: This board is intended for experienced users due to the high voltage involved.

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