MOSFET B+ Drop Kit

Want to “brown” your amp’s tone? The MOSFET B+ Drop kit provides a more cost effective method of reducing B+ (high voltage) than the traditional high wattage zener diode, and is much easier to install than power scaling or VariWattage. It is installed between the power transformer’s secondary center tap and chassis ground.

A MOSFET and a few small components give you a range of reduction options.
Choose (below) between eight zener diodes to cover the range of reduction from 22v to 100V. The kit includes detailed instructions, all components, mounting hardware, and wire.

NOTE: FOR USE IN AMPLIFIERS THAT HAVE A CENTER TAPPED PT SECONDARY ONLY. IF USED IN A 1959 MARSHALL OR SIMILAR 100 WATT AMPLIFIER THAT USES A VOLTAGE DOUBLING RECTIFIER, THE B+ WILL ONLY BE REDUCED BY HALF OF THE ZENER VALUE, E.G. A 22V ZENER WILL RESULT IN AN 11V B+ DROP.

DISCLAIMER: Please review your amp and/or schematic to determine if this mod kit can be installed before ordering. User assumes all risks. Performing these modifications WILL void the warranty on your amplifier. Working on amps can be deadly if you do not take proper precautions. Follow the instructions very carefully. Basic soldering skills are required. If you are at all unsure of your ability to perform these modifications STOP and take your amp to a professional to be modified. You can also send your amp to us for modification. Contact us for pricing.

DIFFICULTY LEVEL: INTERMEDIATE [Follow safety guidelines for working with electricity. Basic soldering skills and knowledge of working with AC/DC circuits. Identify all terminals of electronic components using data sheets. Read resistor color codes and capacitor values. Measure and connect high and low voltage AC and DC. Understand basic working of vacuum tubes. Use all functions of a multimeter. Understand Ohms law and apply to basic circuits. Work with basic hand and power tools.]

Pricing and Options

$20.00

5 in stock (can be backordered)