Safe, Accurate, HANDS-FREE plate voltage measurement

for the tube amplifier technician



In the past, conducting a plate voltage measurement- a necessary step before troubleshooting problems or correctly adjusting the bias involved removing the chassis from the amplifier, blocking the chassis upside down without damaging the tubes, making the necessary speaker and electrical connections, and then probing the underside of the chassis at the bottom of the tube socket to measure the running plate voltage.

This procedure exposes even the most experienced tube amplifier technician to dangerous high voltages, as well as running the risk of the test probe shorting two pins of the output tube socket together, which can cause at the very least quite a surprise, and at the worst could do some very expensive damage to the amplifier.

The BiasTool PVT is a handy and convenient device which enables a totally hands-free measurement of the running plate voltage of any tube amplifier. Installed between the output tube and the amplifier tube socket, this device connects directly to any multi-meter using the industry standard banana plugs. When used correctly and according to the detailed instructions, the BiasTool PVT will yield an accurate and very safe plate voltage measurement, keeping the technician's hands, and all multi-meter test probes safely away from the dangerous high voltages which are found inside of a tube amplifier chassis.

The BiasTool PVT can eliminate the need to disassemble quite a few of the tube amps in production today. Those amplifiers which have the bias trim adjustment accessible from the rear or top of the amplifier chassis can now be measured and adjusted without ever removing the chassis, saving a lot of time and work, which works out to more units repaired per hour, which equals more money for the technician.

The BiasTool PVT is constructed of all high-grade parts, utilizing 18ga. internal construction, 20 gauge, double-insulated lead wire and fully insulated banana plugs. Our unique design makes the BiasTool PVT so rugged, you will most likely never need to buy another, ever. Each unit comes with a full manufacturers' warranty, and is built to last.




The BiasTool PVT is available in the standard Octal-based configuration, and in a 9-pin mini version, which tests plate voltage on the EL84/6BQ5 output tubes!


Octal BiasTool PVT:

This version works with all the "standard" 8-pin output tubes, including:


Price- $26.99


Mini BiasTool PVT:

This version is for the 9-pin mini output tubes such as:


Price- $26.99


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