KT150

KT150 has no equivalent designation confirmed by the archive. Completed sales put the typical price at $109.86 per tube.

The KT150 is a beam pentode power amplifier tube primarily designed for audio service. It uses an oxide-coated, indirectly heated unipotential cathode and can be operated in any mounting position.

Construction

The KT150 is built on a large wafer octal base with barriers, JEDEC 7AC, and uses a seven-pin low-loss B7-99 base. The Tung-Sol datasheet specifies a heater voltage of 6.3 volts with a heater current of 1.7 to 2.0 amperes, and a heater supply voltage limit of 6.3 ± 0.6 volts. Maximum heater-cathode voltage is 300 volts DC and peak, with the heater either negative or positive with respect to the cathode.

Ratings

The KT150 has a plate dissipation rating of 70 watts. The Tung-Sol datasheet gives maximum plate voltage in tetrode connection as 850 volts DC. Maximum grid 2 voltage is 650 volts DC in triode connection and 650 volts DC in pentode connection, but 600 volts DC in triode and ultralinear connection. Maximum grid 1 voltage is −200 volts DC. Maximum grid 2 dissipation is 9.0 watts. Maximum cathode current is 275 milliamperes in pentode connection and 250 milliamperes in triode and ultralinear connection. Maximum grid 1 circuit resistance is 51,000 ohms for fixed bias and 240,000 ohms for self bias. Maximum bulb temperature is 250 degrees Celsius.

Capacitances

Without a shield, the KT150 has a grid 1 to plate capacitance of 1.75 picofarads, an input capacitance of 20.5 picofarads, and an output capacitance of 10 picofarads.

Applications

The KT150 is designed for push-pull amplifier designs up to 200 watts output.

Per-tube prices from completed sales, 2026-06-21 to 2026-08-20. Matched pairs and quads are divided out. See the price index for how these move over time.

Original manufacturer datasheets for KT150, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• **TUNG-SOL**