T-6550-TUNG-MP - Apex Matched Pair version | Bulb Temperature | 250°C |

Capacitance, grid to plate | 0.8 pF |

Capacitance, input | 15 pF |

Capacitance, output | 10 pF |

Cathode Current (I_{k}) | 190 mA |

Grid 1 Voltage | -300 V |

Grid 2 Dissipation | 6 W |

Grid 2 Voltage, Pentode | 440 V |

Grid 2 Voltage, Triode | 500 V |

Grid Circuit Resistance (R_{g}), Fixed Bias | 50 kΩ |

Grid Circuit Resistance (R_{g}), Self Bias | 250 kΩ |

Heater Cathode Voltage, Negative | 300 V |

Heater Cathode Voltage, Positive | 100 V |

Heater Current | 1.6 A |

Heater Voltage | 6.3 V |

Plate Dissipation (W_{a}) | 42 W |

Plate Voltage (U_{a}) | 660 V |

T-6550-TUNG-MQ - Apex Matched Quad version | Bulb Temperature | 250°C |

Capacitance, grid to plate | 0.8 pF |

Capacitance, input | 15 pF |

Capacitance, output | 10 pF |

Cathode Current (I_{k}) | 190 mA |

Grid 1 Voltage | -300 V |

Grid 2 Dissipation | 6 W |

Grid 2 Voltage, Pentode | 440 V |

Grid 2 Voltage, Triode | 500 V |

Grid Circuit Resistance (R_{g}), Fixed Bias | 50 kΩ |

Grid Circuit Resistance (R_{g}), Self Bias | 250 kΩ |

Heater Cathode Voltage, Negative | 300 V |

Heater Cathode Voltage, Positive | 100 V |

Heater Current | 1.6 A |

Heater Voltage | 6.3 V |

Plate Dissipation (W_{a}) | 42 W |

Plate Voltage (U_{a}) | 660 V |

T-6550-TUNG-MS - Apex Matched Sextet version | Bulb Temperature | 250°C |

Capacitance, grid to plate | 0.8 pF |

Capacitance, input | 15 pF |

Capacitance, output | 10 pF |

Cathode Current (I_{k}) | 190 mA |

Grid 1 Voltage | -300 V |

Grid 2 Dissipation | 6 W |

Grid 2 Voltage, Pentode | 440 V |

Grid 2 Voltage, Triode | 500 V |

Grid Circuit Resistance (R_{g}), Fixed Bias | 50 kΩ |

Grid Circuit Resistance (R_{g}), Self Bias | 250 kΩ |

Heater Cathode Voltage, Negative | 300 V |

Heater Cathode Voltage, Positive | 100 V |

Heater Current | 1.6 A |

Heater Voltage | 6.3 V |

Plate Dissipation (W_{a}) | 42 W |

Plate Voltage (U_{a}) | 660 V |

T-6550-TUNG - Single version | Bulb Temperature | 250°C |

Capacitance, grid to plate | 0.8 pF |

Capacitance, input | 15 pF |

Capacitance, output | 10 pF |

Cathode Current (I_{k}) | 190 mA |

Grid 1 Voltage | -300 V |

Grid 2 Dissipation | 6 W |

Grid 2 Voltage, Pentode | 440 V |

Grid 2 Voltage, Triode | 500 V |

Grid Circuit Resistance (R_{g}), Fixed Bias | 50 kΩ |

Grid Circuit Resistance (R_{g}), Self Bias | 250 kΩ |

Heater Cathode Voltage, Negative | 300 V |

Heater Cathode Voltage, Positive | 100 V |

Heater Current | 1.6 A |

Heater Voltage | 6.3 V |

Plate Dissipation (W_{a}) | 42 W |

Plate Voltage (U_{a}) | 660 V |

## Product Reviews

Excellent quality and no gas.

I installed a quad of these in my Conrad-Johnson Premier 11 power amp in place of a set of EHX. I bought the amp used and one of the power tubes was starting to fail so I decided to replace all four. I read some reviews for hifi use and I’m glad I went with the Tung-Sol’s. They sound great. Lots of power, lots of detail and not too bright. You need to burn them in for at least. 24 hours for them to sound their best.