KT88-STR, Redbase, Tube Amp Doctor, Matched Vacuum Tube

The TAD KT88-STR Redbase® is built in the style of the early British MOV KT88 with the big and heavy glass envelope and beautifully polished metal base. The Redbase® features a gold control grid for outstanding performance and reliable stability. A breath-takingly big and precise tone and great appearance make the new TAD KT88-STR Redbase® the best choice for both, high-end audio applications and powerful bass guitar amps, providing a natural and three dimensional tone with pleasingly full warmth and fine, subtle highs.

A very musical response, with great sound and finest details in mids and top-end; a linear and harmonious overall response with a very organic tone, make the TAD KT88-STR Redbase® TAD’s favorite tube in the KT88 and 6550A class.

Product Measurements

Body Height: 104 mm
Bulb Temperature: 250°C
Cathode to Heater Voltage: +250 V
D.C. Cathode Current, AF Power Amplifier: 230 mA
D.C. Plate Voltage, AF Power Amplifier: 800 V
Grid 1 (control) Voltage, AF Power Amplifier: -200 V
Grid 1 Control Voltage, Class A1: -16 V
Grid 1 to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance: < 15 pF
Grid 1 to Plate Capacitance: < 1.4 pF
Grid 2 Dc (screen) Dissipation, AF Power Amplifier: 8 W
Grid 2 Dc (screen) Voltage, AF Power Amplifier: 600 V
Grid 2 Screen Voltage, Class A1: 250 V
Heater Current: 1.65 A
Heater Voltage: 5.8 V - 6.8 V, 6.3 V nominal
Item Diameter: 53 mm
Item Height: 118 mm
Load Resistance: 6 kΩ
Output Power (POut) @ 5% Distortion: 18.5 W
Peak AF Grid 1 Control Voltage: 15 V
Plate Dissipation, AF power amplifier (Wa): 42 W
Plate Voltage, class A1 (Ua): 400 V
Plate to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance: < 12 pF
Signal Plate Current, Class A1, maximum: 105 mA
Transconductance (nominal): 10000 mS
Zero Signal Plate Current, Class A1: 85 mA