KT66 Tubes For Sale: KT66 Data Sheet, Tube Specs, & Substitute Info
KT66 tubes for sale
We offer single or multiple KT66 tubes for sale in matched configurations to suit a range of hi-fi and guitar amplifier requirements.
KT66 matched pair
KT66 matched trio
KT66 matched quad
Each KT66 tube for sale at Pentalabs is selected for dependable audio performance and consistent operation in demanding replacement and upgrade applications. Whether you need a single tube for maintenance, a matched set for output-stage replacement, or help comparing current-production options, we can assist with practical selection guidance. If you are reviewing brand alternatives or checking fit for a specific amp design, we can also help identify a suitable KT66 tube equivalent based on electrical requirements, bias settings, and the intended use of the amplifier.
KT66 tube specs
The KT66 is a classic beam power tetrode used in both vintage-inspired and modern audio equipment. It is commonly chosen where a KT66 amp is expected to deliver strong musical headroom, smooth response, and the broader bottle-style construction associated with this valve family. Below are general specifications for reference. Full operating values, curves, and recommended conditions should always be confirmed on the relevant data sheet for the exact tube version being used.
Below are general specifications. Please refer to the downloadable datasheet for complete details.
| Specification | Details |
|---|---|
| Tube Type | Beam power tetrode |
| Base | Octal, 8-pin |
| Heater Voltage | 6.3 V |
| Heater Current | 1.27 A |
| Maximum Plate Voltage | 500 V |
| Maximum Screen Voltage | 400 V |
| Plate Dissipation | 25 W to 30 W, depending on data source and tube version |
| Screen Dissipation | 3.5 W |
| Cooling | Natural air / convection |
KT66 data sheet download
Download the KT66 data sheet to review electrical characteristics, pinout, limiting values, and typical operating conditions for KT66 amplifier servicing, replacement planning, and amplifier design work.
KT66 vacuum tube substitute & equivalent information
The KT66 is widely used in audio applications and is commonly compared against both vintage-style and current-production replacements from major tube brands. Common search intent includes Genalex, Mullard, JJ Electronic, PSVANE, TAD, and Shuguang KT66 replacement options, especially where buyers are trying to match tone, fit, and operating behavior across modern production runs.
KT66 tubes are also regularly associated with amplifiers from brands such as Marshall, Tone King, Dr Z, and Victory. In some amplifiers, 6L6GC, 5881, and sometimes KT77 are considered possible substitutes, but that is never a universal rule and should always be confirmed against the amplifier’s circuit design, bias requirements, socket compatibility, and manufacturer guidance before installation.
If you need help choosing the right replacement set, contact Pentalabs. As experienced vacuum tube dealers, we can help you compare options for HiFi tubes and guitar amp tube replacement.
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