KT66 was originally developed as European counterpart to 6L6GC. KT stands for Kink-less Tetrode. KT66 has higher filament draw than a 6L6, but can handle 30W.
In audio application, KT66 are smoother sounding with great texture. In a guitar amp, KT66 gives more aggressive voicing as demonstrated by Marshall JTM45 Bluesbreaker.
There are several current production KT66 on the market today.
- GENALEX GOLD LION KT66 Matched Pair - Beautifully constructed, with the gorgeous looks of the original GEC KT66. Excellent in audio applications, really shines in guitar amps. This is our favorite KT66.
- JJ KT66 -
Heavy duty KT66 in KT88 form. This is a very rugged tube that can be pushed hard.
- Shuguang KT66 - Faithful replication of original GEC KT66, and gets great reviews used in audio applications.
- GROOVE TUBES KT66HP - Out of production, but KT66 Gold Lion makes an excellent replacement.