The MESA® EL-34 STR 446 is a premium quality EL-34 in the classic style and sound. They have nice harmonic reach, layering and complexity in the top end and a bit more fullness mids and richness in the low end when compared to some vintage renderings. With these favorable qualities they are a good choice for most EL-34 based amplifiers and certainly for our Badlander and Triple Crown EL-based models, as well as great alternate power tubes in our Mark and Rectifier lines.