AC
Founder
Astatic Corporation
1933– · Conneaut, Ohio
The original blues harp element before the Green Bullet existed
Astatic was not one man — it was a company. But its JT-30 microphone became the foundation of Chicago's amplified harmonica sound.
Astatic Corporation was founded in 1933 in Conneaut, Ohio, by a small team focused on crystal microphones — primarily for radio and dictation. The JT-30 launched in the late 1930s and was built to be cheap, rugged and sensitive.
Early Chicago blues players picked it up before the Shure Green Bullet even existed. The crystal element gave a brittle, midrange-forward sound that fit straight into a small tube amp. Big Walter Horton and Sonny Boy Williamson II played through JT-30s long before it became common practice.
Anecdotes & moments
- The crystal element is fragile — it breaks if you drop the mic, or if it gets too hot on a summer tour. That's why many JT-30s today have replacement elements from modern makers like Hohner and Shure.
- Astatic has been bought and sold several times; the brand is still on the market, but not the original company.