Argonne M131 Big Walter

Produced in the 50s and 60s. Along with the Astatic JT30 this microphone was played by Big Walter Horton as one of his favorites.

It came under different brandnames Herald, Monarch, Calrad and Primo.

The crystal element has been replaced with a Shure CM element 99a86 March 1968

All new wiring and Switchcraft connector.

In beautiful original mat green.