JJ (Tesla) ECC83/12AX7 Preamp Tube
The JJ ECC83S is the equivalent to the 12AX7 tube. Formerly known as Tesla, this Czech tube manufacturer has been in business for many decades and they make a reliable, rugged preamp tube with a smooth, even response. The shorter plate construction gives high gain without excessive noise. They also work great in combo amps due to their extremely low microphonics.