The project is known as NP-100v12 which refers to a simple headphone amplifier built around the 12AU7 vacuum tube. The 12AU7 is also known as ECC82 in Europe that is popular in the audio world since ...
Recently, the voice push to talk circuit in [Ryan]’s BITX40 radio was keyed down for a very long time. Blue smoke was released, a MOSFET was burnt out, and [Ryan] needed a new IRF510 N-channel MOSFET.