Not content with just a simple (but still awesome) vacuum tube tattoo, Jonathan decided to get schematic symbols for vacuum tubes. You see, he’s an electronic designer and hobbyist training to be an engineer that specializes in vacuum tubes. These aren’t just any random vacuum tubes though. Each one represents a vacuum tube he’s used in a project. He writes:
The top symbol is a pentode, specifically a 6AU6, that I used to build a tube radio. The one on the left, 0A2, is a cold-cathode regulator that I used in my tube power supply. The one on the right is a 12AX7, a twin-triode most commonly used in guitar amplifiers.