The jj ECC803 is a long-plate version of the standard 12AX7, the longer plates give the tube higher gain, it has a rich and full tone with creamy distortion that does well in any 12AX7 application. Spiral Filament for reduced microphonics. Jj tubes are known for known for their high quality, durability, and their excellence in tone, formerly produced by Tesla, jj tubes are still made to exacting standards, they work well in all applications.