The AD1 Triode

AD1. The AD1 is a European triode dating to the 1930’s and is sort of the European equivalent to the 2A3. It was only made in small numbers just before the Second World War, and after the War it became prohibitively expensive to produce and not many were made in total. It does sound magnificent; having warmth, tone, a sense of space and an effortlessness presentation. Tube data for the AD1 can be found here.

The AD1 and its American contemporary, the 2A3.