the famous F2a11 vacuum tube in single-ended triode
operation mode for an output power of 2x6 watts into
a 4, 8 or 16 ohm load. The F2a11 tube is a power tube
of matchless built quality, exclusively manufactured
by SIEMENS (& HALSKE) in the 1950s and early 1960s
which has been specifically designed for the most
demanding industrial applications. It belongs to the
famous so called POSTRÖHREN family of German tubes
and is widely known for its usage in the iconic SIEMENS
KLANGFILM cinema amplifiers.
When operated in triode mode the F2a11 offers excellent
sonics on par with the finest classic filamentary triodes
such as 300B, 2A3, AD1 or PX25.