The F2a11 Integrated Amplifier utilizes 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 is a power pentode of matchless built quality exclusively manufactured by SIEMENS in the 1950s and early 1960s which has been specifically designed for the most demanding industrial applications. When operated in triode mode this extraordinary tube offers excellent sonics on par with the finest classic filamentary triodes such as 300B, 2A3, AD1 or PX25. A 12SN7GT double-triode is employed in the driver stages. The triode sections of the 12SN7GT tube are equivalent to a 6J5GT single-triode, a highly regarded classic medium-gain octal base triode with fairly low transconductance from the early times of tube electronics, unarguably one of the most linear amplification devices ever developed in the history of electronic technology.