Shuguang Hifi Series 6550B
Chinese Shuguang 6550B.
The beam power quadrupole 6550B has an anode limiting power of 35W (42W). In the audio amplifier, two tubes A1 and AB1 can be used for push-pull output and reach 100W power. The 6550B can also be used in an electronic voltage regulator circuit.
The 6550B is similar to the KT88 and can be used interchangeably.