(ALSO KNOWN AS ECC35) This tube is an octal-based high mu twin triode with separate indirectly heated cathodes. It was originally designed in the 1930s as an audio frequency voltage amplifier. It is a pre-cursor to the B9A ECC series. It was widely used for input amplification in older audio amplifiers. The Golden Dragon 6SL7GT is an excellent example manufactured in China to strict UK specification and should not be confused with the inferior examples of the same tube types which are available at a lower price elsewhere but which are not considered of sufficient quality to be included in the Golden Dragon range.