The Quad 22 – II btube preamp and power amp combination is the predecessor of the 33-303 preamp and power amp combination. In 1953 the Quad II mono power amplifier entered the market together with the QC-II mono amplifier. The Quad II remained in production until 1971 and achieved a production volume of 90,000 total. The QC-II was succeeded in 1959 by the 22, a stereo version of the QC-II preamp. With the pre-amplifier 22 and two power amplifiers II, it was possible to enjoy music in stereo.
The 22 – II combination was often sold in combination with the FM1, AM2 tuners.