This photo features Quad's (or more accurately The Acoustical Manufacturing Co's) first domestic hifi system - the Quad I (sometimes just called Q.U.A.D.) pre and power combo. It began production in 1951 following-on from the Acoustical Man. Co's QA12 amp, and paved the way for the QCII & II system. The control unit/pre bears a very strong resemblance to later units (such as QCII and 22) and has a similar EQ filter circuit.

Here's another Quad I power amp, along with instruction manuals & valves, and with an ESL57 as a backdrop. This beautifully atmospheric photo was used by Göran as a Christmas card in 1996...