The Marconiphone Type A2 two stage voice amplifier (Type A.2) was designed to be used in conjunction with the similar looking Marconiphone Type V.2 Receiver. The A2 and V2 together (including ancillaries) cost £47 in the mid 1920s.
The left-hand switch, labelled ‘Tone’, is a three-position volume control. The right-hand switch, labelled ‘Valves’, allowed two types of valve configurations to be used. If 6 volt filament valves were fitted ( 2 x DE5 valves) then the switch would be moved to the DE5 position. If 2 volt filament valves were fitted (1 x DER and 1 x DE6) then the DE6 position would be used.