Australian Sound Systems from Melbourne closed in 1947. Essential school additions include a Bell pot and EF86 relaxation oscillator bell generator module with rate and decay pots, plus Garrard TA MkII for playing the national anthem.Īustralian Sound Systems A13 amplifier circa 1946-7. Features high quality construction, Woden MT101 mic transformer and 12AX7 preamp, EF86-12AU7-quad 6CA7 PP amplifier with A&E 2096 PT, and 2596 OT, and 6A元 plate-ground catch diodes for PP stage. Combination radio, record-player, microphone input, monitor speaker, PA amplifier in free-standing steel cabinet. Victorian school PA System circa mid 1960's - Made by Australian Sound & T.V.

6BM8 PP UL 9k output stage cathodyne PI with direct coupled triode preamp 12A?7 input preamp with baxandal bass/treble tone controls and volume and balance controls 12A?7 gain recovery. Ferguson PF170 PT, and A&R OT2632 OT.ħW Stereo Amplifier circa 1959-1960 - Made by Australian Sound & T.V. 6GW8 pentode, cathode bias PP output stage. Unknown manufacturer - probably a kit of parts. Trimax TP1895 PT with 5V4G rectifier.Īustralian 6GW8 amplifier circa late 1960's. Microphone and Pickup inputs via separate front panel 2501 microphone sockets. Unknown manufacturer - probably from Melbourne. Microphone input to 6J7 pentode stage and 6V6 SE output stage with Rola output transformer and 8' speaker.Īustralian 15W amplifier circa 1952. Rack mount chassis.Īustralian 5W combo amplifier circa late 1940's. 12AU7 long-tail PI to KT66 PP common cathode bias, with 18 to 300 ohm speaker tappings. 6AU6 pentode stage mixer for Radio and Gram inputs. I have amplifier restoration details on the following:Īudio Engineers 30W PA amplifier circa 1959. Information on self-split push-pull circuits, valve reliability articles, other valve related goodies, and articles I've put together. Linked files sometimes get updated, so please refresh your cache (F5) if you want the latest file version. Self-split push-pull including Parry Cathamplifier.

Amplifier restorations (including additional material on Williamson amps and Selmer organ).Inherent safety and circuit protection are typically improved or added, and performance is improved where appropriate. My present focus is documenting amplifiers of Australian origin and sympathetically restoring them - often as a guitar and/or bass amplifier, but sometimes as original. I am happy to share details and insight into vintage amplifier restoration.

Split cathode vs shared cathode