Orange Amp Field Guide: ORS100 HEAD


Some close-up pics from an original "pics-only" GRO100 Graphic (thanks to Bart Davis):

Year: 1968-1972/73
Model Number:ORS100/GRO100/OR100
Control Panel:Plexi panel
Control Panel Layout:Input - F.A.C. - Bass - Treble - H.F.Boost - Gain - Reverb Send - Reverb Return - Pilot Light - Power
Rear Panel Layout:Mains chord - Voltage selector - 2 fuse holders - Slave output - Impedance selector - 2 speakers outs
Speakers/Load:4/8/16 Ohms
Speaker model:N/A
Output:100 Watts
Preamp tubes:1.5 x 12AX7 ???
Power tubes:4 x EL34
Bias:Fixed bias
Rectifier:solid state
Phase Inverter:Cathodyne type: 1/2 x 12ax7
Circuit:certain type of schematic?(link to schematic?)
Chassis layout:certain type of layout (pcb number/hand-wired?)
Comments:These are the original "Graphic" models. According to a thread in the Plexiplace Orange Forum there are three virtually identical types of amps that have a pics-only description of the knob functions. The model number of this type changed from ORS100 over GRO100 to OR100 without much changes inside the amp. Eventually this lead to the OR120/OR80 Graphic range with text and small pics. It is not very clear if there are OR120 amps with Graphics only.