My model A Hammond Organ
The photos below show one of my Hammond model A organs that dated from the 1930s. The Model A was the first Hammond organ and set the style for the "B3" cabinet although the A was quite dainty and small in comparison. The model A did not have an internal amplifier or power supply so my model was fitted with a modified Rogers valve amplifier which fulfilled those functions. As with all the organs on this page the photos show the original condition when I got them working but before they got a clean up and a polish. The model A produces a sound that is immediately recognised as a Hammond but it is a different sound to that of a C3.
The organ shown here without its pedal board or stool but with the makeshift amplifier underneath which had a microphone input allowing the organ & vocal sound levels to be mixed together
There was some rust on the metal strip under the upper manual keyboard needing a paint job.
As can be seen the interior was in good condition. The electronic chassis on the left of the picture is the one valve pre-amplifier after the matching transformer. The cabinet is jammed full of stuff and is complex to work on although electronically this organ is simplicity itself. In most respects it is a "mechanical" organ rather than an "electric" organ.
The Vibrato control knobs switches on an effect which is really more of a tremolo sound.
The drawbars of the model A (and other earlier models up to the B3 and C3) have a switching action at each number so that they go clunk-clunk-clunk rather than having a smooth action. This means they cannot be adjusted whilst playing without the risk of "clicking" noises being heard.