A past article from the pages of

Reel Deals


The Australian Made Klee Sound attachment for the Pathescope Gem 9.5mm Projector.

The 9.5mm film gauge was introduced to the world in 1922; it was of course a silent film format. at that time, Pathe released a range of silent films,; which were in the main abbreviated 9.5mm versions of Pathe theatrical releases and documentary subjects. A camera was introduced a year or so later, which heralded the start of the 9.5mm home movie era.

In 1932, Kodak introduced a sound version of their 16mm gauge. Pathe followed suit, and their 9.5mm sound on film system appeared in 1934. A range of sound films and their first sound projector; the Vox (Latin for voice), appeared. Most were  British ‘B’ features and shorts, however, by arrangement with Paramount Pictures, Pathe released onto 9.5mm sound a range of the immensely popular Betty Boop and Popeye cartoons.

Pathescope Gem on the Klee Sound sound adaptor

Pathe produced two more 9.5mm sound-on-film projectors after the war, the Pax in 1949 and the Son in 1951. He Pax was Pathe’s best efffort and it rivaled the 16mm machines of the time for performance. The Son was basically a Gem with an extended chassis containing the sound section. These projectors all utilising photocells and valves (tubes) for amplification were quite expensive, and in many cases beyond the pockets of would be home showmen.

In the early 1950s, here in Australia, an enterprising engineer in the employ of Home Cinemas, the Melbourne distributors of Pathe products, designed an add-on attachment for the popular Gem 9.5mm silent projector.

This unit took the form of a base containing an amplifier and the necessary optical train to recover the sound from the tiny optical sound track on the 9.5mm film. The rotary stabiliser and scanning system were based on the Pax design. The engineer was Alan Kleeberg, and the unit became known as the Klee Sound Adaptor.

It is not known how many of these ingenious devices were manufactured, but estimates put the number in excess of 50.

The unit was supplied in a sturdy carry case, which incorporated the speaker, and had sufficient room to carry both the Klee Sound Adaptor, as well as the Pathescope Gem projector.


For many of us in the Australia of today, where virtually no domestic electronic equipment is produced, the manufacture of such a specialised piece of equipment would seem all but impossible.

Prior to the early 1980s, Australia had a very active radio and television manufacturing industry. With this background, and the availability of locally manufactured components, the production of this unit went ahead.

The Klee Sound appears to have been manufactured from all Australian made parts, and used the following valve line up. 927 PE Cell, 6J7 Preamplifier, 6SJ7 Intermediate Amplifier, 6L6G Output and a 5Y3GT Rectifier. The speaker was a 10-inch Rola model 10G, which was mounted in the combined carry case–speaker box.

Close-up of Sound Head

However, a projector power (both motor and lamp) switch is incorporated into the control panel of the Klee Sound unit.

From the above illustration, it will be seen that the exciter lens is located within a locking sleeve mounted on the deck. The light slit is projected upwards onto the tiny sound track from the exciter lamp mounted under the deck plate. The exciter lamp is a 6 volt ‘tail light’ type globe, fed by AC. The hum, which would normally occur when AC is used on an exciter lamp, is all but eliminated by the use of a high current filament, relying on the ‘thermal inertia’ effect of the filament. A small mirror mounted on a hard wire arm just above the film reflects the light variations caused by the sound track. The reflected light then strikes the photoelectric cell, located in the vertical cylinder at the bottom of the illustration.

Under view of the Klee Sound Unit

The overall construction of the unit is very good, even the amplifier sub-chassis is rubber mounted to eliminate vibrations from the projector motor.

In operation, the unit performs well. The biggest single drawback is the variable speed of the Pathescope Gem projector. However, a strobe disc was mounted on the main sprocket to assist with speed adjustment.

The need for the projector to be located close to the sound head (due to the spacing between sound and image on the film) make the motor and lamp switches difficult to access.

                    9.5mm optical sound film

Copyright 2002 Mike Trickett. Geelong, Australia