R5 Triple Wave Shaper "TWS"

On the 1973 version of the Tripe Wave Shaper, all of the input pull down resistors are 22k, not 100k as shown in this schematic. The components for the AC coupled outputs are mounted on the back of the jacks themselves. By around 1975, these outputs were dropped, and both output jacks were simply wire linked. As the input is AC coupled, there was probably very little gained by having both AC and DC coupled outputs. 25k pots are used for the input level controls. Later two-column panel designs dropped the second outputs altogether, and added a Join switch that coupled the three stages together, one input jack being used, the others being disconnected. The pots were moved from the PCBs to the panel, but the PCB remained essentially unchanged.

On the schematic for the CGS85 version shown here, the 220k input resistors and 470n input capacitors have been switched with each other, allowing a second 220k input resistor to be added. The new Join switch wiring connects all three wave shapers in series, but allows input and output connections to each stage. The output of the three stages being taken from the lowest jack.

Photos are from a unit made in 1975.


 
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