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RotorDrive
RotorDrive is my first attempt at building a solid state DIY Guitar Overdrive. Design is based on a dual transistor gain stage for power overdriving.
Design constraints were kept to the minimum : only components with nominal values (multiples of 10), only one gain control for the first stage.
The distortion is asymetrical and provided by the unique diode which can be connected or not according to the switch position.
When switch is open, Rotordrive is in BOOST mode, providing a slight crunchy overdrive on single coil microphones, reasonalby maintaining the instrument timbre at the output.
When switch is closed, unit is in overdrive mode, with highly distorted sound and weird harmonics.
Schematic
Operation
A few time diagrams from Tina are shown herebelow to illustrate both boost and overdrive modes.
Both diagrams represent the effect of the Gain potentiometer from 0 to 100% when Rotordrive is fed by a 60mV peak input signal, close to a standard Mic.
Boost
Drive
