Mixer, offset, attenuverter
Shades provides 3 channels of audio/CV processing which can be configured either as active attenuators or as attenuverters.
A bicolor LED monitors the polarity and intensity of the audio or CV signal on each output.
Unconnected inputs are normalized to an internal precision voltage reference, which can produce either a +5V or +10V constant voltage.
Normalization on the outputs allows the module to be used as a mixer or offset generator: when no jack is inserted in an output, the signal from this output is summed into the next output. Combined with the internal voltage reference, this allows the module to be used as a CV offset control.
When output 1 is left unconnected, the signal on output 2 is the sum of channels 1 and 2. Channel 3 can be used for another purpose (attenuation, attenuversion, or constant CV generation).
When output 1 and 2 are left unconnected, the signal on output 3 is the sum of channels 1, 2 and 3.
Leave channel 1′s input and output unconnected, and connect a CV source to channel 2′s input. Channel 2′s output will contain a scaled and offset copy of the input CV. Channel 1′s level knob will control the offset and channel 2′s level knob will control the signal scale and polarity.
• Input impedance: 100k.
• All inputs DC-coupled.
• Low-distortion audio op-amps (LME49720) and thin film 0.1% resistors improve transparency in audio mixing applications, and allow exact unitary gains for precision summing of pitch CV signals.
• Current consumption: +/-12V: 15mA.
• Open-source hardware (schematics).