Available as an assembled Module and as a DIY project.
This Module is currently available.
Specs are approved by the manufacturer4 channel CV attenuverter, offset and mixer
CVMod4 is functionally identical to the Avalon Harmonics CVMod8 V2, but provides 4 channels instead of 8, making it more compact for smaller cases. Additionally, it is Avalon Harmonics' first ever SMD module. Features a golden (ENIG coated) panel.
The module provides 4 channels of independent CV attenuverters and offset controls, as well as offset polarity switches and forward switches for mixing the channels together.
Each channel can be used as a static voltage source with the output available on the top-most row of jacks. Sliders control the voltage, and the voltage can be bipolar (+5V to -5V) or unipolar (+5V to 0V) by flipping the corresponding switch on the bottom. Behavior is bipolar when switched to the left and unipolar when switched to the right. Internally, voltage regulators ensure a precise voltage source. Note that there is a 5V spike when switching the polarity.
Each channel also has a signal input (second row of jacks) with a corresponding attenuverter knob below. The knobs have a centre detent as this is where the input gain is set to 0. When turned clockwise, level of the signal can be adjusted up to unity gain. When turned counter-clockwise, signal gets inverted up to a negative unity gain. The input signal is mixed together with the previously mentioned slider value, allowing the sliders to offset the incoming signal.
Output of each channel can be forwarded to the next channel by flipping a corresponding switch to the right in the upper row of switches. The signal is then mixed together with the attenuverted CV and offset of the next channel. Each channel has the following formula:
output = input * attenuverter + offset + output_prev
input is whatever signal is plugged into the second row jack.attenuverter is the position of the attenuverter knob and can range from -1 to 1.offset is the offset voltage set by the slider and polarity switch. Can range from +5V to -5V or 5V to 0V.output_prev is the output signal from the previous channel, if the forwarding switch has been flipped.The forwarding feature can be used to chain multiple channels together acting as a CV mixer with outputs still available on each channel. Plugging a cable into one of the outputs does not interrupt the forwarding, so it is possible to make use of submixes. If a need arises for an audio mixer, setting offsets to unipolar mode and sliding them all the way down will achieve this kind of behavior.
Lastly, a bipolar LED exists for each channel as a clear indicator of the status of the output voltage.
NOTE: Initial built units of this module will be shipped with resistor arrays instead of inidividual resistors. I am trying to use up the resistor array boards to have less waste. PCB sets however come as inidividual resistor footprints, because that is significantly easier to solder.
1 Users are observing this
