# MUTU – DUAL VCO A synthesizer with two oscillators in a mutual relationship with each other. ## Goals - flexible sound-generator - simple and DIY-friendly - eurorack-compatible (CV inputs for FM and VCA, size fits eurorack) ## Non-Goals - No perfect tonal tracking intended - No features that raise the parts count too much ## Topology  ## Interface Panel draft with 16 HP (~80 mm wide, 119 mm tall) <img src="panel/mutu_panel_top.svg" style="width:340px;" /> ### Inputs | Name | Function | Normalization | | ---------- | ------------------------------------------------------------ | ------------------------------------------------ | | `CV-VCA-A` | CV-Input for the first VCA. Positive voltages turn up the level of the first oscillator | Fixed positive voltage | | `CV-VCA-B` | CV-Input for the second VCA. Positive voltages turn up the level of the second oscillator | Fixed positive voltage | | `CV-FM-A` | Frequency modulation (FM) input for the first oscillator | - | | `CV-FM-B` | Frequency modulation (FM) input for the second oscillator | Signal plugged to the first FM-Input (`CV-FM-A`) | ### Knobs | Name | Function | | ---------- | ------------------------------------------------------------ | | `FREQ-A` | Sets the base frequency (pitch) of the first oscillator | | `FREQ-B` | Sets the base frequency (pitch) of the first oscillator. If `Track` is on, this gets added to the frequency set by `FREQ-A` | | `MOD-A` | Changes the amount of frequency modulation (FM) the second oscillator applies to the first | | `MOD-B` | Changes the amount of frequency modulation (FM) the first oscillator applies to the second | | `ATT-FM-A` | Attenuates any incoming (external) modulation signal plugged into the input `CV-FM-A` | | `ATT-FM-B` | Attenuates any incoming (external) modulation signal plugged into the input `CV-FM-B`. If no signal is plugged into `CV-FM-B` the signal of `CV-FM-A` is used here. | | `FORM-A` | Morphs the waveform of the first oscillator between triangle and sawtooth. Might also detune the oscillator | | `FORM-B` | Morphs the waveform of the second oscillator between triangle and sawtooth. Might also detune the oscillator | | `LVL-A` | Sets the level of the first oscillator. If something is plugged into the CV-input `CV-LVL-A` this knob attenuates the level of the incoming CV-signal. | | `LVL-B` | Sets the level of the second oscillator. If something is plugged into the CV-input `CV-LVL-B` this knob attenuates the level of the incoming signal. | ### Switches/Toggles | Name | Function | | --------- | ------------------------------------------------------------ | | `S_TRACK` | Switches on or off the tracking function where the second oscillator follows the frequency changes of the first. | | `S_SYNC` | Hardsyncs the second oscillator to the first one | ### Outputs | Name | Function | | -------- | --------------------------------------------- | | `OUTPUT` | Outputs the summed signal of both oscillators |