The Dual VCO is a 4hp Dual Voltage Controlled Analog Oscillator Eurorack Module available as a DIY Eurorack Kit, PCB and Panel, or Built.

Each VCO has square, triangle, and sine wave out, coarse and fine tuning controls, a control voltage input, and a switch for selecting exponential or linear cv in. When a control voltage is inserted, the fine tune control becomes an attenuator for the incoming voltage. In exponential mode, when the attenuator is fully clockwise, the VCO will track around 5 volts per octave.

There are a couple quirks to these 8038 VCOs:

Below 300Hz the waveform symmetry is slightly off. triangle waves get a little uneven in the lfo range, the sine is not completely perfect to begin with the bottom trough and in the lfo range it slopes slightly, and the square turns more trapezoidal above 1khz(see scope shots) Also it doesn't track 1 volt per octave perfectly. usually the 1st and 3rd octave will be a couple cents off.

Other than those idiosyncrasies, it is a powerful, stable dual oscillator in a small footprint with no cross talk between oscillators. It's great for: drones and beating sine or triangle waves, cross modulating itself for interesting clocks / LFOs, creating complex waveforms / timbres through lin / exp frequency modulation.