Grendel - Drone Commander 2 (model of 2020)

More than just an Eurorack variant of the popular but discontinued Drone Commander in the funky ammo box - the DC2 continues where its father left off. It remains a drone-ish analog synthesizer with an unique, fantastic transistor sound and internal rhythmical modulation but it's been expanded by an envelope, a second filter, glide and more. Each of the twelve potentiometers has a switching function allowing you for even more control!

The Drone Commander 2 consistrs of two oscillators between which you can crossfade. The mix is sent to two filters, a resonant bandpass and a switchable 24dB low pass filter.
Internally there's a extensive clock generator and LFO section with a number of tempo multiplication and divider circuits.
There are also two LFOs with fixed frequencies (0.55Hz and 0.75Hz) whose mix controls the oscillators' pulse widths. An AR-type envelope is responsible for modulating the cufoff of the -24dB low pass filter.

Parameters:

• OSC1 and OSC2: Control the oscillator frequency. Push/Pull function changes the wave form from square to sawtooth..
• MIX determines the mixture between the oscillators. Pulling the potentiometer will mute the secons VCO.
• TEMPO of the internal clock generator. Pulling the potentiometer activates pulse width modulation.
• LFO determines the frequency of the sawtooth LFOs which modulate the band pass filters. The frequency is a multiple or a division of TEMPO. Pulling the control will deactivate the slide effect (see below).
• SLIDE is activated once per LFO cycle and it processes the square waveform, alternating and fading between it and an inverted version of itself. The control determines the duration of the crossfade. When the control is pulled the routing to the filters will be changed (MIX passes either both filters serially or VCF2 only).
• MOD sets modulation intensity of the clock generator and the LFOs to the VCO pitch. If you press the potentiometer only VCO1 will be modulated.
• SWEEP controls the modulation intensity of the sawtooth modulation to VCF1’s cutoff frequency as well as the direction (rising or falling sawtooth). If you pull the potentiometer you will activate a second sawtooth modulation which has the TEMPO’s rate.
• SHAPE is responsible for the waveshape of the pulse and mod waveforms, from asymmetric to symmetric. Pulling the pot will deactivate the modulation.
• FILTER is a cutoff control for the band pass filter. Pulling or pushing alternates between low and high frequency range.
• PULSE sets the modulation depth for both cutoff frequencies. Pushing or pulling the pot changes the timbre and the routing.
• ENV is a linear AR-type envelope generator which modulates the cutoff frequency of the 2dB low pass filter. Envelope times: 0.25 to 45 seconds. Pulling the pot opens the gate and therefor slowly the cutoff.