Dreadbox Erebus V3 Semi-Modular Duophonic Analog Synthesizer

Description

Building upon the success of the Erebus V1 and V2 synthesisers, the Dreadbox Erebus V3 is a desktop semi-modular analogue duophonic synthesiser designed for musicians, sound designers, producers, or anyone looking for a compact yet powerful analogue instrument with Eurorack compatibility. Several enhancements have been made to V3 including a third oscillator, triple ring modulation, an expanded patchbay with 35 patch points, an analogue clock generator, a patchable sample-and-hold circuit, and dedicated envelopes for both the VCF and VCA.

The instrument can create a massive sound via the three oscillators. Oscillator 1 provides a saw or square wave output, while oscillator 2 offers a saw or triangle output. Both offer tune knobs, glide faders, and octave switches (3-octave range). A mix fader allows you to blend between the two. Oscillator 3 provides six waveforms including saw-up, saw-down, pulse wave (with PWM), triangle, Sinae, and double saw, along with white noise. By default, oscillator 3 tracks the pitch of oscillator 1, but can be forced to track free by inserting a dead-patch into the CV3 patch point, which allows the circuit to double as an LFO (0.01 Hz to 15 kHz).

The multimode filter is a 2-pole state variable circuit with low-pass and high-pass selections. A fader blends between the two modes and when in the centre, acts as a notch filter. The resonant filter can self-oscillate and provides a wide pallet of timbres from smooth to aggressive. The first envelope is pre-wired to the filter cutoff, but can be patched to any other circuit via the patchbay. The envelope also offers a loop switch, which effectively allows it to be behave like an LFO that can be shaped with ADS controls. The amplifier envelope is hardwired for convenience. The echo circuit provides a variety of lo-fi, classic delay effects and is capable of generating reverb, chorus, lo-fi echo, tape echo, pitch shift modulations, or a standard delay.

The rear panel offers a 1/4" main output and input for instrument processing. Additionally, there are two MIDI connectors (In, Thru), which function as a well-spec'd MIDI to CV interface, offering note tracking, gate on/off, pitch wheel, and mod wheel. There is a series of dip-switches on the rear panel that allow for some clever programming such as setting MIDI channels, changing from duophonic to unison modes, automatic tuner settings, and Sysex updates. The Dreadbox Erebus V3 includes a 12 VDC power supply.

Features

General Features

• Analogue duophonic synthesiser
• Three voltage-controlled oscillators (with auto-tuning to prevent drift)
• Auto tuning function
• Triple ring modulator
• Two-pole, state-variable resonant filter with both 12dB/oct low pass (LP), high pass (HP), and notch settings
• Filter is capable of self-oscillation
• Dedicated ADSR envelope for VCA
• Lo-Fi echo/delay effect
• ADSR envelope for VCF with loop function
• Loop function acts like ADS shaped LFO
• White noise generator
• Up to 4 LFOs (LFO, Filter Envelope, OSC 3, and Clock)
• Individual patchable VCA
• Analogue clock generator
• Patchable sample & hold
• Extensive modulation options with 35 patch points (3.5mm)
• MIDI In/Thru via 5-pin DIN connectors
• Main input and output via 1/4" connectors

Oscillator Controls

• OSC 1 and OSC 2 Controls:
• Tune Knob: Allows for precise tuning of the VCO (approximately ± 11 semi-tones)
• Octave Switch: Transpose the VCO pitch over 3 octaves
• Wave Select Switch: Select either the saw wave or pulse wave for OSC 1 or the saw wave or triangle wave for OSC 2. If neither wave is selected, the VCO is turned off
• Glide Slider: Allows independent control of the glide amount for each VCO
• Mix: Controls the mix or comparative loudness between both OSC 1 and OSC 2. If either VCO1 or VCO2 is switched off, then the MIX control doesn’t affect the remaining oscillator (it will play at maximum volume)
• Triple Ring:
• Slider 1 (1/2) controls the amount of the modulation from OSC 1 on OSC 2
• Slider 2 (1/3) controls the amount of the modulation for OSC 1 to OSC 3
• OSC 3 Controls:
• Wave Select Knob: Sets OSC 3 to one of 6 wave forms including saw-up, saw-down, modulatable pulse wave, triangle, Sinae, double saw, as well as a white noise source
• Tune: Allows for course tuning of OSC 3 from as low as 0.01 (letting the VCO also act as an LFO) up to 15 kHz
• Fine: Controls finer tuning of OSC 3 ±11 semitones
• Level: Controls the amplitude (loudness) of OSC 3 in the overall mix
• FM: Controls the amount of frequency modulation from OSC 3

Filter Controls

• Filter Controls:
• Cutoff Knob: Sets the cutoff frequency of the filter
• Res Knob: Controls the amount of resonance (sometimes referred to as Q) to the filter cutoff frequency
• Mode Slider: Balances the amount of signal from the high-pass and the low-pass filters. With the slider position fully closed, only the signal through the LP filter will be heard. With the slider position fully open, only the signal through the HP filter will be heard. The area in between is a Notch mode

Envelope and Amp Controls

• Envelope 1 (Envelope): Hard-wired to control the filter cutoff, but it can also be patched to modulate several other targets
• Envelope 2 (Amp): Hard-wired to control only the voltage-controlled amplifier (VCA)—the loudness of the patch over time
• Filter Envelope Time: Varies from 10ms up to 60 seconds for each of the stages
• Envelope Controls:
• ADSR Sliders: Controls the attack, decay, sustain, and release stages of the envelopes
• Level Slider: Controls how strongly the envelope affects the filter and the amplifier
• Loop Switch:
• Sets envelope to loop from the end of the release stage
• Behaves like an LFO that can be shaped with the ADS controls
• "R" will not affect the looping envelope

Low Frequency Oscillators

• Up to Four LFO Sources:
• LFO: Offers triangle wave that can be patched from patch point labelled “LFO”
• LFO is hardwired to equally modulate the frequency or pitch of all 3 oscillators (OSC 1, OSC 2, and OSC 3)
• Rate Slider: Controls LFO Rate from .0167 to 20 Hz
• Filter Envelope: Set to loop, the envelope can be patched from patch point “ENV” to modulate other targets, for example an LFO
• OSC 3: Tune down to LFO range and variably sweep through saw (up-ramp and down ramp), pulse/square, triangle, Sinae, and double-saw waveforms
• Clock: Use as a square wave LFO

Echo Effects

• Inherited from earlier incarnations of the Erebus
• Provides the same lo-fi, classic delay
• Reverb
• Chorus
• Lo-Fi echo
• Tape echo
• Pitch-shifting modulations
• Standard delay

MIDI Control Functionality

• Note tracking
• Gate on/off
• Pitch wheel
• Mod wheel
• Channels from OMNI up to 7