Erica Synths SYNTRX II

Refined and redesigned in modern all-black paneling, the SYNTRX II from Erica Synths is a brilliant analog synthesizer inspired by the spirit of the EMS Synthi AKS. SYNTRX II holds true to the previous version in its fully modular state with 256 path points across the 16×16 digital matrix patchbay, patching CV and audio signals throughout the device as well as external signals via the DC-coupled audio inputs or CV and gate inputs. Each section of SYNTRX II expands outwards with more control, performable switches, and circuitry both enhanced and refined for pristine yet powerfully characterized sonic and control options.

The first two oscillators provide not only supreme stability but a wide variance in waveforms through the shape and level controls of the two square, sine, and saw outputs. SYNTRX II retains oscillator sync as well as adding finer tuning and octave control, alongside switchable PWM options for oscillator one and two based on the shape parameter. The third oscillator can follow the incoming MIDI note with less tuning control, or it can run freely as a fully functioning LFO with triangle and square outputs that share a variable shape control. Useful as a sound source or modulation source, the variable noise module features attenuation alongside a tone control for sweeping between a rumble to a sweet, higher sounding noise. Additional modulation can be found in both the Random section, which shares an output with oscillator three’s triangle output, as well as the Trapezoid’s looping ASR envelope generator with flexible loop points.

What’s fantastic about SYNTRX II’s modulation capabilities lies in both the internal routing options as well as the external ones from both audio and CV sources. On top of external CV modulation and gating applied to the envelope generator, the two audio inputs are DC-coupled to work as great modulator sources for straight FM to pitch or filter frequency as well as creating an envelope follower signal from the first input. The envelope follower features threshold, level, and decay controls as well as a “To Gate” switch for use as a comparator gate on the Trapezoid’s envelope. Performing the SYNTRX II can be daunting with all the different knobs and patchpoints, but thankfully the lower-right joystick control allows you to mutate and loop automation and gestures with adjustable voltage ranges and LED indicators.

Along with control modulation signals, ring modulation is a fantastic feature of SYNTRX II with a carrier input that may be fed from one of the 16 sources on the matrix, and a select choice of seven audio signal options for the modulator to creatd unnaturally metallic timbres. More tonal shaping features include the flexible filter section that can run the highpass and lowpass types in series for single sweeps or bandpass-style filtering with adjustable gain and resonance. Another useful feature is SYNTRX II’s solid delay for adding rhythmic and elongation to your sounds, sporting a variable time and feedback as well as a hold/add control for performative delay gestures by adding and holding sections. All signals must be routed to one or both of the output channels with independent level controls and panning, and additional lowpass filters per channel are great for toning down or performing filter sweeps on outgoing audio.

All routings on the dot matrix are completely saveable to up to 254 memory patches and can easily be recalled, edited, and saved over. Further management of patches can easily be selected via the patch button for flipping back and forth to quickly grab a sequential set of patches. One of the largest additions to SYNTRX II, beyond the outstanding audio and control features, is its onboard piano-roll sequencer utilizing the dot matrix for creating arpeggios, bass lines, melodies, and any other form of sequencing you’d like. With MIDI functionality and an improved VU meter with selectable audio or CV monitoring, the SYNTRX II boldly stands on its own with the beautiful influence of a beloved synth classic.

SYNTRX II Features

Highly intricate and programmable analog synthesizer
Two perfectly stable audio oscillators with variable shape, oscillator levels, sync, and PWM
Modulation oscillator with variable shape skew, oscillator level, and key follow capability
Random/S&H modulation running freely or via gate
Variable noise color with independent level
Series run high and low pass filter with resonance and type-selection
Dual DC coupled external inputs, one with envelope following and the other with mic/line adjustment & signal inversion
“Trapezoid” looping envelope generator and VCA
Ring modulation with flexible modulation source options
Master filters on both channels as well as master delay with performative controls
Dual independent outputs with level and panning control
16×16 digital matrix patchbay with dual patch controls as well as patch scroll (254 memory slots), save, and recall functionality
Onboard piano roll sequencer viewed/edited from digital patchbay
Joystick controller with adjustable modulation amounts, gate button, and even modulation recording
VU meter to monitor audio or CV scaling
Two CV inputs and one gate input with MIDI I/O/Thru