Red Witch Synthotron Analog Guitar Synthesizer

Two discrete analog circuits open up a world of vintage synth tones for guitar players.

By Chris Loeffler             

Analog synthesizers have flourished and helped shape modern music since the op-amp circuits of the 60's brought funky, futuristic sounds to keyboard players and marked a clear move toward "electricizing" music. Guitar players got in on the fun in the early 70's with circuits like EMS's Synthi Hi-Fli, Maestro’s USS-1 Universal Synthesizer, and various releases from Ludwig, Frogg, etc. While these circuits were essentially early analog multi-effects combining distortion, waveform shaping, ring modulation, and filtering, the end result was a remarkably faithful emulation of the spacey sounds keyboards were the sole owners of up to that point. Being limited to monophonic applications and carrying extremely high price tags, these tools tended to be exclusive to the financially affluent player and sonic freaks.

Despite notable entries in the category from Roland, Electro-Harmonix, 360, and more, economic challenges, high price-points, and a niche market kept analog guitar synths from gaining a foothold as a "must have" effect, and the rise of digital essentially put the nail in the coffin for all but the biggest enthusiasts through the early 2000's. The last half decade has seen a healthy resurgence in interest in lo-fi and "sound effect" effects, resulting in experimental designers introducing modern-tweaked, more affordable analog synthesizer options to the guitarist. Red Witch Effects of New Zealand is looking to bring those tones, both vintage and futuristic, to the guitar with the Synthotron.

The Red Witch Synthotron is a true-bypass, dual channel analog monophonic synthesizer for guitarists featuring sample/hold and envelope filtering with amplitude modulation and dual synthesizing oscillators. Both effects are engaged independently and are conveniently broken up into four rows of control. The pedal is powered by an included 9v, negative tip adaptor. 

What You Need to Know 

• The Red Box is the first synthesizer "voice" and includes three controls- Octave Toggle (one octave up or original pitch), level, and decay. The octave up, like all the octave divisions in the unit, tracks incredibly well on the neck pickup with the tone rolled down a bit. The tone is more bell-like and chirpy than a traditional Octavia effect and has an overall smoother sound... more effected and less guitar-like. The Level knob controls the output of the synth signal and the Decay controls the fading characteristic of the note, from a gated stutter at the lowest setting to full sustain at the highest.

• The Orange Box is the second synthesizer "voice" and includes three controls- Octave Toggle (one octave down or two octaves down), level, and decay. One octave down brings smooth, fuzz-like tones with a sheen around it that recalls light ring modulation or even a touch of bit crushing. Two octaves down is even thicker and woollier, with a bit less stability and more wild pitch shifting between notes. The Level and Decay controls function the same way (and with the same effect) as those in the Red Box

• The Light Blue Box controls amplitude modulation (similar to a tremolo pedal) with an On/Off Toggle, Speed control, and Dry control. The depth of the tremolo is set at a rather seasick warble that has the interesting effect of pulling the upper octave in slightly ahead of the lower octaves; a neat piece of sonic trickery that implies pitch modulation without actually doing it. The Dry knob, the only knob not exclusive to the Box it is contained in, allows the blending in of the guitar with the synthesizer to add clarity and stabilize the sound, if that's what's wanted. 

• The Dark Blue Box contains controls the sample/hold and envelope filtering with Velocity and Range controls. In sample/hold mode, the pedal offers a gurgling, step-sequenced filtering that drastically cuts between different filtered frequencies for a hypnotic, seemingly randomly sequenced pattern. The Velocity knob takes the speed of the steps from almost inaudibly fast to a step every 750ms, and there's an internal control to adjust the resonance of the filtering from dark and chewy to bright and shimmery. In Envelope mode, an envelope sensitive filter creates a wah pedal sound that sweeps open and closed based on the strength of the input signal. Dig in hard and the envelope completely opens... gently strum and it will quiver somewhere halfway open. The sweep is a little elastic as it closes on sustained notes, creating slight modulation. The Range control adjusts the frequency of the filter from bassy and thick to trebly and fragile, and an internal control allows for input adjustments to dial in the best signal to hit the filter with based on a given guitar's output signal and the pedal's placement in the chain.

Limitations

• As is the case with any true analog synthesis, the pedal is meant for monophonic applications. Playing multiple notes will create glitchy oscillation that jumps between notes and throws out decidedly unmusical overtones.

• Powering the effect via a daisy-chain or generic adaptor is highly discouraged. Because the pedal runs on a negative tip adaptor and most daisy-chains and "all use" adaptors are positive tip there is a high likelihood the circuit (or adaptor and everything attached to it) could be fried. Stick to the factory provided adaptor. 

• Like all analog synthesizers for guitar, careful pickup selection and volume/tone knob tweaking yields optimal results. The pedal favors the neck pickup of most guitars and tracks best above the 9th fret.

Conclusions

The Red Witch Synthotron brings a plethora of vintage synth tones to the guitar player with tight and responsive tracking. With four synthesizer voicing combinations, two distinct filtering options, and amplitude modulation, the pedal opens up sonic territory that leads to vintage Moogs, funky flute synths, and filter-swept square wave electronica pulses. The ability to use the filtering and synthesizers independent from each other only expands on the utility of the pedal for those seeking more "traditional", less effected sounds.

Resources 

Red Witch Synthotron at Musician's Friend (MSRP $489.99, Street $399.99)

Red Witch Synthotron Product Page on Red Witch

Red Witch Synthotron Overview Video

Red Witch Synthotron Synth Function Video

Red Witch Synthotron Filter Function Video

Red Witch Synthotron Synth w/ Filter Video