Soma Laboratory Harvezi Hazze

The Harvezi Hazze is a distortion pedal from SOMA Laboratory, and its circuit is unusual: instead of the bipolar transistors or op-amp clipping stages found in most fuzz and distortion boxes, its core is a waveshaper built around a unijunction transistor, a component type from the early days of the semiconductor industry¹. SOMA describes that one component as replacing a number of complex devices, and says that depending on the operating mode it can act as a distortion, a limiter, a waveshaper and a generator, with smooth transitions between those roles¹.

The name translates from Georgian as "a fault on the transmission line" or "signal jamming", and the transistors themselves were sourced from the e-waste bins of flea markets in Tbilisi, Georgia². For a player, the practical result is a box that Guitar World's reviewer described as "a vast universe of distortion and fuzz effects and much more"³.

Inside the signal chain: compressor, amplifier, waveshaper

The signal passes through four stages in order¹²:

1. An optical compressor with fixed parameters, always set the same way
2. A dual-mode distorting amplifier that offers either softer or harsher clipping
3. The waveshaper built around the unijunction transistor
4. A tone stack section for EQ shaping

The optical compressor at the front is not a control you dial in: its parameters are fixed, and it is switched in or out from the side of the pedal. Its job is to level the incoming signal before the distorting amplifier, which is where the character of the drive is set. A three-position mini toggle on the top row selects the amplifier's soft clipping, harsh clipping or total feedback mode³. The waveshaper after it is the part of the circuit that produces the tones a typical fuzz or distortion circuit cannot, since the unijunction transistor behaves differently from the bipolar transistors most fuzz pedals use³.

The controls and side switches

On top, the pedal has six control knobs, a three-way switch and a footswitch². The bottom three knobs are the familiar Level, Tone and Gain controls³:

The remaining knobs, listed by MusicRadar as Spoil and Spread, shape the waveshaper's behavior⁵. The Tone knob is worth a closer look: Guitar World found it provides "dramatic EQ sweeps rather than the typical 'mush to bright' range of a typical fuzz/distortion box", with its range and characteristics changing depending on which side switches are engaged³.

Turning the pedal on its side reveals six extra controls with switches for each, letting you engage features like the tone stack or compressor and adjust EQ-centric functions like bass boost and high cut⁵. Premier Guitar's product page details three of them²:

• Compressor: routes the signal through the compressor
• High Cut: attenuates high frequencies
• Tone Mode: changes the behavior of the Tone knob, between tilt or lowpass

The footswitch routes the signal through the effect circuitry or from input to output directly, which is the true bypass².

There are some useful presets in the manual to start from if you are unsure where to begin with this many interacting controls⁵.

Power and connections

The pedal runs on a standard 9V DC, 50 mA supply through a 2.1 mm center negative jack, the same arrangement as most modern pedalboard power supplies⁴. It is a mono pedal throughout: one 1/4 inch mono input, one 1/4 inch mono output⁴. MusicRadar noted that the lack of stereo might put non-guitarists off⁵. The enclosure is all-metal with rubber feet and an all-black texture, and MusicRadar found it "very giggable" with decent weight behind it⁵.

What reviewers said

Guitar World gave the Harvezi Hazze four and a half stars out of five, calling it "an outrageously versatile distortion/fuzz box that generates a huge variety of highly musical dirty tones and textures that users can fine tune to their discriminating taste"³. Their listed pros included "truly unique distortion/fuzz tones and textures" and "excellent dynamics and note definition", and they credited the side-mounted switches with providing detailed tone shaping capabilities³. On the downside, they noted there is no memory for saving settings³.

MusicRadar's reviewer called it "a genuinely fun take on the classic distortion-slash-fuzz pedal", praising its versatile control set and calling it great fun experimenting with its myriad settings overall⁵. In terms of voicing, they placed it "very much in the vein of a fuzz pedal or RAT-style distortion", and found it responds brilliantly to picking dynamics⁵.

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