The Drunk Beaver Kupiansk Sub Fuzz is a dual op-amp twin sub-octave fuzz, released in September 2026. It generates two sub-octave signals, one and two octaves down, and mixes them with a fuzz voice at the end of the signal path. Guitar Pedal X describes it as "Vitalii's custom dual op-amp twin sub-octave fuzz", an entirely original circuit rather than a take on an existing pedal.1
Availability and price
The Kupiansk Sub Fuzz was offered as a limited run of 30 units on the Drunk Beaver Rocks Webstore, available "as soon as you see this article go live", according to Guitar Pedal X's announcement of 4 September 2026. The price was set at $150 / €150 / 559 PLN.1
This is a limited pedal drop, not a general release. Drunk Beaver's drops have historically sold through quickly, so the 30-unit run may no longer be available.
The controls
The pedal carries four controls, covering the fuzz voice, the two octave voices and the overall output1:
| Control | What it does |
|---|---|
| Octave-2 Level | Sets the level of the two-octaves-down signal1 |
| Octave-1 Level | Sets the level of the one-octave-down signal1 |
| Fuzz / Gain | Sets the fuzz or gain amount1 |
| Volume | Sets the output volume1 |
Having separate level controls for each octave means the sub-octave content can be dialed in independently of the fuzz, from a subtle layer under the fuzz voice to a prominent synth-like sub tone1.
Inside the circuit: two clipping stages
The circuit is an op-amp-based fuzz built around a NOS Soviet KR574UD2V dual op-amp, with each half of the chip handling one of the pedal's two stages1:
- First stage: a non-inverting amplifier configuration with soft clipping, using an AL103 Soviet LED and two KD522 diodes.1
- Second stage: an inverting amplifier with transistors doing the hard clipping.1
The octave signals become glitchy and jumping on heavy attack, a tracking behavior typical of octave circuits pushed hard, before the fuzz is mixed with the two octaves at the end of the signal path.1
Guitar Pedal X's Stefan Karlsson, writing at announcement time, was positive about the build quality: "You can see that the PCB is heavily populated with premium components. I'm expecting really great things here."1
Where it sits in the Drunk Beaver range
Drunk Beaver's pedal drops alternate between recreations and original circuits. Recent releases include the Bashtanka Muff, a Big Muff 2 op-amp fuzz take; the Huliaipole Anarchy Fuzz, an evolution of the Jordan Boss Tone; the Bucha Square Wave, based on the Univox Square Wave Fuzz; and the Seattle Driver, an octave fuzz inspired by the Boss PW-2. The Kupiansk Sub Fuzz stands out in that company as one of the builder's fully original designs, and as a fuzz with dedicated sub-octave voices built in. For more on the effect type, see Fuzz Pedals and Octave & Pitch Pedals.1
Questions
Who designed the Drunk Beaver Kupiansk Sub Fuzz?
The Kupiansk Sub Fuzz was designed by Vitalii, the builder behind Drunk Beaver. Guitar Pedal X describes it as Vitalii's custom dual op-amp twin sub-octave fuzz, and notes that the circuit is an entirely custom design, a Vitalii original, rather than a recreation of an existing pedal.
How many Kupiansk Sub Fuzz pedals were made?
Drunk Beaver offered 30 units for sale on the Drunk Beaver Rocks Webstore, available as soon as the announcement article went live on 4 September 2026. Like the builder's other pedal drops, it is a limited run rather than a general release.
What chip does the Kupiansk Sub Fuzz use?
The circuit is built around a NOS Soviet KR574UD2V dual op-amp. The two halves of that chip carry the pedal's two stages: a soft-clipping first stage and a hard-clipping second stage.
Why do the octaves sound glitchy on heavy attack?
The octave signals become glitchy and jumping when the pedal is played with heavy attack, before they are mixed with the fuzz at the end of the signal path. That tracking behavior is a described characteristic of the circuit, not a fault.
How much does the Kupiansk Sub Fuzz cost?
The Kupiansk Sub Fuzz was priced at $150 USD, with European pricing given as €150 and 559 PLN, when the 30-unit run went on sale in September 2026.
Sources (1)
- Guitar Pedal X, Guitar Pedal X, 2026-09-04
