The Drunk Beaver Kostiantynivka Dominator Preamp is a preamp with tube tremolo, built around a 190V internal rail for what the maker calls authentic high-voltage valve response. It was a limited run: only 30 units were available through the Drunk Beaver Rocks Webstore, and the pedal was still listed there at the time of writing1. The reviewer behind the Pedal Drop series called it "a very unique Pedal Drop - which I expect to be snapped up incredibly quickly!"1.
A tube tremolo preamp from the Watkins Dominator
The circuit is based on the V-Front Vibrato channel of the vintage Watkins Dominator, a British amplifier. Guitar Pedal X's Stefan Karlsson, writing at launch, described the pedal as delivering "pure vintage British grit and hypnotic pulse!"1
At its heart is a NOS Soviet 6N17B-V subminiature dual-triode tube running at a 190V internal rail, which the source describes as giving authentic high-voltage valve response. One triode serves as the main gain stage while the second acts as an LFO oscillator, so the single tube handles both the preamp and the tremolo1.
How the tube bias tremolo works
The tremolo here is tube bias tremolo, historically labeled "Vibrato" on vintage amps. Guitar Pedal X explains that the circuit generates its tremolo by directly modulating both the gain stage's high-tension (HT) supply and its bias, pushing the signal into overdrive at the wave peaks. That modulation of the tube's own operating conditions, rather than a separate effect stage, is what gives the effect its character1.
The controls
The pedal keeps an amp-style layout, with the classic Volume and Tone controls joined by tremolo knobs and an input toggle1.
| Control | What it does |
|---|---|
| Volume | Amp-style volume control1 |
| Tone | Amp-style tone control1 |
| Speed | Sets the tremolo rate1 |
| Intensity | Knob to dial in the throb1 |
| High/Low input toggle (0dB/-6dB) | Tames hot pickups or cleans up your signal1 |
Availability and reception
The Kostiantynivka Dominator Preamp was available through the Drunk Beaver Rocks Webstore at the time of the launch article, limited to 30 units. Stefan Karlsson of Guitar Pedal X called it "a very unique Pedal Drop - which I expect to be snapped up incredibly quickly!"1
With only 30 units in the run, this pedal may be hard to find once the initial drop sells through.
It sits in Drunk Beaver's series of limited Pedal Drop releases, alongside other tube preamps such as the Drunk Beaver Ternopil Pentode Preamp and the Drunk Beaver Trainer TS-15 MKII. For more on the category, see Preamp Pedals and Tremolo Pedals.
Questions
How many Kostiantynivka Dominator Preamps were made?
The Kostiantynivka Dominator Preamp was a limited run of 30 units. Guitar Pedal X reported that only 30 would be available on the Drunk Beaver Rocks Webstore at the time of the article, and the reviewer expected the drop to be snapped up incredibly quickly.
What tube does the Kostiantynivka Dominator use?
It uses a NOS Soviet 6N17B-V subminiature dual-triode tube. One triode serves as the main gain stage while the second acts as an LFO oscillator, and the tube runs at a 190V internal rail for what Guitar Pedal X describes as authentic high-voltage valve response.
How does tube bias tremolo work?
In this pedal, the tremolo is generated by directly modulating both the gain stage's high-tension (HT) supply and its bias. That pushes the signal into overdrive at the wave peaks, which is what gives the effect its character. Vintage amps of this kind labeled the effect 'Vibrato'.
What is the Watkins Dominator?
The Watkins Dominator was a vintage British amplifier. Drunk Beaver's Kostiantynivka Dominator Preamp recreates the Dominator's V-Front Vibrato channel in a pedalboard-friendly format, which Guitar Pedal X describes as delivering pure vintage British grit and hypnotic pulse.
How much does the Kostiantynivka Dominator Preamp cost?
The pedal was priced at $175 USD, which the source also gives as €175 EUR or 649 PLN, as of the 14 October 2026 release.
Sources (1)
- Guitar Pedal X, Guitar Pedal X, 2026-10-14
