The Drunk Beaver Zhytomyr Sunset Preamp is a preamp pedal built as a hybrid of the Sunn Beta Lead Preamp and a Traynor TS-25/50/100 passive tone stack. It was released on 27 October 2023 as Drunk Beaver's 15th Pedal Drop, offered through the Drunk Beaver Reverb.com Store for $175 plus shipping and taxes1. Designer Vitalii Bobrov tweaked the Beta gain stages for clean-to-saturated fuzzy sounds1.
How the circuit works
The core of the circuit is based on two opamp gain stages, and more interestingly four CMOS inverters1. CMOS inverters are usually deployed in digital circuits, but they can be used in an analog application to overdrive a guitar signal; on the original Beta Preamp they were labeled "Digital CMOS Technology"1. Each CMOS inverter is a pair of MOSFET transistors, and MOSFET transistors are able to generate really natural, tube style overdrive, which Stefan Karlsson of Guitar Pedal X describes as very much part of the Beta Lead signature sound1.
This approach has a lineage: there is a bunch of pedals that use CMOS inverters to overdrive the signal, including the Way Huge Red Llama and some Darkglass pedals1. The Red Llama, documented on the Guitar FX Layouts technical blog, is built around the unbuffered CD4049 hex inverter, and its output capabilities are described as legendary, with more than enough gain to force even the cleanest, most stubborn amps to submit their headroom2. The Zhytomyr Sunset differs by adding the Beta Lead gain stages and a full passive tone stack on top of the CMOS overdrive idea1.
Controls
| Control | What it does |
|---|---|
| Drive | Sets the amount of gain from the opamp and CMOS stages1 |
| Bass | Low band of the Traynor style passive tone stack1 |
| Mid | Mid band of the tone stack1 |
| Treble | High band of the tone stack1 |
| Master | Overall output level1 |
What reviewers said
Guitar Pedal X's review by Stefan Karlsson accompanied the release and included a demo, described as sweet and short, but one that really shows what the pedal is capable of: "sounds great to my ears"1. Karlsson noted it was the first ever demo for a Pedal Drop edition1.
Other Drunk Beaver preamps
The Zhytomyr Sunset was offered through the Drunk Beaver Reverb.com store for $175 plus shipping and taxes1. For more on the category, see Preamp Pedals and Overdrive Pedals.
Videos
Drunk Beaver Pedals
Questions
What knobs does the Drunk Beaver Zhytomyr Sunset Preamp have?
The pedal has five controls: Bass, Mid, Treble, Master and Drive. The three band EQ comes from the Traynor style passive tone stack side of the design, while the Drive knob sets how hard the gain stages push and the Master sets the overall output level.
What are CMOS inverters doing in a guitar preamp?
CMOS inverters are chips usually deployed in digital circuits, but they can be used in an analog application to overdrive a guitar signal. Each inverter is a pair of MOSFET transistors, and MOSFET transistors are able to generate really natural, tube style overdrive. The Zhytomyr Sunset Preamp uses four of them after two opamp gain stages.
What is the Sunn Beta Lead preamp?
The Sunn Beta Lead is an amplifier preamp whose gain stages form the core of the Zhytomyr Sunset Preamp's circuit. Drunk Beaver combined the Beta Lead preamp with a Traynor TS-25/50/100 passive tone stack, and tweaked the Beta gain stages for clean-to-saturated fuzzy sounds.
Is the Zhytomyr Sunset Preamp related to the Way Huge Red Llama?
They share a circuit idea rather than a design. The CMOS inverter overdrive approach used in the Zhytomyr Sunset Preamp is also used in the Way Huge Red Llama and some Darkglass pedals. The Red Llama is built around an unbuffered CD4049 hex inverter, while the Zhytomyr Sunset combines two opamp gain stages with four CMOS inverters plus a tone stack.
Who designed the Drunk Beaver Zhytomyr Sunset Preamp?
The pedal was designed by Vitalii Bobrov, who makes pedals under the Drunk Beaver name. The Zhytomyr Sunset Preamp was his 15th Pedal Drop, and he tweaked the Beta gain stages for clean-to-saturated fuzzy sounds.
Sources (2)
- Guitar Pedal X, Guitar Pedal X, 2023-10-27
- Guitar FX Layouts: Way Huge Red Llama, Guitar FX Layouts (tagboardeffects.blogspot.com), 2012-06-04
