The Sterling Vermin is a distortion pedal from ACT Entertainment's RAT brand, first announced in May 2025 and available immediately at launch1. It takes the classic Pro Co RAT circuit as its starting point and rebuilds it as a hand-soldered boutique pedal, built in small batches at the company's Jackson, Missouri headquarters1. At its heart is the LM741 op-amp, the chip associated with the original RAT design, paired with a mini-toggle that selects between two clipping diode types23.
What sets it apart from a standard RAT is range as much as refinement. Premier Guitar's John Bohlinger described it as "equally at home delivering snarling distortion or articulate, low-gain overdrive, with a wide, usable tonal range throughout the entire gain spectrum"4. Delicious Audio similarly characterized its range as running "from snarling high-gain grit to nuanced overdrive"5, which makes it a candidate for players who want one box to cover both overdrive and full distortion duties.
A RAT-based distortion with a low-gain range
The Sterling Vermin's lineage is explicit. The maker's product page says it "takes the legendary RAT formula and sharpens it for a new generation of players"2, and the launch announcement describes it as having "the soul of a traditional RAT pedal"1. Guitar World's reviewer, Paul Riario, framed it as "a premium, boutique take on the traditional ProCo RAT circuit"3.
The tonal range is where it diverges from a stock RAT. Where the classic three-knob RAT (Distortion, Filter, Volume) is best known for its aggressive upper-gain character6, the Vermin is voiced to work down into low-gain territory. Bohlinger called it "a modern twist on the iconic Rat distortion" with "a voice all its own"4. The two clipping modes shape that range:
| Clipping mode | Diodes | Character |
|---|---|---|
| SI | Traditional RAT-style silicon | Punchy, mid-heavy, classic RAT grind25 |
| BAT41 | BAT41 Schottky | Smoother, more balanced, more articulate25 |
Delicious Audio's Paolo De Gregorio described the silicon setting as delivering "punchy, mid-heavy distortion" and the BAT41 setting as giving "a smoother, more balanced tone"5. Bohlinger characterized the silicon option as "a punchy, mid-range bite"4.
Circuit and build
The circuit is straightforward in concept: an LM741 op-amp driving a pair of clipping diodes, selected by a mini-toggle3. The LM741 is the op-amp most associated with vintage RAT units; by contrast, newer standard RAT models moved to a Texas Instruments OP07DP as a replacement op-amp72. The Vermin returns to the original chip.
The build is where the price goes. Guitar World's review rated build quality five stars, citing "hand-soldered, premium CTS pots and boutique-built in the USA" construction3. The enclosure is polished stainless steel with a mirror finish, decorated with laser-annealed calligraphic swirls3. Bohlinger noted the CTS pots and oversized knobs give "a satisfying smoothness to the rotation, with just the right amount of tension"4.
- LM741 op-amp at the core21
- Selectable clipping diodes: silicon or BAT412
- CTS pots with oversized knobs34
- Polished stainless-steel enclosure with laser-annealed graphics13
- Hand-soldered in small batches in Jackson, Missouri13
The pedal was designed by Shawn Wells and Matt Gates5.
What reviewers said
Guitar World's Paul Riario concluded that "the traditional RAT circuit has been refined into a boutique-quality stompbox," listing the two selectable clipping diodes, hand-soldered construction, and premium looks among the reasons to buy3. His review also noted the top-mounted jacks, a practical touch for tight pedalboards3.
"The result is a pedal that's equally at home delivering snarling distortion or articulate, low-gain overdrive, with a wide, usable tonal range throughout the entire gain spectrum."
Videos
Premier Guitar
Performer Magazine
Performer Magazine
News
Questions
Is the Sterling Vermin a RAT clone?
It is a refined take on the RAT circuit rather than a straight copy. ACT Entertainment, which owns the RAT brand, describes it as having the soul of a traditional RAT pedal, and Guitar World's reviewer called it a premium, boutique take on the traditional Pro Co RAT circuit, with the LM741 op-amp and selectable clipping diodes setting it apart.
What op-amp does the Sterling Vermin use?
It uses the LM741 op-amp, the same general-purpose chip associated with the classic RAT design. That is confirmed by the maker's product page, the launch press release, Guitar World's review, and Premier Guitar's demo video. Newer standard RAT models have used a Texas Instruments OP07DP as a replacement op-amp.
Where is the Sterling Vermin made?
It is built in small batches and hand-soldered at ACT Entertainment's headquarters in Jackson, Missouri. Guitar World's reviewer rated the build quality five stars, citing the hand-soldered construction, premium CTS pots, and boutique US build.
How much does the Sterling Vermin cost?
The launch press release gave the retail price as $349 USD, and Guitar World's review lists it at $349. Premier Guitar's demo video showed $349.99. The sources differ slightly on the exact figure, but it sits around $350.
Does the Vermin use silicon diode clipping?
Yes, but only as one of two options. A mini-toggle selects between traditional RAT-style silicon diodes, which give a punchy, mid-heavy response, and BAT41 diodes, which the maker and reviewers describe as smoother and more balanced.
Sources (7)
- Act Entertainment Launches Sterling Vermin Pedal, Premier Guitar, 2025-05-07
- Sterling Vermin RAT by Sterling Vermin, RockBoard PedalPedia, 2026
- Act Entertainment Sterling Vermin Rat Distortion Pedal review, Guitar World, 2026-04-06
- John Bohlinger Demos the Sterling Vermin Rat, Premier Guitar, 2025-06-05
- RAT Sterling Vermin Distortion, Delicious Audio, 2025-06-06
- Best distortion pedals for metal: get the ultimate metal tone, Guitar World, 2022-04-26
- Pro Co Rat Analysis, GuitarPCB
