The Muir Audio Silicon Steel Distortion is a distortion pedal from Muir Audio, released in November 2025 as the third pedal in the Silicon Steel Series, following the Boost and the Overdrive1. Its voice comes from a complex layering of input gain, diode clipping and transformer action, which Guitar Pedal X's Stefan Karlsson described as "a gorgeously textured sort of smooth and creamy distortion with a complex layering of input gain, diode clipping and tra..."2
How the circuit works
The distortion voice comes from the sum of several stages interacting at different gain levels: an input stage, a silicon signal diode stage, a transformer gain stage, and another asymmetric diode stage1. In other words, the clipping is not produced by one diode pair alone but by stages that engage differently depending on how hard the input and drive are set.
The diodes themselves are what Muir Audio calls top secret Silicon Signal Diodes. Germanium diodes were tried during product development and rejected1. The transformer is a hi-fidelity audio output transformer, a component Muir Audio also uses across the Silicon Steel Series; a Guitar Pedal X write-up of the series said "the combination of superior components and hi-fidelity audio output transformer delivers superior results!"3
Controls
| Control | What it does |
|---|---|
| Output | Sets the output level1 |
| Drive | Sets the drive amount1 |
| Bass | Bass EQ control1 |
| Treble | Treble EQ control1 |
The two EQ controls are tuned to interact. On the series' overdrive, Muir Audio's approach is that mid-cut and mid-boost frequencies are subtly tuned differently in the two EQ controls, which interact with each other to offer a broader EQ range4.
How it compares with a Rat
Guitar Pedal X's reviewer put the gain range in Rat territory but drew a clear line between the two pedals: "The range of gain available is probably comparable to say a Rat pedal - but The Silicon Steel Distortion is a very diffe..."1. So a player shopping against a Rat should expect a similar spread of gain settings but a different character, built from the transformer and multi-stage clipping rather than a single clipping stage.
The Silicon Steel Series
The pedal is part of a three-pedal line Muir Audio calls the Silicon Steel Series Trifecta: Boost, Overdrive and Distortion1. The Boost came first as a high-headroom, high-fidelity tone enhancer using an audio output transformer and active dual-band EQ1, and the Overdrive followed, announced in October 2023 as a transformer gain stage overdrive pedal. The Distortion completes the set1.
What reviewers said
Guitar Pedal X reviewed the pedal on release in November 2025 and named it a BRONZE pick in its 2025 best new distortion pedals roundup the following month2. The reviewer's overall verdict was unambiguous:
"The Silicon Steel Distortion is one of my favourite ever Distortion sounds!"
The design is credited to Colin of Muir Audio Design, whose notes the review quoted at length1. The listed price differs between the two: the November 2025 review listed the pedal at £199 on the Muir Audio Webstore1, while the December 2025 roundup listed it at £1952.
Videos
MUIR AUDIO DESIGN
Joe Perkins
Questions
What other pedals are in the Muir Audio Silicon Steel Series?
The Silicon Steel Series has three pedals: the Boost, the Overdrive and the Distortion. The Distortion is the third and newest, following the Boost and Overdrive. Guitar Pedal X refers to the three together as the Silicon Steel Series Trifecta.
What kind of diodes does the Silicon Steel Distortion use?
It uses silicon signal diodes, which Muir Audio describes as top secret. Germanium diodes were tried during product development and rejected. The clipping comes from a silicon signal diode stage plus a second asymmetric diode stage later in the circuit.
Is the Silicon Steel Distortion similar to a Rat?
Only in gain range. Guitar Pedal X's reviewer says the range of gain available is probably comparable to a Rat pedal, but that the Silicon Steel Distortion is a very different pedal with its own distinct character.
What controls does the Silicon Steel Distortion have?
Four controls: Output sets the output level, Drive sets the drive amount, and Bass and Treble form a two-band EQ. The EQ controls interact, with their frequencies subtly tuned differently, which broadens the effective EQ range.
Who designed the Muir Audio Silicon Steel Distortion?
It was designed by Colin of Muir Audio Design. Guitar Pedal X's review quotes Colin's design notes directly, calling them the perfect summation of what makes the distortion unique.
Sources (4)
- Guitar Pedal X, Guitar Pedal X, 2025-11-25
- Guitar Pedal X, Guitar Pedal X, 2025-12-05
- Guitar Pedal X, Guitar Pedal X, 2023-12-16
- New Pedal: Muir Silicon Steel Drive, Delicious Audio, 2023-10-06