The Airis Effects 51-Filthy is a high-gain preamp pedal, described by Guitar Pedal X as the company's latest "Nasty" high-gain preamp. It delivers what the reviewer called "searing, focused high-gain distortion with solid low-end and mix-cutting clarity," and its circuit lineage combines Block Letter 5150 and Diezel Hagen traits. It is a further evolution of the Airis Nemesis Preamp1.
Sound and character
Airis describes the pedal as "the perfect nasty searing high gain distortion, not with massive amounts of low-end, but a rather a more focused but very solid sounding distortion." In other words, the low end is tighter and more focused than huge, which is where the Block Letter 5150 and Diezel Hagen influences show: a voicing aimed at cutting through a band mix rather than filling it1.
Guitar Pedal X's Stefan Karlsson summed up his impression of the demos:
"The demos sound great - it’s that perfect punchy crunchy high gain distortion sound - which cuts hrough the mix pretty well."1
He added that he was sold on the overall tone, and that the pedal will feature in the site's next "Full Metal Racket" rundown of high-gain gear1.
The controls: a classic 3-band EQ
The 51-Filthy keeps its control layout simple, using a classic 3-band EQ topology1.
| Control | What it does |
|---|---|
| Gain | Sets the amount of high-gain distortion |
| Bass | Low EQ band |
| Mid | Middle EQ band |
| Treble | High EQ band |
| Volume | Sets the pedal's output level |
For a player, that means no hidden menus or secondary functions: the three EQ bands shape the voicing, Gain sets how aggressive the distortion is, and Volume matches the pedal's level to the rest of the rig1.
Availability and price
As of February 2025, the 51-Filthy was priced at $209 CAD on the Airis Effects webstore, which Guitar Pedal X gave as approximately $149 USD1. The pedal is not a continuously stocked product: it is made in several small batches, and those batches sell out very quickly, so finding one can take patience1.
The 51-Filthy is produced in small batches that sell out quickly1.
Where it sits on a board
As a preamp-style distortion pedal, the 51-Filthy belongs to the wider family of preamp pedals and distortion pedals. Its focused low end and mix-cutting clarity place it firmly in the high-gain camp, aimed at players who want an amp-like searing distortion voice in a pedal1.
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Questions
What is the Airis Effects 51-Filthy based on?
Guitar Pedal X describes the 51-Filthy as combining Block Letter 5150 and Diezel Hagen traits. It is a further evolution of the Airis Nemesis Preamp, and Airis describes it as the perfect nasty, searing high-gain distortion with a focused rather than massive low end.
How much does the Airis Effects 51-Filthy cost?
As of February 2025, Guitar Pedal X reported the 51-Filthy priced at $209 CAD on the Airis Effects webstore, which it gave as approximately $149 USD.
Why is the Airis Effects 51-Filthy hard to find?
Guitar Pedal X reported in February 2025 that the 51-Filthy is made in several small batches which sell out very quickly, so availability is limited.
Is the 51-Filthy related to the Airis Nemesis Preamp?
Yes. Guitar Pedal X describes the 51-Filthy as a further Nemesis Preamp evolution, carrying that pedal's high-gain preamp approach forward with new voicing.
Does the 51-Filthy have a bass control?
Yes. Its controls are Treble, Mid, Bass, Volume and Gain, arranged as a classic 3-band EQ topology, so bass is one of the three EQ bands.
Sources (1)
- Guitar Pedal X, Guitar Pedal X, 2025-02-11
