The Mythos Cestus is a small boost pedal from Mythos Pedals built around a single "Louder" control, which the maker describes as a way to "breath life into your signal or ask your amp for mercy"1. It was later discontinued, and in February 2023 Mythos re-released it as the Cestus Treble Booster, built around the silicon treble boost circuit developed for the SusMaryOsep! V2 signature pedal2.
In its current form it is a Range Master inspired treble booster: Mythos says it takes "that iconic topology and tweaks it to work for all players"3. Where a vintage Dallas Rangemaster used a germanium transistor, the Cestus uses a silicon one, which changes both the sound and the practicalities of owning one.
What the Cestus does to your sound
The 2018 Cestus was a clean boost with a single control, which Premier Guitar's announcement described plainly: "A single 'Louder' control. Use it breath life into your signal or ask your amp for mercy."1 It provided up to 30 dB of boost4, and its small footprint meant "you can sneak it onto an already crowed board"1.
The reissued version is a different animal. Delicious Audio described it as a treble boost with "a unique grit and hair" that "works well even on slightly cleaner guitar amps"2. On That Pedal Show's New Pedal Day video, Mick and Dan noted that silicon's more aggressive upper mids might seem like the wrong choice for a treble booster, but found the opposite:
"which you'd think would be the worst thing for a treble booster but actually that's that's sing beautifully isn't it"
Controls
The reissued Cestus keeps the pedal simple: one knob and one switch.
| Control | What it does |
|---|---|
| SET (output) | Sets overall output, from a slight re-voicing of the signal to "amp crushing power when dimed"2 |
| Toggle, center | Classic treble boost3 |
| Toggle, up | Mid range boost3 |
| Toggle, down | Bass heavy Fat boost3 |
| Internal bias adjustment | Trim control inside the pedal3 |
That Pedal Show described the toggle as giving "that aggressive high-end treble boost somewhere in the middle and th..." across its three positions5, and Delicious Audio called it a 3-way voice toggle taking the tone "from classic/thin boost tones to more mid-foward tones and to bass heavy tones"2. Guitar.com's boost pedal buying guide summed up the design as "with only one knob, but there is still a voice switch for a range of, well, frequency ranges"6.
Silicon instead of germanium
The defining choice in the reissued Cestus is its transistor. Inside is a Military Spec Silicon 2N2222A, which Mythos says "was chosen for its great sound in this circuit"3. Delicious Audio reported that the new version uses the silicon transistor "in lieu of a germanium transistor for more consistent performance"2.
The practical difference matters to anyone who has owned germanium gear. Mythos says that unlike germanium versions, the silicon Cestus "doesn't require a specific type of power and won't fluctuate in tone if the sun comes out at your next gig"3. Guitar.com's buying guide adds that the silicon transistor also makes the pedal "relatively affordable" compared with pedals loaded with an original OC44 germanium transistor6.
Where the circuit comes from
The Cestus is Range Master inspired, as That Pedal Show noted: "it's a silicon transistor as well the original range master was germanium"5. Mythos describes the pedal as "inspired by classic Treble Booster circuits," taking that topology and tweaking it3. The enclosure artwork is a nod to that lineage: Delicious Audio reported it "is inspired by the original amp top boxes that inspired this unit"2.
History and availability
Mythos announced the original Cestus alongside the Herculean V2 overdrive at Summer NAMM 20184. It retailed for $1394 and was hand assembled in Nashville with full size through hole components1. The pedal was later discontinued, as That Pedal Show mentioned when covering its return5, and in February 2023 Mythos re-released it as the Cestus Treble Booster5.
If you find an original 2018 Cestus, it is a clean boost, not the treble booster of the 2023 reissue. The two share a name but not a circuit.
That Pedal Show's New Pedal Day video covers the Cestus alongside the Maestro Agena, Aclam Woman Tone and TC Bucket Brigade, with the Cestus intro at 10:10 and sounds from 11:557. The full demo is worth a watch for how the silicon treble boost sits against a range of other pedals:
Videos
Premier Guitar
Mythos Pedals
Mythos Pedals
Questions
Is the Mythos Cestus based on a Rangemaster?
Yes, in its reissued treble booster form it is Range Master inspired, taking the classic treble booster topology and tweaking it. On That Pedal Show, Mick and Dan described it as a silicon take on the circuit, where the original Dallas Rangemaster used a germanium transistor.
What does the toggle switch do on the Mythos Cestus?
The three-way toggle selects the boost's voicing. Center is the classic treble boost, up is a mid range boost, and down is a bass heavy Fat boost. It lets one small pedal cover thin, cutting boost tones through to fuller, low-end-rich ones.
Does the Mythos Cestus use a silicon or germanium transistor?
The reissued Cestus Treble Booster uses a Military Spec Silicon 2N2222A transistor instead of the germanium transistor of a classic Rangemaster. Mythos says this makes it more consistent, and it does not require a specific type of power.
Where is the Mythos Cestus made?
Mythos Pedals builds its pedals with full size through hole components, assembled by hand in Nashville, Tennessee. The Cestus was announced alongside the Herculean V2 overdrive at Summer NAMM 2018.
How much does the Mythos Cestus cost?
The original 2018 clean boost version retailed for $139. The reissued Cestus Treble Booster's price is not given here, but the silicon transistor was chosen partly to keep it relatively affordable compared with pedals loaded with an original OC44 germanium transistor.
Sources (7)
- Mythos Pedals Launches Herculean V2 & Cestus Booster, Premier Guitar, 2018-06-29
- Mythos Cestus Treblebooster, Delicious Audio, 2023-02-06
- Cestus Treble Booster, Mythos Pedals
- Mythos drops new boost and overdrive pedals, Guitar.com, 2018-07-04
- Maestro Agena, Mythos Cestus, Aclam Woman Tone, TC Bucket Brigade New Pedal Day, That Pedal Show (YouTube), 2022-12-13
- Need a lift in signal? Boost pedals explained, Guitar.com, 2025-08-28
- New Pedal Day Maestro Agena, Mythos Cestus, Aclam Woman Tone, TC Bucket Brigade, That Pedal Show, 2022-12-13
