The Tsakalis AudioWorks AC Master is a boost and overdrive pedal that puts two classic British circuits in one enclosure: a Top-Boosted AC30-style preamp and a RangeMaster-style treble booster1. That pairing is deliberate. It is the signal chain behind Brian May's solo tone and Rory Gallagher's snarling leads: a treble booster driving the Top Boost channel of a Vox AC30, the sound of nearly every British invasion record2.
The AC section recreates the jumpered AC30 experience, with Normal and Top Boost channels you can blend against each other, plus an output section with Tone Cut and Master Volume23. The Master section is the treble booster, and Delicious Audio reports that Tsakalis added two things the original one-knob Rangemaster lacked: a Volume control, and a 3-way frequency switch offering Treble, Mid or Bass voicings2.
The two sections and how they are controlled
Each half of the pedal has its own control set, laid out much like the amp and booster it is modeled on13.
| Section | Controls | What they do |
|---|---|---|
| AC (Top Boost channel) | Volume, Bass, Treble | Bright, chimey overdrive with tone shaping34 |
| AC (Normal channel) | Normal | Blends in the second channel, jumpered-AC30 style12 |
| AC (output) | Tone Cut, Master Volume | Tone Cut rolls off high-end fizz; Master Volume sets the overall level23 |
| Master (booster) | Boost, Volume, Range | Rangemaster-style treble boost with added level control13 |
| Master (frequency switch) | Treble / Mid / Bass | Treble for classic glass-cutting bite, Mid for solos that punch through, Bass for thicker, almost-overdrive textures2 |
The 3-way frequency switch is the most practical departure from the original booster. A stock Rangemaster is a fixed treble boost; here you can pull the boost down into the mids for solo cut, or into the bass range for a thicker, near-overdrive push2.
A small design detail worth noticing: the crown on the "A" in "Master" on the enclosure tracks back to the vintage Vox logo1.
Using the sections separately
Both sections have independent I/O, with dedicated input and output jacks for each23. Guitar Pedal X lists the full port layout as TS Mono In, TS Mono Send, TS Mono Return and TS Mono Out1. That means you are not locked into the booster-into-preamp order: you can run the AC preamp alone as a Vox-voiced overdrive, run the booster alone into another pedal or amp, or patch other effects into the send and return, creating an FX loop between the two sections2.
Gearnews found this flexibility central to the pedal's appeal, noting that it can be operated like a Vox amp with a Range Master boost in front of it, and that it delivers that British-amp tone convincingly4.
Silicon, not germanium
The classic Rangemaster treble booster used a germanium transistor, which is part of its sound but also part of its reputation for inconsistency. In the AC Master's Master section, Tsakalis used a carefully selected silicon transistor that mimics the feel without the unreliability of germanium2. For a player who wants the booster half of the Brian May chain without hunting for a stable vintage germanium unit, that is the practical trade on offer.
Maker and price
Tsakalis AudioWorks is the maker of the AC Master. The pedal puts two classic circuits in a single enclosure: an AC-style preamp section with a Tone Cut control that rolls off the high-end fizz, paired with a treble booster section2.
The AC Master lists at $2692. Delicious Audio describes it as the sound of Brian May's solo tone, Rory Gallagher's snarling leads, and every British invasion record, aimed at players chasing those tones2.
"The Tsakalis Audioworks AC MASTER delivers that British-amp tone convincingly and can also be operated like a Vox amp with a Range Master boost in front of it."
Videos
Tone Chase Basement and TsakalisAudioworks
intheblues
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Questions
Can the AC Master's two sections be used separately?
Yes. Both sections have their own input and output jacks, so the AC30-style preamp and the treble booster can run on their own. Because each section has dedicated send and return jacks, you can also patch other effects between the two sections, effectively creating an FX loop inside the pedal.
How much current does the Tsakalis AC Master draw?
It draws about 36mA from a 9V DC power supply with a center-negative 2.1mm plug. The power supply is not included with the pedal, so you need a standard 9V pedal power unit to run it.
Does the AC Master use a germanium transistor?
No. The treble booster section, which is based on the Rangemaster circuit, uses a carefully selected silicon transistor instead. According to Delicious Audio, Tsakalis chose silicon to mimic the feel of the original germanium design while avoiding germanium's reputation for unreliability.
Where is the Tsakalis AC Master made?
It is handmade in Athens, Greece, by Tsakalis AudioWorks, a small maker that has been building pedals there since at least 2020, when it introduced its Molecular Boost multi-function pedal.
What is the Tone Cut control on the AC Master?
Tone Cut sits in the AC section's output stage alongside Master Volume, and it rolls off the high-end fizz, just as the Tone Cut control on a real Vox AC30 does. It is the control you reach for when the Top Boost channel gets too bright or harsh.
Sources (4)
- Guitar Pedal X, Guitar Pedal X, 2026-04-23
- New Pedal: Tsakalis AC Master Boost + Overdrive, Delicious Audio, 2026-04-24
- Introducing AC MASTER British Style Overdrive and Booster from Tsakalis Audioworks, Premier Guitar, 2026-04-23
- Tsakalis Audioworks AC Master: British Drive & Boost, gearnews.com, 2026-04-27
