The Tsakalis Audioworks AC MASTER is a two-in-one boost and overdrive pedal that combines a RangeMaster-style treble booster with a Top-Boosted AC30-style preamp in a single box1. Announced in April 2026 and handmade in Athens, Greece, it is aimed squarely at players chasing classic British tones: Premier Guitar describes it as "a VOX-style overdrive and a Range Master inspired booster" whose two sections cover "everything from sparkling edge-of-breakup, sweet-singing overdrive tones to aggressive classic rock saturation"2.
The idea behind it is a famous pairing. Brian May ran a Rangemaster-style treble booster into the Normal channel of Vox AC30 combos3, and the AC Master puts both halves of that signal chain, the booster and the amp-style preamp, on one pedalboard-friendly unit.
A Rangemaster-style treble booster and an AC30-style preamp
The AC Master holds two independent circuits with flexible routing options2. The AC section recreates the jumpered AC30 experience, with Normal and Top Boost channels that can be blended together, plus an output section52. The Master section is the RangeMaster-style booster half2.
Where the original Rangemaster was a one-knob germanium design, Tsakalis used a carefully selected silicon transistor that, as Delicious Audio puts it, "mimics the feel without the unreliability" of germanium5. That is a practical difference for players: no temperature-sensitive germanium quirks, and the booster side also gains a Volume control the original one-knob design never had5.
The two channels of the AC section have distinct characters, as Premier Guitar describes them2:
| Channel | Character | Controls |
|---|---|---|
| Normal | Warm, thick and slightly fuzzy overdrive | Volume only |
| Top Boost | Bright, chimey overdrive | Volume, Bass, Treble |
Blending the two is what an AC30 player does with a jumper cable between the Normal and Brilliant inputs, and here it is done with knobs instead of patch cables5.
The controls: the AC side and the Master side
Each side has its own control set, and each side has its own footswitch1.
- Normal and Top Boost channel controls, blendable
- Bass and Treble shaping the character of the Top Boost channel
- Tone Cut and Master Volume in the output section, with the Master Volume keeping the overall level down
- Boost, Volume and Range controls
- A 3-way frequency switch: Treble for what Delicious Audio calls classic glass-cutting bite, Mid for solos that punch through, and Bass for thicker, almost-overdrive textures5
The Range control and the 3-way switch are what separate this from a straight Rangemaster copy. The original had one knob and one fixed frequency emphasis; here you can aim the boost at the treble, the mids or the bass depending on the amp and the part51.
Both sections have independent I/O, with TS Mono In, Send, Return and Out ports on the enclosure15. That opens up routing options: the booster can feed the preamp in series for the full May-style chain, or the two sides can sit at different points in a larger pedalboard, for example with the Send and Return looping in other effects.
A small design detail worth noticing: the crown on the A in "Master" on the artwork references the vintage Vox logo, as Guitar Pedal X points out1.
Brian May and Rory Gallagher tones
The pedal's stated target is "Brian May and Rory Gallagher tones, including searing melodic lead lines"1. Delicious Audio frames the AC section's sound the same way: "It's the sound of Brian May's solo tone, Rory Gallagher's snarling leads, and every British invasion record"5.
The historical basis is real. Brian May used a couple of Vox AC30 combos with the Rangemaster in front of the Normal channel3, which is exactly the booster-into-preamp arrangement the AC Master puts in one box. Guitar Pedal X's reviewer went further on the feature set:
"It has exactly the right complement of controls to get maximum impact out of this combination - and achieve the full range of those Gallagher and May tones - all the way to those searing melodic lead lines."1
The same reviewer's one criticism was the layout, not the sound: he would have preferred the enclosure in portrait format rather than landscape, but added that he "can't really grumble" given the feature set1.
Power, price and availability
The AC Master runs on 9V DC, center negative, through a 2.1mm plug, drawing about 36mA; the power supply is not included2. At 36mA it is an easy load for any pedalboard power supply.
On price, the press does not agree, so both figures are given: Premier Guitar lists the US MAP at $2692, while gearnews.com reported $245 (with £220 and €249 equivalents) at the end of April 20264. Guitar Pedal X gave the price as €249 / $269 / £2191. The pedal is available through dealers such as Thomann4.
Tsakalis AudioWorks is a small Greek builder; its earlier release, the Molecular Boost, was a mini pedal combining boost, buffer, preamp and volume pedal functions. The AC Master is a much more focused instrument: one amp voice and one booster, both aimed at the preamp side of a pedalboard.
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Questions
Can you use both sides of the AC Master at the same time?
Yes. The AC Master contains two independent circuits with flexible routing options, and both sections have their own inputs and outputs, so you can run them together or separately. Each side also has its own footswitch, so you can bring the booster in and out over the AC30-style preamp like running a Rangemaster into an amp.
What power does the Tsakalis AC Master need?
It runs on 9V DC from a center-negative 2.1mm plug, drawing about 36mA. The power supply is not included, so you need a standard pedalboard supply. There is no battery option mentioned.
Can the AC Master get Brian May and Rory Gallagher tones?
That is the stated aim. The pedal combines a RangeMaster-style treble booster with a Top-Boosted AC30-style preamp, the same pairing Brian May used with his Vox AC30 combos, and reviewers describe it as covering the full range of the Gallagher and May tones, from edge-of-breakup overdrive to aggressive classic rock saturation.
Where is the Tsakalis AC Master made?
It is handmade in Athens, Greece, by Tsakalis AudioWorks, a small builder that also makes the Molecular Boost utility pedal. The AC Master was announced in April 2026 and is available through dealers.
Sources (5)
- Guitar Pedal X, Guitar Pedal X, 2026-04-23
- Introducing AC MASTER British Style Overdrive and Booster from Tsakalis Audioworks, Premier Guitar, 2026-04-23
- RM Majestic Treble Booster, treblebooster.net, 2025
- Tsakalis Audioworks AC Master: British Drive & Boost, gearnews.com, 2026-04-27
- New Pedal: Tsakalis AC Master Boost + Overdrive, Delicious Audio, 2026-04-24
