The Shift Line A+ Astronaut III Fireworks is a limited edition of the Astronaut III, a compact "multiverb" pedal from Russian maker Shift-Line that packs 22 reverb, delay and sampling algorithms into one box1. The Fireworks version is purely cosmetic: Shift Line says you can order a limited cosmetic edition of the pedal with no changes to its sound or functions1. It sits in a compact and lightweight aluminum enclosure1.
The pedal is built around a fully analog dry signal path, so your unprocessed guitar signal never goes through conversion, while the wet side handles the 22 algorithms1. Delicious Audio, reviewing the standard Astronaut III, called it "the third generation of an atmospheric powerhouse," noting the V3 arrived in a slightly wider case than the previous version2.
The Fireworks edition is a limited cosmetic edition, with no changes to its sound or functions1. The standard Astronaut III carries the same sound and functions.
The controls
The front panel keeps things simple: three knobs and one footswitch, with three LEDs for indications2.
| Control | What it does |
|---|---|
| PROGRAM knob | Selects the effect algorithm1 |
| VOLUME knob | Controls the OUT volume, with an option to boost it1 |
| CHARACTER knob | Controls an extra parameter that depends on the selected algorithm1 |
| BYPASS switch | Multifunctional (see below)1 |
The BYPASS switch does several jobs depending on how you use it1:
- Press once to turn the effect on or off.
- Press and hold to enter Infinity Mode.
- Press and hold while selecting an algorithm to access Bank 2.
- In the Force Roar and Force OctDn algorithms, press to freeze another sound.
Because the CHARACTER knob changes its job from algorithm to algorithm, the same three knobs cover a lot of ground without a menu or screen12.
The 22 algorithms
The pedal contains 22 varied algorithms, split into two banks of 11, selected via the PROGRAM knob, with Bank 2 accessed by holding the bypass switch1. RockBoard's listing for the Astronaut V describes the family as offering "22 unique sound-processing algorithms, each with flexible controls"3. The set includes extended versions of some algorithms from the earlier Astronaut, Astronaut V.2 and the Shift Line Force, and the freeze algorithms were ported from the Shift Line Force microsampler and improved upon1.
A few algorithms the maker and press describe in detail:
- ShimUp 2 and ShimUp 1: classic shimmers with different sound characteristics. CHARACTER is a resonant low-pass filter on the reverb tails in ShimUp-2, and a resonant low-pass filter for the input octaver in ShimUp1.
- ShimUpDown: combines octave-up and octave-down shimmers, with CHARACTER providing mild low-pass filtering1.
- Force Roar and Force OctDn: differently voiced freeze reverb algorithms from the Shift Line Force. The DECAY knob is inactive here, and CHARACTER controls a resonant low-pass filter1.
- Universe M-2 and Universe M-1: complex effects aimed at creating walls of sound, which can turn a guitar into an organ through rotary speakers, a reverb and a mild flanger/phaser. CHARACTER controls the flanger/phaser rate1.
- Eva Octave Arp: randomly goes through octaves and sounds good with chords1.
- Eva Random Arp: adds completely random intervals1.
Players after more conventional delay or reverb sounds will find the algorithm list leans atmospheric and experimental, but the shimmer and freeze families cover familiar ambient territory.
Bypass modes and connections
Three bypass modes are available: Tails, No tails with no input monitoring (the standard mode), and Continuous input monitoring1. Tails lets the reverb ring out after you switch the effect off; continuous input monitoring keeps feeding your playing into the effect even while it is bypassed.
The Astronaut III uses active bypass rather than true bypass. Shift Line states the dry signal is completely unaffected and there are no clicks in the sound, which the fully analog dry path supports1. Delicious Audio confirms the same behavior on the standard version2.
Connections are minimal: one mono input and one mono output, both unbalanced, with 1MOhm input impedance and 100Ohm output impedance1. There is no stereo output, no MIDI and no expression input in the facts the maker publishes.
Power requires a regulated 9V DC supply only, with a 2.1/5.5mm barrel and negative tip1. There is no battery option in the maker's specifications.
Fireworks: a cosmetic limited edition
The Fireworks edition exists for players who want the Astronaut III's feature set in a different finish. Shift Line is explicit that it is a limited cosmetic edition with no changes to its sound or functions1, so the 22 algorithms, the Infinity Mode, the bypass modes and every specification match the standard Astronaut III. The standard pedal's enclosure is described by Delicious Audio as a compact and lightweight anodized aluminum enclosure with laser-engraved graphics1; the Fireworks version carries the same compact and lightweight aluminum construction1.
Shift Line has also offered other cosmetic editions of the Astronaut III, such as the Astronaut III Ribbons, and the family extends to the Astronaut V and the stereo Everest II reverb and delay pedal released in September 2023.
Videos
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Brett Kingman
ShurSoma
Questions
Does the Fireworks edition sound different from the standard Astronaut III?
No. Shift Line describes the Fireworks as a limited cosmetic edition of the pedal with no changes to its sound or functions. The enclosure finish is the only difference; the 22 algorithms, controls, bypass behavior and specifications are identical to the standard Astronaut III.
How does Infinity Mode work on the Astronaut III?
Press and hold the bypass switch for more than 0.3 seconds to enter Infinity Mode, an infinite sustain mode. The same switch is multifunctional: a single press turns the effect on or off, and in the Force Roar and Force OctDn algorithms a press freezes another sound.
Does the Astronaut III have stereo outputs?
No. The Astronaut III has a mono, unbalanced 6.3mm input with 1MOhm input impedance and a mono, unbalanced 6.3mm output with 100Ohm output impedance. It is a single in, single out pedal with top-mounted jacks.
Is the Astronaut III true bypass?
No, it uses active bypass. Shift Line states that the dry signal is completely unaffected in bypass and that there are no clicks in the sound, thanks to a fully analog dry signal path.
Sources (3)
- A+ Astronaut III Fireworks, Shift Line, 2026
- Shift-Line's A+ Astronaut III Reverb/Delay/Sampler, Delicious Audio, 2020-03-19
- A+ Astronaut V by Shift Line, RockBoard (www.rockboard.de), 2026
