The Spaceman Effects Atlas IV is a preamp booster: a booster, a pre-amp and a tone enhancer in one hand-wired box. Spaceman classifies it as a clean boost, but the Atlas IV offers two levels of harmonic enhancement, adding what the maker calls richness and sparkle with up to 15dB of boost power1. In practice that means more volume, more harmonic sparkle and more amp saturation, with light tube-like harmonics and response when you push a tube amp's front end1.
The Atlas IV is the next generation of the highly regarded Atlas III Preamp Booster, which has been out of production for several years. It keeps the same voice and adds two modes, Thrust and Axis, on a pair of toggle switches1. Guitar Pedal X noted it had been 8 years since Spaceman released the Atlas III, then just a single-knob affair2.
A clean boost with harmonic enhancement
On the surface the Atlas IV looks simple: one big knob and two small toggles3. Under the hood it is what Guitar Pedal X calls a full-fat THT circuit, featuring 7 JFET transistors and what looks like a single diode, likely asymmetric clipping and likely engaged with the Thrust switch2. For a player, that means the pedal is not a flat volume lift. Spaceman describes it as adding light tube-like harmonics and response, and Pedal of the Day found it has a natural tone and wide dynamic response, adding an extra dimension to your existing tone without compromise3.
The maker also points to quiet toggle-switching for safe use with cranked amps1, so the Thrust and Axis switches can be flipped mid-song without loud pops through a loud rig.
Pedal of the Day's reviewer was taken with what it does to an amp3:
"This is one of those pedals that makes your amp instantly come to life as soon as you turn it on, becoming a part of our revised demo pedalboard almost immediately."
The same reviewer called it, in the studio, "the ultimate recording tool, by slamming the front end of tube amps for legendary distortion tones"3. Guitar Pedal X's Stefan Karlsson was more measured: "This doesn't really threaten my favourite ThorpyFX Heavy Water Dual Boost, but it is a highly appealing candidate" and he wrote that he was sorely tempted2.
The controls: Boost, Thrust and Axis
Three controls do all the work. The single Boost knob sets the level, up to 15dB2. The two toggles shape what that boost does to your tone.
| Control | What it does |
|---|---|
| Boost (knob) | Sets the boost level, up to +15dB2 |
| Thrust (left toggle, On/Off) | Increases the harmonic saturation of the circuit, slightly lowering headroom and increasing max output by 5dB1 |
| Axis (right toggle, Shift/Origin) | Shifts the voicing up, reducing bass and increasing treble; can turn the Atlas IV into a treble boost or balance between different pickups1 |
Guitar Pedal X summarized the two toggles from a player's angle: the left Thrust one enhances harmonics when engaged, and the right Axis one engages a treble booster essentially2. With both switches off, the pedal behaves as the straight clean boost, the same basic voice as the Atlas III; Spaceman added the two additional modes to make the pedal more powerful than the original3.
Editions, price and availability
The Atlas IV launched in three signed and numbered First Editions: Gray, Black, and White1. The ultra-limited Gray Edition came with a vintage dimmable aerospace indicator, a vintage Soviet Big Muff knob and one of those vintage LED lens caps12. The Black and White Editions were set for general release2.
| Edition | Price (June 2025) | Status |
|---|---|---|
| Limited Gray | £279 GBP | Sold out very quickly2 |
| Black | £249 GBP | Pre-order at launch, general release2 |
| White | £249 GBP | Pre-order at launch, general release2 |
As of August 2025, Pedal of the Day reported that all versions of the pedal were sold out on the Spaceman Effects website3. Spaceman has since added a limited White Light Edition that is only available through stores1. In the UK, Guitar Pedal X suggested stock might appear at Andertons or Axe and You Shall Receive2.
Build and origin
Every Atlas IV is completely soldered and wired by hand in Portland, Oregon1. The pedal sits in a cast-aluminum enclosure with a durable, engraved vinyl faceplate and a jewel indicator light on top3. For players comparing it against other boost pedals or preamp pedals, the hand-wired THT construction and the two-voice toggle arrangement are what set it apart from mass-produced clean boosts.
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Questions
How much boost does the Spaceman Atlas IV give?
The Boost knob delivers up to 15dB of boost power. Engaging the Thrust switch increases the harmonic saturation of the circuit, slightly lowering headroom and raising the maximum output by another 5dB, so the pedal can push an amp's front end considerably harder than the knob alone suggests.
Can the Atlas IV be used as a treble booster?
Yes. The Axis switch shifts the voicing up, reducing bass and increasing treble, which Spaceman says can turn the Atlas IV into a treble boost. Guitar Pedal X described the right-hand Axis toggle as engaging a treble booster essentially. It can also be used to balance the pedal between different pickups.
Is the Spaceman Atlas IV true bypass?
Yes. The Atlas IV uses true-bypass switching via a soft-click footswitch, and it also features quiet toggle-switching, which Spaceman describes as safe for use with cranked amps, so flipping Thrust or Axis mid-song should not produce loud pops.
Where is the Spaceman Atlas IV made?
Every unit is completely soldered and wired by hand in Portland, Oregon, at Spaceman Effects' own workshop. The pedal sits in a cast-aluminum enclosure with a durable, engraved vinyl faceplate and a jewel indicator light.
Is the Atlas IV Grey Edition sold out?
Yes. The ultra-limited Grey Edition, priced at £279 GBP and fitted with a vintage Soviet Big Muff knob and a vintage LED lens cap, sold out very quickly after the June 2025 launch. By August 2025 Pedal of the Day reported all versions sold out on the Spaceman website.
Sources (3)
- Atlas IV: Preamp Booster, Spaceman Effects
- Guitar Pedal X, Guitar Pedal X, 2025-06-26
- Spaceman Effects Atlas IV: Preamp Booster, Pedal of the Day, 2025-08-16
