The Spaceman Rumblefuzz is a fuzz pedal built to hold together at the bottom of the frequency range. Spaceman Effects describes it as "designed to work with lower frequencies," providing "a fat fuzz-stortion, with enough bite to cut through the mix"1. Where many fuzzes thin out or flub out on low notes, this one was voiced so guitar, baritone, bass and even synth keep their body through the effect1.
It was the very first pedal Spaceman Effects ever released, back in 2009, and it existed only as a limited run of 50 numbered handmade pedals12. The company now lists it as a legacy product3. In 2024, for its 15th anniversary, Spaceman brought the circuit back in redesigned form as the Rumblefuzz II4.
A low-frequency fuzz built for bite
The Rumblefuzz sits in the overlap between overdrive, distortion and fuzz. Spaceman says its controls "provide a wide range from light overdrive tones to earth-shaking sonic mayhem"1, so a player can dial it back toward amp-like grit or push it into a full saturated wall. The maker's own tagline for the pedal calls it "the warmest, fattest fuzz on the planet"1, which sets the expectation: this is a thick, low-end-forward fuzz rather than a raspy, cutting one.
Because it was designed around lower frequencies, the pedal is not guitar-only. Spaceman states plainly that it "sounds great with guitar, baritone, bass, synth and more"1, which puts it in the small group of fuzzes a bass player can reach for without losing the fundamental.
The pedal is housed in a die-cast aluminum enclosure topped with a durable engraved faceplate, and each one was handmade in Portland, Oregon1. The 50 units were split into two finishes:
- Numbers 1 to 5: durable Blue powdercoat finish, Blue LED "eyes," Spaceman serial numbers 00001 to 000051
- Numbers 6 to 50: unfinished enclosures, with Red LEDs1
Guitar Pedal X's Stefan Karlsson noted that the original was "long since gone by 2016," with second-hand prices of over $2000, and at times near $30002. That scarcity is what led to the 2024 revival.
The controls and the germanium diode switch
The original Rumblefuzz keeps its control set simple. Spaceman describes the range as running from light overdrive tones to full-on fuzz, with the gain structure shaped by the knobs1. The one switch on the pedal is the tonal wildcard:
| Control | What it does |
|---|---|
| Knobs | Wide range "from light overdrive tones to earth-shaking sonic mayhem"1 |
| Toggle switch | "Adds in a NOS germanium diode, for a different tonal shade"1 |
That toggle is the pedal's second voice. The toggle switch adds in a NOS germanium diode, for a different tonal shade, so the switch gives two shades of the same fat fuzz without touching the knobs1.
The switch also became the seed of the redesign. On the Rumblefuzz II, Spaceman upgraded it from this two-way arrangement to a 3-way voice toggle, with each position affecting bias, compression and presence in different ways34. Guitar Pedal X lists the II's full control set as Fuzz (output volume), Rumble (bass, tight to fat), Bite (gain), and the 3-way switch combining bias, compression and presence options2.
The Rumblefuzz II: the circuit lives on
In July 2024, Spaceman Effects revived its first pedal as the Rumblefuzz II, timed to the company's 15th anniversary4. Delicious Audio reported that the redesigned version keeps the original circuit at its core but adds upgrades, including increased output and tonal range, "mostly due to the upgrade to a 3-way voice toggle (from the previous 2-way one) affecting presence, bias and compression"4.
The II is powered by hand-selected BC108 transistors and runs from transparent amp-like overdrive to a thick, sustain-laden fuzz3. Its control names carry over from the original: FUZZ controls output volume and can overdrive your amp even on low BITE settings; BITE controls the gain of the circuit, with overdrive, distortion and fuzz levels on tap; and RUMBLE tailors the bass response, from tight overdrive tones to incredibly fat fuzz3. Delicious Audio's practical advice on the Rumble knob: keep it low for amp-like tones at low fuzz levels, and turn it up when maxing the fuzz for a fat wall of sound4. The II also adds an EXP / control voltage jack, a 0 to 5V DC TRS input with over-voltage and reverse-voltage protection3.
Like the original, the II is a handmade pedal built in small numbered batches3. The first run was split into two finishes: numbers 1 to 5 carry a durable Blue powdercoat with Blue LED "eyes" and Spaceman serial numbers 00001 to 00005, while numbers 6 to 50 are unfinished and fitted with Red LEDs1. The pedal is housed in a die-cast aluminum enclosure topped with a durable engraved faceplate1.
"This a gorgeously textured extra thick and fat fuzz - which voicing is entirely to my liking"
Karlsson, who owns serial number 057 of the 60 White first-edition units, also found the II combines beautifully with octave fuzzes on his board2. Spaceman itself describes the II as shining on bass and baritone guitars, with full round lows and a unique bite that cuts through the mix3, carrying forward the low-frequency brief that defined the original.
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Questions
Is the Spaceman Rumblefuzz still in production?
No. The original Rumblefuzz was a limited run of 50 numbered pedals released in 2009, and Spaceman Effects now lists it as a legacy product. It was long gone by 2016, with second-hand prices reported at over $2000 and at times near $3000. Spaceman revived the circuit in 2024 as the Rumblefuzz II.
How many original Rumblefuzz pedals were made?
The original run was 50 numbered pedals. Numbers 1 through 5 were finished with a durable Blue powdercoat, have Blue LED eyes, and carry Spaceman serial numbers 00001 through 00005. Numbers 6 through 50 are unfinished, with Red LEDs.
What does the toggle switch do on the Rumblefuzz?
On the original Rumblefuzz, the toggle switch adds in a NOS germanium diode for a different tonal shade. On the Rumblefuzz II, the toggle was upgraded to a 3-way switch, with each position affecting bias, compression and presence in different ways.
Can the Rumblefuzz be used with bass?
Yes. Spaceman says the original Rumblefuzz sounds great with guitar, baritone, bass, synth and more, because it was designed to work with lower frequencies. The Rumblefuzz II is described by the maker as shining on bass and baritone guitars, with full round lows and a bite that cuts through the mix.
What is the Rumblefuzz II?
The Rumblefuzz II is a redesigned version of the original 2009 circuit, released in 2024 for Spaceman's 15th anniversary. It keeps the same control layout but adds a 3-way voice toggle, an expression/control voltage jack, and increased tonal range on the Rumble control. It was made in signed, numbered limited editions.
How much current does the Rumblefuzz draw?
The original Rumblefuzz draws 6.5 mA engaged and 0.5 mA in bypass, running on 9V DC. The Rumblefuzz II draws 2.5 mA engaged and 0.75 mA in bypass, also on 9V DC, negative center via a 2.1mm jack.
Sources (5)
- Rumblefuzz, Spaceman Effects
- Guitar Pedal X, Guitar Pedal X, 2024-07-25
- Rumblefuzz II, Spaceman Effects
- New Pedal: Spaceman Rumblefuzz II, Delicious Audio, 2024-07-16
- Guitar Pedal X, Guitar Pedal X, 2024-12-18
