The Mad Professor Mad-Rbo is a Mad Professor distortion pedal, currently around $185.26. Close alternatives include the Keeley KO-Als Distortion and the EarthQuaker Devices Westwood. It pairs well with the Fender Prosonic and the Marshall JTM45 45W Tube Guitar Amp Head.
Mad Professor Mad-Rbo
Mad Professor · pedal
The Mad Professor Royal Blue Overdrive covers a wide range from light overdrive into full distortion, with Volume, Distortion, Treble, and Bass controls. At its lowest Distortion setting the pedal behaves almost like an EQ stage, adding minimal filtering for a transparent boost. Turning the Distortion knob up moves it into a crunchy, tube-amp-like breakup and eventually into heavier gain. Both Treble and Bass are boost/cut shelving controls, giving broad tonal shaping rather than a single fixed voicing. It is built to go from subtle amp-like grit to genuine distortion within one pedal, and forms the basis of Mad Professor's Supreme A-side circuit.
What stands out
“The Mad Professor Royal Blue Overdrive covers a wide range from light overdrive into full distortion, with Volume, Distortion, Treble, and Bass controls”
— from the listing
“Both Treble and Bass are boost/cut shelving controls, giving broad tonal shaping”
— from the listing
“It is built to go from subtle amp-like grit to genuine distortion within one pedal, and forms the basis of Mad Professor's Supreme A-side circuit”
— from the listing
“Regarded as a flexible workhorse overdrive that covers transparent boost through real distortion in one box, useful for players who want to”
— from the community notes
“Turning the Distortion knob up moves it into a crunchy, tube-amp-like breakup and eventually into heavier gain”
— from the listing
- distortion
- treble
- amp like
- transparent
- breakup
- bass
- exact signature tone
- grit
Price updated Oct 23, 2026
Genres the Mad Professor Mad-Rbo is commonly used in
- Classic Rock
- Blues
- Rock
- Alternative
cited
Inferred from shared tonal signals, not a stated genre tag. - Indie Rock
cited
Inferred from shared tonal signals, not a stated genre tag. - Metal
cited
Inferred from shared tonal signals, not a stated genre tag.
Amps that pair well with the Mad Professor Mad-Rbo
Fender Prosonic
amplifier
24% matchfills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (bright → warm)
Where this leans bright, Fender Prosonic answers back warm
Comes later in the signal chain
Marshall JTM45 45W Tube Guitar Amp Head
amplifier
24% matchfills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (bright → warm)
Run Marshall JTM45 45W Tube Guitar Amp Head after it and the bright edge settles into something more warm
Comes later in the signal chain
Ampeg V-4
Ampeg
tonal matchComes later in the signal chain
Ampeg V-4's warm balances out the bright tone
Ampeg BA 108
Ampeg
tonal matchComes later in the signal chain
Where this leans bright, Ampeg BA 108 answers back smooth
Park P45H
Park
tonal matchComes later in the signal chain
Where this leans bright, Park P45H answers back warm
Hiwatt Park P18LH 'Little 45' Handwired18W
Hiwatt
tonal matchComes later in the signal chain
Hiwatt Park P18LH 'Little 45' Handwired18W leans warm right where the bright tone needs it
Orange BT1000H Terror Bass 1000-Watt Bass Amp
Orange
tonal matchComes later in the signal chain
Orange BT1000H Terror Bass 1000-Watt Bass Amp's warm balances out the bright tone
Orange Terror Bass
Orange
tonal matchComes later in the signal chain
Run Orange Terror Bass after it and the bright edge settles into something more warm
Pedals that stack with the Mad Professor Mad-Rbo
MXR Micro Amp
MXR
22% matchfills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (bright → warm)
Run MXR Micro Amp after it and the bright edge settles into something more warm
Comes earlier in the signal chain
Spaceman Explorer 6-Stage Phaser
Spaceman
21% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Spaceman Explorer 6-Stage Phaser's lush voice goes after Mad Professor Mad-Rbo in the signal chain — it's not there to compete with Mad Professor Mad-Rbo's own bright character
Comes later in the signal chain
Electro-Harmonix Green Russian Big Muff
Electro-Harmonix
20% matchfills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (bright → smooth)
Run Electro-Harmonix Green Russian Big Muff after it and the bright edge settles into something more smooth
Comes later in the signal chain
SahBro? Audio Ross Kempressor
Sahbro Audio
17% matchfills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (bright → warm)
What SahBro? Audio Ross Kempressor brings here leans toward compressed — that's worth building a pairing around
Comes earlier in the signal chain
T-Rex Junior Roomate
T Rex
14% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Keep T-Rex Junior Roomate after Mad Professor Mad-Rbo in the signal chain, clear of Mad Professor Mad-Rbo's own gain stage — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
Line 6 DL4 Delay Modeler
pedal
12% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Keep Mad Professor Mad-Rbo's bright voice out front: Line 6 DL4 Delay Modeler goes after Mad Professor Mad-Rbo in the signal chain so its warm voice doesn't muddy it — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
Dunlop Echoplex Preamp
Dunlop
tonal matchComes later in the signal chain
Dunlop Echoplex Preamp's smooth balances out the bright tone
SolidGoldFX Commodore Breaker Overdrive
Solidgoldfx
tonal matchComes earlier in the signal chain
SolidGoldFX Commodore Breaker Overdrive's smooth balances out the bright tone
Cheaper alternatives
MXR Super Badass Distortion
MXR
58% similarityShared character: treble, boost, transparent
Fuzzrocious Baxstabber EQ/preamp/tone shaper
Fuzzrocious
56% similarityShared character: treble, simple
Walrus Audio 385 Overdrive
Walrus Audio
56% similarityShared character: grit, wide range, volume
Caline CP-12 Blue Pure Sky
Caline
55% similarityShared character: boost, treble, transparent
Bogner Ecstasy Blue Mini Overdrive
Bogner
55% similarityShared character: wide range, boost, subtle
Demon FX Full BB Preamp
Demon Fx
55% similarityShared character: volume, boost, treble
Boutique & premium upgrades
Electronic Audio Experiments Longsword V4.5
Electronic Audio Experiments
59% similarityShared character: boost, treble, subtle
Electronic Audio Experiments Longsword Eastside Exclusive Mono Camo
Electronic Audio Experiments
56% similarityShared character: boost, treble, bass
Origin Effects DCX Boost
Origin Effects
55% similarityShared character: treble, subtle, boost
Analog Man King of Tone
Analog Man
95% similaritysimilar tone character
Similar charactersee all similar tone character →
Keeley KO-Als Distortion
Keeley
61% similarityShared character: treble, bass, distortion
EarthQuaker Devices Westwood
EarthQuaker Devices
60% similarityShared character: boost, treble, subtle
Cusack Music Orthrus Distortion
Cusack Music
60% similarityShared character: high end, treble, simple
Friedman BE-OD Deluxe
Friedman
58% similarityShared character: wide range, volume, treble
Carl Martin Contour
Carl Martin
56% similarityShared character: treble, boost, bass
Electro-Harmonix Crayon
Electro-Harmonix
55% similarityShared character: treble, transparent, gain
See all alternatives to the Mad Professor Mad-Rbo (cheaper + boutique) →
Questions people ask
What are good alternatives to the Mad Professor Mad-Rbo?+
The closest matches in character are the Keeley KO-Als Distortion, the EarthQuaker Devices Westwood, the Cusack Music Orthrus Distortion. Budget picks: MXR Super Badass Distortion, Fuzzrocious Baxstabber EQ/preamp/tone shaper, Walrus Audio 385 Overdrive. Boutique upgrades: Electronic Audio Experiments Longsword V4.5, Electronic Audio Experiments Longsword Eastside Exclusive Mono Camo, Origin Effects DCX Boost.
What pairs well with the Mad Professor Mad-Rbo?+
Strong matches from rig and tone-complementarity evidence: Fender Prosonic, Marshall JTM45 45W Tube Guitar Amp Head, Ampeg V-4 — Where this leans bright, Fender Prosonic answers back warm.
How much does the Mad Professor Mad-Rbo cost?+
Around $185.26 (live listing price, updated Oct 23, 2026).