The Mad Professor Stone Grey Distortion is a Mad Professor distortion pedal, currently around $119.99. Close alternatives include the JHS PG-14 Paul Gilbert Signature Distortion and the Keeley Filaments. It pairs well with the Mesa Boogie Mark Five:25 1x12 Combo and the Marshall JTM45 45W Tube Guitar Amp Head.
Mad Professor Stone Grey Distortion
Mad Professor · pedal
The Mad Professor Stone Grey Distortion is a high-gain distortion pedal with Volume, Distortion, and Tone controls, the Tone acting as a boost/cut shelving EQ similar to a bright switch. It is built to retain note clarity and a tight low end even at extreme gain, staying usable on extended-range guitars such as seven, eight, and nine strings without turning to mud. Lower Distortion settings behave more like an overdrive, while higher settings deliver a fierce, high-gain attack, making it a distortion pedal that can also function as an overdrive rather than only excelling at one end of the gain range. It is designed to add drive on top of an amp's own voicing rather than overriding it.
What stands out
“Range from light overdrive to heavy distortion in one pedal”
— from the reviews
“Praised for razor-sharp note definition at high gain, a trait many lack”
— from the community notes
“It is built to retain note clarity and a tight low end even at extreme gain, staying usable on extended-range guitars such as seven, eight, and nine strings”
— from the listing
“cut shelving eq similar to a bright switch”
— from the listing
“Lower Distortion settings behave more like an overdrive, while higher settings deliver a fierce, high-gain attack, making it a distortion pedal that can also function as an overdrive”
— from the listing
- distortion
- overdrive
- high gain
- low end
- tight
- bright
- clarity
- gain
Price updated Oct 22, 2026
Genres the Mad Professor Stone Grey Distortion is commonly used in
- Metal
- Hard Rock
- Djent
cited
Inferred from shared tonal signals, not a stated genre tag. - Death Metal
cited
Inferred from shared tonal signals, not a stated genre tag. - Rock
cited
Inferred from shared tonal signals, not a stated genre tag. - Alternative
cited
Inferred from shared tonal signals, not a stated genre tag.
Amps that pair well with the Mad Professor Stone Grey Distortion
Mesa Boogie Mark Five:25 1x12 Combo
Mesa Boogie
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 → smooth)
Mesa Boogie Mark Five:25 1x12 Combo's smooth balances out the bright tone
Comes later in the signal chain
Marshall JTM45 45W Tube Guitar Amp Head
amplifier
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)
Where this leans bright, Marshall JTM45 45W Tube Guitar Amp Head answers back warm
Comes later in the signal chain
Ampeg V-4
Ampeg
tonal matchComes later in the signal chain
Where this leans bright, Ampeg V-4 answers back warm
Ampeg BA 108
Ampeg
tonal matchComes later in the signal chain
Run Ampeg BA 108 after it and the bright edge settles into something more smooth
Park P45H
Park
tonal matchComes later in the signal chain
Run Park P45H after it and the bright edge settles into something more warm
Blackstar Unity Bass U250
Blackstar
tonal matchComes later in the signal chain
Blackstar Unity Bass U250 leans warm right where the bright tone needs it
Gallien-Krueger Fusion 210
Gallien Krueger
tonal matchComes later in the signal chain
Where this leans bright, Gallien-Krueger Fusion 210 answers back warm
Orange Little Bass Thing
Orange
tonal matchComes later in the signal chain
Orange Little Bass Thing's warm balances out the bright tone
Pedals that stack with the Mad Professor Stone Grey Distortion
Electro-Harmonix Green Russian Big Muff
Electro-Harmonix
21% 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)
Electro-Harmonix Green Russian Big Muff leans smooth right where the bright tone needs it
Comes later 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.
Keep Spaceman Explorer 6-Stage Phaser after Mad Professor Stone Grey Distortion in the signal chain, clear of Mad Professor Stone Grey Distortion's own gain stage
Comes later in the signal chain
Nobels ODR-1
Nobels
19% matchfills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (transparent → mid-forward)
Into a transparent tone, Nobels ODR-1 brings a pull toward mid-forward that's missing
Comes earlier in the signal chain
Pigtronix Gloamer Volume Swell
Pigtronix
16% 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)
Pigtronix Gloamer Volume Swell's own smooth character is the real reason this is worth trying
Comes earlier in the signal chain
Suhr Discovery
Suhr
13% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Suhr Discovery's warm voice goes after Mad Professor Stone Grey Distortion in the signal chain — it's not there to compete with Mad Professor Stone Grey Distortion's own high gain character — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
Boss DD-3 Digital Delay
Boss
13% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Run Boss DD-3 Digital Delay after Mad Professor Stone Grey Distortion in the signal chain, clear of Mad Professor Stone Grey Distortion's own gain stage — 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
Where this leans bright, Dunlop Echoplex Preamp answers back smooth
Walrus Audio Lillian Multi-Stage Analog Phaser
Walrus Audio
tonal matchComes later in the signal chain
Put Walrus Audio Lillian Multi-Stage Analog Phaser after Mad Professor Stone Grey Distortion
Cheaper alternatives
MXR Super Badass Distortion
MXR
60% similarityShared character: bright, boost, gain
Walrus Audio Fundamental Drive
Walrus Audio
58% similarityShared character: bright, distortion, high gain settings
Vox Joe Satriani Satchurator
Vox
55% similarityShared character: high gain settings, clarity, distortion
Electro-Harmonix Nano Operation Overlord
Electro-Harmonix
94% similaritysimilar tone character
ProCo RAT 2
Proco
94% similaritysimilar tone character
Boutique & premium upgrades
Airis Effects -Nemesis Preamp
Airis Effects
59% similarityShared character: high gain settings, hard rock, clarity
Airis Effects 51-Filthy
Airis Effects
58% similarityShared character: hard rock, distortion, high gain settings
Revv Amplification Mauler
Revv
58% similarityShared character: boost, clarity, distortion
Carl Martin Greg Howe Lick Box
Carl Martin
58% similarityShared character: high gain settings, clarity, full
Wampler Dracarys
Wampler
52% similarityShared character: clarity, distortion, high gain settings
Fortin Amplification 33
Fortin Amplification
50% similarityShared character: attack, boost, distortion
Similar charactersee all similar tone character →
JHS PG-14 Paul Gilbert Signature Distortion
JHS Pedals
56% similarityShared character: high gain settings, hard rock, clarity
Keeley Filaments
Keeley
55% similarityShared character: clarity, distortion, high gain settings
JHS Morning Glory
JHS Pedals
54% similarityShared character: volume, bright, boost
Fender Pugilist
Fender
52% similarityShared character: hard rock, attack, gain
NuX NDS-5 Fireman Distortion Dual Brown Sound
Nux
52% similarityShared character: hard rock, clarity, gain
Black Country Customs Monolith
Black Country Customs
52% similarityShared character: volume, hard rock, gain
See all alternatives to the Mad Professor Stone Grey Distortion (cheaper + boutique) →
Questions people ask
What are good alternatives to the Mad Professor Stone Grey Distortion?+
The closest matches in character are the JHS PG-14 Paul Gilbert Signature Distortion, the Keeley Filaments, the JHS Morning Glory. Budget picks: MXR Super Badass Distortion, Walrus Audio Fundamental Drive, Vox Joe Satriani Satchurator. Boutique upgrades: Airis Effects -Nemesis Preamp, Airis Effects 51-Filthy, Revv Amplification Mauler.
What pairs well with the Mad Professor Stone Grey Distortion?+
Strong matches from rig and tone-complementarity evidence: Mesa Boogie Mark Five:25 1x12 Combo, Marshall JTM45 45W Tube Guitar Amp Head, Ampeg V-4 — Mesa Boogie Mark Five:25 1x12 Combo's smooth balances out the bright tone.
How much does the Mad Professor Stone Grey Distortion cost?+
Around $119.99 (live listing price, updated Oct 22, 2026).