The Universal Audio knuckles is a Universal Audio preamp pedal. Close alternatives include the Mesa Boogie Rectoverb 25 MkII 1x12 Combo and the Blackstar HT Club 40 MKII. It pairs well with the Browne Amplification Gritador and the J. Rockett The Dude.

Universal Audio knuckles

Name: Universal Audio knuckles
Brand: Universal Audio

Universal Audio · pedal

The Universal Audio UAFX Knuckles '92 Rev F is a DSP amp-in-a-pedal emulation of the Revision F Mesa/Boogie Dual Rectifier, the high-gain amp that defined modern rock and metal rhythm tone. The Rev F circuit and power transformer gave increased clean headroom and a tight, punchy bass response, and the pedal captures that thumping low end without muddiness alongside the throaty, scooped midrange character of the original. Three switchable channels move from clean and articulate, through a balanced mid-gain crunch, to a heavy, aggressive saturated lead voice, while selectable solid-state or tube rectifier modes trade tight, immediate attack for softer, spongier sag and feel. A TS-style overdrive and boost, a noise gate for tight gated chugs, six cabinet emulations and room modelling derived from UA's OX Amp Top Box complete the rig, with deeper editing, 6L6 or EL34 output tube selection and bonus cabs available over Bluetooth or USB-C.

What stands out

“the high-gain amp that defined modern rock and metal rhythm tone”
— from the listing
“Universal Audio's Mesa Dual Rectifier simulation in premium UAFX format”
— from the community notes
“Build quality is excellent”
— from the community notes
“Three switchable channels move from clean and articulate, through a balanced mid-gain crunch, to a heavy, aggressive saturated lead voice, while selectable solid-state or tube rectifier modes trade tight, immediate attack for softer, spongi…”
— from the listing
“A TS-style overdrive and boost, a noise gate for tight gated chugs, six cabinet emulations and room modelling derived from UA's OX Amp Top Box complete the rig, with deeper editing, 6L6 or EL34 output tube selection and bonus cabs available…”
— from the listing

Trade-offs

“the rev f circuit and power transformer gave increased clean headroom and a tight”
— from the listing

high gain
mid gain
attack
crunch
bass
clean headroom
balanced
clean

Good for

Silent Recording
Silent Stage
Studio

Genres the Universal Audio knuckles is commonly used in

Metal
Rock
Hard Rock
^cited
Inferred from shared tonal signals, not a stated genre tag.
Heavy Metal
^cited
Inferred from shared tonal signals, not a stated genre tag.
Alternative
^cited
Inferred from shared tonal signals, not a stated genre tag.
Black Metal
^cited
Inferred from shared tonal signals, not a stated genre tag.

Pedals that stack with the Universal Audio knuckles

Browne Amplification Gritador

Browne Amplification

25% match

$219via Reverb

fills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (scooped → mid-forward)

What Browne Amplification Gritador brings here leans toward full — that's worth building a pairing around

Comes earlier in the signal chain

J. Rockett The Dude

J Rockett

25% match

fills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (scooped → mid-forward)

J. Rockett The Dude's own mid-forward character is the real reason this is worth trying

Comes earlier in the signal chain

Orange Series Phaser

Orange

21% match

sits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.

Run Orange Series Phaser after Universal Audio knuckles in the signal chain, clear of Universal Audio knuckles's own gain stage

Comes earlier in the signal chain

Pigtronix Philosopher's Tone Micro

Pigtronix

21% match

$119via Reverb

fills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (scooped → mid-forward)

Pigtronix Philosopher's Tone Micro's own mid-forward character is the real reason this is worth trying

Comes earlier in the signal chain

MXR Analog Delay

MXR

12% match

sits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.

Put MXR Analog Delay after Universal Audio knuckles in the signal chain, clear of Universal Audio knuckles's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Comes later in the signal chain

Universal Audio Golden Reverberator

Universal Audio

11% match

$329via Reverb

sits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.

Universal Audio Golden Reverberator's spring voice goes after Universal Audio knuckles in the signal chain — it's not there to compete with Universal Audio knuckles's own high gain character — goes in the amp's FX loop (or last, into a clean amp)

Comes later in the signal chain

Maxon OD808

Maxon

tonal match

$134.23via Reverb

Comes earlier in the signal chain

Maxon OD808 is voiced for Mesa-style amps — Universal Audio knuckles gives it exactly that

Caline CP-16 MR. Mark

Caline

tonal match

Comes earlier in the signal chain

Caline CP-16 MR. Mark's own voicing points at Mesa-style amps, and Universal Audio knuckles delivers it