Skip to main content
MusicRadar MusicRadar The No.1 website for musicians
UK EditionUK US EditionUS AU EditionAustralia SG EditionSingapore
Sign in
  • View Profile
  • Sign out
  • Artist news
  • Guitars
  • Controllers
  • Drums
  • Keyboards & Pianos
  • Guitar Amps
  • Music Gear Reviews
  • Synths
  • Software & Apps
  • More
    • Recording
    • DJ Gear
    • Acoustic Guitars
    • Bass Guitars
    • Tech
    • Tutorials
    • Reviews
    • Buying Guides
    • About us
More
  • Tiny Dancer
  • Browser DAWs
  • 95k+ free music samples
  • Restring your guitar
  1. Guitars
  2. Guitar Pedals

Review round-up: guitar synth pedals

News
By Alex Lynham
Published 24 July 2019

Transform your electric guitar into a synthesizer with these offerings from Keeley, Electro-Harmonix, Pigtronix and Seymour Duncan

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Analogue synthesis has, somewhat rightly, a fearsome reputation for complexity, with terms like LFO and VCO thrown around in abandon. 

Until recently, guitarists had to learn the keyboard before being able to utilise synthesiser tones, or resort to weird and wonderful gadgets like the Roland V Guitars, or external hex pickups.

Now, however, advances in tech have put synthesis in the hands of your average axe-slinger, with no external gubbins or jargon required... or so the manufacturers claim. 

We thought we’d put this to the test, so we’ve got four of the best analogue guitar synth pedals together to see if we can wrap our luddite minds around them. Synthtopia or epic fail? Let’s find out...

Page 1 of 5
Page 1 of 5
Keeley Synth-1

Keeley Synth-1

Inspired by the legendary Boss Slow Gear, the Synth-1 is an envelope filter with some added synth goodness. 

The ‘chaos’ switch adds octave artefacts and overtones - which leads us to assume it’s probably a feedback circuit of some kind – while the filter control is a band-pass for the wave generator. There’s options for triangle, sine and square waves, and also for using an expression pedal, for almost wah-like control of the filter. 

In terms of tone, it’s thick, fuzzy and particularly tasty in the triangle mode with a slow attack. With the blend all the way up, we could see how this could become a trusted studio tool. 

4 out of 5 

Page 2 of 5
Page 2 of 5
Electro-Harmonix Mono Synth

Electro-Harmonix Mono Synth

With a reasonably compact form factor and functional good looks, the EHX Mono Synth definitely has the cool points going for it even before we plug it in. 

From then on it’s hard to get our jaw off the floor. The ‘Nu Wave’ patch is pure Gary Numan, and has us Googling the tab for Cars; ‘Unison’ sounds like giant mechs battling over Tokyo; ‘XOX’ is a RATM-style bass synth envelope; ‘Ghost’ is organ-like; and ‘Tinker’ slightly chiptune-esque. 

Throughout, the tracking is not bad at all, so long as it’s the first pedal in the chain; certainly more than good enough for guitar or bass live.

5 out of 5

Page 3 of 5
Page 3 of 5
Pigtronix Mothership 2

Pigtronix Mothership 2

In terms of pure tracking, the Pigtronix is a staggering achievement. 

We spent a few minutes trying to wrong-foot it with bends and detunes by pushing the headstock and it reacted perfectly, so long as we stuck to single notes and not chords. It combines square, triangle and sub octave sine wave oscillators into a single heavily-customisable synth sound, with extra expression input and a dedicated sub output. 

We had the most fun in the octave and unison modes, but on the whole it’s easy to find good synth tones from this unit, even if the number of controls on the front is initially a bit overwhelming. 

4 out of 5

Page 4 of 5
Page 4 of 5
Seymour Duncan Fooz

Seymour Duncan Fooz

Our rule of thumb with gear is that we should be able to roughly work it out without the aid of the manual - after all, the intuitiveness of the guitar is half the fun, right? 

With the great power of the Fooz synth, fuzz, trem, filter and all, comes a complexity that does require some reading. However, once it’s dialled in it serves well as a filter and envelope follower with more than your usual array of tweakable parameters. 

Though it does do the auto-wah thing well, that’s essentially the one core sound on offer, even if it can be altered via the filter, trem, fuzz and wave- shape control on the LFO. 

3.5 out of 5

Page 5 of 5
Page 5 of 5
Alex Lynham
Alex Lynham

Alex Lynham is a gear obsessive who's been collecting and building modern and vintage equipment since he got his first Saturday job. Besides reviewing countless pedals for Total Guitar, he's written guides on how to build your first pedal, how to build a tube amp from a kit, and briefly went viral when he released a glitch delay pedal, the Atom Smasher.

Read more
Neural DSP Quad Cortex
Guitar Pedals Best multi-effects pedals 2026: Our pick of the best all-in-one guitar FX modellers
 
 
Three new additions to the $99 JHS Pedals range: Glitch Delay, Bit Crusher and Ring Modulator – all compact stompboxes with white enclosures and three knobs
Guitars Meet the $99 stompbox that’ll crush your bits – JHS expands its affordable 3 Series with three exotic effects for your pedalboard
 
 
Electro-Harmonix Dual Op-Amp Big Muff Pi 2
Guitar Pedals Electro-Harmonix Big Muff Pi 2 Dual Op-Amp Fuzz review
 
 
synths
Tech 5 innovative synth plugins daring to do things differently
 
 
Meris Ottobit X
Guitars Meris unveils the Ottobit X, a high-end purveyor of lo-fi guitar sounds inspired by the ‘80s
 
 
Stranberg x Jam Stik MIDI
Electric Guitars “Sounds you'll never have heard from a guitar before”: Strandberg x Jamstik Chameleon review
 
 
Latest in Guitar Pedals
Electro-Harmonix Dual Op-Amp Big Muff Pi 2 Deluxe
Guitars “The final boss of the lost Dual Op-Amp circuit”: Electro-Harmonix unveils Deluxe Big Muff Pi 2
 
 
Strymon TimeLine MX
Guitars Strymon supercharges its flagship delay – meet the TimeLine MX
 
 
Walrus Audio Lüm Texture Engine
Guitars Walrus Audio’s Lüm is a feature-packed “Texture Machine” for when your guitar tone feels predictable
 
 
Electro-Harmonix Dual Op-Amp Big Muff Pi 2
Guitar Pedals Electro-Harmonix Big Muff Pi 2 Dual Op-Amp Fuzz review
 
 
A Blackstar ID:X Floor Three multi-effects pedal and amp modeller on a worn, wooden floor
Guitar Pedals “An effortlessly usable unit that delivers dynamically playable sounds”: Blackstar ID:X Floor Three review
 
 
MusicRadar Guitar Gear Round-up June 2026
Guitars MusicRadar’s epic guitar gear round-up: June ’26 edit, ft. EHX, PRS, Fender’s mega-launch and more
 
 
Latest in News
Pink Floyd DSOTM tape
Gear & Gadgets Pink Floyd’s legendary Dark Side of the Moon officially returns to the cassette format
 
 
ag cook
Tech AG Cook and Native Instruments team up for signature synth plugin Super*Saw
 
 
Questlove and Prince
Artists Questlove on the moment he discovered what ended up becoming his favourite Prince song
 
 
Electro-Harmonix Dual Op-Amp Big Muff Pi 2 Deluxe
Guitars “The final boss of the lost Dual Op-Amp circuit”: Electro-Harmonix unveils Deluxe Big Muff Pi 2
 
 
British pop star Davy Jones before he changed his name to Bowie following the success of the Monkees and their lead singer Davy Jones
Singers & Songwriters “At the end of the session Jimmy said, referring to Pity the Fool, 'Well, it's definitely not going to be a hit.' And he was right.”
 
 
suno
Tech Suno scraped millions of songs from YouTube, Deezer and stock music libraries, according to hacked data
 
 

MusicRadar is part of Future plc, an international media group and leading digital publisher. Visit our corporate site.

Add as a preferred source on Google Add as a preferred source on Google
  • About Us
  • Contact Future's experts
  • Terms and conditions
  • Privacy policy
  • Cookies policy
  • Advertise with us
  • Accessibility Statement
  • Careers

© Future Publishing Limited Quay House, The Ambury, Bath BA1 1UA. All rights reserved. England and Wales company registration number 2008885.

Please login or signup to comment

Please wait...