When I got back into guitar, Modulation was not an area I was overly familiar with initially. I understood overdrives, distortion and fuzz, and had a good handle on delay and reverb, as well as a touch of tremolo. For the longest time I thought tremolo was my favourite modulation effect, but I was often confusing that with vibrato, high oscillation chorus or stuttery phaser even. It’s only been relatively recently that I’ve fully got to grips with all the different flavours of modulation, understand the various different waveforms, and can differentiate between the most obvious varieties of oscillation.
I was quite early on drawn towards the Strymon big box workstations - acquiring the TimeLine, BigSky and Mobius in short order. At the time I had not done anywhere near as deep a research as I have now, but in considering what was available at the time I would most definitely have made the same decision. The Mobius is a great one-box solution for modulations, it benefits from Strymon’s usual sweet-spot magic, and all the major effects sound lush and pristine, and you have a few odd ones for added fun.
Back then I only really considered the Mobius vs the Eventide ModFactor, but since I already had the TimeLine and BigSky it made sense to complete the set with the Mobius. The Eventide ModFactor kind of set the scene for Strymon though, and it remains a worthy alternative. Eventide latterly brought out the H9 Harmonizer - which in its Max Stomp Box version gives you access to every single Effects Algorithm Eventide have ever made - for ModFactor, TimeFactor, Space, PitchFactor and several other exclusives. The H9 really needs some sort of 3rd party control device / Midi Controller though - as you can’t easily footswitch between presets on the pedal. It’s great if you have a GigRig G2 style professional switching looper, but kind of out of sorts within a regular pedal chain. You can buy several 3rd party control devices to get more out of the H9 - which I always feel kind of defeats the object of having said pedal so compact in the first place.
For a long time it was really just Eventide vs Strymon in the upper reaches of all-in-one studio-level modulation pedals. But then along came Boss with its Dual Simultaneous Effect MD-500 - and kind of stole some of the spotlight away from both of them. I had already acquired and was loving the Boss RV-500 Reverb, and it was a no-brainer for me to get its almost equally fabulous sibling. Again, like the BigSky vs the RV-500 there is not much to separate the two in terms of effect types and sound quality - the key factor is that with the Boss you can have two effects active simultaneously - series / parallel / A/B stereo split - which makes for some amazing modulation possibilities - particularly for those experimenting with ambient textures.
The somewhat old-fashioned Line 6 MM4 still looks to have some miles left on its clock - it certainly comes packed with lots of options for a relatively low outlay. I have rather more of a preference for the Keeley Super Mod Workstation which has two separate Channels of 8 effects each - combining modulation with delay and reverb - all in the one pedal.
The Empress Nebulus and TCE Dreamscape are just different interpretations of the same sort of thing - Chorus/Flanger/Vibrato - the larger pedal with 9 options and the smaller with 7 - but one of those is a super-configurable TonePrint. Lastly, there is the mini Mooer Mod Factory which somehow manages to fit 11 modulations into its tiny enclosure - not all classics by any means, but super versatile for its size.
I already believe I have the 2 main contenders here in the MD-500 and the Mobius - I quite fancy the tiny Mooer just for a bit of fun - that will likely happen anyway - as I like my mini pedals too. The Keeley Super Mod Workstation intrigues - to have all Delay, Reverb and Modulation in such a tiny box, but it is much more limited in scope than the leading contenders here. I also fancy that at some stage I will try out the Eventide H9 - just for sake of completion. Eventide has been in this game for a very long time, and has some truly exceptional unique algorithms - like the ’Blackhole’ that I would love to get my hands on. It is a very feature-rich and capable pedal, but the very opposite of the Empress EchoSystem I like so much - with far too much going on in sub-menus and apps, and no quick and easy way to stomp between presets - unless you have some form of professional switching looper or midi controller.
As a postscript to the intro, I still feel that this particular category is somewhat underdeveloped - there are of course lots of multi-effect boxes like the Line 6 M5/M9/M13 etc. - but not a lot of regular or medium enclosure pedals which cover this ground. I find it a little odd that the Mooer Mod Factory can have 11 algorithms, but then you have to ramp up to the Keeley to find something sort of equivalent - I would have thought TC Electronic would have benefited by doing a Modulation equivalent of the regular-sized Flashback and Hall of Fame - same for say Strymon to do more combined effects in their Medium-sized enclosure. Strymon has the BigSky and BlueSky, the TimeLine and DIG / El Capistan, but nothing which comes remotely close to its Mobius offering. I would have thought there would be obvious openings in the marketplace for regular-sized multi-modulation, as well as medium-sized - perhaps Source Audio will follow up its Nemesis and Ventris with a Modulation pedal of the same size - I feel there is definitely an opportunity there!
Pedals pictured and listed alphabetically by brand.
This is my current top choice - I so loved its Boss RV-500 sibling that I quickly ordered this soon after. As a universal modulation workstation - there's not a lot to separate this from the Strymon in terms of core sounds - I do much prefer Boss's menu system, how the footswitches work, and of course the ability to run Dual Simultaneous effects. Boss has made use of the latest technologies and the latest R&D - meaning that it should darn well be an improvement over the several years old Mobius - that does not mean the Mobius is out for the count - I still love it, and will retain it as an alternative for certain specific effects. The Boss MD-500 contains the following modes - Chorus | Flanger | Phaser | Classic Vibe | Vibrato | Tremolo | Dimension | Ring Mod | Rotary | Filter | Slicer | Overtone. I have to say that I use Ring Mod, Slicer and Overtone a lot more than I did with the more unusual flavours of the Mobius - in terms of core effect types, I find the Boss overall just a little more to my taste.
As mentioned in the intro, this to me seems like Empress's interpretation of TC Electronic's much loved Stereo Chorus Flanger - albeit this version is in mono. Combining different flavours of Chorus, Vibrato and Flanger - you get an even spread of modulation effects, but not quite up with the upper echelon here or the similarly sized Keeley Super Mod Workstation. What you can always be sure of with Empress though is top-notch build and components - with the most hi-fidelity of pristine output - across the following modes / sub-modes - Chorus | Multi-Chorus | Chorus w/Trem | Uni-Vibe | Vibrato | Rotary | 60s Flanger | 70s Flanger | Thru 0 Flanger. So there is certainly a significant amount on tap - just not quite enough for my needs.
If you want to buy into the full-fat version of H9 - it is truly quite pricey, but then remember that the Space alone is priced around £500 = so for around £150 more - you're getting the whole kit and caboodle of everything Eventide has to offer. However, the H9 is not as much fun to manipulate as the various Eventide Factor pedals - having only 2 footswitches and a single large dial for active control / tweaking - the other 5 buttons simply access presets and parameters. I'm the kind of person that likes to be able to tweak on the go - ideally using surface dials. I'm not much of a fan of diving into apps and sub-menus to raise a setting by 1 degree. That said - you cannot get a more powerful modulation pedal than the fully loaded H9 - which comes preloaded with 49 Effect Algorithms, over 500 presets - and all of Space + TimeFactor + ModFactor + PitchFactor + H9 Exclusives. I will quite likely get one of these at some stage in the future, but certainly not for a while - I have other priorities to settle first.
Like the TimeFactor, I feel this is starting to show its age a little. The large number of surface dials is superb, as are the included modes - Chorus | Phaser | Q-Wah | Flanger | ModFilter | Rotary | TremoloPan | Vibrato | Undulator | RingMod. The limited screen display though is a bit of a waste - particularly when you compare it to the Boss 500 serues displays - which give you all the information you need in the most intuitive of fashions. If this was a mobile phone it would be equivalent to 4th generation, Strymon is 6th generation and Boss is bang up-to-date with its 8th generation type!
The mid-size Keeley is a wonder of engineering with its two separate Channels of 8 effects each - mixing up Modulations with Delay and Reverb - Channel 1 - Harmonic Trem | Phaser | Chorus/Vibrato | Flanger | Rotary | Digital Delay | Hall Reverb | Plate Reverb, and Channel 2 - Tremolo | Harmonic Trem | Filter/Wah | Phaser | Automatic Double Tracker | Rotary | Digital Delay | Analog Delay. I think it's a great solution for a compact pedalboard, but not necessarily broad enough in its coverage to provide long-term satisfaction, at least not for my tastes. The Delay Workstation is more to my liking really - this combination of Delay + Reverb + Modulation across two channels is probably a step to far, and leads to quite significant compromises all-round - for full satisfaction you really need 3 separate channels for Modulation, Delay and Reverb - that way you get to broaden the scope of effect types available too. A clever solution nevertheless, even though it is a touch compromised.
A touch more expensive than its green delay workstation sibling - this old-school pedal has no less than 16 modulation effects modes and 4 footswitch buttons for presets and switching. Not quite up to the pristine quality of the more modern big box workstations featured on this page, but neither is it to be sniffed at - coming in at circa 1/2 the price of the new Boss - if you are strapped for cash - this is certainly a decent option (and there are various modded versions out there too). Modes included are - Opto Tremolo | Bias Tremolo | Phaser | Dual Phaser | Panned Phaser | U-Vibe | Rotary Drum | Rotary Drum & Horn | Analog Flanger | Jet Flanger | Analog Chorus | Dimension | Tri Chorus | Pitch Vibrato | Ring Modulator | Panner. Note that the pedal is quite wide and will take up somewhat significant space on a pedalboard. Really rather a decent modulation pedal though despite its odd looks.
This one is not really supposed to compete with the best that's featured here - but if you want to experiment with modulations, get a flavour of them, or are strapped for pedalboard space or cash - then this one is yours for less than a third of the nearest priced alternative. Note that a few of the effects are a touch squiffy, but you do get 11 to play with, and some of them are far better sounding than they have any right to be really - the 11 modes are Chorus (CH) | Flanger (FL) | Phaser (PH) | Envelope Phaser (EPH) } Tremolo (TR) | Stutter (ST) | Vibrato (VB) | Univibe (UV) | Auto Wah (AW) | Touch Wah (TW) | Ring Modulation / Envelope Ring (ER).
This is now my reserve / alternative / second favourite - though of course still excellent and it effortlessly creates the most lush and pristine soundscapes - has a good 10 to 15 fantastic presets that I use all the time - it is not my day-to-day active choice, but there are some things it still does better than the Boss, it just does not have Boss's fabulous additional feature set or easy controllability and navigability. Something Strymon could sort with a better screen and more intuitive navigation. I still don't think anyone has got it perfect right yet - I love having a screen, but I have a slight allergy to diving into sub-menus too - so I like to know exactly what is going on, but would prefer more / dedicated dials to be able to immediately and intuitively tweak the output. Effects included are - Chorus | Flanger | Rotary | Vibe | Phaser | Filter | Formant | Vintage Trem | Pattern Trem | Autoswell | Destroyer | Quadrature.
This is the more modern and compact version of TC Electronic's classic Stereo Chorus Flanger (SFC) pedal. It also happens to be John Petrucci's signature modulation pedal, although it has been noticeably absent from his pedalboard of late. It is full stereo in and out, and a more compact version really of what the Empress Nebulus covers - Chorus 1 | Flanger 1 | Vibrato 1 | Chorus 2 | Flanger 2 | Vibrato 2 | TonePrint. I still wonder why Tore and TC Electronic have not done a more full-featured modulation pedal at this size - to sit alongside the Flashback and Hall of Fame - they could 'own' the regular-size pedal market even more than they already do. The battle in this category is kind of between the traditional Boss workhorse hinge pedals, and TCE's more modern TonePrint-enabled ones. Of course there is room for both, but for me TC are kind of kicking Boss's butt in that category at the moment. It is understandable why Boss has gone after Strymon, but it needs to guard its bread-and-butter territory too, because TCE is seriously coming at it in all sorts of areas. I like both and support both - they do there own thing and are consistently excellent at what they deliver.
As a mini postscript here - I really want a MASH-enabled regular-sized modulation workstation from TC Electronic - I just wish they would hurry up and build it. I see space for Source Audio to bring out a modulation companion pedal to its Nemesis and Ventris - at that same slick form factor. I do worry a little for Strymon though in that Source Audio is hitting them hard at the medium-sized form-factor, while Boss is going hard at the bigger boxes. Strymon has obviously been concentrating on drive pedals of late - they need to get back to innovating in their heartland, otherwise they may start to loose market-share.