This article was triggered by the recent release of the diminutive Old Blood Noise Endeavors Expression Slider - which has yet to reach distribution on this side of the pond. I’ve long held a love/hate relationship with expression pedals - where the only one acquired to date has been the Dunlop DVP4 Volume (X) Mini - which enjoyed a relatively short stint in my pedal-chain.
I really like the idea of TC Electronic’s ’MASH’ functionality - which brings the expression function onboard the pedal and within the footswitch - although on pedals like the Brain Waves Pitch Shifter it does not always work as smoothly as you would like - in some ways I would really just prefer a momentary switch - where I can control the rate of change and which parameters are impacted.
For a while I was considering the Classic Audio Effects Expression Roller, and then the Seafoam Pedals Expression Knob - yet I feel the newest - the OBNE Expression Slider may be the one that suits my needs the best - although of course I would be using it against deployment advice - with my foot. I believe my ’foot control’ is sufficiently refined so as to not compromise the supposed delicacy of this pedal - yet it’s pricing is such as to make replacement a very straight forward exercise.
The fifth pedal here - the ’X’ mini switch is an extrapolation of my own - which combines the level display from Dr Scientist’s Boost Bot with a momentary switch. I imagine two modes - fluid and sticky q.v. - to give you a very simple but effective expression control in the smallest possible form factor.
I covered this in my recent '2 Laid to Rest' piece - a very elegant roller-based expression control pedal - where the LED gets lighter or dimmer - depending where along the 'curve' you are. The mechanism of this is such that this requires a power supply - which is probably not ideal, but it's a relatively compact and neat solution - especially compared to the more typical wah-style rocker pedals of yore.
I acquired this back in the day for two main reasons - its compact form-factor, and its combination of Volume and Expression Control. Yet it's still a pedal that takes up a whole slot on the pedalboard - and based on how much I used it then - it did not really justify its inclusion. I still retain this pedal as it works really well - but I'd really want something a little more compact which still retained the same degrees of versatility. As a sidenote here Shnobel Tone do a modded version of these with built-in TC Electronic Mini PolyTune Tuner - which is a really cool but somewhat pricey innovation.
This is my own extrapolated concept - essentially a momentary mini switch with Level display borrowed from the Dr Scientist Boost Bot. The idea is that you have two modes onboard - fluid and sticky. The former works just like the DigiTech Ricochet momentary switch in terms of attack and release as you press on the switch and then let go. The second 'sticky' setting would retain the setting at the top of the path - when you let go - for sort of cocked-way style control. Clicking once switches the pedal on/off in that position while a prolonged press returns it back to base again in usual momentary fashion - and a double click resets it! I don't believe such a pedal exists yet, but I imagine the electronics for this would be relatively simple - and could be eminently doable at this micro enclosure size. You could have another version at the same Mini size as the OBNE Expression Slider with knobs to adjust the taper - speed and range of the curve - that would make for a very simple and easy controller.
This is my favourite of those options currently available - only just recently come on the market and indicated against control by foot! Rules are for fools though and despite supposed inherent frailties - I still feel that I could effect successful 'foot-control' which I do for most of my other pedals - turning knobs and flicking toggle switches with my toes! This is a passive device too which is a bonus - no power supply requirement. Of course people with larger / heavier and less controllable feet should not use against permitted parameters - but I feel my own touch is delicate enough to work. And in the worst case scenario - the keen price on these makes replacing them somewhat straight forward. I'm just waiting for these to reach these shores now.
There are a number of these types of mini knob expression pedals on the market - but I feel Seafoam's take on the format - with two inputs - is the best I've seen to date. The main knob is slightly offset for easier 'foot-manipulation' and is sufficiently knurled and rubbery to effect an ideal grip or contact. This pedal is not really suited for my fairly loose pedal-chain but requires very secure fixing to whichever board it is applied. This is probably the most ergonomic of these designs available - although it could really do with a better indicator - so you know exactly where along the curve you are!
My principal thoughts really are to include expression control within the pedal by way of a secondary / separate momentary footswitch - which you can often see used for Swell control say on pedals like Walrus Audio's recent dual footswitch Slö Reverb. TC Electronic has tried to evolve this further into its 'MASH' button - which has an additional pressure sensor - which actually requires a fair amount of pressure to accelerate effectively. TC Electronic still has only a single footswitch on its pedals which I don't believe is optimal (at least not for my use), and I find that deploying the MASH buttons is rather finicky and difficult to control at times - as per both my Quintessence Harmonizer and Brain Waves Pitch Shifter pedals - it just does not seem to work as elegantly for me as a more basic momentary switch - I much prefer using my DigiTech Ricochet for instance than the more feature-rich TC Electronic Brain Waves. You could add settings for more refined taper control - range and rate for instance. But I would imaging most pedal builders would not really want to have to add those additional controls every time - so probably you could settle on some best-fit combination instead. I still feel that the ideal method for me is onboard momentary footswitch expression control.
When onboarding expression control is not a possibility, then for sure the new OBNE Expression Slider would seem to be my preferred stand-alone option. Being unpowered and the size of a mini enclosure pedal sort of makes it ideal. OBNE warn you not to use your foot to control the pedal - but I feel I have the delicacy to ensure that the pedal does not get damaged in the process. Those with clompier feet probably need a different solution in any case.
If you still like the old-school rocker or treadle style pedal - then the Dunlop Volume (X) Mini is still a great solution. I also feel that the Seafoam Mini Knob is probably the best of its type - but anchoring it sufficiently and controlling it effectively may prove to be too tricky for some.
I still like the idea of my own Mini Momentary Expression Switch - and I'm sure we will see something similar materialise any day soon - by it's very nature though it does require a power supply which is not wholly ideal! All in all though there are quite a number of these compact style solutions currently available - meaning you really don't need those large paddle/flipper style pedals of old. With the dynamics of modern pedalboards - having a huge expression pedal is probably a step too far for most nowadays...