Posted by
Apr 16, 2020

A Guide to the Best Pedals for Synths with CV Compatibility

CV (an acronym for “Control Voltage“) is a system that allows the remote of parameters of synths and pedals remotely – exactly like Midi, CV surpasses that format in smoothness and flexibility. With just a modicum of planning, CV is easy to integrate into any setup and doesn’t require any special cables. It’s truly one of the more expansive control platforms, and it’s only becoming easier to operate.

In this article, we tell the story of this format, its application to guitar pedals, and we list the best pedals that are compatible with it.

JUMP TO PEDAL CATEGORY

Expression and Control Voltage, a Parallel Story

Right around the same time in the late ‘60s, two men, thousands of miles apart from one another, reinvented the way folks pluck electric guitars.

[Click the black arrow to read more about this topic] – 

Bradley Plunkett of Thomas Organ Company in California and Fumio Mieda of Japan developed ways to manipulate a guitar effect in real-time without the use of one’s hands. Plunkett’s invention—the wah—was originally intended for trumpet players and controls the center point of a bandpass filter, while Mieda’s invention was the Psychedelic Machine, which was inspired by modulated short-wave radio circuits and eventually became the Uni-Vibe.

Though the use of a large foot-controlled pedal was a novel idea in the ‘60s, a sparse number of manufacturers implemented them. However, the first stone was cast: Expression pedals, as they came to be called, offered a dynamic performance arc that standard pedals just couldn’t match. 

Meanwhile, in the world of synthesizers, CV was all the rage. Bob Moog implemented it in all of his synth designs as a way to automate certain synth functions. While it differs from expression control in terms of extremital usage, its goal is nearly the same: control a parameter remotely without having to manually fiddle with the thing.

For years, CV and expression control advanced in parallel, with the two paths never crossing. They glanced in 1977 when Roland developed the GR-550 guitar synth, but it wasn’t until far later that synth players and guitarists broke bread at the auxiliary control roundtable and began offering one discipline’s mechanics on the other’s devices.

CV vs. Expression: the Differences

While expression and CV circuits are nearly identical, they differ in a crucial way: expression controllers operate passively and requires voltage to be fed into them, so that they may manipulate a parameter via an onboard potentiometer, then redirect the CV back into the original box. 

[Click the black arrow to read more about this topic] – 

The expression pedal does so with a stereo cable, carrying the information on the tip or ring, and back to the box it’s controlling via the other. A CV device, on the other hand, is always powered and will deliver the voltage straight into an auxiliary unit, and thus it is controlled with a standard mono cable.

It stands to reason then that any powered unit is capable of generating control voltage, and that’s where we find ourselves—rigging our pedalboards up with CV devices and seamlessly controlling one another the old-school way: volts and volts alone. 

Using the Expression Input as a CV Input

Some kind of urban legend out there is spreading the belief that any Expression pedal input works the same way as a CV in and will, therefore, accept any CV signal. As mentioned in the previous paragraph, that’s not exactly true. There are risks involved in trying that experiment, but you can find extra enlightenment on the topic (and a mod that may work for you) in this article.

BEST CV CONTROLLER PEDALS

Click on the black arrow to read more about these CV Controller Pedals.

If you’re looking for an all-in-one CV distribution powerhouse to control your CV compatible pedals, the Source Audio Reflex is the king of all expression devices. Featuring three assignable CV outputs, it’s the only guitar-centric three-CV unit on the market. Beyond the Reflex, you’re out of luck, as the next best on the market is the discontinued Moog MP-201, which now sells for around $700. Fret not, however, as many pedals output a single stream of CV, and distributing them among your thirsty inputs yields impressive results. The Mission Engineering 5-CV outputs two foot-controlled CV streams at once, letting you shift dynamic waves of change with just one-foot motion. Spicy!

Some of today’s expression pedals and control devices give you the option of plugging in a standard mono cable to output CV, and it is here that beginners should start their quests. Items such as the Electro-Harmonix Expression Pedal and Selah Quartz Timer output CV in two totally different ways, via foot operation or BPM pulses. However, the smart money is on the Electro-Harmonix 8-Step Program, which allows you to sequence bursts of control voltage and delivers them unto your CV-equipped board. If you’re going to pick one CV-centric control box, this is probably the one, but the more recent TWA Side Step (basically an LFO expression controller) is also a very creative tool in a smaller package, and – like the 8-Step – it works both with Expression and CV in. And if you really want to connect your non-CV stompboxes to your Expression pedal, the Copilot FX Broadband lets you split one Exp/CV In into 3 cv independent outs.

EFFECT PEDALS WITH CV OUT

Besides foot controllers, many regular stompboxes are capable of handling CV information, mostly through a female CV in 1/8″ jack. A more limited number of pedals also feature a CV output that is normally tied directly to the pedal’s low-frequency oscillator (LFO), which in most cases is used in the stompbox’s circuit for some form of modulation. Here’s a list of the best ones we found:

Click on the black arrow to read more about these pedals with CV Out.

Pedals like Dwarfcraft’s Happiness filter and Dreadbox’s Komorebi feature an LFO out; adjusting the rate of the filter similarly adjusts the CV emitting from the unit. You can then plug this CV into a different pedal that accepts it and sync up the units with a single cable. Others such as the WMD Protostar offer up an even greater degree of CV connectivity, with outputs for both the envelope and the LFO on the unit’s top panel. Pigtronix’s Philosopher King is an envelope generating machine that similarly has a CV out—use it to let your picking dynamics do the talking as they control the action of the King and its adjacent CV-equipped pedal. Of course, many pedals with this feature also support CV in, so you can use them to chain multiple CV devices together.

PEDAL LINES WITH INTEGRATED CV COMPATIBILITY

Click on the black arrow to read more about these pedals with integrated CV compatibility.

To make their products palatable to synth-heads, some forward-thinking manufacturers started including CV compatibility in all their pedals. Rather appropriately, the first one to do so was synth giant Moog, when it entered the pedal market with the Moogefooger line back in 1998. Electro-Harmonix has flirted with synths throughout its long existence, and over 30 of their pedals are compatible with CV inputs through their Expression Inputs. Malekko, another builder that has walked the line between synths and pedals, has all but mastered the art of guitar pedal control voltage; its newest pedal platform that includes the Scrutator, Charlie Foxtrot, Downer and more offers user-assignable CV control over as many as five knobs simultaneously, and in any direction. All Red Panda’s pedals also accept CV, and the company even sells a custom expression-to-CV adapter or gives you plans on how to make your own. The myriad devices crafted by Chase Bliss make a great choice as well, all of the brand’s DIP switch insanity works with CV. Meris is another manufacturer that included CV compatibility for all its knobs by modding the Expression input in all of their stompboxes so that it can accept CV (a 1/4″ to 1/8″ cable is required, and make sure you read about each device’s voltage requirements before you connect the gear). 

Don’t forget—CV originated in synthesizers and is still immensely popular in that world, and so manufacturers that handle both guitar and synth products are more likely to implement CV to interface with their synth products. 

These product lines alone give you access to a number of incredibly creative effects of all kinds with the potential of greatly expanding your synth’s sonic possibilities.

There are plenty of single pedals offering CV compatibility, here are a few lists for you, organized by kind of effect.

FILTER PEDALS WITH CV IN

Filters are central to subtractive synthesis and are therefore the most common effects associated with synths. Here’s a list of the ones we found that feature a CV in.

ADDITIVE SYNTHESYS PEDALS WITH CV IN (Pitch Shifters)

If filters are central to “subtractive synthesis,”  is there an “additive synthesis”? Yes there is: it consists in using existing signals to generate other signals, something these pitch-shifting pedals do very well.

SYNTH PEDALS WITH CV IN

These are pedals that feature internal oscillators tracking the input, so they may be redundant if you already have a synth, but check out the PLL ones, a type of circuit that transforms the input into a square wave and then divides that wave into higher or lower frequencies like octaves or fifths.

MULTI-FX PEDALS WITH CV IN

These pedals could be exactly what the doctor ordered for the synth and keyboard players in need of a variety of effects in one box.

 

MORE CV COMPATIBLE PEDALS ORGANIZED BY TYPE:

Here’s a useful video about using CV with guitar pedals.

By Nicholas Kula and Paolo De Gregorio