Ultimate Guide to Filter,
Synth & Ring Mod Pedals

These pedals definitely aren’t for the faint-hearted... they’re truly for the experimentalists!

Filter, Synth and Ring Modulator pedals are notorious for providing unique, quirky and otherworldly sounds. Used as inspiring creative tools, these effects pedals allow guitar players to take one step into the realm of electronic music.

Written by

Elliot Stent

What are Filter, Synth & Ring Mod Pedals?

These are the unsung heroes of the pedal world. Often overlooked for being too diverse for the bog-standard rock guitarist, filter, synth and ring mod pedals however are used by many modern players to expand their tonal palettes.

Filter pedals for example can totally transform your guitar tone. In fact, with extreme settings they can make your instrument sound like something almost completely different! Essentially boosting frequencies with a moveable sweep, with a filter pedal you can enhance certain areas of your EQ to bring out harmonic overtones for expressive vocal-like timbres. Further electronic wizardry helps in creating their sound too, and envelope filters are very recognisable to the ear.

A synth pedal does what it says on the tin. It makes your guitar sound like a huge, engulfing synthesiser! Great examples available today can closely emulate the sound of a real synthesiser, but when applied to guitars some can sound almost like a hybrid, which is a totally unique and usable sound in itself.

Ring modulator pedals are entirely different beasts however. Giving you randomly detuned chaos, ring modulators are perfect for really adding some unpredictability to riffs, really catching your listeners off guard. Although rarely used in mainstream music due to their tonal instability, ring modulators are used often in experimental electronic music.

Despite their wonderful weirdness, these effects pedals let guitarists transcend the gap between rock and electronic/pop genres, and have even more of a place in the music world than ever before. And here at Andertons Music Co. we have a great selection of these peculiar pedals available. But first, we’re going to explain all of their details and functions. This is so we can give you a better idea of how to get the most out of them, so you can integrate them successfully into your rig.

Filter Pedals

What Does a Filter Pedal Sound Like?

As we said in the introduction, a filter pedal ultimately takes your guitar tone and enhances it by adding (or taking away) certain frequencies. However, it doesn’t work like any regular EQ pedal, as an envelope filter dramatically changes the tonal qualities of your guitar signal using further processing. The result is an effect that can give a vocal-esque quality to your tone, by embellishing notes to produce a variety of vowel-like sounds.

Most filters will use an LFO (low frequency oscillator), which assists in adding movement to your signal. This isn’t dissimilar to how modulation pedals work in processing a signal, with the LFO adjusting the waveform in this instance to manipulate its shape. Filter pedals also work in a fairly similar way to wah pedals too, with a ‘peak’ moving across the frequency spectrum.

That’s why ‘auto wah’ pedals can be categorised as a filter pedal. This is because a regular wah pedal works as a moveable peak in your signal’s EQ, sweeping from a nasally and anemic tone to a treble-boosted scream. Auto wah pedals essentially work in the same way, however rather than using your foot to manually adjust the effect sweep via a rocking plate, with an auto wah you can tailor the attack/speed of the frequency sweep to simulate the movement of your foot.

Filter pedals (and auto wahs) are really in their element when used for playing funk. This is because they give a bubbly character to fast lead lines and chord progressions, and as the effect of a filter pedal is triggered by the attack of a note that you play, it makes them suitable for the demands of the usually fast, staccato-style playing that funk guitarists employ.

Jerry Garcia of the Grateful Dead is arguably the most famous pioneer of the envelope filter effect on guitar, which can be heard extensively on the track “Estimated Prophet”:

Envelope Filters for Bass?

Envelope filters are also incredibly popular with bass players. Used often for funk music like their guitar playing counterparts do, on bass, filter pedals are also used in heavier styles of music too. For example, Justin Chancellor of the progressive metal band Tool has an envelope filter pedal amongst his arsenal of effects units.

Just adding another dimension to the music to intrigue the listener, he has used an envelope filter in songs such as “Jambi” and “The Pot”. You can hear his MXR M82 Bass Envelope Filter pedal in all its glory in this rig rundown (skip to 2:55):

We have also demonstrated the MXR M82 in one of our episodes of 'All About the Bass' on Andertons TV, where we take a close look at the various sounds that you can get out of this pedal. With 5 tone-shaping controls, the range of wonderful sounds that this pedal is capable of is evident in this great video!

MXR M82 Bass Envelope Filter on Andertons T.V.

How Do I Use a Filter Pedal?

A filter pedal is typically used in the front of an amplifier. So in terms of the signal chain, you should run your instrument into the input of the pedal with the output of the pedal running straight into your amp’s input. If you’re intending to use a filter pedal in conjunction with other stompboxes, such as an on a pedalboard, a filter pedal should generally be placed as early in your pedal chain as possible.

This is because maximum sensitivity will occur earlier in the chain, so in a way the effect will react more efficiently to the input signal, getting ‘more’ of the effect out of the pedal. Think about it in a similar vein to wah pedals, where you would conventionally place it before overdrive pedals. This is so the sweep of the effect sounds more natural, rather than exaggerated or overly synthetic.

That is also why using an envelope filter will probably sound bad through the effects loop of your amp too. In the effects loop, the sound of an effect will be clearer and more pristine as it will bypass the preamp of your amplifier. Time-based and modulation effects will therefore sound better in the effects loop of an amp due to their qualities, but a filter pedal will sound too harsh or piercing if run through an effects loop, especially if using extreme settings.

What are the main Filter Pedals Out There?

There’s a great selection of Envelope FIlter pedals available at Andertons Music Co. From established brands such as Electro Harmonix and Earthquaker Devices, we’re confident you’ll find a great filter pedal to add to your pedalboard!

Electro Harmonix dominate the filter pedal category, with multiple stompboxes available at a range of price brackets. The Q-Tron pedal is a modern classic, used extensively by a raft of players for its versatility and iconic sound. The range starts at the Micro Q-Tron, a simple 3 control pedal fitted in a pedalboard-friendly enclosure.

The pedal’s Drive control determines the sensitivity of the filter sweep, affecting the width of the sweep range against the input signal. The Q knob will let you find the peak frequency of the filter, becoming more dramatic and treble-boosted the further it is turned. And lastly, the Mode control will let you choose which frequency range the filter passes through. LP (low-pass) for example will give you a throatier filter sound, with the other modes affecting higher frequency bands.

The standard Q-Tron features even more controls for further sound-shaping. An Up/Down control can let you choose the shape of the filter wave, whilst an additional Boost knob can give you an extra kick of volume when you engage the effect. The even more high-end Q-Tron+ has a built-in effects loop to let you place other effects between the pedal’s preamp and filter section, letting you combine effects for some truly unique tones. A Response switch also lets you choose between a slow and smooth vowel-like attack, or a fast, snaked response.

Boutique brands such as Mojo Hand and EarthQuaker Devices produce their own filter pedals too, delivering even more experimental sounds than their EHX counterparts. The Spatial Delivery from EarthQuaker is reactive to your picking attack, giving a faster response and wider sweep depending on how hard you play and where you set its Range control. It also has a Sample & Hold mode, which generates random filtering to give you some old-school sci-fi style sounds!

EarthQuaker Spatial Delivery on Andertons T.V.

Synth Pedals

What Does a Synth Pedal Sound Like?

A synth pedal will provide you with a nostalgic range of sounds, taking you all the way back to the heyday of the 80s! Emulating a classic synthesiser sound to make it possible for guitarists to attain a variety of electronic-style tones, synth pedals have become increasingly popular. With the renaissance of mainstream electronic music and acclaimed series' such as Stranger Things using synths exclusively in its soundtrack, there's a reason why these pedals are more in demand.

So, how does a synth pedal work? Most synth pedals work by detecting the pitch of your input signal, and using that to tune and engage an oscillator within the circuitry. So whereas something like a modulation pedal modifies and processes you signal, the synth sound will actually be generated by a functioning synthesiser circuit within the pedal.

A good synth pedal will therefore give you loads of tonal flexibility similar to their full-fat counterparts, with a variety of controls to let you tweak the waveform shape, attack, decay and more. As a synth adds loads of extra harmonic content to notes, guitar synth pedals will often feature octave up/down functionality, and sometimes further intervals to give you the thickest and fullest sound.

How Do I Use a Synth Pedal?

Just like filter pedals, you will get the most out of a synth pedal when it’s placed early in your signal chain. This is to ensure that the rawest amount of signal is being fed into the pedal’s input, giving it the best chance to process that signal for ultimately the best and most genuine tone it can achieve.

Setting it up early in the signal chain will also mean that the tracking of the effect will be better. ‘Tracking’ is a term used to denote how well a pedal identifies a signal and how quickly it can affect it. If a pedal tracks well, that means that it will pick up notes and idiosyncrasies with great detail, with little to no audible latency. Something that tracks badly will have noticeable latency, making it difficult to use successfully. That’s why placing it as early as possible in your pedal chain will give you the best results!

What are the main Synth Pedals Out There?

There are plenty of synth pedal options available out there, and here at Andertons Music Co. we have many to choose from and compare. Similarly to envelope filter pedals, Electro Harmonix lead the way when it comes to synthesiser pedals for guitar. Boss also have a couple of high-end guitar synths, with even more tweakability and options.

So if you’re looking for a soft pad style synth, or a dirty and abrasive-sounding lead synth, there are many synth pedals from these brands that can get close to the real thing!

The SuperEgo+ is the flagship synth pedal from Electro Harmonix, with numerous controls and modes to let you find multiple synth sounds and timbres. With this feature-packed pedal, you can create not just pumping synth waves but also immersive pads with infinite sustain, letting you achieve engulfing soundscapes and textures.

With a built-in effects section that gives you 11 different effect types, you can further sculpt and experiment. An expression pedal input can also let you adjust parameters on the fly, to bring out more of a particular effect or control the attack of the synth for example.

Another noteworthy unit is EHX’s Micro Synth, a full analogue synth for guitar. Giving you truly old-school Moog-esque tones, the Micro Synth has a number of sliders to let you carefully craft your optimal synth sounds. Although not as versatile as the SuperEgo+, the Micro Synth has that super-nostalgic synth vibe, letting you attain smooth synth pads to pulsing lead lines.

Boss’ SY300 Guitar Synthesiser unit is an even more spec’d out synth machine, with an incredible range of features. Whereas previous Boss/Roland systems required the use of a special guitar-mounted pickup, the SY300 can be plugged straight into with virtually zero latency. With 70 synth presets built-in, you can also create and save a further 99 sounds for almost endless possibilities. And with MIDI compatibility, you can easily switch between your patches via an external MIDI controller such as a pedal switcher.

Boss SY300 on Andertons T.V.

Ring Mod Pedals

What Does a Ring Mod Pedal Sound Like?

Ring Mod pedals aren’t for everyone, lets make that clear. It’s an incredibly unique-sounding effect, which isn’t exactly used to make something sound more musical. Giving you a brash, metallic sound, this effect is rarely heard in mainstream pop or rock music, but it has more of a place in soundtrack work.

Giving you the sound of a malfunctioning robot, ring mods have a close association with sci-fi genres and in a musical context they can work well when used in heavy, industrial styles. The song “Glass” by US alternative rock band Incubus features a ring mod effect, used on the main guitar riff:

As its name suggests, Ring Modulation is a type of modulation effect on a base level, affecting amplitude. Combining your original signal with an oscillator to create what is known as a ‘carrier wave’, these waves are either cancelled out or enhanced when the signals clash. Most ring mod pedals feature a control that lets you alter the pitch of the ‘carrier wave’, creating a more broken up, stuttering sound the lower it is set.

How Do I Use a Ring Mod Pedal?

As ring modulation is such a bizarre effect, the placement of a ring mod pedal in your signal chain is totally subjective. In my opinion, I’d place it in front of my amp and fairly early in the chain for the best possible tracking, but there’s no right or wrong essentially.

A cool way to use it could be in the effects loop of your amplifier, so that it can react directly with your reverb or delay pedals. For example, if you place it just before those aforementioned pedals then the reverb/delay trails will have this super-exaggerated bit-crushed sound, something that could be amazing if you like to create weird and wonderful soundscapes.

What are the main Ring Mod Pedals Out There?

Electro Harmonix aspire to build more-uncommon and wacky effects (as you would have gathered), and ring mods are no exception to that philosophy. With a couple of ring mod pedals available from EHX, Fairfield also produce their own iterations as well as the legendary Moog and DOD brands.

The Gonkulator from DOD can deliver the craziest off-kilter tones conceivable. With a gnarly built-in distortion circuit, the Gonkulator can achieve some seriously insane sounds to take your tone into another dimension.

With the Frequency and Ring knobs letting you control the peak frequency and carrier wave respectively, the Gonkulator can go from moderately twisted modulation to pure atonal chaos! Our friends Mick and Dan from That Pedal Show demonstrate the Gonkulator in all its glory in an episode from late 2015 (skip to 3:00):

DOD Gonkulator on That Pedal Show

Electro Harmonix's Ring Thing is a highly tweakable ring modulator pedal with plenty of tone-shaping controls. More musical-sounding than some others on the market, the Ring Thing is capable of doing pitch-shifting, preset tuning and letting you select from various different waveforms for a raft of ring mod flavours. And with 9 savable presets, you can fully programme this unit to suit a range of musical applications.


After all of that, I hope that this guide has enlightened you. These pedals certainly are hard to grasp at first, and they can be difficult to integrate into your setup. But, they can also be very inspiring and capable of giving you some outside-the-box ideas, which is important in a time where thinking up new and original ideas can be tough.

There's clearly quite a lot of choice out there for all three of these pedal types, so whichever effect you're most interested in purchasing then I'd encourage you to try it out in person. As they are so diverse compared to your typical overdrive or fuzz stompboxes, these pedals demand more attention and research.

Shop Guitar Pedals!

Recently Viewed Items

Recently Viewed Items