M117R Flanger

The MXR M117R Flanger. This is a flanger that you've undoubtedly heard on all kinds of recordings; In most cases, you just not able recognize it. The artist who really made a unique sound associated with the MXR Flanger, and in turn made it famous was Eddie Van Halen. This effect can be and has been used, not just in heavy music, but across all kinds of different music genres. Unlike the impression that the famous EVH "Swoosh" probably gives when you first hear it, the M117R Flanger is an effect pedal that can also be used very subtly and tastefully. When you learn about all that the pedal can do, it's actually a pretty remarkable little effect. The design and execution are definitely inspired.

If you've followed our site for any length of time, you're probably also aware that we do not hold artist-editions of musical equipment in higher esteem than standard work-a-day instruments and equipment. We think it's important to point out that our favorite, and your favorite artists were only ever awarded limited-artist-signature-edition equipment AFTER they became famous. Everything they did to get famous was most likely standard version equipment that they played or that they tweaked-and-then-played themselves.

...Then again, despite the friendly finger-wagging, we're also just human beings. In rare instances, we've been known to defy our own public pronouncements and consider grabbing a limited edition "something". The rare occasions this happens are if and only if we're able to find an exceptionally good deal. In our own personal gear collections, you'll mostly find us using "vanilla" equipment, including the M117R.

Thermionic Studios owns four (4) copies of this pedal. We have two standard M117Rs, one EVH117, and one EVH117SE.

As always, please contact us if you're interested in renting one!

Controls

Image of M117R from Musician's Friend

• Knob 1 - "Manual": This knob sets the center-point of the sweep of the flanging effect. Turn counter-clockwise to make a "bassier" flanger sweep; clockwise for a "more trebly" sweep.
• Knob 2 - "Width": This knob controls the "width" of the sweep of the flanger. Turning the knob clockwise increases the width of the sweep.
• Knob 3 - "Speed": This controls how quickly the swell sweeps across the width of the flanger effect. Turning the knob clockwise increases that speed.
• Knob 4 - "Regen": This knob controls the intensity of the flanging effect. Turning the control completely counter-clockwise makes the flanging effect very faint. Turning clockwise increases the intensity.

Width Knob = Weird!

The Width knob is pretty interesting in its function, and the manner in which it works on this pedal is worth remembering.

1. Turning the Width completely counter-clockwise will remove any influence of the Speed control from the flanging effect. The knob will still turn, of course... It just won't have any effect. At first, this seems bizarre, but consider the following:
   • If Width is zero then any oscillation in the flanger is, by definition, impossible: the points between which any oscillation could occur have converged.
   • If the Width or "window" available for any sweep is now zero, then the only result that's logically possible for the Speed control is for it to become functionally irrelevant.
2. Alternatively, turning the Width knob fully clockwise removes the Manual control from the effect. Again, the Manual knob can be turned, however turning it won't make any impact on the sound. This is because when Width is turned to maximum, the points between which the flanger oscillates end up occupying the furthest edges of the effect. Said another way, as the Width of the oscillation "window" gets wider and wider, the Manual control gets forced closer and closer to the "natural center" of the effect. At maximum Width, the flanger oscillation sweeps across the entirety of the effect's frequency spectrum. This in turn results in no spectrum remaining for the Manual control to operate.

Bypass: Buffered

Most Dunlop/MXR pedals have a high-quality (non-audible) buffer in their design. All versions of the M117/EVH117 also use buffers.

General Information

The original MXR Flanger was first released in 1978. One of the bigger features that made it attractive was the built-in AC power cord (seen below, circled in red). Now, while Boss had also used AC power in the form of an AC adapter for their BF-1 Flanger, MXR took a different tack. While the attached power cord may have telegraphed to artists that the MXR Flanger would be a boon for them (no batteries to chew up), MXR's engineers embraced the tangent: because their flanger drew AC current from a standard wall outlet, they would also be free to design a much higher headroom flanger effect. Most other flangers, Boss's BF-1 for example, may have also been designed to use only an AC adapter, but Boss then also decided to design a circuit that used only 9-volts. Such decisions prevented these competitors from offering similarly lush flanger effects.

Interestingly,Electro-Harmonix, like MXR, also decided that it was preferable for their Electric Mistress flanger to use higher power in order to have higher headroom, and a lusher sound.

Image of vintage MXR Flanger from AudioFanzine.com
Copyright of image not found. Presumed Public Domain.

The modern retooled version, the M117R, attempts to carry on the tradition of high headroom (at least somewhat) with under-side access for two 9-volt batteries, and a jack for an 18-volt AC power adapter at the top.

Vintage versions of the original MXR Flanger can still be found for what we believe are ("now", 2018) "reasonable" prices. They're especially "reasonable" when compared to the prices for vintage Electro-Harmonix Electric Mistress flangers. That said, we don't happen to believe that vintage MXR Flangers sound so much better than the newer reissues that it's worth bothering about.

Tricks

When you consider how the controls behave, a couple of tricks with the M117R become apparent:

• Easily set a preferred frequency space for your flanging effect:

If the Width is set not-quite fully counter-clockwise, the impact of the Manual control becomes far more pronounced. By doing this first, then playing your instrument and listening, you can get a sense of where, frequency-wise, you want the flanging effect to sit in your mix. Once decided, it's not much more effort to adjust Width, Speed, and Regen to taste.

• Why the first knob is called Manual, or "D.I.Y. Flanging for Beginners":

With the Width set all the way off, if you turn the Manual knob back and forth while playing your instrument, you'll notice that you're able to manually sweep the Flanger. Here at Thermionic Studios, we've actually thought it might be a cool idea to put such an effect into a treadled pedal (like a Wah-wah) so it would be possible to control your flanger swoosh in the same way you can control a wah-wah.

Pedal Manual(s)

• MXR M117R Flanger Owner's Manual

• MXR EVH117 EVH Flanger Owner's Manual*

• MXR EVH117SE EVH 35th Anniversary Flanger Owner's Manual

A newer version of the standard EVH117 Flanger is available on the Jim Dunlop website, but we believe the older manual, available here, offers just a bit more technical information.

EVH117 Flanger

Image of EVH117 from Sweetwater.com

This is the original Eddie Van Halen version of the MXR Flanger - built for him by Dunlop. It features the original "Van Halen I" black-stripes-on-white motif that Eddie painted on his Frankenstrat. This version of the pedal differs from the standard M117R in that it offers an "EVH Button" that instantly reconfigures the pedal to Eddie's favorite flanger setting.

We own a copy of this model because we thought it would be cool to pair with our 2-color black-and-white EVH90SE 35th Anniversary Phase 90 phaser pedal.

EVH Button

• Button 1 - "EVH button": Depressing this button (it's a toggle) overrides the pedal's knob settings and activates the settings preferred by Eddie Van Halen. This provides the familiar "And The Cradle..." or "Unchained" swoosh.

Eddie's Swoosh

One of the things that many players hunger to emulate but don't know how to get is the famous Eddie-Van-Halen-Swoosh (note to wiki staff: get an audio clip of the first 4 seconds of "And the Cradle Will Rock" and link it here). Most players can get close, but there's "something" about the EVH sound that makes the flanger effect so much more pronounced than what usual signal chains can provide. Most of the time, people have come to believe and accept that the reason they can't emulate this sound is because it was added after the track was laid down.

This is incorrect. We have recreated this sound and can do it faithfully.

The EVH Button alone will not necessarily get you the Van Halen "Swoosh"...

The secret is to put the flanger pedal in between the guitar and the distorting amplifier. There is something about distortion, and in particular (at least according to our ears) something about tube distortion that accentuates the effect and really brings it forward. We wondered about this, some time ago, when we were looking at some stage and pedalboard pictures of early Van Halen arena concerts. We noticed that what EVH has previously shared in interviews about his pedals appeared to be true... "just put 'em on a piece of plywood". Pics showed the MXR Phaser, Flanger, and 6-band EQ. Only later did the realization set in. Of course! EVH probably did with his flanger the same thing that he did with his phaser.

So then we reversed the effect order, chained the flanger into the distortion, and Eureka!

EVH117SE Flanger

Image of EVH117SE from Jim Dunlop

The 35th Anniversary Special Edition or "EVH117SE" was released with what we would consider a motivation to pleasing those who might want to buy a vanity version of the MXR Flanger. Jim Dunlop issued the EVH 35th Anniversary version of the original MXR EVH117 Flanger. The only thing separating this Flanger from the EVH117 is the paint job and a "high gloss" finish. Otherwise, the EVH117SE is exactly the same as the standard edition EVH117 Flanger with the additional "EVH button".

Just like the standard EVH117 Flanger, the 35th Anniversary version also includes the EVH Button.

We own a copy of this model because we thought it would be cool to pair with our 3-color red-black-and-white EVH90 Phase 90 phaser pedal.

Phase Inversion: Unknown

From our view of the schematic, these are the only active electronics that actually touch the instrument signal. We're not yet clear on how the SAD1024 and the CD4013AE affect the signal so the jury's still out on whether a signal going into an M117R gets its phase inverted when coming out, unfortunately:

Schematic ID	Electronic Part	Action	Phase State
IC1b("U4.b"	CA1458	Does not Invert	Original
IC2b("U2.b")	CA1458	Does not Invert	Original
IC3("A1")	SAD1024	???	???
IC4("U3")	CD4013AE	???	???
IC5a("U1.a")	CA1458	Does not Invert	TBD
IC5b("U1.b")	CA1458	Does not Invert	TBD
IC1a("U4.a"	CA1458	Inverts(?)	TBD

This other list of active electronic parts are also clearly in the schematic, however, no audio signal appears to actually goes through them. From what we can ascertain, their purpose is to modify how the CD4013AE and the SAD1024 integrated circuits manipulate the signal and interact with the controls. Since they don't touch the actual signal, their presence shouldn't affect the audio signal's phase as it goes through the pedal:

Schematic ID	Electronic Part	Action	Phase State
Q1	2N4126	Inverts	NA
Q2	2TX109C	Does not Invert	NA
Q3	2TX109C	Does not Invert	NA
Q4	2TX109C	Does not Invert	NA
IC1b("U2.a")	CA1458	Does not Invert	NA
IC1a("U5.b")	CA1458	Inverts	NA
IC1b("U5.a")	CA1458	Inverts	NA

Schematic

Schematic of vintage MXR Flanger: not Dunlop's M117R reissue. Image found at Shredaholic.com. Original image clearly MXR's. © Copyright status presumed @ JimDunlop.com

Artists

• Eddie Van Halen
• Randy Rhoads
• Frank Zappa
• Michael Anthony
• Stone Gossard
• Kerry King

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Additional Sources

• http://equipboard.com/items/mxr-m117r-flanger-guitar-effects-pedal
• https://www.youtube.com/watch?v=qyxejQpLK9U