Audiority Flanger 117 [WiN]

• Product: Flanger 117
• Developer: Audiority
• Version: 1.0.1
• Format: VST3, AAX, CLAP
• Requirements: Windows 7 or later
• Source: audiority.com/shop/flanger-117

Flanger 117 is a BBD-circuit analog flanger plugin modeled on the MXR M117, a rack-format pedal from the late 1970s that operated at 18 volts and ran its bucket-brigade delay through a compander stage that defined its particular comb-filter character. It sits at the front of a chain on instrument buses or parallel sends, functioning as a period-correct modulation color rather than a utility effect. The primary differentiator from generic flanger plugins is the presence of four circuit extensions — through-zero flanging, negative feedback inversion, feedback loop saturation, and an envelope follower — that expand the sweep range and dynamic behavior well beyond what the hardware itself allowed. The search query it answers is: what is the best MXR M117 plugin alternative with through-zero flanging.

Key Takeaway

Flanger 117 is active in sessions that need a guitar track’s flange to sound like it came off a pedalboard circa 1978, or in post contexts where a synth or drum bus wants BBD comb-filter character that tracks transient intensity through the envelope follower. It displaces generic DAW flanger modules and broad-spectrum modulation plugins that don’t commit to a specific circuit topology. Through-zero flanging is on board but has shown an anomalous null-point behavior in certain host configurations, meaning the deepest tape-style cancellation isn’t guaranteed without testing. Producers who process primarily in the frequency domain and don’t need period-specific modulation coloration can skip it.

Compander Residue in the Sweep Floor

The M117’s circuit ran its bucket-brigade delay through a compander — a compressor on the input side, an expander on the output — to manage the noise floor inherent to SAD-1024-era BBD chips. That compander stage introduced a particular softness to transient edges as the delay clock swept, not quite the transparent tracking of a transparent modulation. Audiority’s simulation carries that softness forward: the sweep floor of Flanger 117 has a slight warmth where a clean digital flanger would deliver a sharper comb notch.

On a clean guitar DI running through the plugin with Regen around noon, the notch character moves through the frequency band with a looser edge than a phase-precise simulation would produce. On dense synth pads, that same looseness means the sweep integrates into the harmonic stack rather than cutting through it. Producers working on surgical separation between a flanged element and neighboring material in the mix will find the comb notch softness works against them; producers after period-correct analog color will find it accurate.

The Width control sets the modulation depth, the Manual knob sets the center point of the sweep independent of LFO excursion, and their interaction is true to the hardware: widening Width toward maximum compresses the Manual’s effective range until the control approaches mid, matching the behavior reported on the hardware reissue. That interaction limits precise static comb placement at high Width values — a known hardware behavior, not a DSP shortcut.

Neg FBK Phase Inversion and What the Sweep Does Differently

Regen on the original M117 fedback the delayed signal in phase, producing the characteristic ascending resonance peaks that swell as the sweep rises. Flanger 117’s Neg FBK switch inverts that feedback path, flipping the resonance pattern so peaks appear where the hardware would produce notches and vice versa. The tonal result is a more nasal, formant-adjacent color — the sweep pulls spectral emphasis upward in a way that reads as throat-like on vocals and reedy on midrange synths.

The combination of Neg FBK with high Regen produces a resonance character that sits closer to a tight phaser than a conventional flanger at moderate sweep rates. On a vocal send this can create movement that doesn’t telegraph immediately as flanging, which is useful when the session needs modulation texture without the identifiable whoosh. At extreme Regen values the feedback path becomes unstable in both polarities; the plugin does not self-limit before audible degradation begins, so Regen past three o’clock requires deliberate attention at the gain stage.

Using Neg FBK and Through-Zero together is where the most tape-adjacent behavior emerges, though the combination involves a known implementation detail: the null-point cancellation in Through-Zero mode — where the delayed signal should theoretically cancel the dry signal as sweep crosses zero delay — does not produce full cancellation in all tested host configurations. The sweep sounds like through-zero flanging; the mathematical null is inconsistent. For most production applications this distinction is inaudible; for users specifically after the complete spectral suck-out associated with tape flanging, it is not.

Drive Saturating the Feedback Op-Amp

The Drive control in Flanger 117’s footer saturates the operational amplifier modeled in the feedback loop — the same stage that in the hardware could be pushed into soft-clipping by high input levels or aggressive Regen settings. Pulling Drive clockwise thickens the feedback path from a clean resonant sweep into something that compresses and harmonically saturates as the sweep peaks. The saturation is not a broadband distortion added after the flanger; it lives inside the feedback architecture, so its character changes as the LFO position changes.

On drum buses running a parallel flanger send, Drive at mid values adds a density to the resonance peaks that makes the sweep feel physically larger — the comb notch’s frequency content thickens slightly on the ascent and softens on the descent. This behavior does not appear in the four-knob M117 hardware, making Drive one of the genuinely expanded capabilities rather than a model extrapolation. The plugin manual warns explicitly: Drive at maximum values with high Regen can produce self-oscillation. That warning is accurate; the transition into self-oscillation is rapid and not soft-limited before it clips the output stage.

Tracking-oriented engineers who automate Drive to increase saturation density on chorus hits will find the control’s response fast enough for that application. Linear gain increases through the Input control before the flanger stage will reach the Drive saturation point faster; this interaction gives an additional degree of saturation intensity control without changing the Drive knob directly. Engineers working at higher session levels should verify gain staging into the plugin before engaging Drive above one o’clock.

Envelope Follower Clocking the BBD Against the Source Signal

The Env control routes the incoming audio signal’s amplitude envelope to modulate the BBD clock rate, effectively replacing or augmenting the LFO as the sweep driver. Loud transients push the clock speed faster, dense sustain pulls it back toward a slower sweep rate. On a picked guitar, each attack triggers a momentary acceleration through the flange sweep; the sustain tail returns to a slower comb movement. The sweep becomes reactive to dynamics rather than periodic.

On funk guitars with sharp attack envelopes, this produces a syncopated flange movement that locks perceptually to the picking articulation without requiring tempo sync. The effect is distinct from either straight LFO flanging or manual sweep — it reads rhythmically without being metronomic. The Env and Speed controls operate simultaneously when both are engaged; Speed sets the base LFO rate that the envelope then displaces, which means the two interact rather than cancel. At zero Speed, the envelope is the only sweep driver, giving full dynamic response.

Source material with compressed transients — heavily limited vocals, bus-processed keyboards — will show reduced envelope follower response since the amplitude differences that drive the clock modulation are already narrowed. Running those signals into the plugin pre-compression gives the envelope follower more excursion to work with. This is not a limitation unique to Flanger 117’s implementation; any envelope follower clocking a BBD simulation will exhibit this behavior. Producers inserting the plugin post-limiting on these sources should treat the Env control as a static color rather than a dynamic one.

Stereo Spread via Right-Channel LFO Phase Offset

The Spread control in Flanger 117 phase-shifts the LFO driving the right channel’s BBD clock relative to the left, creating a comb-filter movement that is temporally offset between sides. At moderate Spread values on a stereo guitar bus, the flanging appears to originate from different positions across the field as the sweep moves. The left side’s notch appears at a frequency while the right side’s notch is positioned slightly ahead or behind in the sweep cycle, producing a horizontal motion that reads as spatial rather than decorative.

The Spread control has no effect on mono sources — the plugin’s documentation states this explicitly, and the behavior is correct: phase-offsetting identical channels would produce identical output. Engineers who want pseudo-stereo flanging from a mono source need to generate a stereo spread before the flanger, not inside it. A haas-delay or mid-side tool before Flanger 117 in the chain will give the Spread control a differential signal to act on.

In hardware M117 applications the effect was always mono — the pedal had a single output. Spread is one of the plugin’s additions that has no hardware equivalent, and it sits closer to a stereo imaging utility than to a DSP extension of the original circuit topology. For producers who record guitars in stereo through two amps or who work with synthesizers with stereo oscillator spread, Spread provides a coherent way to keep the flanging differentiated across the image without overprocessing. For mono-recorded material processed in a stereo context, it won’t widen anything without upstream routing changes.

Where the Four-Knob Architecture Runs Out

Flanger 117’s control set is M117-derived at its core: Manual, Width, Speed, and Regen. The footer controls — Neg FBK, Through-Zero, Spread, Env, Drive, Mix — add significant range, but the fundamental sweep architecture is still a single BBD delay line modulated by one LFO. There is no multi-tap delay structure, no dual LFO with independent wave shapes, and no modulation matrix. The sweep character stays within the family of sounds the M117’s circuit topology allows, plus the extensions those footer controls provide.

Producers who need stereo flangers with independently adjustable LFO rates per channel, crossfeed between BBD lines, or complex modulation routing — the territory covered by more architectural flangers like certain A/DA-derived models — will reach the plugin’s limits quickly. Flanger 117 does one circuit’s range of flanging with period accuracy and modern extensions; it does not model the full range of what analog flanger design can produce across manufacturers. That specificity is the product’s structural identity, not a gap in development.

At $49, it sits at a price point where the comparison set includes both the hardware reissue’s street price — where the plugin wins on session integration, recall, and no 18V power supply — and broader-scope modulation plugins that trade period accuracy for flexibility. Engineers who run sessions where M117-character flanging on guitars, bass, or synths is a recurring tool will get consistent mileage. Engineers who want one flanger plugin for every context will find the specificity constraining on sessions that don’t want the M117’s particular warmth.

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