Envelope Filter Fixed Wah

The BYOC Envelope Filter Fixed Wah pedal is a pretty interesting beast. Its closest relative is probably the discontinued MXR Q-Zone. The Q-Zone replicates the signature Michael Schencker (and a few others) sound of a wah-wah pedal that's been turned on, but left with the treadle in a location on the sweep which provides a sort of nasally-sounding tone. Michael Schencker actually made this sound, he used a Vox wah-wah pedal that he would leave on and would purposely not rock the treadle. The problem is that when used in this way, a wah-wah can be a tone-suck and there are better means of achieving the same end. The BYOC fixed wah can do that. It's fixed wah function doesn't offer the same kind of tone shaping possibilities that the Q-Zone does, but it's not meant to offer that.

Because this pedal also offers an envelope filter to help you get your funk on.

Controls

Image from BYOC Pedal of the Month

• Knob 1 - "Range": Controls the intensity of the envelope filter effect.
• Knob 2 - "Manual": Controls the tone or the "where in the sweep of the wah" when "Switch 1" is in "Fixed Wah" position.
• Knob 3 - "Attack": Controls amount of sweep of the envelope filter on the sound being played.
• Knob 4 - "Sensitivity": Controls how hard you need to pick in order to trigger the envelope.
• Switch 1 - "Envelope / Fixed Wah": Toggles between the Envelope Filter and Fixed Wah functions
• Footswitch 1 - "On/Off": Toggles the pedal between Bypassed (off) and Engaged (on).

Bypass:True

The Envelope Filter Fixed Wah is True Bypass.

General Information

Be warned that this pedal may not behave according to your initial expectations. Regardless of which function you've set the pedal to, not all the knobs will work. This doesn't mean that the pedal is broken. The split nature of this pedal means that while one of the controls is shared (Range), each pedal function, has its own controls. If we look at the schematic and trace through both functions, we can see that when the Fixed Wah function is engaged, this pedal only uses two of the knobs: Range, and Manual. Alternatively, when the switch sets the pedal to the Envelope Filter function, the pedal uses the Range, Attack, and Sensitivity knobs.

Proceed accordingly!

Phase Inversion: Yes

Yes. This pedal inverts signal phase.

Analyzing the phase on this pedal was sort of unusual. It reminded us of the exercise of walking the schematic on the Armstrong Twin. Based on the schematic, and given the function of this pedal, it only makes sense to chart out the signal flow in two pieces:

• First, for the circuit piece of the Fixed Wah function of the pedal:

Fixed Wah

Schematic ID	Electronic Part	Action	Phase State
IC1a	TL072	Inverts	Inverted
IC2a	LM13600	Does not Invert	Inverted
IC2a(7)	LM13600	Does not Invert	Inverted
IC2a(8)	LM13600	Does not Invert	Inverted
IC2b	LM13600	Does not Invert	Inverted
IC2b(10)	LM13600	Does not Invert	Inverted
IC2b(9)	LM13600	Does not Invert	Inverted

• Second for the additional envelope filter circuit piece that's added by the toggle switch:

Envelope Filter
(including Fixed Wah circuit from above)

Schematic ID	Electronic Part	Action	Phase State
IC1b	TL072	Does not Invert	Inverted
Q1	2N5088	Does not Invert	Inverted

Pedal Manual

BYOC has not issued a pedal manual. The best references, as we understand to exist, are either this wiki page, or the pedal build guide (linked above) at the BYOC website.

Schematic

© Copyright 2010, BYOC LLC.

Artists

We are currently unaware of any artists actively using the pedal now, or who have in the past.

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Additional Sources