Player’s guide

Before you plug in

Open the printable control reference

Power

Use a regulated 9 V DC pedal supply, center-negative, with a standard 2.1 mm plug. The October 2026 bench setup drew 148 mA at 9 V. Use an output rated at least 300 mA; 500 mA gives startup margin. A regulated 12 V supply also works but adds no audio headroom. The internal rails are designed to rise gradually at power-up.

The input includes reverse-polarity blocking. Use regulated 9 V or regulated 12 V power; do not use 18 V. Over-voltage protection is limited and does not guarantee protection against every supply fault.

Do not use unregulated wall adapters. Their output can exceed the label voltage, damage protection components and require a repair. A technician can use the power-and-protection reference to diagnose a supply fault.

Hook it up

1. Guitar, or the pedal before this one, into IN.
2. OUT to your amp or the next pedal.
3. Set Volume low and Dist fully down, the Clean switch to Clean, and CRz and Comp off.
4. Plug in the supply last. Stomp the pedal on and bring Volume up until it matches your bypassed level.

Where it goes in your chain

Start where you would place a drive pedal, into a clean amp or interface. With your instrument tone open and amp EQ neutral, set Malice first; then adjust the rest of your rig to taste. Its tone controls do not replace every function of an amplifier or cabinet.

The one rule

Every panel knob follows it: clockwise means more low end on Wall of Ice, more carve on Twin Assassins, more gain on Dist, more brightness on Aurora Curtain and more level on Volume. Clean selects the hard-clip ladder, CRz selects the fuzz, and Comp independently selects the preset compressor and gate. Internal trimmers are bench adjustments with their own documented directions.

Set the controls in this order

Each control changes what the next one is working on, so work from the front of the pedal to the back:

1. Wall of Ice sets how much low end reaches the drive.
2. Twin Assassins carves the midrange, once the low end is under control.
3. Dist and the Clean and CRz switches set the gain and the character. Accept that it may sound harsh at this point.
4. Aurora Curtain takes the harshness back out.
5. Volume matches the pedal to your bypassed level.

Stiward Thære Sæ, the compressor, is set at the factory, so it needs nothing from you but its switch.

Hot sources and big speakers

Synthesizers, keyboards and line outputs are usually stronger than a guitar. Turn the source’s output all the way down before you plug in, then bring it up slowly while you listen. Modular gear running at ±10 V will drive the first stage into distortion; the input won’t be damaged, and a little attenuation in front fixes it.

Fully open, the pedal passes and distorts energy far below what a guitar normally produces, and guitar speakers can’t always take it. Bring the amp up gradually, let the cabinet tell you where its limit is, and use Wall of Ice to keep the deepest content out when you need to.

Where to start, by instrument

• Guitar. Wall of Ice around 10 o’clock, Aurora Curtain around 2 o’clock, guitar tone knob wide open.
• Bass. Wall of Ice open, Aurora Curtain between 10 and 12 o’clock.
• Synthesizer. Turn the synth’s output all the way down, plug in, then bring it up slowly. Running a modular at ±10 V? A little attenuation in front keeps the first stage clean.

Wall of Ice

The low-end control. Lower-left knob, beside the footswitch.

What it does

Wall of Ice sets how much low end passes into the pedal. Turn it clockwise for more bass; turn it counter-clockwise to roll the low end off. Like every knob on the Malice Madrigal, clockwise gives you more.

Wall of Ice is a high-pass filter ahead of the drive. Turning counter-clockwise raises its corner, progressively reducing sub-bass, boom and body. Fully clockwise gives the lowest corner, about 12 Hz; this is its broadest setting, rather than a physical bypass.

Why you would shape the low end

Low frequencies carry a lot of energy, and distortion works on everything it is fed at once. There is a point where the low end simply becomes too much: the bass grows large enough that it begins to cloak the notes above it, and the detail you want to hear — the pick, the chord, the top of a lead line — sits behind it and is harder for the ear to pick out. The sound is still good; it is just crowded. Wall of Ice is how you make room again, easing the low end back until the rest of the note steps forward.

Shaping low end before clipping changes which frequencies drive the nonlinear stages. Filtering the output afterward changes the spectrum of the distortion already produced. These are different tools: use Wall of Ice for the first and Aurora Curtain for the second.

Clarity is not the only reason to reach for this knob. Sometimes less bass is the sound. The classic hard-clipped distortion voice lives in a midrange hump: it clips hardest in the mids and lets the low end stay comparatively clean, which is where its bite and definition come from. Shaving the bass down before the drive leans the pedal toward that character; a thinner, mid-forward signal clips differently than a full one, and the result is a tighter, more cutting grind. Open the knob back up and the same drive stage turns thick and heavy. Wall of Ice is not just a fix for too much low end; it is a way of choosing what kind of distortion you get.

A few places that idea takes you:

• Chug. Palm-muted low-string riffs want definition more than depth — each hit should land as a distinct thump, not blend into the next. Pull Wall of Ice down toward the middle, switch in the ladder, and the chugs get their edges back; the tightness is what makes fast, percussive playing read.

• Sludge and doom. Open Wall of Ice, switch in the fuzz or ladder, and let more low end reach the clipping stages. The CRz fuzz adds its own low cut near 100 Hz, while the other voices have a broader bass response. Bring the amplifier up gradually and use Wall of Ice to limit low-frequency energy when the cabinet needs it.

• Mid-forward bite. Shave the bass, switch in the ladder, keep the notch out of the way: a mid-forward, cutting grind with the classic clipped-mids character.

The one habit worth learning

It is tempting to start with the bass all the way up — more low end sounds bigger at first. Do the opposite. Start with Wall of Ice rolled most of the way down (counter-clockwise), then slowly open it up while you play.

Rolled down, the pedal is tight and focused and you can hear every note. As you bring the knob up, you add low end back a little at a time, and you will hear the point where the bass starts to crowd the rest of the sound. Stop just before that point — that is where the low end is as big as it can be while everything above it still comes through clearly. That spot is different for every instrument, every pickup, and every amp. Finding it by opening up to the edge of crowding, rather than backing down out of a crowded sound, is faster and lands you in a better place.

By instrument

• Electric guitar. Start around the middle and open up until the low strings feel full but still clear. For heavy rhythm, leave it lower — the tightness is what lets fast passages stay defined under distortion.

• Bass guitar. Start with Wall of Ice open, then trim lows if the room or rig is booming. The drive is intended to retain bass fundamentals; the overall response still depends on the other filters, coupling stages and whether CRz is engaged.

• Synthesizer. Synths can put out enormous low end, far more than a guitar. Roll Wall of Ice down first, then open it up to taste. You decide how much sub reaches the drive, which is where a lot of the character lives.

• Microphone or vocals (through a preamp). Turn Wall of Ice counter-clockwise to reduce rumble, stage thump and handling noise before the drive. Stop before the voice loses the warmth you want.

• With the CRz fuzz switched in. The fuzz trims the deepest bass on its own, rolling off below about 100 Hz, which is what keeps a fuzz from turning to mush. Because of that, the fuzz actually likes more bass coming in: turn Wall of Ice up further than you would for the other voices, and let the fuzz’s own voicing do the tightening. If the fuzz sounds thin, give it more bass, not less.

A note on hot sources

The pedal is happy with instrument and line levels. Synthesizers, keyboards, and line outputs are usually stronger than a guitar, so before plugging one in, turn that device’s volume or output all the way down. Plug in, then bring its level up slowly while you listen. Stop when it sounds full and driven but not harsh or spitting. This protects your ears and your speakers and lets you find the sweet spot instead of overshooting it.

Working with the other controls

• With the Notch. Set Wall of Ice first to get the low end where you want it, then use the Notch to carve the mids. They work as a pair; a controlled low end makes the Notch far more effective.

• With Distortion. The more you drive the pedal, the more the bass character shifts (see above), and heavy settings can want Wall of Ice a little lower to keep the definition up front. If a high-gain sound is starting to feel crowded on the bottom, open a little room here before touching anything else.

• With the three switches. Comp, Clean and CRz each change how the low end behaves. The fuzz in particular wants more bass than the others because it trims the deepest bass on its own. Reach for Wall of Ice whenever you flip a switch.

Try it on everything

This pedal was built to be used on more than guitar. Put a bass, a synth, a drum machine, or a whole mix through it and Wall of Ice will treat them all the same — a clean, steep low-end control that never colors what it keeps. If you find a use that surprises you, we would like to hear about it.

Start low, open up

Begin around 10 o’clock and turn clockwise while you play. Stop just before the bottom end starts to crowd the notes above it. More distortion usually wants a little less; the fuzz wants more.

Reach for it when

• Palm-muted chugs are blurring into each other
• The low end is crowding the notes above it
• You want doom and sludge: open it all the way and add fuzz
• A vocal or synth needs its rumble gone

The circuit behind it: Wall of Ice technical reference

Twin Assassins

The midrange notch, blended against the dry signal.

The fixed pair is a deliberate voicing choice, inspired by corrective low-mid EQ. Use the blend by ear; those frequencies will not need cutting in every instrument or mix. Because it sits before clipping, it is not an exact substitute for a ReaEQ preset placed after distortion.

Current tuning. At the fully notched end, the bench-tuned board reaches about −12 dB near 325 Hz and −5 dB near 630 Hz. Around two-thirds of the blend’s travel gives the “Mud Free” starting curve, about −6 dB and −3 dB.

What it does

Two notches set into the midrange, where boxiness and blur live. The blend decides how deep they cut, from out of the way to a carved, scooped voice. If a driven sound is blurry or boxy rather than harsh, this is the knob that fixes it.

What to expect as you turn it

How to set it

Set Wall of Ice first. A controlled low end makes the notches far more precise; the two are meant to be used as a pair.

Know which problem you have. If a sound is harsh, that is a job for Aurora Curtain. If it is blurry or boxy, that is a job for Twin Assassins. They fix different problems, and they work in different places: the notch sits in the middle, between the two sweep filters, without overlapping either.

Leave it out for bite

For a mid-forward, cutting grind with the classic clipped-mids character, keep Twin Assassins out of the way, shave the bass with Wall of Ice and switch in the ladder.

Reach for it when

• A driven sound is boxy or blurry rather than harsh
• You want a carved, scooped voice
• You want mid-forward bite: leave it out of the way

See it on a chart: the response explorer

The Drive of Malice

Dist and Volume, with the Clean and CRz switches. The Comp switch is a separate dynamics choice.

Production drive values and response charts · Signal path and configuration

From cleaner gain to deliberate overload

At minimum Dist, the main drive amplifier approaches unity gain. With the hard-clip ladder bypassed and CRz off, the LED network stays connected but conducts little at sufficiently low signal levels. The filters still shape the signal, and hot sources can overload other stages.

As Dist or input level increases, two opposing strings of six red LEDs add nonlinear feedback and round the peaks. R53 is 470 Ω, with a soft knee around 9 V and ceiling around 12 V. Onset depends on playing level: about 50 % Dist on a hot pickup and 80–95 % on a light touch. Rail grind begins above about 1.5 V peak at the input jack.

Four combinations from two switches

The stages run in series. The Clean switch adds or bypasses the hard-clip ladder; it does not remove the LED feedback network. CRz independently adds the transistor fuzz.

The production two-step zener ladder begins its soft shoulder near ±3.65 V and reaches flat clamps near ±4.55 V. CRz adds a separate transistor fuzz. Each stage reshapes what arrives from the one before it, so the combined voice depends on the switches and Dist setting.

Playing the transition

Set moderate Dist with the ladder and CRz off. Try reducing the guitar’s volume, then bringing it back up: a smaller input can stay below significant LED conduction, while a larger input pushes further into rounding. Pickup level, the pre-drive filters and the fitted amplifier all affect the transition. The buffered input gives this its own response, rather than promising the cleanup of a particular vintage fuzz.

The VCA compressor is optional

The input stage, filters, LED drive, hard clipping and fuzz all operate with Comp off. The LED network’s compression-like rounding is nonlinear feedback. Comp adds the separate SSI2162 VCA compressor and gate after Aurora Curtain, using the internally calibrated preset.

Start with cleaner signal shaping

Turn Volume down and Dist fully down. Select Clean, set CRz off and Comp off. Keep Twin Assassins at its unnotched end, Wall of Ice open for more bass and Aurora Curtain open for more brightness. Engage the pedal and bring Volume up to match bypass. Then try the filters individually, or raise the level into the next device if there is enough output available.

With filters open, the reported low-frequency response is flat to ±0.1 dB from 20 Hz upward in the low-frequency band, with every inter-stage coupling corner below 2 Hz. The presence shelf, intentional filtering and selected clipping still determine the full response. Available clean level depends on the source, output gain and headroom.

Volume

Volume controls the final output level. Start low and match your bypassed level, then adjust for the next amplifier or device.

Inside the portal: the fuzz trimmers

Lift off the front portal plate where the Malice figure sits and you reach three small adjusters for the CRz fuzz, plus the op amp socket. Unplug the power first. The trimmers only change the sound when the CRz switch is on.

Revision C starting point. Asymmetry at mid-travel (about 2½ turns from either end), Fuzz Gain at mid, and Fuzz Level fully up. This flattens the bottom half, like the hard clipper, without sputtering.

• Tool. A small flat jeweler’s screwdriver. Each screw is 1.5 mm across with a 0.5 mm slot.
• Travel. About five full turns end to end. At either end the screw free-wheels: that is a built-in clutch, not damage.
• Set and forget. Each trimmer is rated for about 200 end-to-end sweeps. Dial it in, then leave it.
• Lost your place? Turn counter-clockwise until it free-wheels, then two and a half turns clockwise to land in the middle.

The removable panel and socketed drive amplifier

The front artwork panel covers the drive-amplifier socket and three fuzz trimmers. The supplied main-board netlist specifies an OPA1641 at U1 on ±15 V rails. A compatible replacement can change headroom, large-signal response or saturation recovery; it may also sound similar or behave poorly in this circuit.

Confirm the replacement assembly first. Ask Desert Sky Audio to confirm the exact device, package or adapter, pin mapping and orientation for your board. It must tolerate ±15 V operation and remain stable through the Dist range and with the actual load. An eight-pin package or a matching voltage rating alone does not establish compatibility. No manufacturer-tested alternative-device list is supplied here.

The TI OPA1641 documentation lists SOIC and VSSOP packages. Check the fitted socket assembly or carrier rather than assuming a bare OPA1641 is a DIP drop-in.

1. Disconnect the power supply and all cables. Use an ESD-safe work surface and handle the assembly by its edges.
2. Remove the artwork panel carefully. Record the fitted assembly and its pin-1 orientation before moving it.
3. Once the replacement is confirmed for this board, lift the removable assembly evenly with the appropriate IC tool. Avoid touching nearby components or adjusting the fuzz trims accidentally.
4. Check every pin and the orientation, then seat the replacement evenly without force.
5. Refit the panel. Reconnect and test at low volume. If it oscillates, becomes hot or stops passing signal, disconnect power and seek support.

The fuzz trims affect the sound only with CRz engaged. They are separate from the drive-amplifier replacement and from the VCA compressor calibration.

Working with the filters

Wall of Ice changes the bass energy reaching the clippers and adds +6 dB ahead of the drive. Aurora Curtain shapes the resulting upper harmonics against the matched presence shelf. CRz has its own low cut near 100 Hz and about 50 ms overload recovery with fuzz engaged; that recovery figure is specific to the fuzz stage.

Production drive values and response charts · Signal path and configuration

Aurora Curtain

The tone control. Top row, centre knob.

What it does

Aurora Curtain sets the upper balance after clipping. The 200 kΩ control closes to a low-pass corner around 3 kHz, matched to the drive’s +4 dB presence shelf. Closed gives a broadly flat balance below the roll-off; open brings in presence. Clockwise raises the corner and lets more upper harmonics through.

Aurora Curtain follows the clipping stages and precedes the optional VCA dynamics section. It filters the signal’s upper frequencies, including the new harmonics made by clipping. How much attack and brightness remain depends on the source and the setting.

Shape the harmonics after clipping

A familiar tone control is a useful starting point, but Aurora Curtain works on the signal after the pedal has clipped it. Its separate low-pass sections give you a broad brightness sweep without changing Dist.

Aurora Curtain uses two second-order low-pass sections. As you turn toward dark, their corners separate: the first section reduces highs sooner, while the second extends the roll-off higher up. This gives a different sweep from a single tone-control pole.

Start with your guitar tone open and your amplifier EQ neutral so you can hear Aurora Curtain clearly. Once its brightness is set, use the other controls in your rig as needed. How much attack remains depends on the setting, source and speaker.

What to expect as you turn it

The presence shelf and the Curtain’s closed corner are matched around 3 kHz so the knob has useful travel across its range. Start open and lower it until the brightness fits the source and amplifier.

How to set it

Set the drive first, then Aurora Curtain. Get Dist and the switches where you want the gain and the character, and accept that it may sound harsh; then bring Aurora Curtain down until the harshness goes. That order matters, because the amount of fizz to remove depends entirely on how hard you are driving the pedal.

A reliable method: turn it fully clockwise, play the loudest, most aggressive thing you are going to play, and slowly turn counter-clockwise. There is a point where the sound stops sounding brittle and starts sounding solid. Stop there. If you keep going you will start losing pick attack and clarity — not immediately, and not unpleasantly, but you will know when you have gone past what you wanted.

By instrument

• Electric guitar. Start around 2–3 o’clock with the drive up. Humbuckers into a dark amp often want it further clockwise than you would expect; single coils into a bright rig usually want it lower. Remember to open the guitar’s own tone knob all the way first.

• Bass guitar. Bass distortion lives or dies on the top end — too much and it sounds like a broken speaker. Roll Aurora Curtain down until the grind sits behind the note instead of on top of it, usually somewhere between 10 and 12 o’clock, and let Wall of Ice handle the bottom.

• Synthesizer. This is where the filter really shows. Synths can produce far more high-frequency content than a guitar, and distorting them produces more still. Use Aurora Curtain as you would a synth’s own filter: sweep it while a patch plays and stop where the tone is right. Its gentle, even slope is deliberately close in character to a classic analogue synth filter.

• Microphone or vocals. A little goes a long way. Vocals reveal a dark filter faster than instruments do — start at 4–5 o’clock and move down only until the sibilance and the edge of the distortion are under control.

• Drum machines and full mixes. Turning it down while a beat runs through the drive is a fast way to get a lo-fi, crushed sound; cymbals and hats are where the harshness lives, and this is what removes them.

Working with the other controls

• With Distortion. More drive makes more high harmonics, so heavier settings want Aurora Curtain further down. If you turn the drive up and the sound gets brittle, this is the knob that fixes it — not the drive knob.

• With the switches. The ladder and the fuzz each generate their own upper harmonics, and the fuzz in particular can get sharp. Expect to move Aurora Curtain whenever you flip one.

• With Wall of Ice. They work on opposite ends and do not overlap. Wall of Ice decides what the distortion is fed; Aurora Curtain decides how much of what it produced comes out. Set the low end first, then the top.

• With Twin Assassins. The notch works in the middle, between them. If a sound is harsh, try Aurora Curtain; if it is blurry or boxy, that is a job for Twin Assassins. They fix different problems and it is worth knowing which one you have.

One thing it cannot do

Aurora Curtain will not make the pedal clean. It sits after the distortion, so by the time the signal reaches it the clipping has already happened; turning the knob down makes that same distortion darker, not gentler. If you want less distortion, that is Dist or the switches. What this control does is decide how much of the result reaches your amplifier — which, for most of the harshness players complain about, is the more useful thing.

Try it on everything

Every source has a top end, and distorting anything makes more of it. Bass, synths, drum machines, a whole mix — Aurora Curtain treats them all the same, and on sources that are not guitars it often does more work than any other control on the pedal. If you find a use that surprises you, we would like to hear about it.

Reach for it when

• The drive sounds fizzy, brittle or glassy
• Bass grind sits on top of the note instead of behind it
• You want a dark, smoky drive that keeps its pick definition
• A synth patch wants a filter sweep

The circuit behind it: Aurora Curtain technical reference

Stiward Thære SæSteward of the Seas

The compressor and gate, last in the chain, after Aurora Curtain. The compressor switch puts it in or takes it out.

What it does for you

Use the Steward for level control after distortion. Its preset can bring chords and single notes closer in level, while the gate reduces noise in pauses. The preset and source level determine how much compression you hear and how long note tails remain.

A compressor before a drive changes the signal feeding the clippers. The Steward sits after them and after Aurora Curtain, so it controls the dynamics of the sound they have already made.

Two detectors and a blend

A fast detector catches the pick and a slow one rides the phrase, so single notes get caught without the level pumping back up between them. A blend mixes the untouched signal back in with the compressed one: the compressed path carries the sustain and body, the dry path carries the attack. It is the parallel-compression trick mix engineers use on drums and bass.

The gate

The production gate uses JP2 = B and a key from the Wall of Ice output through TO_COMP (J23) into compressor J10. It hears the signal before distortion, so changes to the clipping stages do not flatten the key’s dynamic range. Check quiet notes and sustained decays with the intended source.

The dynamics preset

The production preset uses JP1 = A, feed-forward from Audio_In, with PEAK unbridged. Compression starts around 0.4 V peak at TP1 and rises about 15 dB per volt, with a maximum reduction near 21 dB. The board blends 65–75 % wet as a starting point, retaining some dry attack.

Set on the board

The board’s thirteen trimmers hold the dynamics preset, so the panel needs only its Comp switch. Calibration should be checked with the intended source and long note decays. A single preset is not guaranteed to behave identically with every pickup or synth level.

Reach for it when

• Chords and single notes should land at the same level
• Fast runs keep disappearing under the drive
• You want silence between phrases without chopped chord tails

For technicians: Production board map and setup · Technical design and bench measurements

Starting points

Seven settings that get you to a good sound in the first minute.