Full reference

PERC8
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Perc8 is an eight-voice drum synthesizer and sequencer for iOS. Each voice has its own engine, macro controls, filter, envelope, LFOs, drive, FX sends, mute/solo state, and routing. Patterns build loops; Chain turns those loops into full arrangements.

Perc8 uses one shared kit across patterns. Patterns A-H store the rhythm, p-locks, conditions, retrigs, mutes, and other step data. The voice engines and base sound settings are project-wide, so changing a kick sound updates that voice everywhere unless a step or chain automation overrides it.


THE FOUR MAIN TABS
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SYNTH — Pattern editing, voice sound design, Chain, FX, and Master mixing.

PRESETS — Save and load Voice, Kit, and Project presets.

SETTINGS — Theme, MIDI routing, sync, output routing, and app options.

HELP — This manual, guided tutorials, and support report tools.


THE SYNTH TAB
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TRANSPORT ROW
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The top row contains playback and live controls:

• Play/Stop — start or stop standalone playback.
• Reset — return the transport to the beginning.
• Tempo — set the internal tempo when Perc8 is not following external sync.
• FILL — latch fill mode for steps or chain slots that use Fill conditions.
• PAT / CHN — choose Pattern playback or Chain playback.
• Wrench — opens context utilities for the current scope.

VOICE ROW
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The numbered voice row selects which voice you are editing. Tap a voice number to select it. The play buttons below the numbers preview each voice without changing the pattern.

Double-tap a voice number to mute or unmute that voice. This is the same mute state shown in Master and ENV/FX.

Touch and hold a voice number to open quick actions:

• Load Voice Preset — load a saved voice into that slot.
• Copy Voice — copy the selected voice sound.
• Paste Voice — paste the copied voice into that slot.

PATTERN ROW
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Tap A-H to select a pattern. Perc8 has eight visible patterns. They share the same kit, but each pattern has its own step grid, p-locks, conditions, mutes, and pattern length.

SCOPE BAR
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The bottom editor scope row chooses the main work area:

• PATTERN — step sequencing and per-voice sound editing.
• CHAIN — arrangement slots and timeline automation.
• FX — global delay, reverb, and modulation effects.
• MASTER — voice mixing, choke groups, output routing, and master bus.


VOICE PARAMETERS
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The selected voice is edited through the section tabs:

TRG — trigger defaults, selected-step editing, retrigs, and Euclidean generation.

ENG — engine selection and the eight engine-specific macro controls.

FILT — post-engine filter.

EQ/DRV — EQ, pre-drive emphasis, and drive.

ENV/FX — envelope, ducking, pan, mute/solo, and FX sends.

LFO — two modulation LFOs per voice.

PL — p-lock record. This appears in Pattern scope and stays lit while p-lock recording is armed.


ENGINE (ENG)
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The engine is the voice's sound source. Each voice can use a different engine. The visible engine picker focuses on the shipped release surface:

• Carbon drum engines for kicks, snares, claps, hats, cymbals, toms, and percussion.
• Noise Perc for rhythmic-noise percussion.
• Noise Tone for pure noise oscillator tones.
• Dual Synth for tonal and layered synth sounds.

Each engine has eight macro controls. The macro names change per engine and are designed to stay musical. Carbon Kick, for example, uses BODY, PUNCH, DECAY, ATTACK, GRIT, TONE, MOTION, and DYNAMICS.

Noise Perc is aimed at rhythmic-noise drum design. Its macro surface is BURST, PRESSURE, METAL, CORRODE, GATE, SPRAY, TUNE, and FEEDBACK.

Noise Tone uses Type A, Type B, Blend, Mod, Color, Focus, Drive, and Tail to blend and shape two continuous noise sources.


FILTER (FILT)
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The filter shapes the voice after the engine.

MODE — Off, low-pass, band-pass, high-pass, or notch.

TYPE — Filter character such as SVF, Ladder, Comb, Formant, MS-20, TB-303, and Metal.

CUTOFF — Filter frequency. Lower is darker; higher is brighter.

RES — Resonance at the cutoff frequency.

ENV — How much the amplitude envelope moves the cutoff.


EQ AND DRIVE (EQ/DRV)
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EQ/DRV is split into three submenus:

EQ — LOW, MID, MIDF, HIGH.

PRE — MODE, FREQ, Q, AMT. This emphasizes or cuts part of the signal before drive.

DRIVE — TYPE, AMT, MIX, BIAS.

LOW / MID / HIGH are centered at 0.5 for flat response. Turn above center to boost, below center to cut.

TYPE chooses the drive character. AMT controls drive amount. MIX is a true dry/wet blend over the pre-drive signal, so lower values preserve more of the original body. BIAS tilts the waveshaper away from symmetry for even-order harmonic character.


ENVELOPE AND FX SENDS (ENV/FX)
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ENV/FX is split into two submenus:

ENV — ATK, DEC, DUCK, SYNC, PAN, and voice utility controls.

FX — FX1, FX2, FX3 sends.

ATK controls how quickly the voice reaches full level. DEC controls how long it fades after the held trigger ends.

TRIG LEN lives on the TRG page. It uses a fixed 1/16-note gate grid, not the current step size. When S.LEN is 1/16, a TRIG LEN of 1/16 equals one step. Shorter values are finer divisions; longer values extend through larger note lengths up to long multi-bar gates.

DUCK is a transport-locked rhythmic pump after the envelope. At 0 it is off. Higher values pull the voice down harder and hold it down longer inside each sync window.

SYNC chooses the DUCK division. Short divisions pump quickly; long divisions create slower rhythmic breathing.

PAN sets stereo position. In Pattern scope, PAN can be p-locked from ENV so individual hits can move across the stereo field.

FX1 sends to DUB delay. FX2 sends to VERB reverb. FX3 sends to MOD chorus/flanger.


LFO
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Each voice has LFO1 and LFO2. Select L1 or L2 inside the LFO page.

WAVE — LFO shape.

TARGET — Parameter to modulate: macros, filter, envelope, level, drive, pan, EQ, FX sends, and more. LFO2 can also target LFO1.

DEPTH — Modulation amount.

RATE — Free-running speed when SYNC is off.

SYNC / DIV — Locks the LFO to musical divisions, including triplets and dotted values.

TRIG — Resets the LFO on each trigger.

PHASE — Bipolar waveform offset centered at 0. Negative and positive values shift the waveform position.

ONE SHOT — Runs one cycle per trigger and stops.

When an LFO targets a visible knob, the knob shows the modulation range as an arc overlay.


PATTERN SEQUENCING
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Pattern scope is where you build loops for the selected voice.

STEP GRID
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The step grid shows up to 16 steps at a time. Longer patterns page horizontally through the same grid.

Tap a step to select it. Quickly tap the same selected step again to toggle TRIG. This keeps selection immediate while preserving a fast trigger shortcut.

Touch and hold a step to open step tools:

• Ghost Hit — quiet trigger.
• Normal Hit — standard trigger.
• Accent Hit — stronger trigger.
• Tie — continue the previous event.
• Trigless Lock — change parameters without triggering a note.
• Clear Step — clear the step.
• Select Multiple — start multi-step selection.

VOICE OVERVIEW
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The collapsible voice overview shows all eight voices against the visible step range. It is read-only and helps you understand the full pattern while editing one lane.

Tap an overview row to select that voice. On larger screens the overview opens by default; on smaller screens it can be collapsed to save space.

PATTERN LENGTH
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Pattern length supports 1-64 steps. Use the length picker to choose common lengths or enter a custom length. When the current pattern is longer than the visible page, the footer shows the current step range and lets you move between pages.

PATTERNS A-H
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Tap A-H to select a pattern. During playback, switching patterns queues the next pattern at the current change boundary so the rhythm stays locked. The pattern display shows the selected or incoming pattern.

Patterns store step data, p-locks, trigger variation, mutes, and pattern length. Voice engines and base knob settings are shared across the project.


TRG PAGE
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The TRG page has STEP, RTRG, and EUC subpages.

STEP
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TRIG — On/off for the selected step.

NOTE — MIDI note or pitch.

VEL — Velocity. Higher is usually louder and brighter.

LEN — Trigger length on the fixed 1/16-note grid.

PROB / COND — Whether and when the step fires. Options include Always, Fill, Not Fill, probability choices, and ratio conditions such as 1:2, 2:3, and 1:8 through 8:8.

Outside p-lock record mode, NOTE, VEL, LEN, and PROB edit the voice defaults unless a selected step carries a meaningful override. In p-lock record mode, matching the default clears the step override instead of leaving hidden placeholder locks.

RTRG
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RTRG repeats a note rapidly inside one step for rolls, flams, and machine-gun hits.

RTRG — Enable or disable retriggering.

COUNT — Number of repeats.

LEN — Duration of each repeat.

VEL — Repeat velocity relative to the original hit.

RTRG can be edited from the selected step context when p-lock record is off.

EUC
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EUC creates Euclidean rhythms by distributing pulses evenly across the current pattern.

PULSE — Number of triggers.

ROT — Rotation offset.

VEL — Velocity for generated triggers.

OP — How to combine the generated rhythm with existing steps: Replace, Add, Subtract, XOR, or Intersect.

The cyan preview overlay shows where the generated rhythm will land. Tap APPLY to commit it.


P-LOCKS
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P-locks change a parameter on a specific step. They are useful for one-off filter hits, pitch changes, pan moves, FX send throws, changing engine macros on one trig, or creating trigless automation inside a pattern.

To record a p-lock:

1. Tap PL to arm p-lock recording.
2. Select a step.
3. Adjust a sound parameter.
4. The step stores that value.
5. Tap PL again to disarm.

Steps with meaningful p-locks show a badge in the grid. Placeholder trigger defaults do not light the badge.

Trigless locks are steps that do not trigger a note but still change parameters. They stay active until a later trigger or override changes the value.

On larger iPad layouts, the Pattern workspace can show a selected-step inspector and p-lock overview. Use those panels to see which step is selected, which parameters are locked, and where locked steps exist in the current voice lane.

To clear a p-lock, select the step and reset the locked control to the base value. The step inspector also offers lock copy, paste, and clear actions when available.


FILL
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FILL is a live latch. Steps with COND = Fill play only while Fill is active. Steps with COND = Not Fill play only while Fill is off.

Use Fill for alternate snare hits, fills, breakdowns, and performance variations. Fill also exists per chain slot, so a slot can force Fill behavior for that section of an arrangement.


WRENCH UTILITIES
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The transport wrench changes by scope.

PATTERN utilities include pattern copy/paste/duplicate actions, Clear Track for the selected voice lane, Clear Pattern for all voices in the pattern, and sound copy/paste/reset actions.

CHAIN utilities include Open Chain, New, Copy, Delete, zoom/follow controls, slot or range actions, and lane cleanup actions when a chain parameter is selected.

The utility menu stays anchored in the transport row so common actions are available without changing tabs.


CHAIN
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Chain turns patterns into arrangements. It has two modes: Slots and Chain.

SLOTS
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Slots are the structure of the arrangement. Each slot references a pattern A-H. Add slots to build verses, drops, breakdowns, and outros.

Add — Insert another pattern slot.

Drag — Reorder slots.

Duplicate — Copy a slot.

Delete — Remove a slot.

FILL — Force Fill behavior for that slot.

Double-tap a slot to open Chain mode focused on that occurrence.

RANGE SELECTION
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Long-press a slot to anchor a range, then tap another slot to close the range. The transport utility menu can then copy, paste after, duplicate, move, delete, or apply parameter actions to the selected range.

CHAIN MODE
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Chain mode shows the arrangement as a continuous timeline. Use it for long-form automation across pattern occurrences.

The timeline strip is a scrubber. Tap or drag it to move the viewport. ZOOM controls how much arrangement time is visible. Follow can keep the viewport near playback.

Select a voice and a parameter, then edit the vertical lane below the timeline.

HOLD means an explicit value persists until the next explicit value.

LINEAR means values ramp between explicit anchors.

RES groups timeline steps when exact per-step editing is too fine.

NODE MEANINGS
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No node — base sound value.

Solid node — explicit chain value.

Hollow dim node — HOLD-resolved inherited value.

Hollow bright node — LINEAR-resolved ramp value.

Editing a resolved value creates a new explicit node. Double-tap a solid node to clear that explicit value.

LANE ACTIONS
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Chain lane actions can shape the selected parameter across the lane or selected span:

• Flat
• Ramp
• Ease In
• Ease Out
• S-Curve
• Sine
• Triangle
• Square
• Pulse
• Random
• Clear Current Parameter
• Clear All Parameters

Generated shapes are seed-aware: they prefer existing endpoints, then fall back to the selected step when no endpoints exist.


VALUE HIERARCHY
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When several layers set the same parameter, Perc8 resolves them in this order:

P-lock > Chain > Sound.

Sound is the base voice value. Chain can override it across arrangement steps. P-locks override both on their pattern steps.

Dim values are inherited from a lower layer. Bright values are overridden at the current layer. Step badges show meaningful p-locks.


FX
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FX scope edits the three global effects. Each voice sends into these effects from ENV/FX, or from the routing sheet available in FX and Master.

The routing sheet batch-edits all voices for:

• FX1 send
• FX2 send
• FX3 send
• Choke group


DUB — DIRTY DELAY (FX1)
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TIME — Delay time. With SYNC on, TIME uses note divisions including triplets and dotted values.

SYNC — Tempo lock for delay time.

FEEDBACK — Echo repeats.

TONE — Darker or brighter repeats.

DRIVE — Saturation in the feedback path.

WIDTH — Stereo spread.

RETURN — Wet output level.


VERB — INDUSTRIAL REVERB (FX2)
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SIZE — Room size.

DECAY — Reverb tail length.

DIFFUSION — Reflection density.

PRE-DLY — Delay before the reverb starts. SYNC maps pre-delay to tempo divisions.

TONE — Dark or bright reverb color.

GRIT — Saturation inside the reverb.

SYNC — Tempo lock for pre-delay.

RETURN — Wet output level.


MOD — CHORUS / FLANGER (FX3)
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MODE — CE-2 chorus or BF-2 flanger.

RATE — Modulation speed.

DEPTH — Modulation depth.

MANUAL — Flanger manual delay position.

RES — Flanger resonance.

WIDTH — Stereo spread.

SYNC — Tempo lock for rate.

RETURN — Wet output level.

BF-2 is tuned as a centered jet-style flanger with a bright feedback path and subtle stereo phase spread.


MASTER
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Master is the mixer. It shows all eight voices and the master bus.

VOICE CHANNELS
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TRIM — Voice level.

PAN — Voice stereo position.

M — Mute.

S — Solo.

CHOKE — Choke group. Voices in the same group cut each other off.

BUS — Output bus assignment for multi-output setups.

The Master page also gives quick access to voice preset loading for the selected voice and the routing sheet for FX sends/choke setup.

MASTER BUS
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WIDTH — Stereo width above the mono crossover.

MONO — Frequencies below this point are summed to mono. At minimum it is effectively bypassed.

LEVEL — Master output trim.

LOW / MID / HIGH / MIDF — Master EQ.

TYPE / DRIVE / THRESH / REL — Master drive and dynamics controls.

CEIL — Output ceiling / limiter.


MUTE AND SOLO
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Each voice has one shared mute and solo state. It is mirrored in:

• The shell voice row.
• Master voice channels.
• ENV/FX voice controls.

Change mute or solo in one place and the other views update immediately.


PLAYBACK
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PAT plays the selected pattern on loop.

CHN plays the chain slots in order.

Pattern changes queue to the current change boundary so playback stays locked.

Fill can be used live from the transport row or forced per chain slot.

In standalone mode, returning to Perc8 after switching apps automatically attempts to recover the audio engine if iOS stopped it in the background. Pressing Play also checks for that stopped-engine state before starting transport.


PRESETS
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VOICE PRESET — One voice sound: engine, macros, filter, EQ, drive, envelope, LFOs, FX sends, and routing-relevant voice settings.

KIT PRESET — All eight voices plus FX and master settings.

PROJECT PRESET — Complete session: kit, patterns, p-locks, chain arrangement, transport, MIDI, and sequencer state.

Use Save, Load, Rename, Delete, Export, and Import from the PRESETS tab.

Common voice preset workflows are also available from the voice row context menu, and from Master for the selected voice.


SETTINGS
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APPEARANCE
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Theme chooses the app appearance. Standard is the default. Perc8 Retro is an alternate visual theme with the same layout and behavior.

TRANSPORT AND SYNC
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Sync Source — Current clock source.

Sync Mode — Internal clock, external sync behavior, or MIDI clock behavior.

MIDI Source — MIDI input device.

MIDI ROUTING
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Single Channel — All voices respond from one MIDI channel.

Multi-Timbral — Voices 1-8 use separate MIDI channels.

Pattern Channel — Dedicated channel for pattern trigger input. Pattern changes can be triggered from MIDI notes on this channel using the A-H map.

OUTPUT ROUTING
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Main Output — Stereo hardware output pair for the master mix.

Per-Bus Routing — Route individual voices or buses to separate outputs when the host or hardware supports it.


SUPPORT
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The HELP tab includes Report a Problem. It can copy or share a compact troubleshooting report for support.

The report includes useful changed state such as globals, changed voice parameters, authored pattern/step data, and meaningful chain data. It omits default and unused values where possible.

Send reports or support questions to joe@terrarum.net.


END OF MANUAL