Acid Rain — Constellation

• Manual PDF

Download: Constellation Firmware V1.1 Manual PDF

Constellation Eurorack Cheat Sheet

OVERVIEW

Constellation is an 8-channel trigger/gate pattern generator with advanced Euclidean rhythm capabilities, rich logic, pattern modifiers (burst, ratchet, chance), polyrhythmic channel clocks, freely assignable CV modulation, and robust save/load options.

QUICK START

1. Patch 1–5 Channel Outputs (top row of module) to drum modules:
2. Ch1: Kick
3. Ch2: Snare/Clap
4. Ch3: Closed Hi-Hat
5. Ch4: Open Hi-Hat

6. Ch5: Rimshot/other sound

7. Power on: Plays "4 on the floor" @120 BPM by default.

8. Press load — select any of the 20 pulsing buttons (central 2 rows) for quick start patterns. Use live mode to play/save slots like a keyboard.

9. Patch a slow-moving 0–5 V CV source into CV Input I for pattern evolution.

INPUT AND OUTPUT JACKS

Inputs

• Clock (clk): External main clock input, expects 0–5V pulse. With cable inserted, switches to external clocking.
• Reset: External reset (rising edge = reset).
• CV Inputs (I–VIII):
• Assignable. Not fixed to channels; can independently or cascadingly control any parameter on any pattern/channel.
• Voltage Ranges:
  • Divide, Length, Ratchet: 0–5V (Unipolar)
  • Events, Rotate, Burst, Chance, Width, Mute, Load: -5V to +5V (Bipolar)
  • See details below for modulation ranges.

Outputs

• Clock: +5V/0V digital pulse (either internal or mirrored external clock, depending on clocking).
• Reset: +5V pulse on reset event.
• Channel Outputs (1–8): +5V when active, 0V inactive — outputting final channel pattern as trigger/gate.

FRONT PANEL CONTROL REFERENCE

Buttons

• Top Row:
• clock, reset, save, load, input, random
• Middle Rows (Horizontal, 8 each):
• Pattern Select (P1–P8), Channel Select (I–VIII), Channel Mute, Live
• Pattern/Channel Parameter:
• AND, OR, XOR, flop, width, burst, ratchet, chance, divide, rotate, events, length
• Others:
• Mute, Live, Flop, Logic, Pattern Select, Pattern Parameter

Encoder

• Navigation through channels/patterns/parameters/menus
• Adjust values (press for coarse/fine adjustment)

CHANNEL AND PARAMETER STRUCTURE

• 8 Channels, each with 8 Patterns (64 patterns total)
  • Each pattern: Divide, Length, Events, Rotate, Burst, Ratchet, Chance
  • Patterns combine via Logic (AND/OR/XOR).
• Channel Parameters:
  • Logic, Flip-flop (gate vs. trigger behavior), Width

PATTERN MODIFIERS

• Burst: Each trigger = sequence of triggers (one per clock).
• Ratchet: Each trigger repeated between clocks (dense cluster).
• Chance: 0–100% probabilistic gate per event.

NAVIGATION & MENUS

• Edit Mode: Default, full parameter editing.
• Clock Menu: BPM (internal clock, tap tempo), main clock div/mult, swing, channel clocks per channel.
  • width button: main clock swing (50–90%).
  • mute button: stops/starts internal clock.
  • AND button: tap tempo.
• Mute Menu: Mute channels/patterns; press again to unmute.
• Save/Load Menu:
  • Save/Load any channel/patterns into 20 slots per bank (999 banks).
  • Save/load channel mutes, main clock, input assignments as options.
  • reset in load menu: forces re-sync.
• Live Mode:
  • Play save slots "momentarily" (release = revert).
  • Momentarily mute channels.

CV INPUT MODULATION SUMMARY

• CV is sampled once per rising edge of the channel clock.

TIPS AND UTILITIES

• Pattern Reset: Hold pattern button + press reset.
• CV Inputs Cascade: Inputs I–VIII cascade L → R for multi-parameter modulation; can disable in settings (cv_norm = 0).
• Save/Load Individual Channels: In save menu, press only channels to save.
• Autosave: Module autosaves every few seconds.
• Factory Reset: Delete all bank folders from SD card for blank state.
• Restore Quickstart Patterns: Download 000.zip from Acid Rain website.

LOGIC MODES (Channel):

• AND: Only outputs high if all active patterns are high.
• OR: Outputs high if any active patterns are high.
• XOR: Outputs high if odd number of patterns are high.

FIRMWARE UPDATES

1. Power off, remove/inject micro SD to PC.
2. Download latest firmware; place FW.BIN on root.
3. Reinsert SD, power on, wait for update animation.

QUICK REFERENCE: BUTTON SHORTCUTS

Manual & Resources:
- Constellation Firmware Manual PDF
- Generated With Eurorack Processor