FlatSix Modular Arp Of Darkness (Black) - 1U CV Arp with a twist & swappable firmware

The Arp Of Darkness is an arpeggiator with a unique twist: it builds dynamic, evolving note sequences using a buffer approach inspired by shift registers and Turing Machines. Unlike traditional arpeggiators that play predefined chord patterns, this module lets you enter notes sequentially into a buffer of variable length — 3 to 16 notes — and play it back in 6 modes: Forward, Backward, Exclusive Ping-pong, Inclusive Ping-pong, Golden Ratio, and Random. Each mode offers both queued and immediate selection, plus reset on the fly.

Golden Ratio Mode is an especially musical one — based on the Fibonacci Sequence, it steps through your buffer using φ-based intervals for patterns that feel both intentional and organic.

You can save and load your buffer to EEPROM — find a phrase you love, save it, evolve it into something completely different, then reload your original to restate the idea.

What's New in v1.4.0 (Updated 05/29/2026)

CV Keyboard Mode
Hold the High C (Shift) button at boot to enter a full monophonic CV keyboard with gate output and portamento via the pot. Play notes directly without swapping firmware.

Remix Buffer
A quick dual-tap of Octave Up + Octave Down shuffles the note order in your buffer on the next clock. Note values stay the same — only the sequence changes. Great for breaking out of a pattern on the fly without losing your phrase.

Auto-Remix Modes
Set the buffer to reshuffle itself automatically every 2, 4, or 8 loops. Activate queued (waits for the end of the current loop) or immediate (fires on the next clock). Deactivate anytime with the same dual-tap.

The Nocturne Alchemy Platform
Each module within the Nocturne Alchemy Platform shares the same robust Arduino-based hardware, allowing you to effortlessly swap functionalities through our intuitive web firmware loader. By purchasing one module, you gain access to the full range of available firmwares — including Arp of Darkness, Slight Of Hand, Seventh Summoner, and Shroud Of Turing — it's like getting multiple modules for the price of just one.

Specs

• Height: 1U (Intellijel format)
• Width: 26HP
• Depth: 40mm ("Skiff-friendly")
• Current Draw: 40 mA +12V, 0 mA -12V, 0 mA 5V

Features

• 4 octaves of control from C0 to C4
• 6 note buffer lengths (3, 4, 5, 6, 8, 16)
• 6 playback modes — Forward, Backward, Excl. Ping-pong, Incl. Ping-pong, Golden Ratio, Random — with cycle select, direct select (queued & immediate), and reset
• Remix Buffer — shuffle note order on the fly with a dual-tap
• Auto-Remix — automatic buffer shuffle every 2, 4, or 8 loops
• Save, load, and clear the buffer to/from EEPROM
• CV Keyboard Mode — boot into a monophonic keyboard with gate out and portamento
• Clock input and CV out calibrated to 1V/0
• Calibration mode with tuning for each note across 4 octaves (Comes pre-calibrated)

Note To International Buyers - FlatSix Modular is more than happy to ship to our international friends, but we're a small company in the U.S. who's not currently setup to collect VAT and other import taxes on behalf of our customers. All international items are shipped with customs forms, but the payment of any import taxes is the responsibility of the buyer. Thanks for understanding!