Overview
Chord v2 is Qu-Bit Electronix’s chord oscillator: one pitch input, several voices tuned into chords, and a wavetable as the sound source for all of them. Qu-Bit’s launch announcement, as reported at the time, described four oscillator voices, eight factory banks of waveforms (traditional shapes, vocal synthesis, organ and chiptune sounds), a full polyphonic mode, and a 14HP panel, half the width of the first Chord.
A microSD slot on the front panel lets you replace the factory set with one wavetable of your own. Qu-Bit also publishes free wavetable libraries for Chord v2 on its site, including a collection by Radek Rudnicki, as ready-made examples of the format.
Wavetables on the Chord v2
Qu-Bit points Chord v2 users to Synthesis Technology’s free WaveEdit editor for custom wavetables, which means the file is a WaveEdit bank: 64 waves of 256 samples. The loading rules on Qu-Bit’s wavetable page are short. Put the file in the root directory of the microSD card, and make sure it’s the only wavetable there, so Chord loads the one you meant. Boot the module, then hold the MODE button for 3 seconds to reach the custom wavetable.
A setting in the chordconfig.txt file on the card decides how Chord splits those 64 waves. With LONGFORM_USERBANK off, the custom wavetable becomes 8 banks of 8 waveforms. With it on, it’s one bank of 64. Qu-Bit suggests the long form for scanning a converted audio sample in one sweep, and the split form for tables made of separate timbral sections.
Chord v2 has no target of its own in WaveStack because the E352 / E370 (WaveEdit) target already writes the file it reads: 64 frames of 256 samples, 16-bit mono. Tables of a different length are resampled to 64 frames. The two Chord modes suggest two ways to build. For the long form, a 64-frame sweep works well: Morph between two tables in WaveStack, or import a sample and let it become 64 frames. For the split form, Build an 8 × 8 grid where each row is a family of related waves. An 8 × 8 grid built in WaveStack is written row by row, and that suits the split mode. Qu-Bit doesn’t say how the 64 waves are divided into its 8 banks, but if it follows file order, each row of your grid becomes one bank.
At 256 samples, a frame holds up to 127 harmonics, enough for full brightness down to about 190 Hz (see frame size). Bright frames from larger tables lose some top end in the conversion. Because Chord holds one custom wavetable at a time, keep your library on the computer and copy over the one you want. WaveStack keeps a grid’s shape in its wt3d chunk, so the project you exported from stays editable.
Specifications
| Format | WaveEdit bank (64 waves × 256 samples, 16-bit) |
|---|---|
| Custom wavetables loaded | 1 at a time |
| Bank layout | 8 banks of 8, or 1 bank of 64 (LONGFORM_USERBANK) |
| Card location | microSD root, only one wavetable file |
| Loading | Hold MODE for 3 seconds |
From WaveStack to the Chord v2
- Build a table in WaveStack. For the split mode, an 8 × 8 grid keeps each group of eight waves together.
- Open Export and pick E352 / E370 (WaveEdit) as what the table is for. That’s the WaveEdit bank format Chord v2 reads.
- Insert Chord’s microSD card in your computer and move any other wavetable files out of the root directory.
- Save the export to the root of the card, or link the card as a folder so Export writes into it.
- If you want one long bank instead of eight short ones, set
LONGFORM_USERBANKto on inchordconfig.txt. - Eject the card, put it back in Chord, power up and hold MODE for 3 seconds to play the new wavetable.
Things to know
- Chord v2’s voice count, factory banks and 14HP width come from press coverage of Qu-Bit’s announcement, not from a Qu-Bit manual we could reach.
Frequently asked questions
What wavetable format does Qu-Bit Chord v2 use?
A WaveEdit bank, the format made by Synthesis Technology’s free WaveEdit editor, which Qu-Bit links to for making Chord wavetables. Chord can split it into 8 banks of 8 waveforms or use it as a single bank of 64, which means a 64-wave file. In WaveStack, the E352 / E370 (WaveEdit) target writes this format: 64 frames of 256 samples at 16 bits.
Why does Chord v2 load the wrong wavetable?
Qu-Bit’s instructions say only one wavetable should be in the root directory of the card, so the module uploads the right one. If you’ve copied several WAV files to the root, move all but one into a folder or off the card. Then reinsert the card, boot the module and hold MODE for 3 seconds to load it. Keep the rest of your wavetables in a folder or on your computer.
What does LONGFORM_USERBANK do on Chord v2?
It’s a setting in chordconfig.txt on the microSD card that changes how Chord divides a custom wavetable. Off, the 64 waves become 8 banks of 8 waveforms, so each bank is a small family of related timbres. On, the whole wavetable is one bank of 64, which Qu-Bit suggests for things like a converted audio sample you want to sweep through in one motion.
Can I use Serum wavetables on Chord v2?
Not directly. Serum tables use 2048-sample frames and up to 256 of them, while Chord reads WaveEdit’s 64 frames of 256 samples. Import the Serum file into WaveStack, then export it with the E352 / E370 (WaveEdit) target, which resamples the table to 64 frames of 256 samples. Very bright frames lose some top end at 256 samples, as explained in frame size.