X-Or FAQ

X-Or is a free two-oscillator monophonic bass synthesizer. Two free-running sawtooth oscillators feed a resonant low-pass filter with its own contour envelope, then a loudness envelope, then an output gain. One voice at a time. Built for bass parts, sub layers, and pedal-bass voicings.

Yes. No license key, no activation, no trial, no demo interruptions, no internet check. Install it, use it commercially, share it. The plugin processes audio entirely on your machine and never connects to the internet.

Producers and players who need focused low-end - sub layers, plucky bass lines, fifth-up stabs, sustained pedal tones. It is not a general-purpose synth workstation; the architecture is narrow on purpose. If your part lives below middle C, X-Or is in the right zip code.

Because bass parts are usually monophonic. Last-note priority means new notes interrupt the current voice; releasing the latest note falls back to the previously held note if one is still held. Soft retrigger keeps note-to-note transitions click-free, so legato phrasing works without enabling glide.

Incoming MIDI notes are shifted down 12 semitones (one octave) before pitch tracking, so a comfortable middle-of-keyboard MIDI part sounds in the low bass register. If you would rather have X-Or follow the keyboard literally, transpose your MIDI track up one octave in the host.

VST3 and CLAP, for Windows and Linux. Both formats ship in the same package.

Not at the v1.0.0 initial release. macOS is not on the immediate roadmap.

No. AU (the macOS plugin format) is not supported because macOS is not supported. AAX (Pro Tools) is not on the roadmap.

44.1, 48, 88.2, 96, and 192 kHz are validated. X-Or runs at host sample rate with no internal oversampling.

0 samples. The synth runs entirely in the time domain at host rate and reports zero latency to the host.

Any 64-bit x86 CPU. 2 GB of RAM minimum, 4 GB or more recommended. Disk space: about 30 MB. As a single-voice synth, CPU usage is very low.

Windows: VST3 goes to C:\Program Files\Common Files\VST3\; CLAP goes to C:\Program Files\Common Files\CLAP\. Linux: VST3 goes to ~/.vst3/X-Or.vst3; CLAP goes to ~/.clap/X-Or.clap. A DEB package is also provided for Debian/Ubuntu derivatives: sudo dpkg -i x-or-1.0.0-linux-x86_64.deb.

Force a plugin rescan in your DAW's preferences (Bitwig, Ardour, Reaper, FL Studio, Cubase, Live, Studio One all expose this in their plugin manager UI). On Linux, confirm the file is in ~/.vst3/ or ~/.clap/. Restart the DAW so it re-mmaps the binary.

Windows: use the standard uninstaller from the installer or the Add/Remove Programs panel. Linux: delete the .vst3 bundle from ~/.vst3/ and the .clap file from ~/.clap/, or sudo dpkg -r x-or if you installed via DEB.

You do not. X-Or is free and has no activation step. There is no license key, no account, no internet check, no trial timer. Install the plugin and the controls are immediately active.

Neither. The plugin works fully offline with no account, no iLok, no dongle, and no license file.

Yes, unlimited machines, personal or commercial. There is no machine count or license enforcement.

No. The plugin processes audio entirely on your machine, does not phone home, and does not collect any usage data.

OSC MIX is a 0-100% cross-fade between OSC A and OSC B. At 0% you hear only OSC A; at 100% only OSC B; 50% is an equal blend. For detune beating to be audible you need OSC MIX somewhere between 5% and 95% - at the extremes one oscillator is muted and any pitch offset of the other becomes inaudible.

OSC B COARSE offsets OSC B's pitch from OSC A in whole semitones, quantized to integers between -12 and +12. 0 = unison, +7 = perfect fifth above A, -12 = octave below A, +12 = octave above A. Use it for fifth-up stabs, octave stacks, and sub layers under a brighter A.

OSC B FINE is a fine pitch offset of OSC B relative to OSC A in cents, between -50 and +50. Use it for natural beating between the two free-running oscillators. 0 cents is locked unison; ±5 cents is subtle movement; ±15 cents is obvious detune; beyond ±25 cents it starts sounding out of tune rather than wide, especially on sub material.

MASTER TUNE applies a global pitch offset to both oscillators in cents, between -100 and +100. ±100 cents equals ±1 semitone. Use it to nudge X-Or into tune with material that is not at A=440 Hz, or to detune the whole voice for design. The OSC B offset (COARSE + FINE) stays the same regardless of MASTER TUNE.

Resonant low-pass with a dedicated attack-decay contour envelope that modulates the cutoff. CONTOUR sets how much the envelope opens the filter on each note-on; the cutoff then decays back to the CUTOFF resting position. There is no separate filter sustain or release - by design, matching pedal-bass voicing.

20 Hz to 5 kHz. The init value is 1000 Hz. Bass voicing typically sits between 200 and 500 Hz; plucky lead voicing 500-1500 Hz; open synthy bite 2-5 kHz. With CONTOUR > 0, the live cutoff opens above this resting value on each note-on.

0 to 100%. 0-20% is a neutral low-pass; 30-60% gives audible character without screaming; 70-100% is acid territory. High resonance with a moving CONTOUR is the classic squelchy bass sound.

CONTOUR controls how much the filter envelope modulates the cutoff. At 0% the filter sits at CUTOFF all the time. At 100% the cutoff opens to its maximum on each note-on and decays back to the CUTOFF resting position. Common values: 40-80% for plucky moving filter shapes; 0% for static filter colors.

Three stages: ATTACK (zero to peak on note-on, 0-1000 ms), DECAY (peak to the SUSTAIN level), SUSTAIN (held while the note is held, 0-100%), and note-off uses the same DECAY time to fall back to zero. There is no separate release stage - the decay carries note-off.

When a new note arrives while the previous note's release tail is still audible, the envelope ramps from its current level into the new attack instead of slamming to zero first. The result is click-free legato phrasing without needing glide on, even when LOUDNESS DECAY is long.

GLIDE adds portamento between overlapping or legato MIDI notes when its toggle is on. GLIDE TIME goes from 0 to 2000 ms. 40-80 ms is natural-feeling legato, 100-300 ms is obvious portamento, longer is sound-design movement. Notes only glide when the next note-on arrives before the current note-off; non-overlapping notes always retrigger cleanly.

-24 to 0 dB final gain stage. The default is -3 dB. Use it to set the overall output level of the patch; the output meters on the right of the chart tell you when to back off.

A built-in chart at the top of the editor previews the post-processing output. WAVEFORM mode shows the time-domain trace; SPECTRUM mode shows log-frequency magnitude from 20 Hz to 20 kHz. Click the pills at the top-left of the chart to switch modes.

A display-only tilt applied to the spectrum trace so sub fundamentals and upper harmonics read at similar visual heights instead of sub being a steep hill at the left. Bins at the silence floor stay flat at the floor; the tilt is only applied to bins with real signal. The audio is unaffected.

Send a sustained MIDI note in the C1-C3 range. Lower CUTOFF to taste (300-500 Hz is a classic bass zone). Raise CONTOUR to 50-70% and shorten FILTER DECAY to 200-400 ms - the filter snaps shut after each note attack, giving you a plucky bass voice.

Set OSC MIX to 0% (solo OSC A), CUTOFF around 200 Hz, RESONANCE 0%, CONTOUR 0%. Use as the layered sub under a brighter bass sample. Keep LOUDNESS DECAY moderate so note tails do not pile up.

OSC MIX 50%, OSC B COARSE +7 semitones, CUTOFF around 1.2 kHz, RESONANCE 50%, CONTOUR 65%, LOUDNESS DECAY 300 ms. Short tail + filter snap + fifth interval = punchy stab voice for short bass riffs.

OSC MIX between 30% and 70%, OSC B FINE between ±5 and ±20 cents. Two free-running oscillators a few cents apart produce slow beating - the wide-but-not-out-of-tune character that two-oscillator bass patches are known for. Beyond ±25 cents at low pitches, it starts to sound out of tune.

Click SAVE in the preset menu. A file dialog opens in the user presets directory; type a name and confirm. Files are written as .xorpreset XML. By default they live in ~/Documents/MousePlugins/X-Or/Presets/ (Linux maps that to your XDG documents folder or your home directory). User presets appear in the preset list after the factory entries. Use IMPORT to load a .xorpreset from anywhere on disk.

The A/B toggle in the header maintains two independent patch slots. Both start as the same snapshot. Tweak A, switch to B, make a different change, then flip between them to compare. Each slot keeps its full parameter state including any preset name you loaded into it.

Check the DAW track's monitoring and routing. X-Or only outputs audio while a MIDI note is held (or its release tail is still audible). If you're testing in the standalone wrapper, also confirm the audio interface is selected.

That is by design - X-Or applies a -12 semitone transpose by default for pedal-bass voicing. Transpose the MIDI track up an octave in the host if you want the note to follow the keyboard literally.

LOUDNESS ATTACK is too short for the material. Lift it to 3-5 ms. Sub-bass especially benefits from a couple of milliseconds of ramp at the start.

LOUDNESS DECAY is long enough that release tails overlap into the next note. Shorten LOUDNESS DECAY, or set SUSTAIN below 100% so notes fade during held sections.

OSC MIX is at 0% or 100% - only one oscillator is in the mix, so its detune has nothing to beat against. Set OSC MIX somewhere between 5% and 95%.

OSC B COARSE is non-zero, so MASTER TUNE shifts both A and B equally but their interval stays the same - you might be hearing the OSC B note dominate. Set OSC MIX to 0% to solo A and verify MASTER TUNE shifts the pitch by exactly ±1 semitone at its extremes.

The DAW's editor window state for an old version of the plugin is cached. Delete and re-instantiate the plugin in the project. Some DAWs cache plugin window state per-instance and will keep showing an empty window otherwise.

Email support@mouseplugins.com with your OS, your DAW, the plugin format (VST3 or CLAP), the X-Or version (menu -> About), and a short description of what's happening. Screenshots help.