Niner

A kick drum synthesizer. Three voices — SUB sine, MID sine+noise, TOP band-passed click — layered into a five-mode distortion palette, a tilt/low/notch master EQ, and a master bus that goes RMS comp → transformer drive → brickwall limiter → auto tube warmth. A parallel 909-style CLAP voice rides alongside. Sixteen-step sequencer, factory + user presets, one-shot WAV/AIFF bounce.

Free forever. Open source forever (GPL-3.0). Built because the kicks we liked cost $90 each and didn’t let us hear what was actually happening under the hood.

Formerly released as Slammer. Renamed to Niner in v0.7.0 due to a trademark conflict. Plugin IDs changed — DAW projects with the old Slammer plugin will need to be re-wired. User presets and settings auto-migrate on first launch.

xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/VST3/niner.vst3
xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/CLAP/niner.clap

What’s here

• Three-layer kick engine — SUB sine with pitch envelope, MID sine+noise blend, TOP bandpass click transient. Independent tuning, amp + pitch envelopes, and drift per layer.
• 909-style CLAP voice — parallel, noise → 2-pole SVF bandpass → baked 3-burst + exponential tail. Tunable 500–5000 Hz, 50–400 ms tail. Bit-identical bypass when off.
• Five-voice distortion palette — Sat Clip (split-band rational), Sat Diode (asymmetric exponential), Sat Tape (drive-reactive LPF + hysteresis), Transformer drive (2nd+3rd harmonic blend with 60 Hz bloom), Master warmth (asymmetric cubic, auto-engages above 0 dB).
• Per-voice clip — optional shaper inside each kick voice, before the amp envelope. Three modes (Tanh, Diode, Cubic), default off. Distinct from the master SAT chain, which runs after the envelope — the per-voice stage shapes attack-rich harmonic content; SAT shapes what’s left.
• Master bus compressor — three macros (Amount, Reaction, Transformer drive) plus a precision strip: Attack 0.3–50 ms, Release 20–800 ms, soft Knee 0–12 dB (Reiss & McPherson quadratic). Bit-identical hard-knee path at Knee = 0.
• Master EQ — tilt, low shelf, variable-Q notch.
• 16-step sequencer — host-synced in a DAW, internal transport standalone. Click or drag to paint.
• One-shot bounce — render the current sound through the full chain to 16-bit / 44.1 kHz WAV or AIFF. Offline, on the GUI thread, against a fresh DSP instance — bit-for-bit reproducible, and live audio keeps flowing during the render.
• Factory + user presets — forward-compatible JSON with #[serde(default)] on every field, so future versions don’t break your saves. Up/Down arrow keys cycle.
• Standalone + VST3 + CLAP for Linux, macOS (Apple Silicon + Intel), Windows.

What’s on purpose missing

• AU. The framework we built on (nih-plug) doesn’t support Apple’s AU format — it would mean rewriting from scratch in a different framework. So Logic Pro users: sorry, we can’t load in your DAW yet. Reaper, Bitwig, Live, Cubase, Studio One, FL, Renoise, and Ardour on Mac are all fine via VST3 or CLAP.
• Polyphony. It’s a kick drum. It’s monophonic on purpose.
• Free-form window resizing. The editor is a 680×444 rack panel with aspect-ratio-locked scaling — it snaps to integer multiples. Egui-baseview limitation, not a design choice.

Listen first

Ten one-shots bounced straight out of the plugin via the BOUNCE button — clean kicks, 808/909 emulations, claps, snares, toms, hats. No download, just hit play: hyperfocusdsp.github.io/niner

Specs

Build notes

Posts from the devlog on what’s inside Niner and why:

• Bouncing a plugin to disk without touching the audio thread — how the BOUNCE button stays off the audio thread, runs against a fresh DSP instance, and produces bit-identical output between clicks.
• Why I stopped trusting tanh for kick-drum distortion — what symmetric tanh does to a transient, where Niner replaced it, and where it still earns its keep.
• The knob I removed from my plugin — why VEL came out, and why ship-and-remove beat ship-and-justify.
• I renamed my plugin two weeks after launch — Slammer → Niner. What broke on purpose, what migrated cleanly, what the new plugin IDs are.

Found a bug? Got an idea?

Email feedback@hyperfocusdsp.com directly, or use the /support form (it just opens your mail client with the fields filled in). If you’d rather use GitHub, open an issue; bug and feature templates live there. Same inbox either way.

FAQ

Is Niner free? What's the license?

Free forever, open source forever. GPL-3.0 — the plugin source is GPL'd. The license governs the plugin code; it doesn't extend to audio you create with it. Bounced kicks go into commercial tracks the same way output from any plugin would.

Which DAWs does Niner work in? Does it support Logic Pro?

VST3, CLAP, and Standalone for Linux, macOS (Apple Silicon + Intel), and Windows. Reaper, Bitwig, Live, Cubase, Studio One, FL, Renoise, and Ardour all load it via VST3 or CLAP. Logic Pro doesn't — it requires AU, and the framework Niner is built on (nih-plug) doesn't support AU. Framework limitation, not a design choice; switching would mean rewriting from scratch.

Does Niner run on Linux? On Apple Silicon?

Yes to both. Linux x86_64 is a first-class build target — every release ships a Linux binary alongside macOS (Apple Silicon + Intel) and Windows (x86_64). All four are tested on real hardware before release, not cross-compiled and shipped blind.

I have projects using Slammer. Will they open in Niner?

Plugin IDs changed in v0.7.0 (CLAP_ID and VST3_CLASS_ID), so DAW projects with the old Slammer plugin need to be re-wired — load Niner in the same slot, the audio path is identical. User presets and settings auto-migrate on first launch. Renaming was forced by a trademark conflict; the DSP didn't change.

Is Niner polyphonic?

Monophonic — one kick at a time, on purpose. It's a kick drum, and polyphonic kicks aren't a thing producers actually want. If you need layered hits, run two instances on parallel tracks.

What does the BOUNCE button do?

Renders the current sound through the full DSP chain to a 16-bit / 44.1 kHz WAV or AIFF on disk. Off the audio thread, against a fresh DSP instance — bit-for-bit reproducible between clicks, and live audio keeps flowing during the render.