筑波音響 / TSUKUBA ONKYO
A saturator that solves circuits sample by sample · free, full version
Valves, transformers, germanium: AD-1 distorts by computing the circuits themselves. It is not passing your audio through a curve shaped to sound about right, which is why the knobs behave differently on every circuit.
Audio Unit / CLAP · macOS 11 or later · Apple Silicon / Intel
The panel above was redrawn for this page. The numbers under the knobs are the same ones the plug-in shows.
One thing before you install: AD-1 is not signed by Apple. macOS marks downloaded files as quarantined, so the plug-in will not appear in your DAW's list as it is. Double-click the bundled install.command and it clears that flag and installs it for you (no administrator password needed).
This is not a knob for picking a flavour of distortion. Every time you switch, the circuit built inside is replaced.
The scope below is not decoration. It draws the waveform measured by running audio through AD-1, exactly as it came out. Pick a circuit, then keep scrolling — scrolling is the DRIVE knob.
12AX7 · 220k · 1.5k Rk
| TRIODE | One valve stage (12AX7). The gentlest of the five; adds sheen |
|---|---|
| PENTODE | A harder valve (EF86). Push it and the sound dips and recovers. Distorts the deepest |
| GERMANIUM | The transistor from old fuzz boxes (AC128 class). Breaks up early, and gets gritty |
| IRON | A transformer. Low notes give way first, so the bottom pulls together. What came before changes how it distorts |
| OP-AMP | Diodes clipping the peaks. The hardest and most angular of the five |
On TRIODE the BIAS knob moves a resistor around the valve; on IRON it moves the magnetic offset in the transformer. So on some circuits turning it up adds distortion, and on others it takes it away. Under the knob you get the real value of whatever part it is moving (Rk, Φoff, and so on).
The figures above are second-harmonic content (h2) — a number that grows the more asymmetric the waveform is, and a fair proxy for valve-like thickness. TRIODE and OP-AMP gain h2 as BIAS goes up; GERMANIUM and IRON lose it. PENTODE barely moves at all (there, BIAS changes how it sags rather than how it distorts). We could make all five behave alike, but that would mean bending what the circuits actually do, so we don't.
What went in runs across; what came out runs up. The other four circuits draw a single line here, but IRON's line does not meet itself on the way back. Magnetism stays behind in the transformer core, so the same level comes out differently depending on what came just before it.
Low notes give way first. The figure above is at 102.5 Hz; at 1 kHz the same setting barely distorts at all. On a bass or a bus, the bottom saturates before anything else.
The lower the note, the more flux builds up in the core (Φ=∫v dt). DRIVE is at 70% in the figure above.
All eighteen are level-matched. Each one was measured and trimmed to come out at the same level as bypass, within 0.05 dB at worst. Nothing jumps in volume when you switch, so you are comparing character and nothing else — none of that trick where the louder one simply sounds better.
AD-1 solves the circuit on a finer time grid than the audio itself. This sets how fine. Higher settings mean less unwanted noise, but ×8 is not simply a better ×4.
Measured, the only circuit that improves from ×4 to ×8 is OP-AMP (−43.9 → −58.6 dBc); TRIODE, PENTODE and IRON get slightly worse, because more stages also pile up more of what gets lost on the way back to the original rate. If in doubt, leave it at the default ×4. It is lighter on the CPU too.
Latency is fixed at 5 samples (0.1 ms at 48 kHz). It is reported to the DAW, so it is compensated automatically. Bypass is delayed by the same amount, so switching it in and out never shifts phase against your other tracks.
When you bounce, AD-1 raises its own accuracy. There is nothing to switch.
During playback there is a cap on how many passes the solver may take, so audio never drops out. Offline there is no deadline, so the cap comes off. The only thing that changes is that unwanted artefacts get quieter — level and the amount of distortion stay where they were.
When you change circuits, AD-1 builds the new one in the background and warms it until it settles before swapping it in. There is no click at the moment you switch.
That work happens away from the audio path. Internal maths is 64-bit, and the sample rate follows the host (verified from 44.1k to 192k).
Check that your DAW is on this list first.
| Formats | Hosts |
|---|---|
| Audio Unit | Logic Pro / GarageBand / MainStage |
| CLAP | Reaper / Bitwig Studio / Studio One 7 and later |
AD-1 cannot be used in Ableton Live or Cubase. There is no VST3 build, and that is a licensing constraint (why). Live has no CLAP support, so at present there is no way for it to load AD-1. We are sorry.
Pro Tools is not supported either. There is no AAX build.
It is not a limited edition, and there is no account to register. The one thing missing is a signature — installing takes one extra step.
Download AD-1 0.1.0 How to install ›
Audio Unit / CLAP · macOS 11 or later · Apple Silicon / Intel