MSDplugins · VST3 & Standalone
FC-2 TURBOTwo-mode distortion.
Most distortion plugins clip your signal. This one drops the loop gain — the way the circuit actually does it.
The part that matters
The diodes are not across the output.
They're inside the loop.
In this circuit the clipping diodes are wired into the op-amp's feedback path. As the signal grows, the diodes conduct and the amplifier's own gain falls away underneath it. It compresses and blooms instead of squaring off — and it tracks your picking hand, because how hard you hit it changes how much gain the circuit has.
That can't be faked with a static curve, so it isn't. FC-2 Turbo solves the clipper's circuit equation once per sample, with the feedback capacitor and the supply rail both inside the solve, at 4× oversampling.
What a waveshaper does
Hard clip — sheared flatThe tops are removed. The same shape at every dynamic level.
What this does
Feedback loop — gain gives wayRounded, still moving, still responding to how hard you played.
Both scopes are drawn illustrations of the two topologies, not captures of the plugin's output. The measured numbers are further down.
Mode I / Mode II
Two modes, and they are two different pedals.
Mode II is not mode I with the gain turned up. A different network feeds the clipper and a different filter follows it. Flip the switch and watch where the weight goes.
Relative voicing
Dashed line: the other mode, for comparison. The curve is a sketch drawn from the measured 1 kHz and 5 kHz figures — not a full frequency-response plot.
Mode I — the straight voice
Mid-forward and still recognisably your guitar. Happy in front of an amp that is already working, where you want push and grit rather than a whole new midrange.
Mode II's tilt is measured against this voice.
Not ear-tuned. Measured.
Every claim here is a number from the harness.
Every release has to pass a headless test harness before it ships: 46 behavioural checks on the compiled plugin, plus 31 self-tests whose only job is to prove the measurement code can actually report a failure. A test suite that cannot fail on purpose has never been shown to work.
| Measured on the shipping build | Result |
|---|---|
| Linear chain vs the hand-derived circuit transfer functions | 0.013 dB |
| Mode II extra 1 kHz / 5 kHz tilt (13.17 dB predicted) | 12.93 dB |
| THD across DIST 0 → 10, monotonic | −16.7 → −11.2 dB |
| Aliasing on a deliberately nasty test tone, 4× | 28.8 dB down |
| Aliasing on an open G — what actually gets played | 70.4 dB down |
| DC on the output, hot, both modes | below 0.001 |
| Stereo channels | bit-identical |
| Reported latency when you stomp bypass | unchanged |
Oversampling, chosen by measurement
8× buys another 9 dB on a torture tone and nothing at all on a real guitar note, where the floor is already 70 dB down. So 4× it is.
Gates and self-tests
Behavioural checks on the compiled plugin, plus self-tests that prove each measurement can report a failure rather than quietly blessing everything.
Model vs derivation
In the oversampled region the running plugin tracks the transfer functions derived by hand from the circuit to thirteen thousandths of a decibel.
Where it lives
Built to sit forward in a busy mix.
Four controls, nothing to learn
DIST, TONE, LEVEL, MODE. Unity sits near noon. The footswitch is also the host's bypass parameter, so the panel and your DAW can never disagree.
Presets that stay out of your way
Save a sound by name. A preset stores those four controls and only those four — loading one will never switch the pedal off or resize your window. Plain XML on disk, so you can copy them between machines.
Bypass you can trust mid-take
The reported latency does not change when you stomp it, so your track never shifts under you halfway through a performance.
Three window sizes
50% / 75% / 100%, from the top bar or a right-click on the pedal. The face keeps the artwork's aspect ratio, so it is never stretched.
What is not claimed
No physical unit was A/B'd against this plugin — there is no hardware here to compare with. It is voiced from the schematic and measured against itself, and every number on this page comes from the build you would be downloading.
Not affiliated with, endorsed by, or produced by any guitar pedal manufacturer.
One download, both modes
Two distortions in one pedal. One of them is mean.
Windows 10/11 64-bit. VST3 plus a Standalone app, so you don't need a DAW to try it. Instant download.