API reference

First-order antiderivative antialiasing of one grid-and-plate stage, evaluated in the grid's own coordinate u = Vg - Vk: y = (G(u1) - G(u0)) / (g(u1) - g(u0)), where g(u) is the input that puts the grid at u and G is the antiderivative of the plate output with respect to that input.

ASIO-backed IAudioDevice.

Queues each line and lets a worker thread write it to another sink, in order.

Direct Form I biquad filter with RBJ cookbook coefficient derivation, its coefficients and state in double behind a float sample interface (docs/archive/superpowers/specs/2026-09-07-grid-knee-antialiasing-design.md section 15).

Fixed-capacity pool of block-sized float buffers with allocation-free acquire/release.

Keeps every line it receives, in arrival order, before write() returns.

Puts the calling thread's FPU into flush-to-zero / denormals-are-zero mode for the guard's lifetime, restoring the previous mode on destruction.

Runs a damped multivariate Newton iteration on the nonlinear port of a DK circuit.

Factorises a dense N x N system by LU with partial pivoting, in fixed storage.

One-dimensional LU, which is a single division; the nonlinear diode fast path pays nothing for the general machinery.

Closed-form 2x2 LU with partial pivoting; N = 2 is the shape of every triode block and of the D6c clip stage's diode pair, so it is the hot Jacobian size in the tree.

Solves one discretised nonlinear circuit block by damped Newton per sample, on the nodal DK method with the trapezoidal rule (include/SushiDSP/README.md).

Power-of-two real FFT.

The passive FMV stack, solved from its netlist by the nodal DK method.

A bank of fixed-centre peaking bands, each ±maximum_gain_db, in series.

2x decimator on a committed Parks-McClellan halfband.

2x interpolator on a committed Parks-McClellan halfband.

Receives formatted log lines and puts them somewhere.

Loads cabinet impulse responses and conditions them for convolution.

Holds one value of a log call: a bool, a character, an integer, a real or text.

Names the module a log line comes from.

Formats log calls and hands each line at or above the minimum level to one sink.

Carries lines from any number of producer threads to one consumer thread.

A long-tailed pair phase inverter, solved as two triodes sharing a cathode node.

Generic Newton-Raphson root finder for a scalar nonlinear equation f(x) = 0.

Models the output transformer: primary-inductance low-end rolloff, leakage- inductance top-end shaping, an explicit tanh core-saturation waveshaper, and a secondary that carries no mean (docs/archive/superpowers/specs/2026-09-07-grid-knee-antialiasing-design.md section 14).

Cascades the first two committed Parks-McClellan halfband stages (see HalfbandCoefficients.hpp) each way for 4x oversampling.

Cascades three committed Parks-McClellan halfband stages (see HalfbandCoefficients.hpp) each way for 8x oversampling.

A node's whole parameter surface, in index order.

Uniform-partitioned overlap-add FFT convolution against a fixed impulse response.

Stateless Koren EL34 pentode: plate and screen currents plus Norman's grid law.

One push-pull half of a power stage: the grid node solved by Newton-Raphson against a Norman grid-conduction law referenced to the cathode, an inverting gain from grid to plate, and a two-sided tanh plate ceiling from the tube's PlateSwing, all in real volts, the composite transfer antialiased by an AntiderivativeAntialiaser.

The feedback leg from the speaker tap to the phase inverter's second grid.

Models power-supply sag: an envelope follower on the rectified signal drives a dynamic gain-reduction factor, so sustained loud playing compresses ("bloom").

Arbitrary-ratio polyphase resampler over one committed prototype filter.

The low-frequency shelf a Resonance or Deep knob places in a power section's negative-feedback path, mirrored to the forward path as a low shelf of the same corner.

A user-editable directed graph of IAudioNode instances, compiled to a topological order and replayed per block.

Publishes RigGraph replacements to the audio thread without locking or blocking it, and frees a retired graph only once the audio thread has moved past it.

Publishes replacement objects of type T to the audio thread without locking or blocking it, and frees a retired object only once the audio thread has moved past it.

Installs a sink on construction; on destruction flushes it and puts the old one back.

SDL2-backed IAudioDevice.

Models a Shockley-law silicon diode with an ideality factor as a nonlinear branch of a DK-method solver; the defaults match docs/reference/spice/models/d1n914.sub.

Offline windowed-sinc sample-rate converter (64 taps, Kaiser beta 8.6).

First-order (one-pole) parameter smoother with a time constant in milliseconds, derived from the sample rate at prepare() so a knob feels the same at every rate and block size.

Lock-free single-producer/single-consumer ring buffer.

Writes [LEVEL] [category] message to stderr before write() returns.

Re-blocks an arbitrary-length input stream onto a fixed-partition PartitionedConvolution.

Stateless Koren 12AX7 triode: plate current plus Norman's soft grid-conduction law.

A common-cathode triode gain stage: the grid node solved by Newton-Raphson against a Norman grid-conduction law referenced to the cathode, an inverting linear plate gain, and a two-sided tanh plate ceiling from the stage's PlateSwing, the composite transfer antialiased by an AntiderivativeAntialiaser.

Reads a subset of the RIFF/WAVE format (PCM 16/24/32-bit or 32-bit IEEE float, any channel count) sufficient for loading impulse responses.

Streaming WAV output: open, append frames, close.

A linear capacitor one-port, discretized via the bilinear transform.

An adapted (reflection-free) linear resistor one-port.

Holds an owned copy of one line a CapturingLogSink received.

The sample rate, block size, and channel counts a device is configured for.

One two-terminal element: its node pair and its value.

Describes a circuit on the control thread: node indices and component values.

Detects a nonlinear port that restates the branch currents the update stamps.

The specialisation that matches when the port declares the hook.

The empty nonlinear port a purely linear DK block is stepped with.

One nullor: an ideal op-amp's input constraint and its output current.

The two resistor sections a potentiometer contributes, plus its track resistance.

Component values of a Fender/Marshall/Vox passive tone stack.

What the stack is driven by and what hangs on its output.

The Norman grid-current law Ig = scale * softplus((Vgk - threshold) / transition), the law the docs/reference/spice/models/*_koren.sub subcircuits evaluate.

One halfband FIR stage: full symmetric impulse response with the zero taps stored as exact zeros and the centre tap exactly 0.5.

A hardware or host output device. Injected — SushiDSP never assumes one exists.

One DSP graph node. Implementations must be real-time safe in process().

A node that can carry a cabinet impulse response in its signal path.

A mono impulse response together with the sample rate it is valid at.

Conditioning applied to an impulse response as it is loaded.

Holds one formatted line on its way to a sink.

The pair's two plate outputs for one sample.

One half's own plate load, headroom and grid drive.

The tube properties both halves of a pair share, at one operating point.

Holds the three capacitances a triode grid presents and turns them, with the resistance driving that grid, into the interstage pole the grid-plate term dominates once the stage's gain multiplies it.

The residual and its derivative at one trial point, evaluated together.

Everything a host needs to instantiate and drive a product, with no knowledge of its internals.

One parameter: what a host sees, how it is written and how it is read.

One parameter write travelling from the control thread to the audio thread.

One automatable parameter exposed by a product's NodeDescriptor.

How far a stage's plate can swing from its idle point before it saturates, and the two-sided tanh ceiling that bounds a linear plate output by it (docs/archive/superpowers/specs/2026-09-07-triode-plate-swing-design.md section 3).

Describes the fixed input/output channel counts of an IAudioNode.

Component values of a feedback leg from the output transformer's speaker tap.

What the inverter presents where the leg reaches its tail.

The constructor constants one PentodeStage takes for a named power tube, every voltage in real volts; the derivations are in the owning module's README.

Parameters supplied to IAudioNode::prepare(), fixed for the node's lifetime.

Per-block processing context. process() must fill exactly [0, frames) of each output channel.

Holds one line by value while it waits in the queue.

Describes a long-tailed pair modelled as a single common-cathode triode: where its grid rests, what one triode's load line gives, what the shared cathode takes back, and the swing that bounds the plate.

A Wave Digital Filter one-port's wave-domain state: incident wave a, reflected wave b, and the port resistance R that relates them to voltage/current.