Struct TapeHeadConfig 

pub struct TapeHeadConfig {
    pub model: Option<String>,
    pub ja_ms: f64,
    pub ja_a: f64,
    pub ja_alpha: f64,
    pub ja_k: f64,
    pub ja_c: f64,
    pub kv: f64,
    pub isat: f64,
    pub gp: f64,
    pub h_bias: f64,
    pub rp: f64,
}

Voltage-driven Jiles-Atherton tape head configuration.

Unlike a transformer core (driven by Ampere-law magnetizing CURRENT, whose knee needs hundreds of mA at studio turns counts), a record/playback head is a tiny gap/coil whose magnetic field is driven by the head GAP VOLTAGE: H = kv * V. With kv chosen so the J-A knee lands at line level (~1 V), tape saturation tracks signal Drive directly.

The J-A hysteresis parameters share physics with the transformer core (Jiles & Atherton 1986; Chowdhury DAFx-19 wave-digital tape realization) but use a SMALL-GEOMETRY head whose saturation occurs at ~1 V:

• ja_a is reduced vs an output-transformer core so the Langevin knee is reached at the small fields a head produces,
• the geometry turns/area/path are nominal (the voltage law uses kv, not Ampere’s law, so they only need to be sane positives).

Fields

model: Option<String>

Optional named head model (for provenance / future library lookup).

ja_ms: f64

Jiles-Atherton saturation magnetization (A/m).

ja_a: f64

Jiles-Atherton anhysteretic shape parameter (A/m).

ja_alpha: f64

Jiles-Atherton inter-domain coupling.

ja_k: f64

Jiles-Atherton domain-wall pinning parameter (A/m).

ja_c: f64

Jiles-Atherton reversible magnetization fraction (0..1).

kv: f64

Field-per-volt coupling (A/m per V) — places the knee at line level.

isat: f64

Saturating magnetic current scale (A) — harmonic drive strength.

gp: f64

Linear leakage conductance (S) keeping the port well-posed.

h_bias: f64

Fixed record-bias field offset (A/m): asymmetric transfer -> even harmonics (the soft, even-rich tape/transformer colour).

rp: f64

WDF port resistance (Ω) — sets the scattering port impedance.

Implementations

impl TapeHeadConfig

pub fn studio_head() -> Self

A studio record/playback head whose J-A knee lands at ~1 V line level.

Values verified in pedalkernel-rt/tests/tape_head_voltage.rs: THD climbs monotonically from ~0.7% at 0.05 V to ~7% at 2 V, Newton converges in well under the iteration budget, output is finite/stable.

pub fn with_model(model: String) -> Self

Trait Implementations

impl Clone for TapeHeadConfig

fn clone(&self) -> TapeHeadConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TapeHeadConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TapeHeadConfig

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for TapeHeadConfig

fn eq(&self, other: &TapeHeadConfig) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for TapeHeadConfig