dspark::wdf::ToneStackFMV< T > Class Template Reference

Exact Fender '59 Bassman treble/bass/middle tone stack. More...

#include <WDF.h>

Classes
struct	AnalogStateSpace
	Continuous-time state space of the same network. More...

Public Member Functions
	ToneStackFMV (double sourceResistance=1e3, double loadResistance=1e6)
void	prepare (double sampleRate) noexcept
	Prepares the network (allocates nothing).
void	reset () noexcept
	Clears capacitor states. RT-safe.
void	copyStateFrom (const ToneStackFMV &source, T inputOffset=T(0)) noexcept
	Copies the capacitor history from an identically prepared stack.
void	setControls (T treble, T bass, T middle) noexcept
	Sets the three controls, [0, 1] each.
T	processSample (T input) noexcept
	Processes one sample (input volts -> wiper volts).
AnalogStateSpace	analogStateSpace () const noexcept

Detailed Description

template<FloatType T>
class dspark::wdf::ToneStackFMV< T >

Exact Fender '59 Bassman treble/bass/middle tone stack.

Topology and component values after Yeh & Smith, "Discretization of the '59 Fender Bassman Tone Stack" (DAFx-06), figure 1: C1 = 250 pF into the treble pot (R1 = 250 k ohm, output at the wiper), R4 = 56 k ohm into the slope node, C2 = C3 = 20 nF from the slope node to the bass rheostat (l*R2, R2 = 1 M ohm) and to the middle pot wiper (R3 = 25 k ohm) respectively. The source is modelled with a series output resistance (cathode-follower buffer) and the wiper drives a grid-load resistance.

Solved exactly as one 12-port R-type. The suite verifies it sample-exact against the bilinear transform of the paper's symbolic transfer function. Controls are not orthogonal – that interaction is the circuit's character.

Definition at line 846 of file WDF.h.

Constructor & Destructor Documentation

ToneStackFMV()

template<FloatType T>

dspark::wdf::ToneStackFMV< T >::ToneStackFMV ( double  sourceResistance = 1e3, double  loadResistance = 1e6  )

inlineexplicit

Parameters

sourceResistance	Driving stage output impedance (default 1 k ohm).
loadResistance	Following stage grid load (default 1 M ohm).

Definition at line 853 of file WDF.h.

Member Function Documentation

analogStateSpace()

template<FloatType T>

AnalogStateSpace dspark::wdf::ToneStackFMV< T >::analogStateSpace ( ) const

inlinenoexcept

Definition at line 963 of file WDF.h.

copyStateFrom()

template<FloatType T>

void dspark::wdf::ToneStackFMV< T >::copyStateFrom ( const ToneStackFMV< T > &  source, T  inputOffset = T(0)  )

inlinenoexcept

Copies the capacitor history from an identically prepared stack.

Stream-owner only: neither stack may be processed concurrently. Both stacks must have the same sample rate and controls. Port connections remain owned by the destination; no allocation or scattering rebuild occurs. An optional input offset shifts all three coupling capacitors by the same DC voltage; the subsequent input must use that reference. The stack blocks DC, so this reference shift preserves its output.

Definition at line 895 of file WDF.h.

prepare()

template<FloatType T>

void dspark::wdf::ToneStackFMV< T >::prepare ( double  sampleRate )

inlinenoexcept

Prepares the network (allocates nothing).

Definition at line 877 of file WDF.h.

processSample()

template<FloatType T>

T dspark::wdf::ToneStackFMV< T >::processSample ( T  input )

inlinenoexcept

Processes one sample (input volts -> wiper volts).

Definition at line 935 of file WDF.h.

reset()

template<FloatType T>

void dspark::wdf::ToneStackFMV< T >::reset ( )

inlinenoexcept

Clears capacitor states. RT-safe.

Definition at line 884 of file WDF.h.

setControls()

template<FloatType T>

void dspark::wdf::ToneStackFMV< T >::setControls ( T  treble, T  bass, T  middle  )

inlinenoexcept

Sets the three controls, [0, 1] each.

Treble and middle pots are linear, the bass pot is a log-taper rheostat (squared approximation), matching the original circuit.

Definition at line 914 of file WDF.h.

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The documentation for this class was generated from the following file:

• WDF.h