pulp::signal::BridgedTComponents Struct Reference

Component values of the TR-808 bass drum's bridged-T network, in SI units (ohms, farads). More...

#include <bridged_t_resonator.hpp>

Public Attributes
double	c41 = 15e-9
	capacitive arm, op-amp inverting input side
double	c42 = 15e-9
	capacitive arm, op-amp output side
double	r161 = 1.0e6
	retrigger-pulse injection; also Q43's leakage path
double	r165 = 47.0e3
	shorted out while the attack envelope grounds Q43
double	r166 = 6.8e3
	Vcomm-to-collector leg of the branch.
double	r167 = 1.0e6
	the resistive bridge
double	r170 = 470.0e3
	feedback-buffer injection

Detailed Description

Component values of the TR-808 bass drum's bridged-T network, in SI units (ohms, farads).

The network is a Zobel bridged-T in the negative-feedback path of an op-amp; its ringing is the entire bass drum sound.

Everything the resonator does is expressed in terms of these values rather than abstract filter coefficients, so a component substitution ("what if C41 were 22n?") is a legal, physically-meaningful edit rather than a reverse-engineering exercise. That is the whole point of the topology.

Lineage: Werner, Abel & Smith, "A Physically-Informed, Circuit-Bendable, Digital Model of the Roland TR-808 Bass Drum Circuit", DAFx-14, Fig. 1.

Member Data Documentation

c41

double pulp::signal::BridgedTComponents::c41 = 15e-9

capacitive arm, op-amp inverting input side

c42

double pulp::signal::BridgedTComponents::c42 = 15e-9

capacitive arm, op-amp output side

r161

double pulp::signal::BridgedTComponents::r161 = 1.0e6

retrigger-pulse injection; also Q43's leakage path

r165

double pulp::signal::BridgedTComponents::r165 = 47.0e3

shorted out while the attack envelope grounds Q43

r166

double pulp::signal::BridgedTComponents::r166 = 6.8e3

Vcomm-to-collector leg of the branch.

r167

double pulp::signal::BridgedTComponents::r167 = 1.0e6

the resistive bridge

r170

double pulp::signal::BridgedTComponents::r170 = 470.0e3

feedback-buffer injection

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

• /home/runner/work/pulp/pulp/core/signal/include/pulp/signal/bridged_t_resonator.hpp