Instrument Signal Path

Keep causes in the correct subsystem

The guitar owns strings, scale, pickup placement, switching, routing, and performance input. The pickup owns transduction and loading. Pedals own effects. The amp owns preamp, tone stack, power stage, transformer, and supply behavior. The speaker and microphone own the acoustic output.

This prevents convenient but misleading controls such as clean, crunch, or fuzz inside a pickup editor. A pickup produces raw DI. Everything that follows remains a separate module with its own physical or algorithmic explanation.

The intended complete path

• Performance event excites one or more modeled strings
• Guitar geometry determines speaking length and pickup observation points
• Pickup construction converts observed motion into loaded electrical output
• Pedalboard routes reusable modules
• Amp stages add gain, nonlinear transfer, tone stack, power behavior, and output loading
• Speaker and cabinet convert electrical drive into an acoustic response
• Microphone position and room contribution produce the final captured signal

One model, many hosts

The standalone designer, complete instrument plugin, and individual module plugins are intended to share the same models. Export is packaging around the sound path, not permission to create a second approximation that drifts away from the design.

MIDI, MIDI files, live audio, and hybrid performance can enter through explicit input modes. Polyphonic pickups can preserve per-string channels instead of collapsing them prematurely.

Why the rig stays legible as it grows

A guitar rig’s particular stage order, string, pickup, pedal, amp, speaker, microphone, is specific to instrument signal chains. What matters beyond ArcoAura is the rule that kept that chain from turning into a pile of convenient shortcuts.

The same argument keeps a data pipeline’s stages honest: a service boundary that resists absorbing a neighboring service’s logic just because it is convenient this sprint, a rendering pipeline where lighting does not secretly do what shading is supposed to do. Legibility comes from refusing the shortcut, not from documenting the mess afterward.

• Refuse a convenient control in the wrong place. Banning a clean, crunch, or fuzz knob inside the pickup editor forces the actual cause, an amp’s gain stage, to live where it belongs instead of being faked one level too early.
• Make the signal path itself inspectable data, the rig array of Stage and Module pairs, rather than a fixed sequence of hidden function calls, so the same chain can be printed, rearranged, exported, or taught without touching the modules.
• Hold every host, standalone designer, full plugin, individual module plugin, to the same underlying engine, and treat export as packaging around that engine, not license to grow a second, quietly drifting approximation.
• Let each stage own only its own physics: strings own vibration, pickups own transduction and loading, cabinets own acoustic conversion. A bug or an improvement in one stage cannot hide inside another stage’s responsibility.