Circuits
Passive Networks
Reusable passive circuit-network modeling notes for tone stacks, coupling, loading, and cable behavior.
Passive networks are reusable circuit components, not model pages. They describe how Greybound represents frequency-dependent loading, tone shaping, and connection behavior shared by amps and pedals.
Current Uses
- Nox30 Top Boost style tone stack.
- Muffin passive tone blend target.
- Future amp tone stacks and FX-loop return networks.
- Cable capacitance in
ConnectionState.
Modeling Rules
- Prefer trapezoidal Modified Nodal Analysis for interactive passive networks.
- Include source impedance and downstream load when the original circuit depends on loading.
- Keep coupling-capacitor state at the boundary where it belongs; do not hide it inside unrelated gain constants.
- Treat potentiometers as split resistors when their wiper interaction matters.
Known Cells
Top Boost tone network:
- Uses split treble and bass potentiometers.
- Includes small treble capacitor, bass-path capacitors, slope path, ground/output paths, source impedance, and downstream load.
- Current implementation uses a seven-node MNA solve.
Muffin tone blend target:
- Low-pass branch target: 39 kOhm and 10 nF.
- High-pass branch target: 3.9 nF and 22 kOhm.
- Blend potentiometer target: 100 kOhm.
- Should be solved as one passive network including source and recovery-stage load.
Connection network:
- Source impedance, load impedance, and cable capacitance affect voltage presented to the next device.
- This is why pedal order matters beyond a sequence of isolated sample transforms.