Tube Stages

Tube-stage notes describe reusable component behavior that amp model pages can reference. They are not tied to one amp target.

Preamp Triodes

Greybound currently uses compact nonlinear stage models for ECC83 / 12AX7 behavior. Component work should preserve:

• input coupling and grid reference behavior,
• plate-load and cathode-network frequency response,
• asymmetric nonlinear gain,
• cathode-bypass capacitor memory,
• stable behavior under silence and overload.

Cathode Followers

Cathode-follower behavior matters when driving passive tone stacks. Models should expose:

• low source impedance into the following network,
• nonlinear but comparatively low-distortion transfer,
• loading changes from the downstream passive network.

Long-Tail-Pair Phase Inverters

The phase inverter should represent opposed drive phases with small imbalance, not a generic stereo splitter. Important state:

• differential drive,
• common cathode/tail behavior,
• phase-dependent nonlinear compression,
• coupling into Cut or presence networks.

Power Stages

Power-stage component notes should separate:

• output-tube current/compression,
• cathode or fixed-bias behavior,
• screen-current behavior,
• output-transformer filtering and core state,
• negative feedback and presence behavior when present.

Supply And Sag

Supply behavior is a shared component concern. The model should keep rail/sag state observable for monitoring and validation rather than hiding it in static waveshaping.