Methods are provided for solid-state implementation of a vacuum tube
replacement device that supplements the functional performance of the
target replacement device, i.e., a traditional glass vacuum tube. Example
functions may include OEM or user adjustable parameters such as gain
and/or frequency response (e.g. transfer function), current and/or
voltage saturation thresholds, bias condition, input and/or output
impedance, linear-to-non-linear transfer function(s) (e.g. soft clipping
parameters), power dissipation, communication protocols, and audio/visual
indication parameters such as signal limiting detection, safety, stress,
or wear-out conditions, and tube emulation model type to name a few. The
methods presented for the vacuum tube replacement device system(s) are
equally useful for non-vacuum tube systems such as audio amplifier
circuits.