For many years I have been a musician with an interest in recording techniques and the associated software technologies ( In the 80's I had a small mobile studio pre the digital revolution ).
This interest has led to my being involved in the repair and construction of custom guitars and valve amplifiers for use as both guitar amplifiers and hi-fi amplifiers, I know find it impossible to go back and listen to music on anything else as it just does not sound as involving and "real".
Recently I have been getting to grips with audio recording software on the Linux OS to aid in teaching some friends to play guitar, mainly creating simplified backing tracks for them to play along with. This has mainly been through the use of Ardour, a truly fantastic DAW ( Digital Audio Workstation ) and a variety of effects plugins. This is when I discovered Guitarix, an amplifier simulation and effects suite capable of some very realistic sounding simulations.
Although happy with the sounds obtained much of the music I play ( old acoustic and electric blues, soul, reggae ) favours cleaner guitar sounds and I found that, at that time, Guitarix was geared towards more distorted tones. Looking at the code it was apparent that although all the basic components of the typical guitar amplifier were there they did not mirror the typical architecture of guitar amps, so I began to experiment with step by step build mimicing, as closely as possible, the circuits of amplifiers I had built myself with a view to comparing and assessing the results with the real thing.
So far it has been a very interesting journey, not least since it has been many years since I revisited the mathematics I studied at degree level ( Numerical Analysis ).
I hope the information is useful to others interested in this side of audio technology.