Interesting!
I have done some work with a overdrive/sag-circuit that is based on the same idea.

I suppose you are 'the' Teemu that wrote the ss-amp book !?
I am really impressed by your work!! 

Hi from a newcomer

I am glad I found this forum, it has really inspired me with my current project. 
In the 80:s I spent a lot of time designing electronics both professionally and as a music electronics hobbyist. I must say things are much easier now with all the free software available.

Now I am starting a new ss-amp project with the goal to simulate most aspects of a good guitar amplifier:
- a Fender Deluxe cabinet with a Celestion blue
- overdrive/sag
- low/no NFB = hi output impedance
- class A 30W
- line-out/headphones with cabinet simulator

I have gathered very useful info using these links:
http://www.thatraymond.com/downloads/solidstate_guitar_amplifiers_teemu_kyttala_v1.0.pdf
http://www.gmarts.org/index.php?go=210
http://www.blackstoneappliances.com/dist101.html

Best Regards