The standard shiva is aimed at moderate high gain vintage voicing lovers, its thick woody open tone is something to be experienced. Some love it and some not so much. It's not a fluid, easy playing type feel or forgiving tone on the lead channel, you have to really dig in and get the power amp working.
What's it based off of? Well, it's based off a few amps actually. The 1st gain stage is shared by the clean and the lead channel and its 100% Soldano with 220k plates and 1.8k/1uF cathode. The 2nd stage is Bogner Ecstasy 100B (aka classic also) with a 100k plate and 2.3k/1.5uF. The final stage and tone stack (EQ) is all Marshall with 820/.68uF and 33k/470p EQ. The power amp is unique and designed to be running on the edge at full tilt with high B+ voltage and it runs hot. Great amp indeed. I ended up modding mine because I love the Ecstasy blue channel but made it be able to go back to the shiva voicing with a switch located on the back.