Why do people on this forum classify the amps and pedals manufactured by Tech 21 as modelers? The term "modeler" is derived from the term "mathematical model." Modelers are little more than computers that are hooked up to analog to digital and digital to analog converters. All signal transformation in a modeler is performed via one or more discrete mathematical approximations that are implemented in digital logic (program code or hardwired logic).
On the other hand, every device that Tech 21 manufactures has a 100% analog signal path. All tone shaping is performed the old fashioned way via gain stages and tone shaping networks. That's why Tech 21's stuff feels closer to the real thing than modeling gear. What Tech 21 is doing with their SansAmp-derived circuitry is known as "emulation." If we have fit Tech 21s stuff into a category, it should be classified as analog solid-state gear. For those on the forum who are too young to remember having to drive to a local drug store or 7-Eleven with a bag full of tubes from ones radio, stereo, or TV in order to run them through a tube tester, the term solid-state was coined when transistorized circuitry replaced tube-type circuitry. The phrase no user serviceable parts appeared at the same time. Transistorized solid-state circuitry basically eliminated routine consumer-level maintenance of electronic devices.