Yes it is. It's not digital. It's not a typical
analog "chip" either. This misconception/rumor/misinformation/myth about the S950 being not
analog has been told so many times over and dug into people's minds for the past 30 years, that people actually think it is a fact that it really is not-
analog, that people only believe that myth now. People most likely started this myth years and years ago, maybe by opening the S950 up back in the day, and couldn't physically locate/see a typical silicon
filter chip.
They have Switched-Capacitor IC filters, but under digital control. So maybe more "modern" than typical silicon chip filters, since it is digitally controlled; though for sure very unique. IC circuits instead of a typical silicon
analog chip (ie: ssm, curtis, cem, etc)..so maybe a DCF? lol, no such thing as that term/acronym I guess (kinda like a DCO synth in terms of control, which has
analog oscillators but under digital control and more stable than VCO). Also, they are 6-pole, which in itself, is another very unique feature/design.
Start messing more with the cut-off, freq, env, velocity and see how phat it really sounds

...maybe even smashes harder than an emax/sp1200 :X