This reminds me of all the dark alleys I went down playing with the 'Q.
I once thought a 31-band EQ would be the cat's a** as far as getting my tone once and for all.
Fighting it for a week reminded me why first-rate PA guys really ARE rocket scientists. It became a bottomless pit. The gradations were way too fine. Don't EVEN ask me about using a stereo 16-band for each side of my biamp rig!
Then when parametrics came along, I thought, 'gee, this looks a LOT more simple!'. Well, there's parametric EQs (bandwidth, Q-frequency, cut/boost) and the more usual semi-parametric EQs (Q-frequency and cut/boost). Most instrument amp builders have gone to the semis as most people haven't a clue just how hard that bandwidth knob can drive an amp IF it's too broad a curve down low enough.
TC Electronic once offered a true 4-band parametric EQ that doubled as an instrument preamp. My favorite music store had one for sale. They'd sell it, then I'd see it back. Sell it again, see it back in a few weeks. People just got lost in it, the center frequences they'd pick out combined with the bandwidth crossing over each other four times, nobody could cozy up to it. Big fat spots and big dead spots.
My EDEN runs semi-parametrics like most amps these days. It reinforced something I'd never considered, though I learned subconsciously from Ron: SO much depends on the designer. How the techno-geekery gets translated into something fairly foolproof and MUSICAL-sounding for us mere mortals. I think this is truly what separates the men from the boys, so to speak.
The ALEMBIC F- preamps, while admittedly descended from Fender designs (and the RCA Radio traditions), show that SOMEBODY with very good ears made conscious decisions with regards to the technical end as to what sounds good on the musical end. This isn't always the case: There's LOTS of tube guitar amps these days, built up from the same Fender DNA, and their tone is all over the place from brand to brand.
Where the Qs fall in my EDEN gear (especially in concert with their cabinets) were obviously selected by good ears. You've seen this/heard it when trying out amps: Some it's hard to find a bad sound, some you just can NOT find any tone you'd want to use. That genius of making these random electronic bits do your bidding in a musical way is NOT to be underestimated. And everybody here hears it: Otherwise we'd be somewhere else.
The SF2 is an utterly unique approach, some of Ron's genius out in broad daylight, as it were.
And a completely 'out of the box' take as a solution to tone control. I wonder what was the inspiration or antecedent that led to this.
There's lots of Q devices out there, any number of which would make most of us happy. But just like ELF, PZMs, Near-Field monitors, low-impedance pickups, sustain blocks, etc., once you hear an SF2, everything else is in a different place. Maybe it is or isn't your cup of tea, but it really is like nothing else.
J o e y