Gregory:
I can't say enough good things about the SF-2. While admittedly it was a little daunting when I first got it, seemingly more complicated than I usually like, once I groked it, the SF-2 turned out to be quite simple to set and an amazingly effective tone shaper. When used with in mono mode, it is essentially a 3 channel mixer - one dry channel and two filtered channels. Each filtered channel can be set for low pass, band pass, or high pass. The key is to adjust one channel at a time. (While one is being tweaked, I turn the other two down to 0). First I turn both filtered channels down to 0, turn up the dry channel and set my amp and guitar controls as normal. Then I turn the dry channel to 0 and one at a time, set one filter channel to accentuate a low frequncy I like and the other to accentuate a high frequency. Back to 0 for the filtered channels and the dry channel is turned up, again. Then it's easy to mix in the low and high SF-2 channels to taste. (In stereo mode, it has two channels per side, one dry and one filtered). Once I understood what was happening, the SF-2 revealed itself as a relatively easy to use common sense design.
While not common, they do seem to come up for sale not too rarely and hold their used value in the $400-500 range. You could always pick one up and try living with it for a while. If it doesn't work for you, you would easily be able to get your $ back, either through our forum or on ebay, craigslist, the usual suspects. Personally, I'd wager that once you try one, you won't be selling anytime soon.
Of course, if you find yourself anywhere near Oakland, you're welcome to come down to my studio and try mine out. We have two - one hooked up to my guitar rig, and one hooked up to my bass player's rig.
Bill, tgo
