After dipping my toes into the world of envelope filters with the DOD FX25B, I did a little more research for a better working filter and came up with this...
I've been listening to clips of the Mutron, EHX Bassballs, EHX Doctor Q, EHX (non tube) Zipper, MXR envelope filter, DOD 440, Mojo Hang Analog Filter 442, EHX Q Tron, Mad Professor Auto Wah... the list goes on. I tried a couple out but the better ones seem to be mega rare.
Most of those range from being a bit too expensive to a bit to rare (and therefore too expensive) or they didn't seem to have a sound I was really into (for example the Bassballs). The AF-9, for me, is different. It's not super cheap but it's not at 'Boutique' prices I don't think. It does a great range of things from a quite subtle underlying effect to really out there noises. The 'Drive' setting reverses the direction of the effect. So playing harder is like rocking back on a wah and the highs come back as the note decays.
With higher peak settings I hear this shimmery sort of effect on chords that is pretty cool.
It doesn't suffer from a volume drop like the FX25B and the the circuit isn't driven by my Nailbomb, which was another issue with the FX25B.
Generic demo:
http://www.youtube.com/watch?v=k8IlX_5ztH8&feature=fvwrel
