I dug up some old posts to summarize my thoughts on some other filters that I have owned in the past - figured it would be good to keep them all in one thread:
QTron (big silver box) - man, the tone on this thing killed. Just the right amount of stanky, very responsive - but the peaks were too much. Had I thought a bit more I would have figured out how to drop the volume when I turned it on, but as it is, it was just too tough to tame. IIRC, this one reminded me somewhat of a harder to tame Q-tron+, with a bit more bass and a bit more stank, but the peakiness to go with it.
MXR M82 - I like this one so much that I bought it twice. It's smooth - definitely didn't have as much of an issue with the peaks, it was very responsive, and very, very easy to get a good sound out of. However, it lacked the stankiness. I think in taming the peaks it lost a little something. Great pedal though, I used it as a grab-an-go filter for awhile because I knew that I could make it work no matter what the situation and I didn't have to worry about killing my speakers. In retrospect, it was kind of tame as compared to some of the others
EHX - Microtron - pretty much a small version of the regular Qtron+; same sound, less flexible, easier to dial in.
Source Audio C4 - Beat this one to death; fantastic pedal in so many ways, but I never got used to menus.
EMMA DiscumBOBulator v1 - One of the best envelope filters I've played through. So easy to get a good sound, tamed the peaks, but tons of stank and rich, quacky tone. This one was literally a space issue. I was choosing between this and a 3Leaf Proton v3, and the Proton won due to space, but the EMMA is every bit as good.
3Leaf Audio Proton v3 - Everything about the EMMA is pretty much true with this one, except it is more flexible tone wise. It's an exceptional pedal. v4 of the Proton has more juice on tap.
Joshwah - (full disclosure, at some point I'm going to pick up another one of these) - Kind of tame and smoooth, IIRC, less stanky, but no harsh, speaker killing peaks to deal with. Like the 3Leaf, it's very musical. The one thing that I don't care for is the gain knob - I keep mine all of the way off, but I am probably in the minority here. For a lot of ppl I think the gain/volume is really nice, does a synthy distorted filter kind of thing and makes the pedal more flexible. For those that don't care for it, it's easy enough to not use. However - I LOVE the volume knob. Big factor in controlling the peaks. I dunno what it is, but I have a hard time liking EF's with built in dirt (see the Enigma below).
Boss Auto Wah AW-2 and Boss Touch Wah. Both pedals sounded good, not great - they were a little thin and lacked booty. Both pedals did drop a little bass when engaged, but not much and definitely not enough to be noticed live., but still noticeable. What made these two unusable is the ultra harsh peaks - not musical at all, very static-like; much better suited for guitar than bass.
Electro-Harmonix Enigma. Great filter section - better than the Q-Tron+, but did not like the dirt section at all. Would have been a winner except for that, and still is a winner for the filter section.
Accufunkture Mini Filter and Agena Maestro Filter - There's not a lot of difference in the two aside from the size - they both cop the vintage Mutron thing pretty well, and it's very easy to get there - in fact, these two are two of the easiest pedals that I have every played to get a great filter sound out of (not quite as easy as the Fwonkbeta, which takes the prize).
Of the two, the Accufunkture sounds darker, a little meatier with higher peaks, while the Agena is snappier with a little more rubber to it. The Agena is a little easier to control and it's also quite a bit more flexible - the sensitivity knob on the Agena has a wider range and it can be more subtle and it also responds a little better. The Accufunkture is very small though, and I would be great for someone looking for a mini EF. The Agena sounds a little better and is quite a bit more flexible, the Accufunkture has size going for it, but both do a great Mutron sound.
Paperboy Meatwad (Meatball clone) - this was one of a few Meatball clones that I had over the years. This one had great artwork, but was a little tough to dial in consistently. I didn't own it long, and I'd like to give a Meatball clone another shot at some point.
PastFX PX101 - I remember liking this, but not loving it - kind of uninspiring, IIRC. That being said, this is also on my list to try again.
DOD 440 (vintage and reissue) - useless for bass, IMO. Too shrill, too much high end, too weak.
