More research has mostly revealed that :
- Most 1590A envelope filters are crap.
- The Melekko E.Filter sounds good when it works, but has trigger issues.
- The Joyo JF-322 Wow Wah seems to be a reasonable Snow White clone.
So I ordered a Joyo, assuming it's the only likely candidate.
It's ... em ... well ... it's an envelope filter and it sounds ... em ... pretty good ... mostly.
Although it's based on a well respected filter (but which I haven't used myself), it isn't quite what I was hoping for.
It seems like a usable guitar envelope filter and I doubt that you'll find better for its size or price.
I certainly rank it way above the Mooer Sweeper.
It's a bit tweaky and it took a while to find the sweet spot.
I have Sensitivity, Bias and Res at about 3:00 with Decay at 8:00.
I managed to get a reasonable quack with a guitar, but it's a bit anemic on bass.
I guess that makes sense as this is presumably modeled on the guitar version rather than the bass.
In the clean path at least, it seems to pass a bass signal at least as far down as low-B.
The problem to my ears is that very little filtering seems to take place in the lower registers.
It's not as tinny and toy-ish as the Sweeper, but it seems considerably short of the
full-spectum weight I get from the Wonderlove and EP2. It also seems to lose some of the highs.
So far it looks like the best readily available micro-filter, but it's not great on bass so if I wasn't specifically looking for tiny, I'd sell it and move on.
I think it has potential though. I might look into whether the filters can be deepened by installing bigger caps.
I'd also like to separate the envelope and filter inputs, but there probably isn't room for another connector.