Just got a new envelope filter called the Proton by three leaf audio. It's a clone of a Mutron and it is only the size of an MXR pedal, shweet!
It's made by a bass player so when I got it about a week ago there were no guitar clips so I made a few.
I recenly tried the Hartman. It didn't work so great with my rig but it had a nice core tone.
The proton is a great Mutron in a small package. The only issue is the decay time is a bit faster than a Mutron because the bass players that demod the pedal prefered a faster decay for funk stuff. Spencer, the builder told me it's a simple one resistor change to go back to the longer classic decay time. I will probably change it in the future but it sounds great as is.
It has a very organic tone and is really responsive and fun to play. Does a pretty good Jerry tone. Check one out.
Bunch of clips here:http://soundcloud.com/alexander-1212/pr ... cia-mutron