They have arrived, and are getting into the test queue. If they meet my requirements, expect to see them around mid-April. Once they are in place (and with another trick I still have up my sleeve, I will have an equivalent solution to every other filter preamp available, but with the advantage you can plug in an FE4 EQ if you want to change things up. More EQ modules are on the horizon...
This sounds interesting. Is this a Q boost via push-pull on the filter knobs?