The new Studio Electronics Boomstar 4075 filter breaks out the Boomstar desktop filter from the legendary ARP 2600 (actually called the 4072 -they tell us) into Eurorack form.
The type filter is a24/db/oct cascaded transconductance low-pass filter, "employing six pairs of hand-matched transistors" with twin CV inputs (saving you a couple of CV mixer channels). It also has a dedicated input and output gain. This means we can drive the filter pretty hard, giving it a really nice warm smudge and changing the character of the resonance and harmonics quite considerably. Additionally, you can control the resonance amount via CV too,
All CV inputs are plus/minus type, though with no centre marker or stop, its a little tricky to get to zero and the scaling is quite sensitive around the 0 point.
But the sound of it really is quite lovely, with all the brass and balls you could hope for.
One other slight niggle was the fact the keyboard scaling was off with my system (Doepfer A-190-3 MIDI/CV module), meaning playing the resonance filter via keyboard tracking didn't quite make the octave range over the keyboard. This can be adjusted via trim pots on the piggy back board, but it is a bit fiddly.
Aside from that, the sound it's lovely, though clearly this is a premium module, but really does deliver that sound.
Available now, priced at £229/$269 MSRP
Size - 12hp
Depth - 39.7mm with ribbon cable attached
Power Usage - 23mA, 30mA (+12 / -12)