I started with the 2 CV jack version, and didn't gel with it at all. He sent me the 4 CV jack version (this one), and it's a whole different story. And I tell you the Zadar is this thing's best friend (with s/h modulation from ModBox). I have 4 Error Instruments modules, and this is my favorite at the moment. I find the way he implements his CV inputs pretty frustrating. For example you can't use Maths without some external voltage offset. Zadar has nice 0 to 10 volt output adjustment, so it's plays well with EI.