While I haven't been able to pick up any other ADDAC filters yet, I did get an ADDAC105 4-Voice Cluster which has an onboard filter, and I love the sound on that one. It's not super-crazy or anything, but just very nice, clean, sharp, and smooth. Love the ADDACs I've been able to use thus far, but I do wish they had more/better CV input options on their lower cost modules.