
Update via the world of next tuesday in the comments:
"Many Soviet synths have copied Moog filters. This one doesn't. Maybe the seller just describes all his Soviet analogs like that? I'd say from what I've heard it has by far the best most original sound of anything easily obtainable. Other Soviet synths can certainly produce some good sounds too though a lot of them I'd chalk up to moog-like filters. Though there is said to be a change in sound between earlier and late filters. I have the earlier filter. The sound on mine is wonderfully overdriven though maybe not so on units built later on. It's not "thin" to me unless you set the bandpass that way rather than use the lowpass. The resonance is nasty ("without pity" says David Korn), which can be used to it's advantage, but it's not going to ever come near doing things like Moog does with resonance for better or worse. The looping envelopes combined with the LFO can do some sounds most monosynths can't do. (then again so can a decent modular but that's another topic). I wound up cleaning a lot of pots. I'm not using any chemicals because I don't know what they are made out of. I got them all working and quiet but a year later they are quite noisy again. The switches and rotary knobs can make noises too."