The Crumar DS-2 has the reputation of being one of the most unreliable vintage synths on the used market, so buying one can be very risky, but also very rewarding, in case you find an intact one!
When it first came out in 1978, the DS-2 was one of the first synths to ever use digitally controlled oscillators, making it very stable in tuning, but maybe a bit less fat sounding than its VCO based competitors at the time. This monosynth can still sound super fat, tho, but that is (amongst other factors) due to its additional 44-voice polyphonic string section! The DS-2 comes with broad modulation features, a super nice sounding VCF, and two very fast ADSRs, making it great for drum sounds too!