Hands up if you've played an RSF Kobol before? I've never even seen one, but now I have the Expander as part of my semi-modular analogue setup, and for the price of four takeaway pizzas pretty much (for two - pizza is expensive here). Having got the WASP, CAT, and 2600M, plus Odyssey keyboard, the Kobol is the one that adds a unique and usable sound with a depth and quality that the DCO-based WASP can't touch, and without stepping too much on the Odyssey's toes.
If I didn't have an Odyssey, the Kobol and an MS-1 MkII would be a great low-cost setup, and that's what I really like about it. The real hardware would costs thousands, but this almost-accurate replication (there are subtle differences on the boards/schematics, of course, and some components do differ) is enough to deliver the distinctive Kobol signature to your tracks.
It's an accessible synth to program and patch, albeit with a few quirks when setting up triggering. The knobs are bespoke to this unit, matching the original in style, and with tuning reference points it's very straightforward for newbies to get confident building a patch from beginning.
The Kobol's filter is not an SSM2040 clone, but a discrete component interpretation of the design. It sounds lovely – and of course, there's the ability to add more control with external sources.
In a time when digital tech and menu diving is the norm, the Kobol can appear simple – yet it's extremely versatile and worth taking time to learn and become familiar with the subtle interaction of the controls.
It's a great synthesizer for a fantastic price, regardless of the history, though, and should be one of the first considered when looking for classic analogue sounds – it's a lot easier to use than the CAT, and a lot less familar than the endless recreations of 3-oscillator Moogness. And it's way, way more versatile and pleasant sounding than the WASP, for not much more money.