I've just bought the Spherical Sound Society Vortex Generator. It's available as a kit for around 80 bucks, super easy build. It's a dual function generator, two rise/fall envelopes with CV control over both, EOC outs, a clock out (sends a signal every 4 loops of envelope 1). Envelopes are loopable btw. And it has a nice Benjolin-Style Rungler output for some additional modulation (only works when both EGs are running in LFO mode!). It's smaller than Maths, cheaper and less confusing :D