CRC - the VFX SD is a great digital synthesizer. The presets are hilariously late 80's sounding and barely hint at what the machine if capable of, but it's a very deep synth. The voice architecture is pretty unique - a "sound" can be made up of six "voices", where each "voice" contains one oscillator, one LFO, 3 (loopable) envelopes, two (non-resonant) filters and 15 modulators. You can then route the voices through two effects (that sound great in a semi-trashy way). So far I typically use two or three voices in a sound, but if you want to make something like a pad with six detuned saw waves, all going through their own filters with their own LFOs, you can do that.
Took a bit of time to get to grips with how it's all organized, but when it clicks it's really easy to program in a way that's typical of earlier Ensoniq stuff. Those guys sure knew how to make an interface for a digital synth. Too bad they sucked at making power supplies (see below).
Soundwise it's cleaner than an ESQ-1 or SQ-80, but it's still pretty grungy for a digital synth. It's not the machine to buy if you want something that will sound like an analog synth. It's unashamedly digital. It's great for pads and glassy/metallic weird sounds that digital synths excel at. And hey if you want to layer that kind of strangeness with some badass marimbas or slap basses, you'll be in heaven! ![wink](https://www.robotsforrobots.net/img/smilies/wink.png)
There are known and well documented issues with them (a keyboard calibration issue with a simple fix, and power supply heat-related issues that can cause it to crash) so it's a bit of a risk, but I knew this one had the keyboard fix already done. It has crashed on me a few times already, but that was after having it on for hours on a hot day. Pointing a fan at the heatsink seems to help.