The Doepfer MS-404 is basically a TB-303 emulator. It's analog, monophonic, has a nice 24dB/oct VCF (filter), a simple envelope and the bonus of two LFOs. As with any 303 emulator, the MS-404 has the typical 303 controls you would expect for the filter and envelope. However the two added LFOs add a whole new dimension to the 303 sound. This is because they can modulate the VCOs! Other common 303 emulator features also found on the MS-404 include an external filter input, CV/GATE interfacing, MIDI implementation and a glide effect. All parameters are MIDI controllable. The slide and accent effects from the 303 are possible on the MS-404 from the glide control and MIDI velocity for accent. The MS-404 ranks high among the 303 emulators under $500, and it sounds pretty darn good too. It has been used by Hardfloor and Josh Wink.
Demos & Media
Images from Doepfer On-Line.