HY-Mono

monophonic synthesizer
Based on the structure of Oberheim SEM.

It is a virtual analog monophonic synthesizer featuring two oscillators and a sub/noise generator, two ADS envelopes (no release parameter), a single LFO, portamento, a 2-slot modulation matrix, and a built-in delay effect. The user interface is fully resizable and also features a built-in patch browser with a rather well implemented patch randomization future. It is possible to prevent certain sections of the synth engine from changing their value when randomizing the patch, which is a neat touch.
Being a monophonic synth it is more than capable of creating some great sounding bass and lead sounds, as well as all sorts of noisy and blippy sound effects. The instrument sounds very nice overall (both the oscillators and the filters are quite decent) and it’s easy to program thanks to the well designed user interface.

http://hyakken.moo.jp/WordPress/product/hy-mono/