For those of you who use LV2 plugins in Carla-LMMS, there is a great new linux Synth called Helm (beta) that I found in the kxstudio repos http://tytel.org/helm/.

It is quite stable in LMMS, unlike a lot of other lv2 instruments. It reminds me of Synth1 x TAL Noisemakr, but not as harsh. It has some notable useful features like: great saturation/feedback effect for analogue-ish warmth and movement; almost any parameter is modulatable by multiple LFOs (many-to-many relationship); a 'stutter' effect; wavetable modulation/mutation; good sounding filters; a great intuitive GUI. No hard sync capabilities, unfortunately.