This is an interesting approach to phase modulation, that really takes advantage of the way the sine function basically has a built-in fract function. I would recommend that you make the audio it's own out, rather than embedding the speaker node, so you can mix more easily. Thanks for sharing!
edit 11:38 - I converted it to a umodules so you can see what I am talking about. Also I am wondering what is up with the funky poly to mono thing going on with the gate? What does it do other than multiply the voice count by 4?
edit 11:45 - Ok, I saw the other thread about the velocity being turned off in most poly nodes, still I think it sounds pretty good without it :)
Thanks ! Yes, it's better with the speaker out of the node. In the original version, there's some delay before the tremolo. Perhaps it could be fine to have a knob to adjust it. The lack of velocity in poly-mode is a real problem when you play with a midi keyboard. I hope this oversight will be soon updated :)