How can i increase LFO speed with keyboard input?

Hi People

I'm trying to replicate the second pulse wave of the OSCar synth which is modulated by an independent triangle LFO that increases in frequency the further you travel up the keyboard, much like the old minimoog did, any suggestions would be great.

I would also like to replicate the 'intro' control which modulates separate LFO source with a ramp up for just one cycle and holds at the top until another key is pressed where it zeros out and starts again.

Thanks.

 

instead of an amount knob [-1 ... +1] you can use an envelope.

ciao herw

 

Thanks herw, Just what I was looking for