well tremolo is variation in volume and vibrato is variation in frequency so you can do both of these with the low frequency oscillator.

sound edit / LFO

page 1 is the vibrato and page 2 is the tremolo.

you can have different amounts, delays, waveshapes, keysyncs, phase, touch etc for different samples in the final sound. The programming is pretty advanced since you have 12 LFOs you can program to affect different samples in different ways.

If you press OVERVIEW you can see how it is all mapped out in the screen.

Try a tiny amount of effect in the actual sound, and some (slightly different settings) more triggered by touch, and some (slightly different settings) more in the wheel, and you have that really complex effect that never sounds like a constant sine wave... You can program any 2 of the 12 LFOs into the modulation wheel.