In addition to setting the Rate knob high, you will probably also want to use Env to Rate to push the LFO past the 20 Hz limit. (My recollection is that internally it can go to at least 40 Hz with this and maybe 80 Hz or more)
Also, the LFO shape is going to affect the timbre of the modulation, especially for the pointier shapes.
Technically the sound of this will be AM rather than RM because the modulator is unipolar rather than bipolar, so unlike RM the original input signal will also appear in the output. Nevertheless, it’s quite similar to RM.
