Classic oscillator pitch mod. with an LFO?

Hi most excellent list,

I'm trying to build a ring mod based on the moogerfooger pedal. I would like to change the frequency of the modulation oscillator with an LFO (which is based on another oscillator)- classic analog style oscillator pitch modulation with an LFO.

Getting ring modulation is easy with a [*~] and an oscillator multiplying the input. Also, I was able to modulate the freq of the modulator by adding [+~] the LFO as in the FM tutorial (8?) example but I'm not getting the same behavior as the LFO section on the moog pedal.

What I'd like to do is at 100% depth setting of the LFO that it would sweep the mod freq from 0hz to whatever its set at or for example if the depth was set at 50% that and that mod freq was 100hz the LFO would sweep the carrier from approximately 25hz to 75hz. In the FM patch the both the high and low range of the carrier gets pushed downward and upward as the depth increases so if I want the LFO sweep to start around zero the mod freq goes higher then its initial setting setting. I guess there must be a pretty simple solution but I'm missing it. I did try LFOing the mod's floating freq input in the control realm with a sig~ and some math to make it unipolar but I could hear a lot of zippering as it swept so I'd like to do this in the audio realm if possible especially now having built a nice new killer LFOs in MSP based on Gregory Taylor's excellent tutorials.

Thanks in advance. Sorry if this was a little meandering.

Best,

Bradford