The pitch envelope normally modulates the operator’s pitch. But I didn’t know that when it’s used on a formant, it modulates the formant frequency. (I forgot to mention that a few of the FS1R’s parameters are idiosyncratic; this is one example of many.)

There’s probably some way to generate a sawtooth wave, or at least a wave with an equivalent spectrum. Some combination of feedback, skirt, algorithm and waveform should do it, but I can’t find the magic combination. It’s hard because the waveforms are derived from a sine wave lookup table, and you can’t just run DC offset through a formant window, as far as I can tell.

My real complaint is that the waves don’t sound bright enough, like the high-end rolls off too quickly. I don’t need a pure sawtooth wave, I just want that high-end punch more than anything.

Now… you just need to figure out how to genearte a sawtooth wave using FM. It can be done!

http://scp.web.elte.hu/papers/synthesis1.pdf

Based on Thomas Gruber’s analysis, it seems like you could find a way to use the formant algorithm to spit out a sawtooth wave since it uses a sawtooth internally for generating the formant output:

“The principle is simple. The sine wave is played, and amplitude-modulated by the window function. The window function looks like a sawtooth wave, except that it is reset to the beginning in regular time intervals. That is, the saw is going up, and reset to zero before it reaches its maximum, if the reset frequency is higher than the saw frequency. If the reset frequency is lower, then the sawtooth wave stays at maximum until the next reset. “

From the link:
Algorithm = 1
Feedback = 5

OP1 = Formant
F.Coarse = 66.87
Freq Scaling = 99
Transpose -12
Skirt = 3
Output Level = 99

FreqEG
Init Level = 48
Attack Level = 10
Attack time = 54
Decay time = 0