modulation shapes

[jhaible]

> Curiously enough, on the guitar effects diy board at Ampage, the
consensus
> is that for a phaser the best LFO shape is like an inverted full wave
> rectified sine, that is, pointy at the top and smooth at the bottom.

That's something I have not yet tried, but it sounds reasonable.
I guess at the low turning point a pitch change effect dominates, and a
sharp corner in the mod signal would cause an unpleasantly
strong pitch change, while on the high end the filter effect is dominating,
and a round corner would just make the filter stay too long in a
rather uninteresing position of the comb filter.
I would not have found that myself, but once I've read about such a 
modulation shape, it's quite reasonable. Who did invent it, btw. ?

JH.