Tips for Making Vibrato Leads That Don't Sound Goofy?

Hey all,

I've been devoting a lot of time to Syntorial and have just completed all modules, including related lesson packs for Sylenth1, Serum, and Massive (except for the "Final Challenges" and the associated lesson pack lessons therein, which I'll dive into after honing the skills taught in the regular modules).

Right now, I'm focused on applying the skills learned on Syntorial to my own music and have been achieving a lot of success so far.

My question today relates to using vibrato to create more expressive sounds. So far, all my attempts at putting vibrato on a sound sound goofy or cartoonish, even if I try to dial in a light amount of vibrato. I make "indie rock" music so this instantly sounds out of place.

Do you have any suggestions on how to make vibrato-like sounds, similar to the rate/range of vibrato found in these songs:

(in the beginning, you'll hear "oooohs" in the background, may have to turn volume up)
https://www.youtube.com/watch?v=QQnc-hM80UQ

(go to 1:28...the speed and range of this vibrato sounds really nice)
https://www.youtube.com/watch?v=c9E2IT1jHQY&start=88

In both these songs, I know it's a human voice creating the vibrato. I'm not looking to make my vibrato patches sound like a human voice. It's more the rate/range ("control," for lack of a better term) that I'm looking for, and the rate/range I hear in my head in that respect sounds similar to the songs above. So I suppose it's human-like vibrato but I'm not necessarily looking to emulate a vocal sound, if that makes sense.

So my questions are as follows:

  1. Any suggestions on how to program in a similar vibrato speed/range? I'm assuming I should use an LFO but which LFO shape? Should I be using Fine or CRS? I'm assuming CRS.

  2. Any suggestions on associated waveforms? I feel like it should be something like a sine wave but with a little more edge (I find that Saw and Square can add to the corniness)?

  3. I'm assuming some portamento should be dialed in. Any other suggestions?

  4. In Serum, I'm still not entirely clear on what "Output" does in the Matrix section (the slider all the way on the right). You can dial in the range of the vibrato on the left but what effect does maxing out the Output (or lowering it) do to that range?

Thank you so much! Looking forward to your thoughts.