Are there any tutorials / tables / lists online relating to vowel sounds and the corresponding VOC1 and VOC2 knob values?
Having a lot of fun programming speech but getting the vowels correct is trial and error and a frustratingly time consuming. Thanks in advance.
Never mind, found this - page 14 - http://www.elektron-users.com/index.php?option=com_docman&task=doc_download&gid=446&Itemid=30
I used to not like the VO synth very much, but then I made a point of getting to know it better and now I like it a lot. I LOVE using distortion on a good crunchy robot voice! 
You really have to go deep and get used to how the parameters effect each consonant and vowel differently.
I find combining consonants and/or vowels, by placing them on neighboring triggers can make achieving certain aspects of speech easier.
P-locks really bring the speech to life too. You can make pitch inflections and hold certain vowels longer/shorter and that really helps make the speech sound more realistic.
I had made a bunch of VO synth material but lost it all and haven’t had the patience to go back and go deep with the VO again.
Yeah you’re right this synth machine relies entirely on P-locks, pretty much.
Having a formant Cheat Sheet makes it really quick to use.
a 120/64
o 80/50
i 32/104
u 25/95
uh 70/70
oe 0/32
ee 70/110
I’m not a big fan of the VO-6 robotic voice. Honestly, do you listen to much robot-voice-music yourself? What I have found usable though is doing choir sounds in poly mode. Very nice.