SEM Power supply?

[Haible_Juergen#Tel2743]

Hi - a short question:

The Voltage that is labled "18.5V" in the Oberheim SEM
schematics - what exactly is it? Unstabilized voltage
at the PSU capacitors? Pre-regulated Voltage?

Background: I have some hints that the exact shape of the
SEM's saw wave might depend to some degree on the exact
value of this voltage.
I have done some Spice simulations - unfortunately
not with the original 2N4302 FETs, but with BF245C.
Maybe these are so different, but maybe not.
In my simulation the saw was shaped to a somewhat "spaced
sawtooth" (in Formant terminology) by the FET stage; the
cap voltage was a perfect saw.
Now, a spaced saw has different harmonic contents - this might
be a reason for the different sound.
Has anybody *measured* a real SEM on the oscilliscope?
(the things *I* was posting recently were done on my clone,
wuth the BF245 ...)

Thanks for any hints,

JH.