A coordinated observation with Olivier for an instructive comparison.
The star VY Scl observed this time from France, but at the very low elevation of 14° above horizon (very strong absorption in the blue because of the air mass). I used a 8-inch Newton only and the Star'Ex spectrograph configured for low spectral resolution (300 lines/mm grating, R = 850 - see description here, at point 4.4
http://www.astrosurf.com/solex/sol-ex-stars-en.html):

Of course, much more noise than in the spectrum of Olivier, but it remains readable (the star is actually at V=12.7).
During the same session and with the same setup, the cataclymic star V794 Aql at V = 15.0:

and the star V704 And spectrum:

Christian Buil