Vortex Sound Research

So I’ve had a deepmind 12 for a few months now and I’ve been after a nice saw sound for a while but I just can’t seem to get it. I can get a really nice saw sound on the lower notes but when I go above the kinda middle C area it just kinda has a clean sound rather than a nice fizzy saw sound. Does anyone have any tips? This is my first synth so I don’t know very much, I’m using a fender hot rod deluxe III amp and I’m beginning to wonder if that is what’s making it kind of clean rather than retaining the saw tone in the higher octaves. Apologies if this is a bad question!