A note on existing MIDI Virtual Rack presets and the sound you are after (and the example with frequency shifters posted):
6648 MIDI Ring Mod
uses freq. Shifters. With low rates you can get the same effect. There is no feedback though.
6661 MIDI VirtRack 2
this has the Ring Mod…but misses other fx you may want for the Gilmour thing
6663 MIDI VirtRack 4
has the Ring Mod and probably better fx options
6644 MIDI VirtRack 5
same as in #2
If I would put together a MIDI VirtRack for the Gilmour sound, I'd probably go for this FX assortment:
MIDI FM Tremolo
MIDI XF4v Modulation
MIDI St Dynamic Dly
MIDI Ring Mod (with added feedback paths)
MIDI Reverb 12
6 fx may be too much in a sigfile…maybe it will run in monolithic mode.Show More...
If it doesn't, then you need to make some economy. In such case I'd cut the compressor off (you already have your compressor on the floor), and/or choose MIDI Reverb 8 which uses less resources than the 12 version.
Or you could even split the whole FX chain across 2 presets, run in both dsps routed in series…
I'm sure you have enough options….