I have a very old Paasche compressor I got with my first Paasche V airbrush when I was in high school (1986) - I noticed an extremely annoying problem in that the air 'pulsed' as it was coming out of the compressor - and created spotty lines coming out of the airbrush. Not the biggest compressor, I might add (I always have wanted a 'silent' Jun-Air)
It was suggested at the time I add a reservoir 'bladder' in line and as I could not find *anybody* who sold bike inner tubes, I went to my local hardware store, got some end connectors and about two feet of soft clear vinyl hose. Just soft enough to contain and iron out the 'pulse' problem and smooth air afterwards. No more pulse or spotty lines...
I have no idea if the diaphragms in the compressor are still intact. I fell in love with this sick airbrush setup that Copic makes - works with their artist markers - no more color cups and having seen a guy painting foam bass popper heads with one... man.... trying to come up with an excuse to get one