john12ax7
Well-known member
The 4000 starts to distort gradually wheras the 9000 series has more overall headroom, but once you reach the clipping amplitude, distortion sets in hard and sounds nasty.
Are the mix bus amps significantly different on the 4000 and 9000? Would be interesting to pinpoint the more gradual overload of the 4000. The newer designs also eliminated a lot of coupling caps in the signal path.