I don't have any sound examples because my recording rig is being renovated at the moment, but here's some written info for you:
I've got two Quad preamps. One built in 1988 (1D) and one built in 1989 or 1990 (1E). I've compared them side by side and there are definitely some differences between the two. I'm not sure if the two versions just have different characters, or if it's that 'something' is up with one of them that affects the sound. To further note, I've actually switched out the tubes identically in both preamps to see if it was the set of tubes giving this difference. Tubes were set in place in both amps, and then switched in exact positions, so both preamps got the same tubage going. It didn't affect the character I'm speaking of, so it's definitely the preamps. But here goes!
Quad 1E from 89-90 has a more 'wide open' sound to it. There is more of a midrange and trebly frequency content than the other. It sounds less controlled and more wild. The 80hz EQ slider gives it a round bottom end, kind of like a wide Q on a parametric EQ. When turning the reverb knob up to 10, there's a definite 'SHHHHHHHHH' sound to it that's overpowering. The noise floor/buzzing is higher than the Quad below.
Quad 1D from 1988 definitely has a more 'controlled' sound, and sounds more like it's a guitar cab when listening right in front of it, so less wide open. Unlike above, the midrange and trebly frequencies aren't as apparent, almost like I'm using a very slight shelving EQ curve or some kind of light lowpass filter. It sounds less wild, and more controlled as mentioned, less wide open. The 80hz EQ slider seems to give it a definite sense of BEEF in the lower range, very punchy, almost like using a bit more of a narrow Q on a parametric EQ. To further that, the EQ on this one definitely has a more apparent effect on the sound, or the chunkiness than above. When turning the reverb knob up to 10 on this one, it's basically like turning the reverb knob on the above Quad pre to 4-5 or so. Definitely less apparent and doesn't have that out of control 'SHHHHHHH' sound. The noise floor/buzzing on this one is less than above, but hey, it COULD be the treble/midrange on that one emphasizing it.
These are my findings when comparing the two. I thought it might be some interesting reading material for people who have Quads. An important note here is that I don't think one sounds better than the other, just DIFFERENT. 1D ('88) is more controlled, accurate, and oldschool cabinet-like sounding, and the EQ sliders seem to emphasize frequencies narrowly, but more. 1E (89-90) is more open, wild, trebly, and punchy (only in a particular way though), and the EQ sliders seem to have less of an effect on particular frequencies, opting for spreading them out instead.
I've got two Quad preamps. One built in 1988 (1D) and one built in 1989 or 1990 (1E). I've compared them side by side and there are definitely some differences between the two. I'm not sure if the two versions just have different characters, or if it's that 'something' is up with one of them that affects the sound. To further note, I've actually switched out the tubes identically in both preamps to see if it was the set of tubes giving this difference. Tubes were set in place in both amps, and then switched in exact positions, so both preamps got the same tubage going. It didn't affect the character I'm speaking of, so it's definitely the preamps. But here goes!
Quad 1E from 89-90 has a more 'wide open' sound to it. There is more of a midrange and trebly frequency content than the other. It sounds less controlled and more wild. The 80hz EQ slider gives it a round bottom end, kind of like a wide Q on a parametric EQ. When turning the reverb knob up to 10, there's a definite 'SHHHHHHHHH' sound to it that's overpowering. The noise floor/buzzing is higher than the Quad below.
Quad 1D from 1988 definitely has a more 'controlled' sound, and sounds more like it's a guitar cab when listening right in front of it, so less wide open. Unlike above, the midrange and trebly frequencies aren't as apparent, almost like I'm using a very slight shelving EQ curve or some kind of light lowpass filter. It sounds less wild, and more controlled as mentioned, less wide open. The 80hz EQ slider seems to give it a definite sense of BEEF in the lower range, very punchy, almost like using a bit more of a narrow Q on a parametric EQ. To further that, the EQ on this one definitely has a more apparent effect on the sound, or the chunkiness than above. When turning the reverb knob up to 10 on this one, it's basically like turning the reverb knob on the above Quad pre to 4-5 or so. Definitely less apparent and doesn't have that out of control 'SHHHHHHH' sound. The noise floor/buzzing on this one is less than above, but hey, it COULD be the treble/midrange on that one emphasizing it.
These are my findings when comparing the two. I thought it might be some interesting reading material for people who have Quads. An important note here is that I don't think one sounds better than the other, just DIFFERENT. 1D ('88) is more controlled, accurate, and oldschool cabinet-like sounding, and the EQ sliders seem to emphasize frequencies narrowly, but more. 1E (89-90) is more open, wild, trebly, and punchy (only in a particular way though), and the EQ sliders seem to have less of an effect on particular frequencies, opting for spreading them out instead.
