Expert Pro 440 vs. 1000

[damonhayhow]

I haven't heard any of the double amps, just the single amp models, so I'm interested in your comments. I have one question.

Did you listen at matched volume levels, and by that I mean listening levels matched by reference to SPL measurements rather than the volume setting displayed by the amp?

0 dB on the Devialet's display is the level at which the amp is notionally outputting full power for a signal with a level of 0 dB so 0 dB on the 1000 would be 1000 W output for a 0 dB input and 440 W output for the 440 with an input signal of the same level. That means that for the same volume setting on the 2 amps, the listening level with the 1000 would be around 3 to 4 dB louder than the 440. Given that the ear becomes more sensitive to high and low frequencies as listening level increases, a 3 to 4 dB  increase in level over the 440 would give thee impression of more bass in the low end and a hotter top end because increasing listening level acts to some degree like turning up the bass and treble tone controls. That's a large part of the reason why it's always recommended to use matched levels for A/B comparisons.

I don't doubt that the 1000 sounded as if it had more muscle, I would probably expect that even at matched listening levels, but if you were setting both amps to the same dB level on the volume control, a 3 to 4 dB difference in the 1000's favour would almost certainly make things sound brighter tonally and fatiguing.

Yes, as I said, it was immediately audibly obvious that the nominal volume level displayed on the amps resulted in significantly different sound pressure levels. So I tested the SPL to match the levels fairly.

In my initial testing, with matched SPL, I thought the amps seemed to sound more similar than different. However, I was purely auditioning the quality of bass at the time, because thats where I expected the most obvious benefit. So the tracks I was listening to were extremely bass heavy (ie Trentemoller).

On the bass tracks, matched for SPL, every time I thought I heard a difference I would switch back and be less sure? The main problem was there was several minutes gap to switch between. I had to shut everything down, swap over all of the cables, then power up and restart the source, every time I switched. So by the time all that was done, and the intro of the demo track had played, I wasnt sure if I was hearing a difference? Eventually I was able to clearly hear some deep bass definition on the D1000 that was not present on the D440. And then with enough back-and-forthing it became more certain the D1000 bass was superior, along with the soundstage size and other qualities I mentioned. 

But I kept noticing the D1000 felt like it needed to be turned up, when the SPL's were apparently the same. So, after confirming the bass was better, and the instrument separation was better, I wanted to test what I would do if I let the amp guide me?

At this point I was actually sold on the D1000. My ego wanted it ;-) the price was too good to refuse, and I preferred the D1000 remote and how the cases looked. Plus, I had finally successfully confirmed that the sound was superior for all of the technical/objective reasons I mentioned (bass, imaging, soundstage etc). However, I have been in this game long enough to know that gear needs to be engaging and unfatiguing above all else. So I stopped matching SPL to see whether the amp drew me into the music?

It was when I stopped matching SPL's that I noticed my fidgetiness and inability to find a comfortable volume with the D1000. I also noticed I was not engaged to listen to my favourite tracks. Thats when I would switch back to the D440, to see if I just wasnt in the mood for music? But virtually every time I switched back to the D440 there was the immediate sense of relaxing straight into the music, and then toe-tapping engagement, and then listening to 2 or 3 tracks in a row before remembering I was supposed to be listening to "my" new D1000.