Dual Pro optimal power output?

[David A]

I can't comment on whether it's better to set the maximum power setting lower. My guess is probably not but that's just a guess.

Should you avoid using a dual pro at max rated power? What do you mean by "use at max rated power"? The way the DAC and the volume control work in a Devialet is that at a volume setting of 0 dB the amp will deliver its rated power for a digital input of 0 dB. How loud that is going to be in your setup is going to depend on the sensitivity of your speakers, your listening distance, and the degree of support your room provides. With speakers of 90 dB sensitivity, that's going to mean that when a peak of 0 dB comes along, you're going to have a level at your listening position of 110 dB or more, probably a bit more. Based on Australian hearing protection standards, the maximum "safe" exposure to a level of 110 dB is around about 2 minutes a day on a "set and forget" basis.. You're into levels where there's a serious risk of giving yourself noise related hearing loss if by using the amp at maximum power you mean setting the volume level to 0 dB and leaving it there. The first symptoms of that damage are actually difficulty in understanding human speech because the damage occurs first in the mid-range frequencies where the ears are most sensitive so your music listening may be less affected than your ability to simply chat with friends over a meal but the damage spreads out to the highs and lows from there. I somehow think that there's not much sense in buying a D1000 Pro if you're going to use it to wreck your hearing so I definitely recommend that you not use the amp at maximum power unless you're playing something which has been mastered with a lot of headroom, ie the peak volume on the recording is well below 0 dB in level. Such recordings do exist.

Now to your comment that the 1000 Pro plays louder than the 250 at -40 dB. Of course it will. With a Devialet a volume level of -40 dB means a level 40 dB below rated output. With the 250 that's 40 dB below 250 watts/ch and with a 1000 it's 40 dB below 1000w/ch so if you're comparing both amps at the same setting, -40 dB on each amp, then -40 dB on the 1000 is gong to be 6 dB louder than -40 dB on the 250 because each doubling of rated power increases the peak volume level you will hear by 3 dB and rated power doubles twice as you go from 250 W to 1000 W.. If you're comparing 2 Devialets of different power and you're trying to match volume levels by matching the settings, the amp with the higher output is always going to sound louder. In order to match volume levels for the comparison you're going to have to play a test signal, something like a 1 kHz sine wave or a white or pink noise source, even the brown noise source the Devialet has for speaker break in purposes,, measure the sound pressure level at your listening position with an SPL meter, and adjust the volume settings on one or both amps so that each is delivering the same SPL at your listening position. Try that with a 250 and a 1000 and the volume setting on the 1000 is going to be close to 6 dB lower than that on the 250 because of their difference in maximum output. It probably won't be exactly 6 dB lower but it will probably be within +/- 1 dB of that.

I wouldn't reduce the 1000's maximum power rating in the Configurator, I'd leave it at 1000 W. If you want to limit the volume you can play things at, then Roon has an option in the Device Setup options for setting maximum and safe volume setting levels which restrict the operation of the volume control in Roon if you're controlling volume via the Roon remote display.