To DPM or not? That is the question.

[Mikeeo]

Hi, 

What Devialet says I do not put too much value in since the Munich meeting! Differences are small, can't say I hear any with digital sources however playing vinyl there is for sure an advantage in off.

/Mike

[brit]

I asked one of the guys from Devialet if DPM improves the sound quality at all and the answer was no. He said it just allows the unit to use less power/electricity and therefore be more efficient and environmentally friendly. If its SQ you care about, keep DPM off. I'm not fussed about saving more electricity for the environment because the Devialet without DPM is already a mile 'greener' than the class a amplifier I had before it

I asked one of the Devialet designers the same question. He said DPM made no difference to SQ so one may as well leave it on...
I don't hear a difference so I do leave it on. At least the lower temps may help longevity.

I have tried  DPM ON, and OFF, and could discern no difference in SQ between them, so I leave it on and do a little bit for the environment .


David

[PhilP]

I experience a difference in temps of 8-10 degrees DPM on/off when running SAM with 8.1.3 so I always have DPM on when I use SAM.

I really like SAM with my speakers (typically running 50%) but am currently trying 7.1.3 again as I'm not 100% happy with 8.1.3 and DPM

[Rufus McDufus]

Funny thing is Devialet's don't seem to be particularly power-hungry anyway so I'm not really sure what the point is in that respect. The major gain does seem to be the temperature regulation where it seems to give maybe 8C lower temps, whch is pretty significant. I sometimes wonder if they're trying to improve thermal efficiency in order to give us another power upgrade (or some other feature that requires extra processing and therefore higher temps). At the very least a more consistent running temperature is going to lead to a more consistent sound quality I'd have thought.

[thumb5]

At the very least  a more consistent running temperature is going to lead to a more consistent sound quality I'd have thought.

I understand your thought process -- although one of Devialet's selling points for the Expert line is "unmeasurable" thermal distortion, which suggests to me that they don't think the amplifier is subject to (any?) thermal effects on sound quality.  Hard to say, since they don't explain exactly what they mean.

[Gentleman]

Yesterday night we have re-adjusted some gear in our reference setup. Even though we applied several tweaks which normaly help to increase the SQ last night we were not happy with the result....

We checked every detail twice but the sound was still too cold and harsh. Finally I had the idea to check the D400 concerning DPM. In fact DPM was switched ON (maybe due to the recent firmware update 9.0.1). Immediately I switched DPM to OFF the SQ increased massively!!!!

So guys do yourself a favour and check this setting. From our point of view this option was sent directly from MP3-HELL ;-)

Besides, last night we experienced some more interesting differences in SQ of digital audio once again. For ages we have been using nicely tuned PCs for ripping of our CDs with dbpoweramp. For christmas I got myself a HFX RIPNAS Solid which uses just the very same software but installed on a Win 2011 HomeServer OS. So last night we compared our files (WAV only) with the WAV files created by the ripnas. To our surprice the files from the RIPNAS sounded much clearer than the same files ripped from the same CD at the same time in the same room with our old PCs........

In Dubio Pro Audio

Jan

[AllenB]

Let alone DPM, does anyone run with the power delay setting disabled (i.e. on all the time). I am doing this lately because it keeps the USB connection alive to HQ Player on my Mac Mini. Does keeping the Dev on all the time have any associated issues?

[Gentleman]

Hi Allen.

We do not use any of the power safe options on our D's. We switch them on very often in the early morning before we go to work to have them nicely settled for a long listening audition in the night. That means we keep them running for up to 18 hours a day without any issues. But normally we switch them off with the remote (into standby) if we do not need them. So we have no real experience with 24/7....

In Dubio Pro Audio

Jan

[Rufus McDufus]

I've tried disabling the power-saving mode and I did actually think it sounded better straight from the off. It just seemed to have that warmed-up sound. The unit did get quite warm back then though when not in use and I was a little concerned, probably for no tangible reason, about it being permanently at a higher temperature. That might've been before some of the better temperature regulation in the firmware so it may stay cooler with no music playing through it now?

[AllenB]

Hi Allen.

We do not use any of the power safe options on our D's. We switch them on very often in the early morning before we go to work to have them nicely settled for a long listening audition in the night. That means we keep them running for up to 18 hours a day without any issues. But normally we switch them off with the remote (into standby) if we do not need them. So we have no real experience with 24/7....

In Dubio Pro Audio

Jan

Thanks Jan

I guess the issue really is with HQP losing the USB connection, and keeping the Dev alive is maybe the hammer to crack a nut approach, I would much prefer it resolved from the HQP end. The Dev is warm, well very warm, but not hot whilst it stays on 24/7, but I have not seen any evidence to say this might be harmful to the unit. When I owned Naim, it was on 24/7 apart from holidays. I could switch to stand-by overnight, but that would mean a re-connection to HQP every day.

Allen