To DPM or not? That is the question.

[rwjr44]

I have consistently tried DPM on and off, each for a few days at a time and think that DPM off sounds better. DPM on sounds very good for a few minutes then the dynamics seem to soften some. I haven't upgraded to Pro yet and probably won't.

[Axel]

Under my 1000 Pro units I created large cooling holes and the units stay quite cool. I can not read the temps because the units are in Paris for the upgrade.
I also prefer DPM off.

[4tLotM]

DPM off, it sounds definitly better. Tested several times with all kind of music.

[K4680]

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.

Hello, have the same experiences with DPM made. No difference found! DPM remains switched on.

[Confused]

I am home today, and the Devialet has been running most of the morning. I am listening at a reasonable volume level, but not that loud, the amp is on about -30dB. About an hour ago I checked the temperatures, all high 30's to low 40's, except the companion power supply at 46. I tuned DPM off, checked an hour later, still high 30's to low 40's. Ummmm. The highest temp I have is still 46deg on the companion power supply, the A amp temps are 42 master, 40 companion. I have turned DPM back on, and after 10 minutes or so the temperatures do not appear to be dropping at all. Another 20 minutes, still no change. Maybe I need to try this another time what I'm pushing the system a little harder?

This does beg the question though, when exactly is DPM doing whatever it does? Some have reported better SQ with it off, but many report no change. Perhaps in some systems, some volumes, music types, speaker efficiencies etc. it is not actually doing very much, if anything at all. I have been trying to find the appropriate Devialet white paper that covers DPM, but can't find it on line now. It would be nice to remind myself of exactly how it works.

One use I have found for DPM is when using the Devialet in pass-through mode for the front stereo channels in a surround system. This is one way of using a Devialet that can yield very high temperatures, so having DPM available for this is most welcome.

[Jean-Marie]

I am home today, and the Devialet has been running most of the morning.  I am listening at a reasonable volume level, but not that loud, the amp is on about -30dB.  About an hour ago I checked the temperatures, all high 30's to low 40's, except the companion power supply at 46.  I tuned DPM off, checked an hour later, still high 30's to low 40's.  Ummmm.   The highest temp I have is still 46deg on the companion power supply, the A amp temps are 42 master, 40 companion.  I have turned DPM back on, and after 10 minutes or so the temperatures do not appear to be dropping at all.  Another 20 minutes, still no change.  Maybe I need to try this another time what I'm pushing the system a little harder?

This does beg the question though, when exactly is DPM doing whatever it does?  Some have reported better SQ with it off, but many report no change.  Perhaps in some systems, some volumes, music types, speaker efficiencies etc. it is not actually doing very much, if anything at all.  I have been trying to find the appropriate Devialet white paper that covers DPM, but can't find it on line now.  It would be nice to remind myself of exactly how it works.

One use I have found for DPM is when using the Devialet in pass-through mode for the front stereo channels in a surround system.  This is one way of using a Devialet that can yield very high temperatures, so having DPM available for this is most welcome.

If I understand correctly what DPM does, it shall not greatly affect temperature when listening at low volume.

From what I understand, if you are listening at let's say -30dB on a D1000, (and with no SAM on for the simplicity of the explanation), it means that the Devialet will deliver at max 1W under 6 Ohms at 0dBFS. Even with DPM off, the Devialet already knows that it will never need to deliver more than 1W and adjusts its internal power and voltage accordingly.

My understanding of DPM is that it does the same kind of adjustment of its voltages and internal power, but dynamically according to the content of the music. 

Now let's imagine that the record you are listening to is having a 3dB Headroom, with DPM on, the D is able to divide his power by two.

if you are listening at -30dB, going from 1W to 500mW shall not change much of the temperature.

On the other hand, if you are listening at 0dB, the difference will be 500W with DPM on vs 1000W with DPM off. The difference if terms of temperature shall be much more noticeable.

best regards,
Jean-Marie

[Wayne Hicks]

I noticed lately my 220 wasn’t as dynamic and transparent. 

I went through the menu on my remote and found I had accidentally turned DPM ON at some time.

Turned it OFF.

To my ears, huge improvement with DPM OFF.

Bryston BDP3
Chord Hugo 2
Devialet 220
Paradigm Persona 3F

Wayne

[disarmamant]

To my ears, huge improvement with DPM OFF.

I’d be interested to know what level you’re listening at, and what sort of music, to hear such a “huge improvement”?

I’ve experimented with DPM on and off at levels from between -30 dB to -15dB and I can hear no difference.

Devialet 440 Pro CI
Harbeth SHL5 Plus.



Sent from my iPad using Tapatalk

[Rama]

For me the sound with DPM (OFF)= Class D, and with DPM (ON)=Class A/D. I find the Devialet to be more musical when the DPM is switched on, if that makes any sense.

[Pim]

For me the sound with DPM (OFF)= Class D, and with DPM (ON)=Class A/D. I find the Devialet to be more musical when the DPM is switched on, if that makes any sense.

Could it be that with DPM on, the bass is a bit less tight and therefore sounds a bit 'rounder'?