In dual mono, why does 200 become 400, but 250 becomes 800?

[Hifi_swlon]

Sorry if this has been asked before, but I'm just curious….

[f1eng]

The original casing is a much more complex but expensive affair which has better heat sinking than the newer models. That is all.

[Hifi_swlon]

Interesting….

But in theory then, shouldn't a single 250 be able to push 400W? Or is less power somehow used by dual-mono compared to one half of a stereo signal (if that makes any sense)?

Edited to say, what I mean is, if each 250 is actually running at 400W in a dual mono, why shouldn't a single unit run at 400W?

[thumb5]

I can understand why the casing differences allow a 250 to deliver more power output than a 200 (with notionally identical electronics).

But surely the question is: why does the output more than double for the 250 when in a dual-mono configuration?

ETA:...which is the same question Hifi_swlon asked, the other way round.

[thumb5]

If I had to guess, perhaps the 250 can actually deliver 400 W (into the same load as an 800) but is limited by the configurator whereas the 800 isn't. Presumably for marketing purposes there needed to be more clear space between the 400 and 800...so maybe the 800 is operating closer to the "real" limit than a 250.

[Rufus McDufus]

So in theory the 250 could be 'overclocked'! Funny thing is I probably buy a single 250 if it output 400W, but 250W for twice the price of a 200 isn't so attractive.

[Antoine]

Devialet 800 = 2x800W (6ohm) not 2x400. So why only 500W in total from a single 250, no idea. Not sure if the 2x800W into 6 ohm have ever been measured BTW.

[Rufus McDufus]

Sorry, I meant 'per channel'. I just didn't write it down!

[Confused]

I while ago I discussed this very question with Devialet's Mathieu Pernot. His answer was along the lines of "the 200 is on the limit, the 250 is not". Another related question is why did the 7.x series firmware give the 170 an extra 30 watts, and the 240 only 10 watts.

One other thought occurs to me, and that is that there are very many examples of stereo power amps that deliver more than twice the per channel power when switched into mono block mode.

So maybe the question is why doesn't the 200 deliver more than 400 watts when in mono mode? Perhaps the answer to this is quite simple, it would overheat.

[Hifi_swlon]

So maybe the question is why doesn't the 200 deliver more than 400 watts when in mono mode? Perhaps the answer to this is quite simple, it would overheat.

I guess thats what I'm confused about. Why would it overheat delivering 800W in stereo mode, if it can deliver 800W in dual-mono mode without overheating?
Surely as far as the amp is concerned 800W generates the same heat regardless?

Or is there something about stereo vs mono block that I don't understand? (likely)