+- Devialet Chat (https://devialetchat.com)
+-- Forum: Devialet Chat (https://devialetchat.com/Forum-Devialet-Chat)
+--- Forum: Devialet D-Premier, Expert 120/200/250, Expert 140/220/250 Pro (https://devialetchat.com/Forum-Devialet-D-Premier-Expert-120-200-250-Expert-140-220-250-Pro)
+--- Thread: Expert Pro sound quality (/Thread-Expert-Pro-sound-quality)
RE: Expert Pro sound quality - mdconnelly - 26-Oct-2016
Maybe what I'm not getting is why the 250 Pro is not really a 500 Pro.... if two of them can produce 1000 watts, why can one only produce 250 watts? I'm guessing there are good tech reasons behind it, but it just doesn't seem to make sense. Has Devialet offered an explanation on this? Just curious.
RE: Expert Pro sound quality - Antoine - 26-Oct-2016
The explanation given by Herman (see link below) is the one I trust the most and find to be the most likely explanation. Hifi_swlon is trying to get Devialet to confirm this but no response yet if I'm not mistaken.
http://devialetchat.com/showthread.php?tid=2980&pid=46056#pid46056
RE: Expert Pro sound quality - Hifi_swlon - 26-Oct-2016
Nothing yet.
Yeah Hermans sounded convincing enough (to perhaps be from inside Devialet?).
But if you can extract 200w extra in dual mono after a complete revamp of case heat sink and major electronics, surely the single box would at least benefit in some way?
I also asked them if the still consider it a current model (in that it's not on their website).
RE: Expert Pro sound quality - Confused - 26-Oct-2016
(26-Oct-2016, 14:13)mdconnelly Wrote: Maybe what I'm not getting is why the 250 Pro is not really a 500 Pro.... if two of them can produce 1000 watts, why can one only produce 250 watts? I'm guessing there are good tech reasons behind it, but it just doesn't seem to make sense. Has Devialet offered an explanation on this? Just curious.
Actually this is the wrong way around. Assuming sufficient current is available from the power supply, a bridged amplifier can produce 4 times the power of it's stereo equivalent. So a 250 watt amp producing 800 or 1000 watts is possible. However, a 200 / 220 watt amp 'only' doubling to 400 / 440 watts is a little low, and indicates other restrictions. Probably thermal in the case of a Devialet.
Some light reading....
https://en.wikipedia.org/wiki/Bridged_and_paralleled_amplifiers
RE: Expert Pro sound quality - Antoine - 26-Oct-2016
In addition to my earlier post. (edit: this post crossed with Hifi_swlon's and Confused's posts) Herman wrote:
Quote:The D250 and the D250Pro are both limited by the maximum voltage the Amp can deliver (slightly below 40 Volt per channel - if bridged it can deliver nearly 80 Volt)
=> 40 V are leading to about 266 W in 6 Ohm
=> 80 V are leading to about 1066 W in 6 Ohm
These values are the same for the D200 and the D220PRO but they are artificially limited to about 35 V for the D200 and about 36.5 V for the D220 to take into account their limited heat sinks.
The heat sinks of a D250 is limiting by about 800 W; the D250Pro is now optimized to handle up to 1000 W
And to eleborate a bit on the simple "math".
The basic Ohm's law formula's:
V: Voltage (in V)
R: Resistance (in Ohm)
I: Current (in A)
P: Power (in W)
V = I * R and so I = V/R
P = V * I and so P = V^2 / R
When max. voltage = 40V:
P = 40^2/6=266,67 W
When max. voltage 80V:
P= 80^2/6= 1066,67 W
RE: Expert Pro sound quality - Antoine - 26-Oct-2016
(26-Oct-2016, 14:25)Hifi_swlon Wrote: Nothing yet.
Yeah Hermans sounded convincing enough (to perhaps be from inside Devialet?).
But if you can extract 200w extra in dual mono after a complete revamp of case heat sink and major electronics, surely the single box would at least benefit in some way?
I also asked them if the still consider it a current model (in that it's not on their website).
Perhaps it's Devialet inside information or perhaps these values are printed on the PCB's. We really don't know and should ask him.
Most probable explanation on your question: the previous limit (before Pro) in dual mono was a thermal limit, the limit in the single box is a electrical limit. We can also conclude from all this that the dual mono Pro models at 1000W@6Ohm per amp are now also on/very near the electrical limits.
RE: Expert Pro sound quality - Antoine - 26-Oct-2016
What I can't yet explain is the differing values in the config files compared to those suggested by Herman. For example in my 250's config file there's mentioned:
Quote: "ADH_CONFIG":{
"VOLTAGE_0DB":55,
"PUISSANCE_0DB":250
},
"PSU_CONFIG":{
"V_RUN_MAX":140
What do these values mean, a max. ADH voltage of 55V when the amp is at maximum? The main PSU outputting 140V at maximum?
Some explanations/insights by Devialet would be really helpful to clear this once and for all!
RE: Expert Pro sound quality - mdconnelly - 26-Oct-2016
(26-Oct-2016, 14:17)Antoine Wrote: The explanation given by Herman (see link below) is the one I trust the most and find to be the most likely explanation. Hifi_swlon is trying to get Devialet to confirm this but no response yet if I'm not mistaken.
http://devialetchat.com/showthread.php?tid=2980&pid=46056#pid46056
Ah, interesting. I must have missed that thread. Thanks!
RE: Expert Pro sound quality - Inox - 26-Oct-2016
(26-Oct-2016, 14:28)Confused Wrote:(26-Oct-2016, 14:13)mdconnelly Wrote: Maybe what I'm not getting is why the 250 Pro is not really a 500 Pro.... if two of them can produce 1000 watts, why can one only produce 250 watts? I'm guessing there are good tech reasons behind it, but it just doesn't seem to make sense. Has Devialet offered an explanation on this? Just curious.
Actually this is the wrong way around. Assuming sufficient current is available from the power supply, a bridged amplifier can produce 4 times the power of it's stereo equivalent. So a 250 watt amp producing 800 or 1000 watts is possible. However, a 200 / 220 watt amp 'only' doubling to 400 / 440 watts is a little low, and indicates other restrictions. Probably thermal in the case of a Devialet.
Some light reading....
https://en.wikipedia.org/wiki/Bridged_and_paralleled_amplifiers
Hi,
That's what I tried to explain in my previous posts relative to bridged amps. The power base is 250 W/6ohms max for a single unit. The Pro uprgrade did not change this.
From Wikipedia :
It is sometimes stated that operating an amplifier pair in bridge mode can give four times the power (of one of the pair). This statement makes reference to the fact that power is proportional to the square of the voltage, implying that if the output voltage is doubled – as it is in bridge mode – then the power available increases by a factor of four. This would be true if the amplifier in bridged mode were used to drive loudspeakers of the same impedance used in stereo mode. However, in this case, the current through the loudspeaker and the amplifier would also double, which could exceed the amplifier ratings and lead to overheating and finally destruction of the amplifier. In fact, the minimum impedance of the loudspeaker in bridged mode should be double the minimum impedance rated for stereo mode.
I asked this question of minimum impedance to Devialet, and another one concerning power ability at 4 and 2 ohms load. I think it's a key point for speaker association. That could explain large differences in terms of sonic result.
RE: Expert Pro sound quality - Pim - 26-Oct-2016
Is anyone still listening to their Devialet?
Back to the topic!
