Apologies if this is old hat and I should have just looked a bit harder on the forum, but I wonder if any denizens have seen and can explain this:
I've just upgraded the firmware on my 800 (which is a 250+250, not an 800) to version 10, and I've noticed that the volume display on the devialet has changed 'level'. I mean by this that whereas in version 9 -40% was at roughly 9PM on the display, in version 10 it is at 11PM. I have no idea whether or not this matters in any practical sense - the amp is still loud enough - but at first sight it suggests to me that the amp has less headroom than it used to. By the way, at my dealer's suggestion, I created a new configuration file, but this has made no difference.
If anyone knows what is going on, or can point me to a thread where this issue is discussed, I should be most welcome.
AG
Could it be that, because V10 was made for the 1000Pro, you are 'meant' to have an extra 200W and the display on the 800 compensates for the lack of that 200W? So, when installed on a 1000Pro, this config will show up with 40% at 9PM.
Any 1000Pro owners here who could help out?
I think it's just a design/presentation thing and has no technical meaning.
@
Pim, the dB scale is a relative scale. 0dB equates to maximum output power. (With anything above 0dB digital amplification is performed but the "anolog" gain is still the same.) So whether the maximum output is 2 x 200W or 1x1000W in both cases it would be 0dB at maximum output.
(08-Oct-2016, 20:36)Antoine Wrote: [ -> ]I think it's just a design/presentation thing and has no technical meaning.
@Pim, the dB scale is a relative scale. 0dB equates to maximum output power. (With anything above 0dB digital amplification is performed but the "anolog" gain is still the same.) So whether the maximum output is 2 x 200W or 1x1000W in both cases it would be 0dB at maximum output.
I understand the 0dB but the digital amplification has got me as confused as Confused
Can you elaborate on that?
It's a bit hard to explain in layman's terms. Above the 0dB volume setting the Devialet's in effect make the original signal "louder" by "scaling it up" in a linear way (equal for all frequencies) using DSP and with it sacrificing headroom (
https://en.m.wikipedia.org/wiki/Headroom...rocessing)). That's why in general there's a risk of clipping (
https://en.m.wikipedia.org/wiki/Clipping_(audio)) when one goes over 0dB and this is not advisable, especially with already loud or the modern 'loudness war recordings' that have little headroom. I do believe the Devialet's prevent the actual clipping from happening by using compression so one doesn't burn his loudspeakers (tweeters usually go first
). Compression is also 'bad' for SQ of course since it introduces distortion.
Antoine & Pim,
Thanks for your comments. It does now look to me as though this is just a change in the way the information is displayed; -40% sounds about as loud as it always did, and the amp dial goes all the way up to +30, a land that I have never felt the need to visit.
On a related note, while looking into this I found that it was possible to configure output (?) level - default is 2.0 - lowering that to 1.5 makes things louderer. Is the expert view that one should not mess with this setting? Also, is doing so equivalent to applying DSP?
AG
This is not DSP but really changing the analog parameters. On inputs and outputs you can configure the "max level":
For inputs (the help text in the Configurator):
"Maximum input RMS level: the amplifier gain is adjusted to make it match the maximum RMS voltage at the speaker output (Factory Setting: 2 VRMS)
An excessive value requires to push the volume control higher and needlessly prepares the amplifier to high power demands, with slightly increased energy consumption and heat dissipation: this is especially the case if you connect the earphone output of a portable player (whose output voltage is limited to protect your ears) without choosing the corresponding low value preset; a too low value leads to clipping of the most dynamic records."
For outputs (no help text is present in the configurator so in my own words): the level allows one to match to the input sensitivity of the device connected to the output. If it's set to 2Vrms than that 2V is the voltage which corresponds to maximum line output level. If the device (eg. an active subwoofer or surround amp) you connect to the output has an input sensitivity of 4V you'll never reach maximum volume so one can match it by adjusting this parameter. If the device has an input sensitivity of 1V there's a risk of clipping. You can check the input sensitivity in the manual of the device or consult the manufacturer of course.
I recently upgraded my 200 to firmware 10.0.2, and noticed two things: 1) there is now a loud click when I change the source, particularly when I change to the Phono input; 2) the Phono input (I use MM) is noisier than before. Has anyone else had these problems?
Just tested, but not a noise here when I change source.
(12-Oct-2016, 16:49)kerkhoffd Wrote: [ -> ]Just tested, but not a noise here when I change source.
Thank you.