05-19-2018, 08:16 PM
(Modification du message : 05-19-2018, 08:55 PM par a supprimer merci.)
Concernant l'utilisation de portables (ou disons d'ordinateurs du marché, non "audiophiles") versus des solutions "audiophiles", les essais effectués par Rob Watts (ingénieur chez Chord) avec des forumeurs de Head-Fi sont assez intéressants. Ces tests ont été effectués en aveugle. Voiri ici un compte rendu:
https://www.head-fi.org/threads/chord-el...t-14103674
En conclusion, l'avis de Rob Watts est le suivant:
"To be fair to Romaz, the high-end server had better tonal balance within the context of the system; the battery lap-top was a touch too dark. My view is that it would be better to brighten up the system in other ways... Also, I know what RF sounds like, and to me it sticks out like a sore thumb. That said, the depth improvement was very easy to hear - but both Romaz and Jay was struggling to hear it (eventually they got it) - I have spent way to many hours listening to subtle changes in depth, and am extremely well trained in it. I do not have magic ears, as some things they could hear, and I couldn't - but I am hypersensitive about depth, and can spot the effects of RF noise a mile off...."
"I guess it depends what you mean by a server sounding better; my experience is that they sound brighter, with the illusion of better transparency; classic hallmarks of RF noise generation"
"...But what we are talking about here is the very specific instance of bit perfect data being delivered to one of my DAC's via USB - and here there is only one mechanism that can possibly alter the sound - and that is RF noise injected into Dave and the rest of one's system. Jitter has absolutely no measured or subjective influence on my DAC's; it's bit perfect data, so the data has no consequence; the only thing that can possibly modify SQ is RF noise, which for sure changes the SQ (I have measured it many times and correlated it to SQ) by generating noise floor modulation. And increased noise floor modulation sounds brighter, and can easily be confused with improved transparency."
"The curious thing is even extremely low levels of noise floor modulation is audible - I have seen (measured by simulation) noise floor modulation at -200 dB being audible - a level which you can simulate for, but would never be able to actually measure."
Pour revenir sur les mesures de bruit, le Levono X201 donne un bruit inferieur à 10 micro volts sur la sortie USB, ce qui est similaire à ce qui est mesuré sur l'USBridge. Sur le site "AudioSicenceReview", des mesures ont été faites sur le microRendu.
- mauvaises mesures avec l'alimentation iFi Power
- bonnes mesures avec l'alimentation SBooster (qui est d'ailleurs maintenant recommandée par Sonore..).
Leur conclusion est que le sonore ne fait rien pour améliorer le niveau de bruit qui dépend fortemment de l'alimentation...
Voici le lien, ou ils decortiquent le Sonore: https://www.audiosciencereview.com/forum...eview.770/
Sur le même site, les mesures faites sur le sotm Sms-200. Mêmes conclusions que pour le Rendu.
https://www.audiosciencereview.com/forum...ayer.1846/
Et sous le capot: https://www.audiosciencereview.com/forum...ures.1855/
https://www.head-fi.org/threads/chord-el...t-14103674
En conclusion, l'avis de Rob Watts est le suivant:
"To be fair to Romaz, the high-end server had better tonal balance within the context of the system; the battery lap-top was a touch too dark. My view is that it would be better to brighten up the system in other ways... Also, I know what RF sounds like, and to me it sticks out like a sore thumb. That said, the depth improvement was very easy to hear - but both Romaz and Jay was struggling to hear it (eventually they got it) - I have spent way to many hours listening to subtle changes in depth, and am extremely well trained in it. I do not have magic ears, as some things they could hear, and I couldn't - but I am hypersensitive about depth, and can spot the effects of RF noise a mile off...."
"I guess it depends what you mean by a server sounding better; my experience is that they sound brighter, with the illusion of better transparency; classic hallmarks of RF noise generation"
"...But what we are talking about here is the very specific instance of bit perfect data being delivered to one of my DAC's via USB - and here there is only one mechanism that can possibly alter the sound - and that is RF noise injected into Dave and the rest of one's system. Jitter has absolutely no measured or subjective influence on my DAC's; it's bit perfect data, so the data has no consequence; the only thing that can possibly modify SQ is RF noise, which for sure changes the SQ (I have measured it many times and correlated it to SQ) by generating noise floor modulation. And increased noise floor modulation sounds brighter, and can easily be confused with improved transparency."
"The curious thing is even extremely low levels of noise floor modulation is audible - I have seen (measured by simulation) noise floor modulation at -200 dB being audible - a level which you can simulate for, but would never be able to actually measure."
Pour revenir sur les mesures de bruit, le Levono X201 donne un bruit inferieur à 10 micro volts sur la sortie USB, ce qui est similaire à ce qui est mesuré sur l'USBridge. Sur le site "AudioSicenceReview", des mesures ont été faites sur le microRendu.
- mauvaises mesures avec l'alimentation iFi Power
- bonnes mesures avec l'alimentation SBooster (qui est d'ailleurs maintenant recommandée par Sonore..).
Leur conclusion est que le sonore ne fait rien pour améliorer le niveau de bruit qui dépend fortemment de l'alimentation...
Voici le lien, ou ils decortiquent le Sonore: https://www.audiosciencereview.com/forum...eview.770/
Sur le même site, les mesures faites sur le sotm Sms-200. Mêmes conclusions que pour le Rendu.
https://www.audiosciencereview.com/forum...ayer.1846/
Et sous le capot: https://www.audiosciencereview.com/forum...ures.1855/
