CM-108 Driver v.220.127.116.119
Originally Posted by erin
Slim, a question for you:
Where did you read that the CM108 only gives 14 bits of resolution?
I would like to read up on that.
I read about the cmedia drivers here : Homebrew CMI 8738 drivers - Hydrogenaudio Forums
By the way, when I chose to uninstall the CMedia drivers the first time I tried them it was based only on my subjective listening. You can read my comment about them here : http://www.head-fi.org/forums/f7/rev...ml#post6042974
Also, since I was in a curious mood today, I did some RMAA measurements this morning for both the generic/stock driver of the Teralink and the CM-108 Driver v.18.104.22.1689.
I put the results in a Zip file if anyone is intersted in them.
First, how did I test it ? I used to the EMU 0404 usb to record the output of my audio-gd dac-100 using the Teralink as a transport.
Since I have tested the EMU with a SNR of 113 db (the SNR drops to 96 db when tested in 16bits which is to be expected) and since the audio-gd dac-100 has a SNR over 100db, if anything is done wrong in the digital domain it would show in the analog stage. If data is lost somewhere in the path it cannot be retrieved.
For what is it worth, my findings are as follow :
The generic windows drivers do not seem to mess with the data.
The CM-108 Driver v.22.214.171.1249 seem to have trouble outputting correctly 16/44 without messing with the data. The SNR is worse by a 4 (and up to 6db) compared to the best results I had with the generic windows drivers.
To my surprise, the 24/96 test with the CM-108 Driver v.126.96.36.1999 drivers improved the results in SNR over 16/44. However the drivers are limited to 48khz. There is a cut-off at 48 khz.
After trying 24/48 and 24/44 I concluded that the benefits comes from going to 24 bits rather than from "upsampling" to 96.
I read in the Valab thread people linking the 24/96 upsampling with the CM-108 drivers. Since I don't own a NOS DAC, I cannot comment on that. All I know is that there is a real loss in transparency using the CM-108 drivers in my system. I understand however that some people might like the "sonic signature" of the CM-108 drivers, but it is not the most accurate driver in my opinion.