korben_dallas
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Gordon,
Have you achieved bit-perfect playback with Vista? If so, what was your setup?
Have you achieved bit-perfect playback with Vista? If so, what was your setup?
Originally Posted by korben_dallas /img/forum/go_quote.gif Gordon, Have you achieved bit-perfect playback with Vista? If so, what was your setup? |
I don't believe there have been any changes in this regard, but the driver will try to select formats in the following order the first time a device is attached to a particular port on a system: 1. 2-channel 16-bit @ 44.1kHz 2. 1-channel 16-bit @ 44.1kHz 3. 2-channel 16-bit @ highest supported sample rate 4. 1-channel 16-bit @ highest supported sample rate 5. alternate setting 1 @ highest supported sample rate If the device doesn't do 16 bit, the correct behavior is probably 24-bit at the highest supported sample rate. After changing the sample rate, channel count or bit depth, the Mac should remember the last setting if you plug it back into the same USB port. One last thing: 10.4.11 and Leopard have the same version of the USB audio driver. |
Originally Posted by Wavelength /img/forum/go_quote.gif KD, Actually as Thomas has indicated in several posts now this is easy to do. Much easier and more assured than XP ever would and also applications where kernel streaming and ASIO were not supported via Direct Sound (iTunes, WMP, etc) can achieve this. It does require a 24 bit dac and setting that option in the device panel. At that point 16 bit audio will cruise through uninterrupted. I tried this out with J River, iTunes and Media Player. Results were much better. Thanks Gordon |
Originally Posted by thomaspf /img/forum/go_quote.gif Vista is not truly bit transparent except that you can pass through a 16 bit stream inside a 24 bit stream as described. Thomas |
Originally Posted by FRANKe /img/forum/go_quote.gif Thomas, is this a general "blanket" statement, or are you specifically referring to the Benchmark DAC and the use of "shared mode" (with iTunes & WMP)? With Vista's "exclusive mode" is it not "truly bit transparent"? FWIW, I believe XXHighEnd is the only media player right now utilizing "exclusive mode". XXHighEnd - Index It would be interesting to see the results of these bit transparent tests done with XXHighEnd. And BTW, it has been reported that XXHighEnd will not lock onto "exclusive mode" with the Benchmark DAC presumably because the DAC is "reporting" as 24bit and at the moment XXHighEnd does not output 24bit. Benchmark DAC1 USB |
Originally Posted by Wavelength /img/forum/go_quote.gif Gang, Elias; I had a long banter with Apple yesterday in regards to the 7.5 stuff... "I don't believe there have been any changes in this regard, but the driver will try to select formats in the following order the first time a device is attached to a particular port on a system: 1. 2-channel 16-bit @ 44.1kHz 2. 1-channel 16-bit @ 44.1kHz 3. 2-channel 16-bit @ highest supported sample rate 4. 1-channel 16-bit @ highest supported sample rate 5. alternate setting 1 @ highest supported sample rate If the device doesn't do 16 bit, the correct behavior is probably 24-bit at the highest supported sample rate. After changing the sample rate, channel count or bit depth, the Mac should remember the last setting if you plug it back into the same USB port. One last thing: 10.4.11 and Leopard have the same version of the USB audio driver." ...So really nothing has changed here and why this came up seems to be a question. |
On the Mac, the OS (i.e. CoreAudio) mixes all of the audio into one stream which it then hands to the hardware. In order for this to work, all of the audio streams must be mixed at the current sample rate of the hw. So, *somebody* has to do SRC and it can either be the app or CoreAudio doing it for you. Pre iTunes 7.0, we let CoreAudio do it. Post-7.0, we do it. One caveat is that iTunes doesn't notice if the user changes the hw sample rate *after* it launches -- It captures it at launch time and leaves it that way. It's certainly possible that these people didn't figure that out, so changing the hw rate after we launch means we'll sometimes be doing SRC *and* CoreAudio might be doing SRC at the same time. For example: 1) At launch, the hw sample rate is 48kHz. We set up our processing chain to run at 48kHz. 2) You play a 44.1kHz file. We do SRC to 48kHz and hand the data to CoreAudio who send it along to the device. 3) You change the hw sample rate to 44.1kHz while we're running. 4) You play the same 44.1kHz file. We now do SRC to 48kHz and give the data to CoreAudio who does SRC back to 44.1kHz! |
Originally Posted by thomaspf /img/forum/go_quote.gif And just to be extra clear about this to avoid any more drawn out discussions with the marketing folks from Benchmark... Cheers Thomas |
Originally Posted by thomaspf Benchmark has been claiming for a while now that by changing the USB firmware in their DAC, they can get the USB audio driver in Windows to produce bit perfect results for applications like foobar as described on their WEB site. I have tried to correct that statement from the beginning since there is nothing any USB device can do to achieve that with applications using WAV or DirectSound APIs using the usbaudio driver in Windows. |
Originally Posted by thomaspf /img/forum/go_quote.gif No blanket statements from me in general... |
Originally Posted by tuffgong /img/forum/go_quote.gif ...how can I split the xlr signal coming out the back of the dac1 so I can get four signals to amplify without messing up the line levels like a normal guitar center splitter. Thanks in advance. |
Originally Posted by Wavelength /img/forum/go_quote.gif Elias, ThomasPF is with Microsoft! He tested your DAC1 USB at Microsoft. ~~~ Look neither of us are your enemies... I don't see you as a competitors and have been trying to help you out here as Thomas has. The only thing we are saying as is most of the rest of the Windows team is that it is impossible to get bit perfect audio without bypassing the KMIXER. That is an easy thing to do and I am sure your insrtuctions for doing that will make it capable of bit perfect resolution. If you follow Thomas's instructions for Vista there too you will get audio nirvana. ~~~~~~~~~ You may want to pick up a Prism dScope III for testing then you can easily see what is and is not working. Since it has native mode it can stream kernel, DirectSound and via drivers and you can quickly see what's bit perfect or not. ~~~~~~~~~ Heck next time we are in your area I say let's have some dinner and drinks at my fav restaurant the Dinosuar (my wife is from Manilus). Thanks Gordon |