HDMI-equipped computers and DACs

[Jacques]

Dear all,

 

This is my first forum posting. I'm not very well versed on the technical aspect of computers and associated DACs, and I'm just dipping my toe into the world of computer audio which I basically discovered through this site. The reason I got hooked into computer audio is that I really care about high-res music for the sound advantage it brings (even in stereo), and I have high hopes that computer audio will succeed in increasing the availability of high-res music where SACD and DVD-A by and large failed. I have already downloaded MediaMonkey and started buying a few downloads (FLAC 16/44 or higher), focusing on stuff only available as downloads.

 

My questions to the forum are the following. Are we likely to see more and more computers equipped with HDMI connectors and proper internal soundcards that take full advantage of them (as this would help consumers at large to use the computer as the native DVD/Blu-Ray player)? And if so, are we likely to see music DACs equipped with HDMI inputs, to replace the USB input? My understanding is that USB inputs, while allowing DACs to be easily connected to computers without the need of external soundcards, often do not allow for the full 24/192 resolution (the Benchmark Pre is an example). Thanks for your help.

 

[audioengr]

You will see 24/192 USB 2.0 interfaces later this year. Has nothing to do with the HDMI connector used for home theater. This connector can be used for I2S interface, but so can other connectors. 24/192 is not supported natively on the PC, so custom S/W drivers will be provided.

 

Steve N.

Empirical Audio

 

[Jacques]

Thanks for the kind answer. Regarding your point that PCs don't support 24/192 natively, does this mean one will need a special sound card to output the 24/192 bitstream via the USB, or that the card will be needed to play 24/192 on the computer? Finally, if one wants to use a computer/outboard DAC as an audiophile source, and using the computer to play Blu-Ray discs (but avoiding mediocre-sounding receivers geared towards video applications), will it be possible to output the audio bistream of a Blu-Ray disc via USB, and the video bistream via HDMI straight to the TV?

 

[BEEMB]

Jacques,

 

More and more PC motherboards are equipped with HDMI outputs, such as the AMG780G based motherboard I have. You'll find a number of graphics cards with HDMI outputs too. The focus until recently has been video related but now we're seeing graphics cards processing (or passing) audio via their HDMI socket such as this: http://ati.amd.com/products/Radeonhd4800/index.html ... so yes, they do already exist.

 

DAC's with HDMI inputs; they do of course exist in the form of home cinema receivers.

Some audio cards are now also supporting Dolby True HD and DTS HD such as the Xonar from Asus: http://www.overclockers.co.uk/showproduct.php?prodid=SC-003-AS&groupid=701&catid=11&subcat=

 

I'm pretty sure it's a dead cert that these cards will happily stream two channel audio to your receiver. What I can't answer is whether or not you're getting bit perfect audio or whether Vista will be playing with your sound. I don't imagine any hifi DAC you'll find within these pages would ever be equipped with an HDMI socket as USB, SPDIF optical/coax and firewire connections all provide enough bandwidth to cope with two channel audio.

 

You can of course take the HDMI connection to a home cinema receiver to benefit from the dolby/DTS HD formats whilst also playing your two channel music through the same amp - it is, after all, just an external amp with a DAC.

 

Thing is though, are cinema amps the best way to playback two channel audio ? probably not. But if you're trying to achieve an all in one package then that would be the way to go I think and some are of course very musical according to the reviews. Arcam receivers are very musical, so I have read.

 

Matt.

 

[Mike19]

Hi Steve -

 

Do you know if Windows XP Home Service Pack 3 upgrades the USB ports from 1.0 (1.1?) to 2.0?

 

Mike M

 

[davidR]

Mike, the differences in USB 1.0 and 2.0 are hardware related. USB 2.0 theoretically has more bandwidth (480Mbps) than 1.0 /1.1 (12Mbps) and most 2.0 devices are backwards compatible with 1.0 ports. Service pack 3 could contain a usb driver update but that's it. Hope this clears things up for you.