Hdmi v. Usb

[Ghardy]

Checking the knowledge base here regarding hdmi as a digital source. Given that many computers have hdmi out ( I.e Mac mini). I realize that few standalone dac have hdmi in. Meridian being one through the hd621. I guess statement av receivers from denon and the like would also allow. Thanks.

 

[Quest]

you have answered your own question. hdmi is mainly used for multi channel applications and usually confined to AV processors.

 

there are very few stereo products that take in hdmi.. i think devialet d-premier will be one of them soon.

 

[Ghardy]

Thanks for the replies. I guess the question is why not hdmi for stereo? Does hdmi have greater jitter problems?

 

[minzyman]

I've always wondered why HDMI isn't more prevalent as an input for dacs. Correct me if I am wrong, but HDMI has enough bandwidth for 8 channels plus in 24/192? Why hasn't this standard been adopted over usb or fW?

 

Just curious.

/LM

 

[RobbieC]

There was some discussion in another thread (Berkeley Audio Design Announces the Alpha USB Asynchronous Interface) on both the suitability of HDMI for computer audio and the amount of jitter inherent over HDMI compared to S/PDIF, which is known to have lots of jitter.

 

The experts here on CA claim that HDMI has jitter about an order of magnitude greater than that of an average S/PDIF implementation. The HDMI 1.3a specification, however, apparently added Audio Rate Control that acts exactly like asynchronous USB to minimize jitter, but it hasn't really been implemented by many manufacturers. Notable exceptions include Sony (proprietary), Pioneer (proprietary), and Ayre with their player (open format).

 

Hope that helps.

 

[minzyman]

Thanks Rob. I was curious as to why this specification hasn't taken off with 2 channel audio. That make sense.

 

 

 

[Audio_ELF]

I'm not sure if you were meaning that it was, but the Meridian 621 is not a DAC. All it does is strips multiple-channel audio from a HDMI signal so that it can be sent (digitally) to a Meridian processor (568.2MM; 861v4 or v6; G68 or G61). Meridian feel that feeding the HDMI signal directly into the processor will cause signal degradation so strip it off to 3 SPDIF (or Meridian's proprietory 8 channel equivolent) signals.

 

Eloise

 

[Ghardy]

Thank you to everyone that joined the discussion. I am trying to get a better understanding of the pros and cons of HDMI as a computer to dac transport. I have been considering the Meridian HD621 for my meridian kit. On paper outputting your digital data via HDMI to the Meridian HD621 with its FIFO buffers and apodizing would seem a better way to skin the cat than than USB. However, in real world some report better results from a USB converter (H.Bidge etc). Probably for the reasons explained by Rob. ANd, given what a pain HDMI is with its ever changing upgrades (not that USB is any different), can not blame anyone from wanting to stay away from HDMI when possible.

But, -- HDMI can be run asynchronous, then I will have to research what it would take to get asynchronous data out on a Mac via HDMI.

 

[bleedink]

Let me clarify that first. However, I thought I would chime in as I am one of the few people on here using HDMI instead of more traditional audiophile cables. I have heard the claims about SQ degradation and it is entirely possible that my mid-fi (perhaps even budget) system is not revealing enough for me to hear the difference. However in my modest 1300 dollar receiver I cannot discern any difference between S/PDIF and HDMI through B and W's. Do note however that I can readily discern in most cases (as my system is sufficiently decent to reveal the differences) Red book from High Rez, and can audibly hear a huge difference between various players. I don't think I would be able to hear those differences were my system not 'good enough'. So it is some food for thought. I have auditioned quite a few amps and speaker set ups out of the range of my budget and to be honest I did not hear enough difference to justify the extra 0's. I also use an HT Receiver which is also sorta approaching heresy on sites like this. However, I enjoy music a great deal and I actively listen to music at least an hour a day doing nothing else. Therefore I consider myself an audiophile, though some may argue phool as well! My sincere advice if you are able is to audition any solution you are looking at. You may well be surprised at how good some of this equipment does sound, even over HDMI. My Oppo sounds flawless over HDMI. The Mac Mini...well, not so much without the right player. My point is, I can't readily hear the difference, but can hear some difference between varying resolutions and bit rates. YMMV of course.

 

[Ghardy]

Thanks Good to hear from a HDMI user. The tech papers I have read on or should I say criticizing HDMI focus on the problem of running your video and audio at the same time on the same cable. Hence, why Meridian will not instal HDMI into their pre-pro, but uses an external adaptor. Just not much info on HDMI audio only, though I do want to see if I can find the writeup mentioned before by berkley audio on the subject.

 

You touch on a great point regarding the mac mini. The "problem" may not be with the HDMI but rather with how the mac uses the HDMI. Do you run usb from mac to receiver?

 

 

 

[bleedink]

I don't run usb from my mac to my receiver. I've based my entire system around HDMI since I built it last year. I personally am quite satisfied with the sound of my receiver. It seems to be every bit as revealing as the recording in question. If the recording sucks, it sucks over hdmi just as much as it sucks over s/pdif. I have not done a lot of research into the whole debate. I just trust my ears. I know that the hdmi implementation on my old pioneer 1019 was not that great. I got rid of the receiver after about 6 months. I could not be more pleased with my Yamaha. It has separate DACs for each channel and I have not yet heard anything that would make me invest more into it by bypassing its internals. I have no doubts an external DAC would probably make it sound even better. However, after sinking about 7-8 grand into my home entertainment I have reached the upper limits of my budget and am firmly at the point where I see diminishing returns. I personally enjoy the flexibility of HDMI and since in systems like the Oppo you can off load the audio and video out different HDMI cables I just don't see the argument that the video signal (which isn't present in the Oppo) degrades the sound. I'm not saying it doesn't, I just have not heard it with my own ears. Regarding the Mini, their implementation seems to be rather good to me. I have used both JRiver in boot camp and players like audionirvana and they are both a huge improvement over the native versions on respective OS's. So it would seem that there isn't that much of an issue in the implementation of the HDMI per se but there are definitely undesirable parts of the OS that seem to interfere with the audio signal no matter what cable you use. And they seem to be eliminated by software that delivers audio in a more precise manner, thus I don't believe it is anything specific to HDMI or that there is something more inherently wrong with it as opposed to other methods of delivering the 0's and 1's. Actually I should say there do seem to be better models of delivering said bits, I personally find HDMI to work well for my purposes. (Big city, small room/apt dwellings.)