advantages using HDMI vs USB

[gellie]

What are the advantages over using HDMI vs USB. Currently feeding my Oppo 105 into a Roon Nucleus. I've been getting some drops when playing 192/24 files via HDMI. 96/24 files are fine. Did not notice the same when using USB. What will I being missing out on if I switch back to USB? I really dont have many 192/24 albums.

[marioed]

Hi Gellie,

As far as I know the the advantage of using HDMI vs USB is that HDMI can carry multi-channel music which I don't think usb can for most dacs. If usb performs better and doesn't sound any worse, unless you're doing multi-channel, I don't think you'll be missing anything by using usb.

Regards,

Mario    

[barrows]

None, HDMI sucks big time for audio.  Do a search...

[Kal Rubinson]

3 hours ago, marioed said:

As far as I know the the advantage of using HDMI vs USB is that HDMI can carry multi-channel music which I don't think usb can for most dacs.

USB carries multichannel music just fine with any multichannel USB DAC I know of.  This is not an issue at all.

[pkane2001]

On 2/18/2020 at 9:10 AM, gellie said:

What are the advantages over using HDMI vs USB. Currently feeding my Oppo 105 into a Roon Nucleus. I've been getting some drops when playing 192/24 files via HDMI. 96/24 files are fine. Did not notice the same when using USB. What will I being missing out on if I switch back to USB? I really dont have many 192/24 albums.

 

HDMI audio timing is usually derived from the video clock, which results in timing errors/increased jitter. USB being an asynchronous protocol has no such issues. And yes, USB works just fine for multi-channel audio.

 

[gellie]

Thanks all. Using USB and have had ZERO drops playing 192/24 files. . I think HDMI has way to many "handshake issues". Especially on my Oppo 105. Which is also connected to my Marantz SR7005.

[marioed]

1 hour ago, Kal Rubinson said:

USB carries multichannel music just fine with any multichannel USB DAC I know of.  This is not an issue at all.

 

1 hour ago, pkane2001 said:

 

HDMI audio timing is usually derived from the video clock, which results in timing errors/increased jitter. USB being an asynchronous protocol has no such issues. And yes, USB works just fine for multi-channel audio.

 

Hi Kal & Paul,

Thanks for the correction. I knew that usb could do multi-channel into multi-channel dacs, I should have included that in my reply.

Regards,

Mario 

[Kal Rubinson]

3 hours ago, gellie said:

Thanks all. Using USB and have had ZERO drops playing 192/24 files. . I think HDMI has way to many "handshake issues". Especially on my Oppo 105. Which is also connected to my Marantz SR7005.

Let's up the ante.  I can play 6 channel DSD256 and PCM 24/352.8 over USB without any problems.

[gellie]

Defiantly impressive. Unfortunately I dont have any multichannel files downloaded. Only physical media for that(DVD-A, SACD) etc

[barrows]

2 minutes ago, gellie said:

Defiantly impressive. Unfortunately I dont have any multichannel files downloaded. Only physical media for that(DVD-A, SACD) etc

Those can be ripped.

[Ryan Berry]

As other said, HDMI's definitely tends to be ugly for audio.  We had to do a lot of work to strip the signal down to just the audio signals, add a dedicated clock, split the HDMI off the video power supply, etc. on the DX-5 when we designed it just to get the HDMI to a respectable level.  Even then, it wasn't a method of exporting audio that we preferred, but it was a lot better than using the normal video HDMI out that the original Oppo player had.

[barrows]

For DVD playing, I tend to use the optical out into my little Chord Mojo.  With a full battery charge this little thing does a fairly good job, I believe it does some kind of re-clocking (maybe even async) on its SPDIF inputs.  But I am no big video guy anyway, and my TV is in the bedroom, not in the living room where my "real" audio system is; I believe in sharing music playback with everyone!

[yamamoto2002]

On locally stored video file playback, if PC sends video and audio using HDMI, its image sequence and audio will be sent completely synchronized manner. also HDMI automatic lip sync function may work.

 

If video is sent to HDMI and audio is sent to asynchronous USB DAC, there are two free-running clocks in the system: GPU RAMDAC clock and USB clock, and two clocks does not synchronized at all. In this situation, which clock becomes master is depend to video playback app implementation.

 

I checked Microsoft media player on Windows 7 and found async USB DAC clock becomes master of movie file playback and audio data sent to USB DAC is bit-perfect while video frame may be skipped intermittently.

 

Another app implementation possibility is, audio data is filtered using asynchronous sample rate converter (such as IAudioClockAdjustment) to match to video clock timings, on this route, all video frame is sent correctly but audio data becomes not bit-perfect.

 

[barrows]

On my MacBook Pro, there is no USB audio output possible when playing video, OSX does not allow that.  I use the optical output, which of course is governed by the internal (to the laptop) clock).  Looks like OSX developers are aware of possible sync/timimng issues using USB audio with video playback.