2. tech-talk
  3. 192105-196045

Why does USB feature so much in discussions about DACs when the newer HDMI seems better?

I am a bit confused about the frequent mention of USB in the context of stand-alone Digital to Analog Converters (DAC).  Why is HDMI left out?  Is this a US versus Europe / Asia thing?

The Universal Serial Bus (USB) was introduced in 1996 by a group of computer manufacturers primarily to support plug-and-play for peripherals like keyboards and printers.  It has only two signal wires, plus two wires that can supply DC power.

The High-Definition Multimedia Interface (HDMI) was specifically designed by a group of television manufacturers for transmitting digital audio and video in many formats.  It hit the shops around 2004.  There are 19 pins supporting four shielded twisted pairs, and seven other wires (3 of which can instead form a shielded twisted pair for Ethernet).

I have three universal disk players from Sony, Panasonic and Reavon, which all have two HDMI outputs, one can be dedicated to audio only, the other carries video or video plus audio.  (Only the Panasonic does not support SACD).  My Marantz AV 8802 pre-processor has 11 HDMI connections and only two USBs.

Of course, both USB and HDMI continue to evolve.  Then there is the Media-Oriented System Transport (MOST) bus designed by the automotive industry, which looks even better.

Why is it so?

richardbrand
vthokie83
1,018 posts
 

richardbrand

That's true, I did not....and I do understand your point. I'm not an electrical engineer (I'm mechanical) nor a builder of audiophile equipment. I was responding to the various USB/I2S/SPDIF/Toslink posts in between, and reflecting on my own personal experience with my system

richardbrand's avatar
richardbrand OP
416 posts
 

@vthokie83 

No worries!  When I started this thread, I was mystified why USB was so prevalent when there is a purpose designed, point-to-point solution for high-bandwidth multi-channel audio in the form of HDMI, which is ubiquitous in modern TVs and Audio Visual gear.  I never expected anybody to mention 'legacy' formats like SPDIF or Toslink  and I had never even heard of I2S.  It seems that the inventor of extending I2S over cable is only interested in 2-channel audio.

I remember the fuss that arose over the introduction of 2-channel stereo when mono had been the only option.  It was going to practically double the cost of HiFi for goodness sake.  Now I am wondering if there is a similar reluctance to move to multi-channel audio, for a similar reason.  Multi-channel high-definition audio has been available on SACD for over 25 years now.

For what it is worth, I have an 8.1 system with no center channel.  The main front speakers are better quality than the rest!  Generally, the rear speakers carry ambient sounds from SACD but some recordings on Blu-ray have Atmos and use all my speakers for truly immersive sound.

Oh, that recommendation to keep HDMI cables short only applies when they are not carrying native HDMI signals!

lordmelton's avatar
lordmelton
942 posts
 

@richardbrand 

You're a total knob jockey, go back to ASR

richardbrand's avatar
richardbrand OP
416 posts
 

@lordmelton 

You're a total knob jockey, go back to ASR

Thank you for your thoughtful contribution.  Maybe you could muster a specific technical issue to debate?  But normally, folk that can only attack the person are unable to rise to that level.

2psyop's avatar
2psyop
1,786 posts
 

Many historically early electronics included USB because it was cheap. Unfortunately many audiophiles got hooked and believe mistakingly that it is a good  way to connect a DAC. It is not. I2S came along in quality devices and before that HDMI. Both are superior for audio. But for those who disagree… fine. You use the connection you like or have. Many people use computers for their source and connection through USB to their audio system. I don’t knock anyone’s setup. If it sounds fine…. there isn’t something to fix.

More to discover