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?

128x128richardbrand

It depends on the manufacturer in my experience. I have a Holo Audio Cyan 2 DAC.  It has multiple inputs.  Holo makes a Red streamer which connects through i2S which is tailored to connect between the two units.  I didn’t like the Red and the apps I needed to use.  I went with a Innuos Zen Mk3 streamer instead which only connects using USB.  It sounds excellent in my system.  Would i2S sound better- possibly if I could even tell the difference with my old guy ears.  I love the Sense app that Innuos uses, even better than the BluOs app which was my previous favorite.  I only use HDMI connections with my TVs.  So many connections and so many different cables.   Pick what sounds good to you in your system.  

@vinylshadow - Toslink, whether glass or some kind of plastic, is THE worst thing to use for audio connections. It's been slagged off for decades, since it was first used for audio in fact, for having terrible sound quality. Obviously opinions will vary, but it totally depends of the resolution of the system - if you have a poor/low quality system, it probably sounds OK.

@daveteauk  I guess so....I was going off the P-Link glass optical cable that Playback Designs uses to connect their streamer to their DAC. That cannot be beat by any cable. 

I would like to find an HDMI splitter, that I can use to feed audio into my dac and have the simultaneous video be fed into my av processor. I’d like to be able to bypass the dac in my processor and maybe I can get it to sound better.

Although, maybe it won’t sound better because my processor is very good. Would love the flexibility to pursue other dac options.