Navigating the depths of digital ignorance calls for a strong submarine.
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?
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@2psyop Thanks to you, I am enjoying Paul McGowan on YouTube. Straight to the point and authoritative. I particularly like his comparison between DSD and PCM - probably because his assessment and mine agree! My understanding is that I2S is a two-channel Pulse Code Modulated interface designed by Philips to connect integrated circuits on a board, and dates way back to 1986. There is no agreed cabling standard. For those who believe that USB covers a lot of audio standards, here is an extract from Wikipedia on HDMI audio: "If an HDMI device has audio, it is required to implement the baseline format: stereo (uncompressed) PCM. Other formats are optional, with HDMI allowing up to 8 channels of uncompressed audio at sample sizes of 16 bits, 20 bits, or 24 bits, with sample rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, or 192 kHz.[5]: §7 HDMI also carries any IEC 61937-compliant compressed audio stream, such as Dolby Digital and DTS, and up to 8 channels of one-bit DSD audio (used on Super Audio CDs) at rates up to four times that of Super Audio CD.[5]: §7 With version 1.3, HDMI allows lossless compressed audio streams Dolby TrueHD and DTS-HD Master Audio.[5]: §7 " I'd just add that Dolby Atmos is supported, with up to 32 channels. There is a licencing cost for HDMI which may put smaller manufacturers off using it. There is also great confusion over the theoretical capabilities each version of HDMI specifies, and the actual capabilities that are implemented by the component manufacturer. They are supposed to list the actual capabilities, which as @devinplombier says, plumbs "the depths of digital igorance" for consumers |
@2psyop how audio file is different from Excel spreadsheet. What is special in 'audio' bit packets over Internet. |
@2psyop the only thing Paul McGowan doesn't say is that I2S was never designed to be transmitted over a cable from one component to another. |
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