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Intrested about I2S format, worth it?

Oukkidoukki

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Hi,

So I have been reading about I2S. It seems to be superior to usb, spdiff etc.. How to do it? Pci-e i2s card to pc-hdmi cable to dac with i2s and thats it? Also, there is usb to i2s boxes, is this worse solution cause data goes thru usb first? Thank you.
 

DonH56

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I wouldn't bother but have not researched or used it much. Originally, IIRC, the idea was separating clock and data signals would yield better data recovery. In practice that is not really needed, and you still have the issue of aligning clock and data. Data transmission standards using the clock recovered from the data are working fine up to many Gb/s; hard to believe standard interfaces are not good enough for audio. The other plus is the ability to synchronize multiple devices from a single master clock, something that doesn't matter in a consumer environment.

To my mind is another serial interface that is not in practice better or worse than many others, and is much less used. The only times I have seen it recently on consumer gear is to connect a disc transport to a DAC when they are in two different boxes. Even then I am not sure the main reason is to be different and use a BNC or some such so it looks more high-end (not RCA, not XLR, not optical, must be really special! :rolleyes:). Clock and data recovery is not that difficult at audio rates (my day job routinely links stuff at 10+ Gb/s) and using an asynchronous interface (like USB) with a dedicated precision low-noise DAC clock means any advantage at the consumer level is nil.

IMO! - Don
 

March Audio

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It's really an "internal" format for connection between components ie input into dac chips. I have used it a fair bit between minidsp dsp boards and dac chips. It will only run over short distances and you won't gain any advantage over properly implemented USB. Just more wires, more signals and more complication. A scope needed to debug when it doesn't work.
 

Kal Rubinson

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The other plus is the ability to synchronize multiple devices from a single master clock, something that doesn't matter in a consumer environment.
S/PDIF can do this.

To my mind is another serial interface that is not in practice better or worse than many others, and is much less used.
Agreed. I put a lot of work into this a long time ago but, in the end, it was not worth the effort.
 

Jinjuku

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I2S is meant for silicon to silicon, PCB traces, on a PCB board. It's not meant for anything other than that. Most audiophiles refuse to accept this reality.
 

DonH56

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I2S is meant for silicon to silicon, PCB traces, on a PCB board. It's not meant for anything other than that. Most audiophiles refuse to accept this reality.

You may be thinking of SPI? Not the same thing as I2S (which is not anything like I2C).
 

March Audio

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You may be thinking of SPI? Not the same thing as I2S (which is not anything like I2C).

Its my understanding its intended as just an inter IC link. That isn't limited to PCB tracks of course, could be on a ribbon cable or other cable. Although obviously it has been bastardised by some into an external link.


Philips Semiconductors
I2S bus specification
1February 1986 Revised: June 5, 1996
1.0 INTRODUCTION Many digital audio systems are being introduced into the consumer audio market, including compact disc, digital audio tape, digital sound processors, and digital TV-sound. The digital audio signals in these systems are being processed by a number of (V)LSI ICs, such as: • A/D and D/A converters; • digital signal processors; • error correction for compact disc and digital recording; • digital filters; • digital input/output interfaces.
Standardized communication structures are vital for both the equipment and the IC manufacturer, because they increase system flexibility. To this end, we have developed the inter-IC sound (I2S) bus – a serial link especially for digital audio.
 
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solderdude

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Paul is correct right up to the point where he states that when unraveling SPdif to I2S again creates 'damage'.
The SPdif signal is put into a circuit that is also clocked and the 'timing' is corrected at the first clock cycle in that chip again so the signal is 'pulled apart' just as good as if I2S would be used directly.
The same 'damage' is done to a digital signal when the signal flows through 4 separate wires as when going through 1 wire assuming the same type of wiring is used.

As Paul cannot back this up with measurements showing the differences between recovered I2S and transmitted I2S he resorts to the ever popular.. 'sounds much better' which does not need clarification because of 'our ears are much better analyzers'.
 
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March Audio

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Indeed, few (although there are some) DACs have problems these days recovering jitter free signals from SPDIF.

"Sounds much better" until the moment you put some controls on the listening test........

In any case just use USB and problem solved ;)
 

Jinjuku

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Paul is correct right up to the point where he states that when unraveling SPdif to I2S again creates 'damage'

This is the schiit that Paul pulls again and again and again that I can't stomach. It's the worst because he either does, or he should, know better.
 

Xulonn

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Cayin (Spark Electronics, China) has been making top-notch tube audio gear for years, and it seems that they are moving slowly into modern digital audio. They have manufactured excellent DAPs for some time now, and I own a Cayin N3 DAP and really like it - an excellent value for $150. (Cayin tube gear was high on my desirability list until I recently managed to focus my aspirations on greener, more efficient digital music storage and playback gear.)

This evening, I stumbled across the $800 Cayin iDAP-6 "digital transport," which I noticed has an I2S HDMI output port. [LINK]

The Cayin iDAP-6 web page is beautifully designed, and contains fairly detailed information on the technologies and standards that they support, including the useful statement that "the implementation of I2S is not an industrial standard, we cannot guarantee compatible [sic] with other I2S device." I think that webpage is one of the best examples of an attractive presentation of consumer audio technical information that I have ever seen.

iDAP-6 Digital Transport:
  • Desktop network player that can supports all common digital file formats: DFF, DSF, SACD-ISO, FLAC, ALAC, WAV, APE
  • PCM supports up to 32Bit/384kHz, DSD supports upto DSD256 with I2S, upto DoP128 with USB and DoP64 on other digital interface
  • Comprehensive digital output options: USB, I2S, AES/EBU, Coaxial, Optical.
  • Support file sharing through Ethernet or WiFi connection, can communicate with large variety of networked devices through Samba, DLNA and Airplay
  • Can plug in SD card (up to 256GB) and USB storage (upto 2TB) directly
  • Transmit or receive through dual Bluetooth v4.1, support Bluetooth remote control profile.
  • Multi-lingua custom designed UI through 3.95” AMOLED screen, display Album Art, music information and control menu in a clear and effective presentation.
[/QUOTE
  • 0841568320.png
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