HDMI to S/PDIF Digital Audio Adapter

Posted by: Silence Kills on 26 March 2016

Hi, I need an HDMI (preferably 2.0 to be future proof) HDMI Adapter that let pass HDMI through (1:1) but does also habe a S/PDIF output (Coax and/or Optical).

I just got an AppleTV 4, but want to connect the Audio to my Naim digital audio input. As the new Apple TV 4 only have HDMI out, I need an adapter.

But most of the China boxes look cheap and I don't have much confidence that they will do a good job. Does anyone have experiences with a box that is doing a good job in seperating the Audio signal but also pass through the HDMI (video and audio) to my TV at the same time in good quality?

Posted on: 26 March 2016 by CharlieP

Until you find the adapter, I assume you could use the TV as an adapter - presumably it has an coax or Toslink digital out. Of course, this might entail use of an additional remote, as well as raise quality issues.

The AppleTV is not the last word in sound quality. If I recall, it uses 48Khz sample rate - thus most audio will be up sampled or down sampled and not be bit perfect.

Charlie

Posted on: 27 March 2016 by feeling_zen

It's not that simple. HDMI provides packetised data wheras SPDIF is a stream. Any device will need to be active since processing is required to do this conversion.

The suggestion to use the TV is a good one. Some AV amps may also be capable of providing a digital out, though most TVs make downmixing surround feeds to LPCM stereo much simpler.

Posted on: 27 March 2016 by Aleg

Something like this from Octava is meant for these kind of situations

https://www.octavainc.com/HDMI...er-EDID-Manager.html

Posted on: 01 April 2016 by Simon-in-Suffolk

feeling_zen posted:
It's not that simple. HDMI provides packetised data wheras SPDIF is a stream. Any device will need to be active since processing is required to do this conversion.

Its not that complicated though as both formats provide streams of audio frames within their respective transport constructs. Although HDMI refers to simple audio stream frames as 'packets' within the 'data island' - it is a framed transport stream just like SPDIF uses a framed transport stream. One observation that HDMI basic stereo audio in lossless PCM is only specced upto 48kHz and upto 192kHz as a single channel.

So HDMI and SPDIF are quite similar in that sense as the receivers in both need to process the transport streams so as to recover the sample data from the transport frames.

Simon

Posted on: 01 April 2016 by winkyincanada

CharlieP posted:
Until you find the adapter, I assume you could use the TV as an adapter - presumably it has an coax or Toslink digital out. Of course, this might entail use of an additional remote, as well as raise quality issues.
The AppleTV is not the last word in sound quality. If I recall, it uses 48Khz sample rate - thus most audio will be up sampled or down sampled and not be bit perfect.
Charlie

Using the TV has the added advantage that audio/video sync issues are likely taken care of. For all video, we run the audio via the TV then to the SN. It also means that there is only one "video sound" input used on the SN.