HydrogenAudio

CD-R and Audio Hardware => Audio Hardware => Topic started by: MDeB on 2019-12-18 18:54:43

Title: HDMI to coaxial audio converter
Post by: MDeB on 2019-12-18 18:54:43
Hi, I want to send hi-res (96 or 192) output from my disc player to a DAC (I am only interested in 2.0 LPCM). The DAC has coaxial and Toslink inputs. The player has HDMI output. I want to be able to send the hi-res signal to my DAC.  We are talking about output from a DVD-V, encoded at 24/96, that is not copy protected as far as I know.

Would one of these converters do the trick? Would it do a perfect digital conversion, not altering the signal in any relevant way?

https://www.amazon.com/gp/product/B07KRWYN4R/
https://www.amazon.com/HDMI-Audio-Ex...dp/B07DFDQ6HG/
https://www.monoprice.com/Product?c_...1002&p_id=5557
http://www.ambery.com/au-hdmiarc.html
https://www.amazon.com/avedio-links-...dp/B07T2WSY3D/


I figure I should probably go with coaxial because I have read conflicting things about whether Toslink supports 192 kHz.

Thank you!

Mark
Title: Re: HDMI to coaxial audio converter
Post by: JabbaThePrawn on 2019-12-18 19:13:23
I don't have anything at 192k, or anywhere near, but I use the coaxial output from a HDMI breakout box (like the one in your first link) and it works just fine. Plus I can use the HDMI output to my TV if I need it.
One advantage I found with coaxial over optical is that there was a second or two's delay before the signal "woke up" over the optical output. I may have just been unlucky with the two converters I tried, or it may be a common problem. Coaxial doesn't miss the opening seconds of a track.

Edit: the above was experienced while playing from my laptop. Disc players probably have a permanently "on" optical output, but I haven't owned one in too long to be sure.
Title: Re: HDMI to coaxial audio converter
Post by: bryant on 2019-12-18 19:52:49
I use a unit that looks identical to the one you mention from Ambery (second to last) except that it's missing the coaxial output. I use it to play from a Raspberry Pi to a Teac DAC over Toslink (obviously).

I don't think you have to worry about the digital conversion because there isn't any. Older HDMI interface standards use S/PDIF for the audio on one of the lines, and these boxes are just passing that to the output. The switch on them to control the format (2ch or 5.1) are just telling the HDMI source what audio formats are supported over EDID.
Title: Re: HDMI to coaxial audio converter
Post by: MDeB on 2019-12-19 20:07:57
Thank you JabbaThePrawn and bryant for your kind replies.  I'll check one of these out and, if I learn anything relevant, report back!  Much appreciated.

Mark
Title: Re: HDMI to coaxial audio converter
Post by: MDeB on 2019-12-25 04:15:37
I tried the first item on the list (the one at https://www.amazon.com/gp/product/B07KRWYN4R/) and it converts the 96 kHz signal to 48 kHz (or possibly, though I think less likely, 44.1 kHz) according to my DAC.
Title: Re: HDMI to coaxial audio converter
Post by: tehabe on 2019-12-25 16:27:01
Isn't S/PDIF limited to 48 khz anyway?
Title: Re: HDMI to coaxial audio converter
Post by: Chibisteven on 2019-12-25 17:58:08
Isn't S/PDIF limited to 48 khz anyway?

Depends on the implementation used, there's quite a few of SPDIF implementations in existence that actually support 96 KHz and some that manage to support 192 KHz.  My guess is that HDMI to SPDIF converter is using a SPDIF transmitter that doesn't support it and is quietly downsampling it to 48 KHz before sending it to SPDIF transmitter chip they're using or it's something the manufacturer decided to put in there for some reason.
Title: Re: HDMI to coaxial audio converter
Post by: bryant on 2019-12-25 18:51:20
That one that you got specifically does not mention anything about higher sampling rates, whereas the Ambery one does. Might have not been the best choice if you wanted 96 kHz or higher.

As I mentioned, I believe these devices are very simple and use cheap HDMI receiver ICs that would not support resampling audio; they simply pass it on. In the Amazon case, they may have used a DAC that only goes to 48 kHz and specified in the EDID that 48 kHz is the maximum rate and your disc player is doing the conversion.