• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

HDMI to IIS/Coax DoP Converter

Rate this HDMI Extractor/Converter

  • 1. Poor (headless panther)

    Votes: 54 56.3%
  • 2. Not terrible (postman panther)

    Votes: 34 35.4%
  • 3. Fine (happy panther)

    Votes: 8 8.3%
  • 4. Great (golfing panther)

    Votes: 0 0.0%

  • Total voters
    96

olieb

Senior Member
Joined
Jul 1, 2023
Messages
379
Likes
618
The extracted samples are running with intrinsic jitter of the video clock. The solutions in higher end processors is to use asynchronous resampler in ESS chips. Or have a high performance PLL that cleans up the jitter. None of these are in the cards for this little box.
I am a noob in these things.
If the coax or optical signal is run through a Minidsp (flex digital) with ASRC and DSP, how much jitter will still be there at the output?
I am using AppleTV with a similar HDMI to Spdif box.
 

Haskil

Senior Member
Forum Donor
Joined
Jul 29, 2019
Messages
346
Likes
639
Location
Gisors, Normandie, France
A much better way to play SACDs is to extract the original DSD64 files and stream them.
There is an extensive thread on how to apply a simple hack to the most common blueray players from Oppo, Sony, Pioneer,…
Or use a player that will do DSD to PCM transcoding internally to send it to the DAC via its HDMI output: what I do with an Oppo mutistandard CD/SACD/DVD player (generation just before Blu Ray)...
 
Joined
Jun 2, 2020
Messages
47
Likes
42
Location
New Zealand
thanks for the review, i use a similar devive for stripping the digital audio from my old xbox 360s hdmi. had issues with the toslink output intermittently clicking/popping like the signal is having clocking issues on my smsl/littledot dacs, works fine with the inbuilt dac on my rotel intergrated idk if the toslink jacks are to blame or theres more indepth issues going on.
 

gvl

Major Contributor
Joined
Mar 16, 2018
Messages
3,530
Likes
4,133
Location
SoCal
In HDMI, the audio clock is derived from video. Video signals are immune to jitter as the pixel position is fixed (was an issue with CRT terminals). Audio was an afterthought and added in spare scan areas of video. The extracted samples are running with intrinsic jitter of the video clock. The solutions in higher end processors is to use asynchronous resampler in ESS chips. Or have a high performance PLL that cleans up the jitter. None of these are in the cards for this little box.

Is DSD affected by jitter same as PCM, more or less? It’s much higher sampling, so my guess is the same amount of jitter time-wise will cause more damage to the resulting analog signal for DSD data than PCM? Considering the clock is not properly recovered on the DAC as it’s often the case when using I2S input.
 

TNT

Active Member
Joined
Jun 24, 2020
Messages
250
Likes
160
That jitter is of course only harmful if the signal measured is used to drive a DA conversion process used as a clock. Any ARSC, FIFO, storage (HD etc) or even simple re-clocking using an other (hopefully better) clock would remove all trace of it. No bits where lost... or - no integrity tests made....

//
 

Beershaun

Major Contributor
Forum Donor
Joined
Oct 3, 2019
Messages
1,894
Likes
1,937
In HDMI, the audio clock is derived from video. Video signals are immune to jitter as the pixel position is fixed (was an issue with CRT terminals). Audio was an afterthought and added in spare scan areas of video. The extracted samples are running with intrinsic jitter of the video clock. The solutions in higher end processors is to use asynchronous resampler in ESS chips. Or have a high performance PLL that cleans up the jitter. None of these are in the cards for this little box.
Does this create the added broadband noise as well?
 

Stoutblock

Active Member
Forum Donor
Joined
Feb 6, 2021
Messages
108
Likes
127
A much better way to play SACDs is to extract the original DSD64 files and stream them.
There is an extensive thread on how to apply a simple hack to the most common blueray players from Oppo, Sony, Pioneer,…
agree.
 

pseudoid

Master Contributor
Forum Donor
Joined
Mar 23, 2021
Messages
5,427
Likes
3,785
Location
33.6 -117.9
Thank you for the review, @amirm,
Unfortunately, you forgot to weigh this thing and how are we to determine if it could potentially be used as a pricey door-stop?;)

I apologize for my laziness and my senility... but do you do any sort of HDMI extraction testing for reviews of receivers and pre-amps which have HDMI inputs?
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,979
Likes
245,192
Location
Seattle Area
but do you do any sort of HDMI extraction testing for reviews of receivers and pre-amps which have HDMI inputs?
Such extraction if it exists, would have to abide by rules of HDCP copy protection for HDMI which forces output to be 16 bits and 48 kHz at best. These other devices ignore that license agreement and pass through the bits as is.
 

mgbpuff

Member
Joined
Jul 30, 2022
Messages
36
Likes
16
I have a GeerFab Audio D.Bob Box which costs quite a bit more and seems to do the same thing sans IIS. GeerFab, however is licensed to do this, whereas I doubt this one is legal.
 
Joined
Nov 30, 2023
Messages
68
Likes
111
I sent this device to Amir, as this specific one has been mentioned in many discussions on various forums as a solution to allow a user to play the 24-bit layer of SACD from a universal player through their own DAC.

The reason for this was I found the reliability of SACD disc players be wanting. I can now see this device is not an acceptable answer where performance is concerned.

Thank you Amir!
 
Last edited:
Joined
Nov 30, 2023
Messages
68
Likes
111
A much better way to play SACDs is to extract the original DSD64 files and stream them.
There is an extensive thread on how to apply a simple hack to the most common blueray players from Oppo, Sony, Pioneer,…
I wonder if the BDP-X800M2 has been worked out for extraction yet?
 

VQR

Active Member
Joined
Oct 15, 2021
Messages
143
Likes
337
Thank you for the review, Amir! Couple questions:

1) Is the jitter performance mostly from the source being HDMI?

2) Would pumping only audio with no video affect the jitter performance?

Some BD and 4K players have HDMI ports dedicated for audio output only, so there could be genuine cases of such a scenario.
 

Lambda

Major Contributor
Joined
Mar 22, 2020
Messages
1,803
Likes
1,539
HDMI MHL Interface Audio I2S DSD Optical Coaxial HDMI To I2S IIS for DOP Board Dashboard Jitter.png
How can there be some Power supply Noise in a Digital to Digital system?
 

GWolfman

Addicted to Fun and Learning
Forum Donor
Joined
Nov 3, 2020
Messages
632
Likes
1,062
“DOU” mode? Audiophonics has a description (something about 5.1 audio), but what’s it supposed to stand for?
 
Last edited:
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,979
Likes
245,192
Location
Seattle Area
1) Is the jitter performance mostly from the source being HDMI?

2) Would pumping only audio with no video affect the jitter performance?
It could be in the source or the device itself or combination.

On #2, it is not possible to only send audio over HDMI. The "Audio Only" HDMI ports send out black video signal. Video is the master and audio is the slave and it must always be there.
 

lewdish

Senior Member
Joined
May 29, 2021
Messages
306
Likes
222
Im curious w/ other tools that serve the same function if they also perform as equally poor
 

Sonic-Wall

Member
Joined
Mar 29, 2021
Messages
58
Likes
44
“DOU” mode? Audiophonics has a description (something about 5.1 audio), buts what’s it supposed to stand for?
It‘s a typo and should be „DUO“ to route the TV signal to the HDMI output and the extracted audio to the digital outputs.
 

raif71

Major Contributor
Joined
Sep 7, 2019
Messages
2,365
Likes
2,580
I bought a similar hdmi to a variety of digital out converter but it was just in pcb with no covering like what amir has in this review. I used it convert dsd output from Sony bluray player (playing SACD) via hdmi out which was fed to the converter and the IIS output was fed to a Gustard X16 dac like so, in this link

 
Top Bottom