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SMSL DO100 PRO - HDMI ARC DAC


They mention every type of connection and its corresponding bitrate limits EXCEPT the arc input. I think that's telling...
ARC bandwidth is limited to 16 bit 48khz PCM stereo*. eARC can handle 24/192 max.

*My LG OLED limits ARC to 16 bit 44.1 for everything no matter what setting. I use an OREI extractor and when I set the LG to use eARC to the OREI it switches to 48khz on my DAC, however my current DAC only shows sample rate and not bit depth, so I can't confirm if it's dithering to 16-bit but I assume so.
 
ARC bandwidth is limited to 16 bit 48khz PCM stereo
ARC requires support for 16 bit 48khz PCM stereo. I'm not sure about 16 bit 44.1kHz. Support for other formats supported by toslink/spdif is optional, and subject to capability discovery. That includes 24/192 PCM stereo.
 
ARC requires support for 16 bit 48khz PCM stereo. I'm not sure about 16 bit 44.1kHz. Support for other formats supported by toslink/spdif is optional, and subject to capability discovery. That includes 24/192 PCM stereo.
Right, it's required. All I was saying is it's also the max possible PCM data bandwidth since ARC is limited to 1.5mbps and my LG OLED refuses to go over 44.1 over ARC. When I switched to eARC, the SMSL (connected via COAX from the Orei) is reporting 48khz. I have tried 24/192 to no avail, so the Orei definitely doesn't support that.

Others have reported 24 bit 48khz PCM capability via the optical on their LG tv's when playing wav files, but due to HDCP protections (as others have stated), if you play a blu-ray or something similar it will be dithered to 16 bit but keeps the industry standard 48khz.
 
Right, it's required. All I was saying is it's also the max possible PCM data bandwidth since ARC is limited to 1.5mbps and my LG OLED refuses to go over 44.1 over ARC. When I switched to eARC, the SMSL (connected via COAX from the Orei) is reporting 48khz. I have tried 24/192 to no avail, so the Orei definitely doesn't support that.

Others have reported 24 bit 48khz PCM capability via the optical on their LG tv's when playing wav files, but due to HDCP protections (as others have stated), if you play a blu-ray or something similar it will be dithered to 16 bit but keeps the industry standard 48khz.
It may be the maximum possible for that combination of hardware, but it isn't the maximum allowed by the ARC standard. One of the chip manufacturers explains in this white paper that the use of CEC for discovery in ARC caused a lot of compatibility problems. If discovery fails you are limited to the required rates, even if all the devices are capable of the highest rates. One of the changes in eARC is intended to make this discovery phase more reliable so there are fewer compatibility problems.
 
It may be the maximum possible for that combination of hardware, but it isn't the maximum allowed by the ARC standard. One of the chip manufacturers explains in this white paper that the use of CEC for discovery in ARC caused a lot of compatibility problems. If discovery fails you are limited to the required rates, even if all the devices are capable of the highest rates. One of the changes in eARC is intended to make this discovery phase more reliable so there are fewer compatibility problems.
I have seen that paper before, but I guess I should rephrase: I am talking about first generation ARC, and not eARC. If you go to the chart in that paper you linked, it clearly states that ARC is limited to ~1mbps (which is stated actually lower than reality at closer to 1.5mbps).

Screenshot 2024-10-01 at 22.31.54.png
 
I have seen that paper before, but I guess I should rephrase: I am talking about first generation ARC, and not eARC. If you go to the chart in that paper you linked, it clearly states that ARC is limited to ~1mbps (which is stated actually lower than reality at closer to 1.5mbps).

View attachment 396026
I'm talking about ARC too. I'd love to know where they got those bandwidth figures from as they don't seem to match reality. The table originally came from eARC promotional material, so they may have been making eARC look like a bigger step up than it really was, using the ~ as a get-out in case it needed explaining away. They still claim ARC has >2x the bandwidth of Toslink though. For comparison Toshiba give the bandwidth of their audio transceivers (TORX117 etc.) as up to 15Mb/s which lines up with the simplistic calculation of 24/96 PCM stereo which we know many DACs support over Toslink.

So back to original sources - from the HDMI 1.4 spec which introduced ARC, in section HEAC 4.2 we have:
An HDMI device that has an Audio Return Channel receiver function shall support two- channel 16-bit L-PCM
audio at sample rates of 32 kHz, 44.1 kHz, and 48 kHz defined in IEC 60958-3 on the ARC connection.
An HDMI device that has an Audio Return Channel transmitter function shall support two-channel 16-bit
L-PCM audio at least one of these sample rates on the ARC connection.
NOTE: Clock frequencies correspond, respectively, to 4.096MHz, 5.6448MHz, and 6.144MHz.
Support of other audio formats as defined in IEC 60958-3 or compressed audio as defined in IEC 61937 (all
parts) is optional. CEC messages may be used to discover the supported audio formats, see section CEC
13.15.3.
IEC 60958-3 is the specification covering consumer applications as used by spdif/toslink for stereo. In case you need confirmation, page 6 covers sample frequency up to 192kHz. IEC 61937 covers the compressed audio normally used for sending surround formats over spdif/toslink. So ARC has optional support for all the same formats you would find on spdif/toslink, including stereo 24/192 PCM.
 
What's the danger of my DO100 Pro playing full blast for some reason? I use the digital volume and generally keep it at 50% so 100% would be way too loud and be really bad. I've heard of "Topping events" but not really heard of people having problems with this unit. Should I be worried? I always check the level before hitting play, though.
 
hello! does anyone know about do100 pro hyperstream 4 or hypersyream previous version? Thanks)
 
FYI. DO100 Pro's DAC core count with two ES9039Q2M is half that of single ES9039Pro. I believe that's why DO100 Pro is a good value.
 
DO100 pro is not necessarily good than d6s, I compared DO100pro with d6s, DO100 pro can produce higher hiss noise than D6S from speaker. When I switch to DO400, speaker is completely silent though.
 
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