• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

HDMI Audio to USB Conversion?

Joined
Feb 15, 2020
Messages
31
Likes
9
#1
I currently use an Oppo BDP-105D for playing discs and streaming from NAS. I have, for some time (since I originally purchased the device new, for example), been unhappy with aspects of the sound which I attribute to the Oppo DAC, since it sounded inferior, in some ways, to the 20-year old Proceed DAP (DAC) which was among the components which the 105D replaced. On this forum, I became aware of the Topping D90 and became intrigued as a possible replacement for the Oppo DAC. I plan on connecting the Oppo digital output to the D90 via SPDIF coax, of course, but then there's the matter of DSD. (Hopefully, the D90 will sound better than the 105D.)
As far as I am can tell, the 105D only outputs DSD digitally via HDMI. A few DAC vendors (e.g. Bryston) include HDMI interfaces on their DACs for just such applications. Topping does not, and I don't fault them for this of course, the D90 being much less expensive. However, short of acquiring a relatively expensive streaming device that outputs DSD to USB, is there any such thing as a device that converts HDMI audio to USB, which I could presumably use to stream DSD files from the 105D to the D90 via USB? (With all due respect, please don't suggest "a computer." I don't want to locate a computer on my AV shelves at this time; maybe as a last resort.)
 
Joined
Mar 18, 2019
Messages
32
Likes
20
#2
It's a little difficult to get DSD data from any form of optical disk player, Oppo or otherwise, to an external DAC.
The only method provided by Oppo for doing so, as you correctly point out, is DSD-over-HDMI. This protocol is not particularly common - usually the devices intended to receive such a signal are Home Theatre Receivers, not standalone DAC's. I understand this is because Sony places restrictions on how SACD can be accessed - so it's a legal/licensing issue. I understand that for Sony to grant an SACD playback license to a vendor who wants to pass the SACD's raw DSD data over HDMI, that vendor must adhere to strict HDCP (High-bandwidth Digital Content Protection) encoding standards. And the receiving device must be licensed to be able to decode this HDMI/DSD data. And clearly manufacturers of HTR's have more interest in going to this trouble than do manufacturers of standalone DAC's.

But it's still possible, for DAC's which allow direct I2S input - and you're in luck, the D90 has such provision - by passing the HDMI signal to an HDMI de-embedding device, as can be found on eBay. These devices de-embed the raw I2S audio data (and raw SDI digital data), convert this data to analogue audio and video, and also re-embed the digital data back to HDMI before outputting to HDMI again. This de-embed/re-embed process has the side effect of stripping off HDCP encoding! See here -
https://forum.psaudio.com/t/getting-oppo-dsd-output-to-the-direct-stream-dac/2744/79
 
Joined
Mar 18, 2019
Messages
32
Likes
20
#3
Oops, the psaudio forum link I provided is slightly wrong. This is the correct link, by forum member Veneet -
https://forum.psaudio.com/t/getting-oppo-dsd-output-to-the-direct-stream-dac/2744/53

Also I was a bit vague about the HDMI de-embedder device that's required - you cannot use a generic HDMI extractor such as this -
https://www.ebay.com.au/itm/Audio-E...I-and-Optical-SPDIF-3-5mm-Stereo/122233881907
because that only does half the job - once the raw I2S audio has been extracted you must then feed it to an LVDS transmitter, then to a suitably wired HDMI cable.

The HDMI-to-I2S converter that Veneet is referring to does the complete job -
https://www.ebay.com/itm/DMI-MHL-In...er-HDMI-to-I2S-IIS-HDMI-OVER-I2S/112655538635

And another tip from that psaudio forum - when using the HDMI output in combination with the aforementioned HDMI-to-I2S converter - on the Oppo's remote control press "PURE AUDIO" for improved sound quality.
 
Joined
Mar 18, 2019
Messages
32
Likes
20
#6
Wow, the D.BOB is US$999. The generic HDMI-I2S extractor is US$43.
Big price difference, but no matter, the OP has disappeared anyway.
 
Joined
Mar 18, 2019
Messages
32
Likes
20
#9
The difference, for any who care, is DSD.
You may have missed it in my earlier post, but this particular HDMI-I2S extractor board -
https://www.ebay.com/itm/DMI-MHL-In...er-HDMI-to-I2S-IIS-HDMI-OVER-I2S/112655538635
outputs genuine DSD data at its HDMI-out connector (even though it does not explicitly advertise the fact) as confirmed and explained by forum member "veneet" on the PS Audio forum -
https://forum.psaudio.com/t/getting-oppo-dsd-output-to-the-direct-stream-dac/2744/53

A handful of DAC's support direct I2S input, or to be more accurate LVDS-I2S, via HDMI connector. The original poster's Topping D90 is one such DAC.
 
OP
mcdonalk
Joined
Feb 15, 2020
Messages
31
Likes
9
Thread Starter #10
I am the OP and have not disappeared; I'll check in more regularly. I am digesting the replies and the PS Audio forum content. However, the D.BOB does not convert to USB. It does convert to SPDIF, but the metallic SPDIF connection on my D90 is already in use. I've never evaluated the alternative optical interface type; would it perform satisfactorily?

I appreciate the responses. I am still trying to figure out the extractor board. I'll check back in shortly.
 
OP
mcdonalk
Joined
Feb 15, 2020
Messages
31
Likes
9
Thread Starter #13
It seems like I've wasted the time of this thread's participants (including myself). Tonight, when streaming the complete Handel's Italian Arias (PCM) from NAS using the BDP-105D as the streamer, I was reminded that the 105D does NOT support gapless streaming. So, I'm going to investigate a different route entirely (e.g. fanless small PC running jRiver Media Center, for which I have a license but does stream gaplessly, or one of the commercial streaming platforms such as the Bryston BDP-3) to dispense with this annoying distraction.

Thanks to all who responded to my query, though. By the way, since my initial query, I have acquired and installed the Topping D90, and I am satisfied that it sounds better than the Oppo BD105D DAC. I did not perform blind testing, however, so I shall not further waste anyone's time by stating my observations.

It seems like the BDP-105D, in my system, shall be relegated to video duties only, and the ripping of SACD's.
 
OP
mcdonalk
Joined
Feb 15, 2020
Messages
31
Likes
9
Thread Starter #15
Someebodyelse:

You are exactly correct in your distillation of the BDP-3, and I am aware of this. The Innuos product line is also very similar. This somewhat summarizes what makes it appealing to me. I am a recently-retired electronics engineer (tele- and satellite communications, not audio), and I have "built" a windows PC and a linux PC (the latter on which I am writing this), so I am versed in implementing my own version of one of these products. However, I also want music playback to be as pleasureable and easy as possible, with the occasional firmware download in which the integrated system has been tested. So, buying a streamer from a vendor, like buying a PC from Costco instead of building one one, has appeal to me. (Besides, I respect Bryston engineering overall.)

The only issues I am wrestling with at this point is the relative cost and platform longevity, and those are mine to decide upon and beyond the scope of this forum.
 
Joined
Nov 9, 2018
Messages
58
Likes
17
Location
New Delhi, India
#16
It seems like I've wasted the time of this thread's participants (including myself). Tonight, when streaming the complete Handel's Italian Arias (PCM) from NAS using the BDP-105D as the streamer, I was reminded that the 105D does NOT support gapless streaming. So, I'm going to investigate a different route entirely (e.g. fanless small PC running jRiver Media Center, for which I have a license but does stream gaplessly, or one of the commercial streaming platforms such as the Bryston BDP-3) to dispense with this annoying distraction.

Thanks to all who responded to my query, though. By the way, since my initial query, I have acquired and installed the Topping D90, and I am satisfied that it sounds better than the Oppo BD105D DAC. I did not perform blind testing, however, so I shall not further waste anyone's time by stating my observations.

It seems like the BDP-105D, in my system, shall be relegated to video duties only, and the ripping of SACD's.
Interesting.
Can you please elaborate the steps taken to rip of a sacd using BDP-105D?
 
Last edited:
OP
mcdonalk
Joined
Feb 15, 2020
Messages
31
Likes
9
Thread Starter #20
After some consideration, I've decided to acquire a fanless PC and install jRiver Media Center to perform my streaming function. The new PC shall be connected to my DAC via USB. However, I think that, in addition, I'll also acquire and install a Matrix Element H "audiophile" USB PCIe interface and see if I can detect any improvement over the motherboard's USB ports.
 
Top Bottom