USB to SPDIF converter for Nvidia Shield Android TV

[boblo]

I'm looking for a way to connect my Nvidia Shield TV to a Fiio BTA30 Bluetooth transmitter/receiver, so I can transmit stereo audio (up to 24 bit / 96kHz) from the Tidal app running on Shield to this BT adapter/DAC. Since the Shield TV does not have optical/coaxial output (it has only 2 USB 3.0 ports) and the BTA30 only can transmit LDAC audio via optical/coaxial input (LDAC codec is needed for 96kHz frequency), I need an USB to coaxial converter , NOT an USB DAC, but an USB audio interface performing bit perfect signal conversion.

I have found these:
InLine USB HD Audio Adapter 24 Bit 192kHz to Digital Coax / Toslink / I2S Converter
Douk Audio U2 USB Converter XMOS XU208 Digital Interface

Both support up to 24 bit / 192 kHz through coaxial output.

Which one do you recommend (sound quality wise)?
Do you have any other candidate?

Many thanks in advance

 

[RayDunzl]

Which one do you recommend (sound quality wise)?

None of my digital i/o devices seem to have any sound quality of their own.

 

[boblo]

None of my digital i/o devices seem to have any sound quality of their own.

Excuse me, but I didn't understand your reply. Could you elaborate, please?
Thanks

 

[RayDunzl]

Excuse me, but I didn't understand your reply. Could you elaborate, please?

You asked which device which takes in data in one container (USB) and repackages that same data in another container (S/PDIF) sounds better.

Neither should have any "sound" if they are at all competent at their stated conversion task.

 

[kipman725]

I have the Douk unit and use the optical out into a Symetrix DIGIO. It uses the generic XMOS driver and works fine with my windows 7 computer. When putting sine waves into it and looking at the scope display in the Symetrix software I get sine waves out that are up to digital full scale so as far as I can tell it works fine and doesn't alter the level of the signal. I don't have any equipment that could perform any further tests. It will work with Asio for all but I normal use the windows mixer and software volume control for normal level adjustments (my system is capable of in excess of 120dB continuous in the listening position so I have software controlled hardware attenuators on my DSP outputs normally at home).

 

[Vincent Kars]

LDAC codec is needed for 96kHz frequency

The max LDAC support is 990 kbs
As a reverence, CD (44.1 kHz) is 1411 kbs
So LDAC can transmit anything up to 96 kHz but it is lossy compression of course.

 

[boblo]

The max LDAC support is 990 kbs
As a reverence, CD (44.1 kHz) is 1411 kbs
So LDAC can transmit anything up to 96 kHz but it is lossy compression of course.

I know, thanks for the reminder, but I think the loss will be almost negligible for my ears (and my old speakers). Ideally, audio data should be transmitted with the new UAT codec (up to 24 bit / 192 kHz, 1.2Mbps, right?), but unfortunately the BTA30 does not support it. Do you know any other BT adapter with UAT support?

On the other hand, the Douk Audio U2 uses the XMOS XU208 chipset, whereas the InLine USB HD adapter uses the C-Media CM6631A. Which do you think is better? (regarding stability, clocks, jitter... ) However, neither ASIO support nor driver support are important for Shield, AFAIK.

I'm hesitant because the U2 has a bad review.

Thanks again

 

[Vincent Kars]

To the best of my knowledge, XMOS has a big reputation, many USB DACs use a XMOS USB receiver.
UAT is HiBy only I'm afraid.

There are even voices stating that if one increases the bitpool, even SBC can be lossless!
https://habr.com/en/post/456182/

Maybe this link is use: https://www.thewelltemperedcomputer.com/HW/USB_SPDIF.htm
It is a bit dated but might get you started.

 

[boblo]

To the best of my knowledge, XMOS has a big reputation, many USB DACs use a XMOS USB receiver.
UAT is HiBy only I'm afraid.

Yes. I was thinking in buying a Hiby r2 DAP to transmit audio to a SMSL SU-9 DAC, but I'm not sure with its battery life using the UAT codec. It's likely playtime will not be higher than 2 hours so this is not suitable for me. Do you know that DAP? Since this DAP has no Android OS, does this device support Amazon Music HD, Deezer and Qobuz?

Thanks again

 

[Vincent Kars]

I'm unfamiliar with the R2
But nice to know there is a UAT in the SMSL

 

[boblo]

Well, I pulled the trigger on the Douk Audio U2 digital interface (€ 52 on Amazon). BUT... I have found a 'modded' version of this device on the Douk Audio eBay store, let's say an 'U2 with steroids' (HERE), rebranded as 'U2 PRO'. It's only listed on Amazon Japan and other asian sites, besides eBay. It's not even advertised on the official web site (www.doukaudio.com) and it has I2S output support (I have no idea what this is) and supports higher sample rate than normal U2 (up to 32 bit / 384kHz). However, the most interesting part is you can order a CUSTOMIZED version of this device with 3 types of crystal oscillators: Standard, TCXO, and Standard + Femtosecond.

So I don't know if an 'U2 PRO' with TCXO oscillators (intermediate model for € 72, reasonable price) would make any difference with the standard U2. Remember that:
I'm going to extract audio up to 24 bit / 96 kHz from my SHIELD TV to the USB digital interface, then audio will be redirected to a Fiio BTA30 DAC/BT transceiver through optical/coaxial input and finally audio data will be transmitted via LDAC to a SMSL SU-9 DAC, so I wonder if better oscillators could reduce jitter even more and this would make a better sound after all.

What do you think?

Thanks again for any advice.

 

[boblo]

I'm unfamiliar with the R2
But nice to know there is a UAT in the SMSL

Vincent, I have seen your web site and seems very informative (and helpful), although a bit outdated. I have realized you're an expert on this matter, so could you tell me if the mentioned 'U2 PRO' with custom crystal oscillators would make any difference in sound? In other words, is this converter worth it or should I stick with the 'normal' U2?

Thanks very much for your reply

 

[Vincent Kars]

Personally I doubt if the difference is audible.

 

[Morla]

I have found a 'modded' version of this device on the Douk Audio eBay store, let's say an 'U2 with steroids' (HERE), rebranded as 'U2 PRO'.

Thank you very much! Ordered a U2 Pro for my shield (Standard Version). Will report results if you can hold out a few days

 

[boblo]

Thank you very much! Ordered a U2 Pro for my shield (Standard Version). Will report results if you can hold out a few days

Yes, sure I can! Do you have the normal U2 too? Mine arrives today. I will report if it works or not.

Thanks again

 

[Morla]

Yes, sure I can! Do you have the normal U2 too?

No I just saw your post and decided not to use a hdmi toslink de embedder for the shield but the u2 "pro". No use for i2s right now but eh.. no real price difference.

It shouldn't make an audible difference anyway and I can't provide any measuring but a report whether it "works" with the shield or not.

 

[boblo]

No I just saw your post and decided not to use a hdmi toslink de embedder for the shield but the u2 "pro". No use for i2s right now but eh.. no real price difference.

It shouldn't make an audible difference anyway and I can't provide any measuring but a report whether it "works" with the shield or not.

Well, I have just tested the normal U2 and works. But SHIELD cannot output audio simultaneously to HDMI and USB, so if I want to use the TV speakers or my receiver, I need to change the output settings to "HDMI" in Advanced Sound Settings.

The thing is that my TV does not support optical audio output when a HDMI device is connected to the same input (Pioneer PDP-LX508D Kuro plasma TV), so could you recommend a good HDMI audio extractor with HDMI and optical/coaxial outputs?

Thanks

 

[Morla]

Something like this?

https://www.amazon.de/Extractor-Con...stützung-HDMI-Audio-Extractor-B/dp/B07F8NWXBD

Why would you want to use the TV speakers?

 

[boblo]

Something like this?

https://www.amazon.de/Extractor-Converter-Ozvavzk-5-mm-Stereo-Unterstützung-HDMI-Audio-Extractor-B/dp/B07F8NWXBD

Why would you want to use the TV speakers?

Here's why:
I have bought bluetooth headphones to listen to TV audio. The thing is that I would like to use a FiiO BTA30 transceiver in order to transmit audio to my headphones (with LDAC quality). However, the BTA30 only has optical/coaxial inputs, it has no AUX 3,5" (in addition, audio from optical input is way better than from AUX input). So I need a device to split video and audio signals into HDMI video and optical/coaxial audio. Does a HDMI to optical digital interface exist like the USB to optical? I would like not to convert the source signal if possible... (I don't want another DAC).

Thanks again

 

[Morla]

However, the BTA30 only has optical/coaxial inputs

But it has optical out...to maybe go to the receiver?