SMSL DO100 PRO - HDMI ARC DAC

[formdissolve]

DO100 Pro

Foshan ShuangMuSanLin electronics Co., LTD. founded in 2009 which located in Shenzhen, China. And our branch company VMV Technology(HK) Company Limited registered in HK in 2013. Our company is specialized in the audio DAC, stereo headphone amplifier, power amplifier, and with own R&D...

www.smsl-audio.com

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.

 

[somebodyelse]

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.

 

[formdissolve]

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.

 

[somebodyelse]

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.

 

[formdissolve]

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).

 

[somebodyelse]

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.

 

[olds1959special]

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.

 

[Vlvvv]

hello! does anyone know about do100 pro hyperstream 4 or hypersyream previous version? Thanks)

 

[staticV3]

hello! does anyone know about do100 pro hyperstream 4 or hypersyream previous version? Thanks)

Hyperstream IV.

 

[Vlvvv]

Hyperstream IV.

thanks a lot)

 

[jed1]

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.

 

[zzcraft]

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.

 

[Progronom]

Hi! If the device is turned on, and at the same time turn off the power - for example, pull 220 volts out of the socket, then turn it back on after a while. Will the DO100Pro turn on itself? Or do I need to turn on the button on the remote control again, or on the Knob handle?​

 

[JIW]

Hi! If the device is turned on, and at the same time turn off the power - for example, pull 220 volts out of the socket, then turn it back on after a while. Will the DO100Pro turn on itself? Or do I need to turn on the button on the remote control again, or on the Knob handle?​

My DL200 does power up when power was disconnected when it was on. When it was in standby with power disconnected it goes into standby when power is connected.

So there is a good chance the DO100Pro will do the same.

 

[ppataki]

I just got my DO100 Pro last week and I am extremely happy with it
They are driving two 3eAudio A7 Mono amps driving my two DIY subs (2×15" and 4x8" DOS)
Strongly recommended

 

[ppataki]

Mine came at 100 percent, tell me the filter and jitter settings, thank you

The filter settings I personally left as-is
The jitter correction you shall set up by ear: start with the lowest value and listen if you hear any cracks/pops if no, you are done, if yes, you shall keep turning it up until there are no more cracks/pops
Mine is at the minimum value

 

[viktorgriga]

thanks

 

[Mkar]

I got my D100 Pro and here are some issues I've faced regarding the HDMI Arc when using with an LG C2:

The janky hdmi arc connection issue is present, need to power it off (cannot just turn it to standby) and on to connect every time if you change inputs to other than arc to make it connect. And using the TV remote to increase or lower volume, its a separate volume meter on the TV that it's controlling instead of directly changing the dac volume.

However, the biggest issue is: there is a constant noise that's playing from my speaker when hdmi arc is connected, its very audible at listening position (1.5m away) and it is also present when nothing is playing. All other inputs I've tried, usb, optical and coaxial, this does not happen. In fact, I've just been using that audible noise to know when hdmi arc has successfully connected since getting the sound to output from arc is already problematic.

I've reported this issue to AOSHIDA which I bought this from, hopefully it's just my specific unit that has this issue, or maybe it's just the TV model issue. I've stopped using the hdmi arc input completely because of this, previously I've used it for streaming on TV, netflix, prime video etc, I'm now using coaxial instead, there is no noise issue from it, maybe the HDMI ports on the C2 are bad.

Anyone else got this issue of noise from hdmi arc? Is it possible the hdmi arc on the dac doesn't actually go through the usual circuits like the other inputs and isn't actually low noise?

I probably won't be returning this, I'm enjoying the overall sound improvement as compared to my previous dac, current using usb for pc, coaxial for TV streaming and optical for bluray player with no issues (other than the popping noise on usb when playing music that happens whenever sampling rate changes, its mild and I don't mind it). In the first place I got this because I was hoping I could use HDMI instead of coaxial for TV streaming, because previously, I had to change DPLL to max every time to prevent audio dropouts, which happened far to many time when streaming Netflix when DPLL is at minimum and then changing it back to minimum when using usb-pc. I was hoping HDMI arc didn't have that issue, however that don't matter now, I've been using DPLL at minimum all the way and so far zero audio dropouts with coaxial when streaming, haven't touched DPLL at all.

I have the same problem with HDMI input set on SMSL DO 100 Pro. There is a constant low buzzing noise on speakers, even when HDMI cable in disconnected. Buzzing stops when other sound input is selected.

 

[jed1]

Does anyone confirm if XLR (balanced) and RCA (unbalanced) outputs are independently buffered? Currently, I feed XLR outputs to powered monitor speakers. I'd like to use RCA outputs, sum the stereo to mono and feed to another powered monitor. Unless XLR and RCA are independently buffered, I may degrade / affect XLR outputs by doing this.

Thanks

 

[ICIETDIYEUR]

Hello.

No, they are not physically independent.

Here is a picture of the PCB to better understand ->

In '1' (green) these are the DAC chips ES9039Q2M, it has one per channel (right and left).

These DAC chips will deliver a CURRENT (I) output which will be converted into VOLTAGE (V) by the OPAMPS in '2' (orange) but also a low pass filtering.

In the case of the output signals on XLR sockets, these signals from the OPAMPS in '2' (orange) concerned by one of the channels (i.e. 2 OPAMPS per channel) will form what is called the 'hot spot' and the 'cold point' necessary for a balanced signal, the latter will first pass through a kind of 'digital relay' in '4' (yellow) before arriving at the socket concerned.

In the case of the output signals on the RCA jacks, the signals from the '2' (orange) OPAMPS that have formed what is called the 'hot spot' and the 'cold spot' for each channel will pass through the '3' OPAMP which will perform what is called a 'differential summation' in order to create a unique signal for each of the RCA channels (right and left).
Then this signal will in turn pass through a 'digital relay' in '4' (the middle one in yellow) to finally arrive at the RCA sockets.

So when you select on your DAC in the 'RCA + XLR' menu, all the 'digital relays' pass the signal and the outputs of the OPAMPS are somehow connected to each other, unless there are capacitors linking to their outputs but we don't have the circuit diagram....

... what is certain is that the more devices you connect to the different outputs of the DAC (RCA and XLR) the more you will expose yourself to possible 'ground loop' problems

That said: above each 'digital relay' we see 'MELF' resistors in series with the signal that serve to protect the OPMPS upstream.

Moreover it seems that since each OPAMP output also provides a 'low-pass filter' function then a capacitor is in series with the signal, but without the diagram we are not sure of anything once again.