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SMSL SU-8 Version 2 Balanced DAC

graz_lag

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... much better than the benchmark but that might be because output is 4.2Vrms vs 4.0Vrms
To what version of the Benchmark were you referring ?
 

TheFixer

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It will still have manufacture warranty just like any where else. I believe massdrops supplier for these is shenzen audio any way.
Oh ok hopefully, but are you sure that's accurate? The general consensus seems to be, and even massdrops FAQ page says that if the product has a warranty it will be in the listing.
 
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In the end, after thinking between EL DAC and SMAL SU-8 V2, I bought SU-8 and it's a very nice DAC, with a lot of build in options.

There is one problem, I'm using Linux and have two outputs from my PC to DAC, USB and optical. When USB input is active, there is no problem at all, the sound is perfect but when I switch to optical one, I can hear random popping from the speakers. Even if there is no music reproducing, I can still hear popping but there is no buzzing. When the music is playing it just cuts off randomly for a very short period. I tried playing through ALSA output, PulseAudio with ALSA plugin for Google Chrome browser, using native PulseAudio with ALSA, also tried deadbeef music player to automatically set clocking rates but no luck, popping is still present. I suspect that the problem is in toslink cable, but it's new. Do you guys have some advice for troubleshooting this issue?
 

graz_lag

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... I'm using Linux and have two outputs from my PC to DAC, USB and optical. When USB input is active, there is no problem at all, the sound is perfect but when I switch to optical one, I can hear random popping from the speakers. Even if there is no music reproducing, I can still hear popping but there is no buzzing. When the music is playing it just cuts off randomly for a very short period. I tried playing through ALSA output, PulseAudio with ALSA plugin for Google Chrome browser, using native PulseAudio with ALSA, also tried deadbeef music player to automatically set clocking rates but no luck, popping is still present. I suspect that the problem is in toslink cable, but it's new. Do you guys have some advice for troubleshooting this issue?
Some comments :

What are your sources ? FLACs/WAVs from the internal HDDs or from external ones ? Spotify or Web Radios ?
What kernel are you running ? General, Low-Latency or Real-Time ?
Did you try turning PulseAudio off ? (I mean via "autospawn = no" in the etc/pulse/client.conf file)
Did you test for bit-accurate reproduction within the USB stream ? (Although the SU-8 displays the bit/sample rate, I always prefer to double check it ...)
Double check with "aplay" or "alsamixer" whether the SU-8 is properly seen by ALSA

There are some other points to double check if the above listed do not help you.

You can also try the live CD of a light and small Linux music player : wtfplay (wtfplay-project.org)

A faulty optical cable, yes it can happen, or a bad cable layout if for example it runs thru a narrow bend ...
 
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Just a FYI,

Massdrop will allow returns if SU8 is DOA. I returned the previous SU8 to Massdrop b/c it was the wrong version --pcb 1.1.

In terms of reliability, have there been any posts about the units failing after a period of time in this thread? I have read about the humming issues and the fade in problems, but as compared to the Topping DX3 pro failure problems, this unit appears to be solid.
 
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What are your sources ? FLACs/WAVs from the internal HDDs or from external ones ? Spotify or Web Radios ?
Using external sources (YouTube) and internal ones from HDD, mainly FLAC and MP3. The same issue was present with both of them.
What kernel are you running ? General, Low-Latency or Real-Time ?
I'm using Debian (last stable release, stretch) with general kernel. Was thinking maybe to try with Fedora, which will provide newer packages, including kernel being close to bleeding edge but tested before release, so maybe that will solve described issue.
Did you try turning PulseAudio off ? (I mean via "autospawn = no" in the etc/pulse/client.conf file)
Yes, that was one of the first tests that I made. Killing PulseAudio with "autospawn = no" in client.cong file and try to play only through ALSA, but no luck with that. Popping was still here.
Did you test for bit-accurate reproduction within the USB stream ? (Although the SU-8 displays the bit/sample rate, I always prefer to double check it ...)
Also tried that. I was using deadbeef music player with ALSA output plugin with ALC1150 PCH digital output without PulseAudio layer. SU-8 displayed bitrate/sample rate was identical to simple rate in /proc/asound/card1/pcm1p/sub0/hw_params.
Double check with "aplay" or "alsamixer" whether the SU-8 is properly seen by ALSA
"aplay -L" command output and "alsamixer" are giving correct information about connected devices. So that part should be ok.

There are some other points to double check if the above listed do not help you.

You can also try the live CD of a light and small Linux music player : wtfplay (wtfplay-project.org)

A faulty optical cable, yes it can happen, or a bad cable layout if for example it runs thru a narrow bend ...
Bingo! No popping while using wtfplay, I have tried random MP3 and FLAC files. The solution was probably fine tuned kernel for music reproducion, now I wonder if I can tune some of settings to get the same result on Debian/Fedora with general kernel shipped with them. Sure, there is an option to get Raspberry Pi and put all music on the SD card and go that way. The cable is nicely tined up with other cables, no narrow bend edges.

Thank you graz_lag on your time, help and suggestions.
 

amirm

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In terms of reliability, have there been any posts about the units failing after a period of time in this thread? I have read about the humming issues and the fade in problems, but as compared to the Topping DX3 pro failure problems, this unit appears to be solid.
I have not seen reports of reliability problems although this device is not as popular as DX3Pro.
 

graz_lag

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... I'm using Debian (last stable release, stretch) with general kernel. Was thinking maybe to try with Fedora, which will provide newer packages, including kernel being close to bleeding edge but tested before release, so maybe that will solve described issue ... Bingo! No popping while using wtfplay, I have tried random MP3 and FLAC files. The solution was probably fine tuned kernel for music reproducion, now I wonder if I can tune some of settings to get the same result on Debian/Fedora with general kernel shipped with them ...
Debian 9.x Stretch is a nice version for the set-up of an Audio Linux-PC, you can install its real-time kernel ... "linux-image-rt-amd64" ... so that you can get minimal latency.
Personally, I am still using the 7.x Wheezy.

The work load and available resources among "the trillions high-speed switches" in your PC matter a lot on the audio signal output quality.
The positive result you got with "wtfplay" confirms that.
Another stripped-down Debian distribution that is worth to try is this : http://linux.voyage.hk/

Have you ever tried the MPD-daemon ? In my installation, the "trio" ALSA-MPD-Cantata is the one that brings the best results. And MPDroid lets me remotely control the playing desktop from my Android phone. (Or MPDluxe for the iOS phones.)

DeadBeeF, or gmusicbrowser, play well as well, but I find the MPDroid remote access feature very handy. ;)
 

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Hi guys I am awaiting my order of this SU-8 from Shenzhenaudio. In terms of streaming lossless audio from Tidal would you guys recommend (1) a long usb (about 15ft) from Mac mini 2018 to dac, (2) a mobile phone on airplane mode with just Wi-Fi enabled to stream same source to dac, (3) a separate dedicated audio streamer like a Bluesound node 2i to dac ? Option 1 and 2 is cheaper but I was wondering how real is the distortion noise interference in these setups? The amp will be the Massdrop THX AAA 789 and will be setup in balanced.
 
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Debian 9.x Stretch is a nice version for the set-up of an Audio Linux-PC, you can install its real-time kernel ... "linux-image-rt-amd64" ... so that you can get minimal latency.
Personally, I am still using the 7.x Wheezy.

The work load and available resources among "the trillions high-speed switches" in your PC matter a lot on the audio signal output quality.
The positive result you got with "wtfplay" confirms that.
Another stripped-down Debian distribution that is worth to try is this : http://linux.voyage.hk/
After a few hours of testing, I have noticed that the loudest (most frequent) popping/sound cuts accores while playing YouTube videos and lower quality music files from harddisk (44100hz/16bit). When playing higher quality music fiiles (96000hz/24bit) from harddisk there is almost no popping and zero sound cuts, which is very werid. Same results are present while using real-time kernel on Debian. While USB PC output/DAC input are active, all sources are perfectly clean, no issues at all. I know that it sounds like i'm crazy, but I checked with various songs. :) There are some reported kernel bugs while using HDA Intel PCH (what I use), but all of them are very old and solved.

Have you ever tried the MPD-daemon ? In my installation, the "trio" ALSA-MPD-Cantata is the one that brings the best results. And MPDroid lets me remotely control the playing desktop from my Android phone. (Or MPDluxe for the iOS phones.)

DeadBeeF, or gmusicbrowser, play well as well, but I find the MPDroid remote access feature very handy. ;)
I'm using MPD for movies, but sure I will check out MPDroid, it sounds like a nice and useful feature. Also tried to play some music with MPD, but same result as with DeadBeeF.
 
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amirm

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Hi guys I am awaiting my order of this SU-8 from Shenzhenaudio. In terms of streaming lossless audio from Tidal would you guys recommend (1) a long usb (about 15ft) from Mac mini 2018 to dac, (2) a mobile phone on airplane mode with just Wi-Fi enabled to stream same source to dac, (3) a separate dedicated audio streamer like a Bluesound node 2i to dac ? Option 1 and 2 is cheaper but I was wondering how real is the distortion noise interference in these setups? The amp will be the Massdrop THX AAA 789 and will be setup in balanced.
If the USB cable works, that would be my choice. Less pieces to go wrong. I had to string a bunch of crappy USB cables to create data loss so you should be OK with 15 feet.
 

graz_lag

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Paul Take

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What are the main benefits of balanced-out versus SE-out from the SU-8 into an amplifier (say THX 789) with balanced-in and SE-in?
 

Jaimo

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Better Common mode niose rejection (CMRR) - this usually translates into reduced noise from induced hum etc. A short well shielded RCA may give similar results if your grounding is good. Balanced outputs / inputs are usually intended for long cable runs and come out of the pro audio world.

Here's a good reference...
 
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What are the main benefits of balanced-out versus SE-out from the SU-8 into an amplifier (say THX 789) with balanced-in and SE-in?
Also bit more power, not saying that THX AAA 789 needs more power, but other amps might..
By the way I'm trying out SH-8, and i'm loving it! The first day I was disappointed, but after leaving it on for 72+ hours to my surprise the thing opened up considerably! To the point I want to keep it (I'm using it single ended and RCA in from SU-8). Sounds really pleasing, I wonder why nobody talks about it..
 

Paul Take

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Better Common mode niose rejection (CMRR) - this usually translates into reduced noise from induced hum etc. A short well shielded RCA may give similar results if your grounding is good. Balanced outputs / inputs are usually intended for long cable runs and come out of the pro audio world.

Here's a good reference...
Your response has clarified my thoughts that if I were to get the THX 789, I should also get the SU-8 instead of the KTB and use the balanced interface between them to get a well optimised DAC/Amp combination.
 
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Hi all,

First post but I've been browsing for a while and it's good to find a resource like this for objective data.

I'm considering buying an SU-8 but after reading through the two main threads I have a few questions I'd be grateful of any responses to:

1) Has anyone successfully run REW frequency sweeps through an SU-8? (I've read that the Topping D50 has a fault that prevents this and I wanted to check it's not a wider issue.)

EDIT: for anyone browsing this thread I'll now answer my own question. Yes, he SU-8 has the same issue as the Topping D50, which is if you run a right-channel only sweep the DAC cuts out. Left channel only sweeps run fine though. You can get round the problem by switching or disconnecting cables but obviously it would be simpler if it could just be done via the software as normal!

2) Does the DAC 'remember' volume settings when switching between inputs, and when fully switched off? I'm considering using the DAC connected direct to a power amp and am wondering about the risk of accidentally sending it a full amplitude signal.

3) Has anyone had any issues with either the volume range being too limited, or the volume steps too course? It would be much easier if it just displayed attenuation in dB...

Thanks .
 
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Jaimo

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Do keep in mind that a poorly implemented balanced circuit is unlikely to perform better than a good single ended circuit. I can’t comment on the massdrop and Smsl products you are looking at.
 

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