SMSL SU-6 Review (Desktop DAC)

[kanjerkoe]

Today I received the SU-6. First track to send through it, was D'Angelo's Brown Sugar from CD, through optical. I've already sold my E30 so couldn't do a direct comparison, but what struck me was the "air" in the tambourines. Overall sound has a nice amount of body to it. I've ordered some new RCA's from Ali, as suggested by Youtuber "Михаил Греков" (video - watched with automatic translations, which works surprisingly well hehe).

Power cycling works great: AC ON = DAC ON, simple as that

One question: does the DAC have an option to switch between preamp mode & DAC mode, like the Topping E30? Or should I just leave it at 0dB and just assume there's no quality loss?

I also tested LDAC over Bluetooth with my old Huawei P20 Pro & Google Pixel 6 and the SU-6.. The Pixel 6 definitely can't handle 990kbps (24bit), no problem with the Huawei.. But this has become a well known problem with the Pixel 6 lineup.

Hey Pieter,

I'm also interested in the SU-6, mainly to use as a bluetooth receiver to incorperate into my existing hifi system. I have already asked another member on the forum, but was wondering what you think about the sound quality of the SU-6 while using LDAC.

 

[pieterv1]

Hi there! Since I only use Spotify on my phone (waiting for their hi-fi tier...), I can't really comment on the "LDAC quality" per se. But it's just a codec really and *can* sound almost as good as cd quality wavs or flacs.. It's a matter of having the right source material playing on your phone.

If I were you, I'd actually add a Raspberry PI, running a network player OS like Volumio or Moode & connected to the SU-6 via USB. This allows for bit-perfect & higher quality playback. LDAC, being a "codec", always converts the audio source.

Depending on the OS you chose, you'll get integration with Tidal, Qobuz, Spotify connect etc. The actual playback happens over wifi/ethernet coming in to the raspberry pi, completely independent of your phone and therefore will be more stable as well. Your phone or computer will be used just as a controller for the playback.

 

[Acerun]

Today I received the SU-6. First track to send through it, was D'Angelo's Brown Sugar from CD, through optical. I've already sold my E30 so couldn't do a direct comparison, but what struck me was the "air" in the tambourines. Overall sound has a nice amount of body to it. I've ordered some new RCA's from Ali, as suggested by Youtuber "Михаил Греков" (video - watched with automatic translations, which works surprisingly well hehe).

Power cycling works great: AC ON = DAC ON, simple as that

One question: does the DAC have an option to switch between preamp mode & DAC mode, like the Topping E30? Or should I just leave it at 0dB and just assume there's no quality loss?

I also tested LDAC over Bluetooth with my old Huawei P20 Pro & Google Pixel 6 and the SU-6.. The Pixel 6 definitely can't handle 990kbps (24bit), no problem with the Huawei.. But this has become a well known problem with the Pixel 6

 

[Acerun]

On the Pixel 6, via UAPP /Tidal I'm showing LDAC at 44.1 16 bit 884 kps

 

[pieterv1]

On the Pixel 6, via UAPP /Tidal I'm showing LDAC at 44.1 16 bit 884 kps

Apparently it should play alright when the screen locks?

 

[Acerun]

I think so. Will let you know if I see differently.

 

[Jerderv]

When my wife connects her phone via Bluetooth the SU6 displays "AAC". She has an Iphone. I looked through the manual I didn't see anything about this. Any ideas?

Edit: nevermind, I googled it. AAC is another Bluetooth codec type.

 

[pieterv1]

When my wife connects her phone via Bluetooth the SU6 displays "AAC". She has an Iphone. I looked through the manual I didn't see anything about this. Any ideas?

Edit: nevermind, I googled it. AAC is another Bluetooth codec type.

Indeed, LDAC is developed by Sony and part of Android Open Source Project since version 8.0

With Apple devices you'll have to rely on just the AAC codec, capped at 256kbps. Kind of funny that Apple provides Lossless quality on Apple Music, but even their 500$ headphones don't support cd quality at least.

 

[Acerun]

When my wife connects her phone via Bluetooth the SU6 displays "AAC". She has an Iphone. I looked through the manual I didn't see anything about this. Any ideas?

Edit: nevermind, I googled it. AAC is another Bluetooth codec type.

Yes, the SU-6 shows the codec being used

 

[Acerun]

I haven't watched it yet but Zeos just reviewed the SU-6 stack. Curiosity will get the best of me and I'll probably watch it later today.

 

[Lupin]

I haven't watched it yet but Zeos just reviewed the SU-6 stack. Curiosity will get the best of me and I'll probably watch it later today.

I can tell you now that Zeos will ramble on for 27 minutes, probably will be completely sidetracked for at least 1/3 of the video.. at least that how it usually goes with his videos.

His videos are entertaining but you'll most likely not going to get anything informative, substantial or useful out of it.. my experience at least.

 

[Nick_L]

I finally received the SU-6 yesterday after 7 weeks of delivery (thanks to the Christmas season and German customs).
It will replace my Schiit Modi 3+ as the popping sound when switching through different sampling rates really annoyed me.

When comparing both DACs, I don't hear any difference (the Modi 3+ is a very good DAC sonically) but I enjoy the much better functionality and usability. Remote control, brilliant display, integrated power supply and silent operation are great features for an incredible price.

I really love it.

Cheers
Nick

 

[mrjktcvs]

Speaking of Bluetooth, is there not support for more than one paired TX? Or does the pairing need to be redone every time you want to change transmitters? I have this unit and a Topping DX 3 Pro +, and have the same problem with both. I wound up having to get a Lightning to USB cable so I could listen to my iPhone since the BT input is already assigned to the TV.

 

[confucius_zero]

so is this the best RCA-only DAC yet?

 

[Nick_L]

so is this the best RCA-only DAC yet?

Hello @confucius_zero

I know this forum is very much focussing on technical specs and measurability (which is great) and the SU-6 measures very well (thanks to amirm's review). Please let me just explain why the SU-6 is FOR MY USECASE the perfect RCA-only DAC.

- I use the DAC in an HIFI setup so I appreciate some information on a display which I am able to switch off if not needed
- I hate popping sound when switching to different songs through my library (whatever the root cause may be)
- A remote control to switch through different sources is a plus
- A proper switch to be able to cut the DAC from power is also great feature for my usecase
- I like the build quality and the size of the DAC
- A price tag below 200 Euros is perfect for my wallet

But I don't know your usecase...

Cheers
Nick

 

[Nick_L]

Speaking of Bluetooth, is there not support for more than one paired TX? Or does the pairing need to be redone every time you want to change transmitters? I have this unit and a Topping DX 3 Pro +, and have the same problem with both. I wound up having to get a Lightning to USB cable so I could listen to my iPhone since the BT input is already assigned to the TV.

Hello @mrjktcvs

You don't have to do a new pairing when switching from one device to another. You have to stop using Bluetooth audio on one device and then connect to the SU-6 with a second device.

A parallel connection to two devices is not possible but one after the other is possible and it is working without any issues.

Cheers
Nick

 

[Acerun]

Does anyone also have the matching SH-6 amp? Amir should be reviewing soon.

 

[confucius_zero]

- I hate popping sound when switching to different songs through my library (whatever the root cause may be)

it has "popping sound" O____O

 

[Nick_L]

it has "popping sound" O____O

@confucius_zero

My DAC Schiit Modi 3+ has this behaviour (please check post #253 of this thread). The SU-6 is silent.

Nick

 

[shrimp_dude]

Does anyone know if reducing volume on this dac to attenuate for a sensitive amp will reduce sound quality?

I ask because I saw on the Gustard X16 thread that Gustard recommended not reducing volume on their dac as it would degrade the SQ (however they said it's okay on their more expensive X18 due to a good post-dac attenuator).

I've always thought reducing volume digitally on a dac would make a marginal difference at most only if attenuated significantly - what is correct here?