S.M.S.L PO100 AK - Measurements / Round 2 (DAC)

[ManniX]

I did notice a little drop with test tones around 12 kHz but nothing really dramatic.
Anyway I'm old and above that frequency can't really hear anything.

I like how it sounds and decodes both PCM & DSD. At least as much as I like most of more expensive DAC.

If you have fine ears and want a workaround for the FR you can use a DSP chain in foobar2000 v1/v2 with dbPoweramp:

Configure the first as follow to up-sample to 88.2 kHz everything below at the same base sample rate:

Excluded rates:
8000,16000,24000,32000,48000,64000,96000,88200,176400,192000,352800,384000,705600,768000

Configure the second as follow to up-sample to 96 kHz everything below at the same base sample rate:

Excluded rates:
11025,22050,44100,88200,96000,176400,192000,352800,384000,705600,768000

If you have something above 768 kHz add the rates at the end of the string of both.

You can do the same with the SoX mod2 plugin but it's only available on foobar v1.

 

[ManniX]

My Aoshida's rep, Tryna, is very nice and available.
Seems the SMSL factory is willing to build at least one other firmware with a different filter.
I asked them to change it to "Sharp Roll-Off" and if possible also another with the "Super Slow Roll-Off" (NOS).
Let's see...

 

[VintageFlanker]

Seems the SMSL factory is willing to build at least one other firmware with a different filter.

Thanks.

If S.M.S.L did the job from the start, they don't need to "build" anything specifically. The PO100 line is firmware upgradable as far as as know, so would be the possibility to apply a different AKM filter that way.

 

[ManniX]

If S.M.S.L did the job from the start, they don't need to "build" anything specifically. The PO100 line is firmware upgradable as far as as know, so would be the possibility to apply a different AKM filter that way.

I'm definitely not even close to being knowledgeable about DAC filters.
I base my whole understanding of AKM filters on this post:

DAC Filters

When it comes to filters, which one do you choose for the most honest and faithful reproduction? Everyone will have their own prefences but that does not mean its the closest to the source, if its even audible in the first place. How do we know which one is the most accurate?

www.audiosciencereview.com

Which is incidentally from SMSL's M300 MK II marketing material.
Which is, as pointed out by @KSTR, "taken right out from AKM's marketing material".

This is a very cheap product so they had to decide one and only one filter to enable (to avoid cannibalizing sales of the more expensive ones).

I suspect the following two outcomes:

• During MQA certification someone suggested to use the "Slow Roll-off" to hide under the carpet some of the MQA's nasty defects
• Someone without knowledge (I swear, wasn't me!) looked at AKM's table and picked the best one in the middle; with the Edge "Middle", the most nice looking Impulse Response graph and the nicest thing in Remarks ("Minimal echo" better than "Short Eco"), hence "Slow Roll-off" is the winner

 

[Toku]

I bought the PO100AK immediately after its release, but at that time I felt that the extension of the high-pitched sound of the analog output was a little lacking. So if the improved version is released, I would like to buy it immediately and compare it

 

[ManniX]

I bought the PO100AK immediately after its release, but at that time I felt that the extension of the high-pitched sound of the analog output was a little lacking. So if the improved version is released, I would like to buy it immediately and compare it

I only noticed it while comparing the amp and the integrated Realtek DAC using 44.1 kHz test tones.
Listening to music not at all; mostly listening to High-Res and the Heil AMT tweeter is very bright by nature.

 

[ManniX]

Unfortunately it's very unlikely that SMSL is going to release a new FW with the Sharp Roll-off filter.
After a few days I asked "Tryna" if there was an update and it seems that now someone else is answering with that nickname.
Definitely not collaborative as the other rep.

 

[Toku]

Unfortunately it's very unlikely that SMSL is going to release a new FW with the Sharp Roll-off filter.
After a few days I asked "Tryna" if there was an update and it seems that now someone else is answering with that nickname.
Definitely not collaborative as the other rep.

That's no surprise. SMSL is a company that has been doing that kind of customer service for a long time. So I don't expect any FW updates at all.

 

[ManniX]

I was definitely not expecting any goodwill action from SMSL.
Was hoping to break the linguistic and cultural barrier with the Aoshida rep.
They sell the SMSL and Topping products and if you can convince them, it's likely they can convince the manufacturer to do anything you ask.

SMSL and Topping are typical Chinese manufacturers; they likely don't produce anything (or almost) in-house.
The mass production is probably outsourced to a number of external fabs here and there in deep mainland China where it's cheaper to produce.

If you check Topping website there's not even a picture.
SMSL has a couple of photos of the offices (that may well be renderings).

There's not a single picture of their production lines.
Since 99% of manufacturers in China are just shell companies that can use a language translator, when they have a production line for real they always strive to show it with some picture and smiling faces.
But of course you need to account that often those pictures are fakes, which happens very often...

I don't expect any kind of proper customer support or QA from these guys
Nice products for a cheap price but you have to be lucky that you'll never need help with anything.

 

[Toku]

SMSL's products may be produced for specific sales channels depending on the model. The PO100 series is not handled by Shenzhen Audio or HIFI EXPRESS and is only sold by Aoshida HiFi. The same is true for AO200, DO100, DO200, and DO300.
Therefore, the PO100 series is probably planned and sold by Aoshida HiFi.
SMSL does not accept any inquiries about such products, and it seems that users need to consult Aoshida HIFi, the planning and sales agency. However, such information is completely invisible to the user. It's very annoying.
(from my experience so far)

 

[ManniX]

There is actually another way to overcome the AK4493S Slow Roll-off 8 KHz passband limitation.
I'm a bit struggling understanding why such a filter even exist in a DAC that is supposedly meant for Hi-Fi audio.
What is it for? Telephony? VOIP?

And of course it's puzzling that SMSL did "choose" it as the default and only option for the PO100.
Doesn't really inspire confidence in their expertise...

Anyway, this method works for the PO100 AK and of course with any DSD native capable DAC.
Disclaimer: forget about PCM bit-perfect decoding.

The DSD Processor, in my opinion, does quite a very remarkable job converting PCM to DSD.
You can set it to convert PCM and the difference is very remarkable.
I always liked more the native DSD content than PCM on this DAC but it's also better for me with all PCM content converted to DSD.

You can set this way the DSD processor:

And also the precision to fp64:

From the limited testing so far even 88,2 and 96 kHz content sounds better converted in DSD.
Still have to test with some high quality DxD content.
And I'm not the kind of guy that can feel the difference in filter settings usually, quite the opposite.

There are some drawbacks of course.

There's no control on the PCM decoding of the DSD Processor.
I have no idea what is doing and what artefacts could produce.
In native DSD mode there's no filter just a sharp cutoff at a very high frequency, see the table below:

It could be very well an issue with very good setups were the unfiltered artefacts could be noticeable.
Unless the DS Processor is doing some filtering while encoding in DSD, unknown.

Another problem is that there's no per device or profile for the DSD Processor.
Basically with this option you are limited to listen thru the ASIO DSD transcoder output.
Any PCM content will not playback on the standard ASIO, DS or Wasapi output.

Also the SMSL driver will crash if any attempt is made to playback DSD thru DS/Wasapi and you have to reboot to restore the device.

This also kills the option to use DSP processing which is a show-stopper for me since I use EqualizerAPO on Wasapi.
Which sounds better than the native bit decoding at low sample rates but still worse than DSD native.

Which lead me to think that maybe I don't like that much the AKM PCM filters in general.
I still have a one week window to return the PO100 so I decided to try something different.

Ordered an Aune X8 XVIII BT and I should receive it tomorrow, it's using an ESS DAC.
I'm curious to see if I find it more likeable to my ears.
Then I will decide if to keep it, at least for a while, or survive a bit more keeping the PO100.

Not sure anyway I'll keep the Aune cause it does have some defects and missing features which I'm not fond of at all.
First, it seems the filter setting is reset after power loss. And that's how I would use it... if I don't like the default filter, I'll send it back.
Second the lack of pairing with Bluetooth which is a serious flaw.
Third I don't like at all the missing 12V trigger ports which are very useful in home automation, which is even worse considering is missing an RCU.

It's also way over the budget I would spend on a Chinese DAC but at least it's supported by the Austrian distributor.
Let's see...

 

[Veri]

Ordered an Aune X8 XVIII BT and I should receive it tomorrow, it's using an ESS DAC.
I'm curious to see if I find it more likeable to my ears.
Then I will decide if to keep it, at least for a while, or survive a bit more keeping the PO100.

Not sure anyway I'll keep the Aune cause it does have some defects and missing features which I'm not fond of at all.
First, it seems the filter setting is reset after power loss. And that's how I would use it... if I don't like the default filter, I'll send it back.
Second the lack of pairing with Bluetooth which is a serious flaw.
Third I don't like at all the missing 12V trigger ports which are very useful in home automation, which is even worse considering is missing an RCU.

It's also way over the budget I would spend on a Chinese DAC but at least it's supported by the Austrian distributor.
Let's see...

I have an Aune X8 but the original. Oddly enough, that model does "remember" the filter setting. So no complaints there.
I have mine since January 2022 now so... I can say I do "like" it. Stood the test of time so far!

 

[ManniX]

I have an Aune X8 but the original. Oddly enough, that model does 'remember' the filter setting. So no complaints there.
I have mine since January 2022 now so... I can say I do "like" it. Stood the test of time so far!

Yes, I've read the original didn't have this issue.
Don't know much the brand so I'm wondering how decent or not their support is.
There are some interesting things like the opamp rolling (probably not my fetish but let's see) and the very high bitrate on SPDIF ports.
Intriguing that there's some additional engineering compared to the rest.
Thanks for the feedback!

 

[ManniX]

Well, didn't have much time to test it as it has arrived in the late afternoon, but it's definitely another class of DAC.
Don't know exactly how to express it in fancy words but the sound of the PO100 AK is thin in comparison, this is definitely better.
"Full bodied" as I've read often.
There's also really much more detail, everything is rendered. Impressive.
Still have to try the other opamp that cam with the DAC.
It's so good that I'm seriously considering to keep it despite the filter bug and the other shortcomings.
BT works really well with LDAC but it does advertise itself also as "aune X1S-LE" as reported.
No support for pairing sadly and it's always on despite the input selection.

 

[VintageFlanker]

Don't know exactly how to express it in fancy words

Honestly, we don't expect you to do so.

Still have to try the other opamp that cam with the DAC.

No, you still have to try a proper controlled listening, that's for sure.

 

[flowjm]

Well, didn't have much time to test it as it has arrived in the late afternoon, but it's definitely another class of DAC.
Don't know exactly how to express it in fancy words but the sound of the PO100 AK is thin in comparison, this is definitely better.
"Full bodied" as I've read often.
There's also really much more detail, everything is rendered. Impressive.
Still have to try the other opamp that cam with the DAC.
It's so good that I'm seriously considering to keep it despite the filter bug and the other shortcomings.
BT works really well with LDAC but it does advertise itself also as "aune X1S-LE" as reported.
No support for pairing sadly and it's always on despite the input selection.

No need for fancy words or any subjective opinions, for that matter. What is the data that shows the 'full bodied' sound, and 'much more detail'?

 

[ManniX]

Honestly, we don't expect you to do so.

Perfect

No, you still have to try a proper controlled listening, that's for sure.

Controlled listening here is very unlikely...

No need for fancy words or any subjective opinions, for that matter. What does the data show?

A subjective opinion it's the only thing I can provide, I don't have any measurement device sorry.
Can do protocol analysis of HDMI, Bluetooth, WiFi, etc but nothing about audio.

 

[VintageFlanker]

Controlled listening here is very unlikely...

At least, measuring output voltage of both is extremely important (a 50€ Digital Multimeter RMS is enough). By the way, are you using the balanced TRS output of the X8 ?
Also, this could be measured if you would be interested for a loan.

 

[ManniX]

At least, measuring output voltage of both is extremely important (a 50€ Digital Multimeter RMS is enough). By the way, are you using the balanced TRS output of the X8 ?

No I'm not using the TRS, jus the fixed line input.
I have a decent DMM, not a Fluke.
Sorry for the ignorance, why is that so important to measure the output voltage of both?
I have a UMIK-1 but no fancy USB input for audio.

Also, this could be measured if you would be interested for a loan.

This could be interesting... but I'm in Europe.
Will definitely have to wait a bit for the return window to close.
That if I decide to keep it of course.

I will try to do some controlled listening but it's very hard here.
There's a huge construction just outside the window to renovate the square in front.
When they are not working there's almost always a lot of people and it's noisy.
It's quiet only when it's forbidden to make noise

 

[VintageFlanker]

Sorry for the ignorance, why is that so important to measure the output voltage of both?

Because if you're comparing a 2.1Vrms (what comes out the PO100 AK) versus, for instance, some 2.6Vrms output, then any listening comparaison is pointless. Almost everyone will (believe to) prefer the higher output, regardless of the real performance. Classic trick from many manufacturers to just have over "standards" output voltage for DACs/CD Players, or exaggerated Gain for amplifiers (which some regular audiophiles may translate into "more powerful", unless it is not).

but I'm in Europe.

Isn't France also in Europe?