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SMSL M500 Teardown & ESS ES9038Pro DAC Thermal Analysis

I wonder if all of those test points on the board are showing stable and expected voltages. This one is running a bit long, but it might be valuable just to test them. I'm pretty sure most folks are of the opinion that this thermal "issue" is a design "issue". Therefore, perhaps something is awry in the implementation.
 
What this means is terrible: there is a narrow temperature range where the ESS DAC in this implementation performs its best. We saw an attempt by Sabaj to deal with this in the D5 whereby they put a heatsink on the ESS DAC chip. This reduced power up performance but allowed temperature to stay low enough within the good performance range of the ESS DAC.

Sensitivity of other components
I cooled off the output OPamps and they made no difference whatsoever. So the sensitivity is definitely in the ESS DAC chip. Note however that this may be circuit dependent.

Conclusions
As with "ESS IMD Hump," ESS seems to be doing a terrible job of providing a stable reference design for designers to use. They are left to deal with these issues on their own. Having a chip lose 3 to 4 dB of performance with 10 to 20 degree temperature change is just unacceptable.

It remains a mystery why the sample I have works in reverse. It may be that it is a DAC chip that is working above its spec when cold and only degrades when it gets colder.
Don't jump to conclusions too quickly! This behavior may be due to incorrect use of the 2nd and 3rd harmonic compensation registers. These registers should be used to compensate for the THD produced by the ESS chip. Unfortunately some manufacturers are using the compensation to correct the THD produced by downstream circuits. It is also possible that they are not using the compensation circuits, and this will cause thermal drifting. Incorrect settings in these registers can cause the ESS chip to drift thermally.

Also, from Benchmark's experience, we get better THD performance from the ES9028PRO than from the ES9038PRO. Benchmark is often asked why we do not use the newer ES9038PRO. The reason is that we place a higher priority on THD than on SNR. If we can solve the THD issues, we will move to the newer chip.

If the 2nd and 3rd harmonic compensation registers are incorrectly set, the thermal drift can be made to degrade with temperature or improve with temperature. Active THD compensation is a tricky thing. It is not easy to make it stable!
 
Lol...have you missed the 'Linearity' measurement under Amir's M500 review? In yes, please check below...nothing is emphasized as you can see.
This SoundNews guy is more like a sales person from what Ive observed. You tell me: how can you receive a V-Shaped signal from a DAC that measures so linear (again!, see below)? If you cant answer that...I suggest you read these subjective reviews with a truck load of salt. If making reviews was your bread and butter...you'd say anything to survive, perhaps like this guy...not necessarily reflected by objective measurements.

I think the Frequency Response graph is the one that tells us if the output sound is V-shaped or not. However, most DACs these days are pretty much linear with less than 0.5dB across audio spectrum.

Maybe the "SoundNews guy" is right when A/B testing DX7Pro vs. M500 with hard-to-drive headphones. Amir's graphs are for resistive loads only, so there might be a slight chance that with some headphones things to be a bit more different, especially when using longer stock cables with higher capacitive inductance.
 
I'm rather surprised that there has not been a response from Mandy or Liu on this issue. This product offers an astounding value proposition if it only remained stable or had more predictable performance.
 
Been using daily for months.
Super stable and predictable performance:).

Also using Tidal every day. Excellent, zero surprises.
Next MQA option is Topping D90 MQA edition. 2+ times the price.
I concur. Been using it with decently high end headphones like Arya and 800S and THX 789...sits perfectly and does what it's supposed to do really well. Always predictable, no glitches. For best MQA performance, set your SW to render first 2 unfolds and use M500 only to render...not that it can't do full decoding of MQA independently. Even if your unit does reduced the SINAD by 3db when hot...that's inaudible plus it only happens when using over 44.1K content....which itself may not have any point. Plus the extra optical is really handy to connect TV.

D90 is an option...but you will probably be getting the same performance beyond audibility for more than double (M500 can be had for USD 300 whereas D90 for USD 800 MQA ver.)
 
For best MQA performance, set your SW to render first 2 unfolds and use M500 only to render...
But why? As opposed to simply (Tidal):
2020-05-05_144101.png
 
But why? As opposed to simply (Tidal):
View attachment 62015
Just my observation... subjective. Don't fall into this trap. Try for your self to disable MQA passthrough and see if anything is audible. As I said...M500 is fully capable to decide MQA with passthrough. I just feel that "maybe" thing sound a bit more smooth with Tidal app decoding the first two layers...
 
On that note...I tried Audirvana with Tidal...a bit off topic...but man that wins the snake oil award of the decade...second maybe could be Audioquest cables and then oversampling of bits and "bit perfect" signals...it's funny how much subjectivity comes into play on the road to self discovery...
 
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I am considering replacing the flimsy power chord with an upgraded cable may be the AudioQuest NRG-3 .
Has anybody pursued this replacement and what differences were observed?
Thank you
 
I am considering replacing the flimsy power chord with an upgraded cable may be the AudioQuest NRG-3 .
Has anybody pursued this replacement and what differences were observed?
Thank you
The amount of AC power req'd for the unit is very small. The power cord upgrade would be a waste of money.
 
I concur. Been using it with decently high end headphones like Arya and 800S and THX 789...sits perfectly and does what it's supposed to do really well. Always predictable, no glitches. For best MQA performance, set your SW to render first 2 unfolds and use M500 only to render...not that it can't do full decoding of MQA independently. Even if your unit does reduced the SINAD by 3db when hot...that's inaudible plus it only happens when using over 44.1K content....which itself may not have any point. Plus the extra optical is really handy to connect TV.

D90 is an option...but you will probably be getting the same performance beyond audibility for more than double (M500 can be had for USD 300 whereas D90 for USD 800 MQA ver.)

A bit OT question, how do you compare Arya with HD800s?
 
Reading this thread at 2:00 a.m. gave me a head ache. I want to see the spec sheets on the adult human, and specifically their temperature/performance characteristics. Note that specs vary in some parameters for the male vs. the female versions, and especially with respect to temperature/performance characteristics. Maybe you've noticed. Are there male and female versions of SMSL dac's?
 
I am considering replacing the flimsy power chord with an upgraded cable may be the AudioQuest NRG-3 .
Has anybody pursued this replacement and what differences were observed?
Thank you
I did change mine for a custom one I a local guy did based of belden wire, good stuff, but I did this in parallel with other upgrades to the system and yes, the system is overall better, but I doubt the cable had much of an influence to the sound, if any. I didn't bother to check the difference sonically to the cable change separately, but I can try to see if there is a difference if that's important to you. Thing is, the that audioquest cable is super expensive for what it is. I know options are hard to find, but you should look around for alternatives. Some stores in AliExpress sell upgrade cables that will be as good of not better for way less money.

here is the one I got: https://allegro.pl/oferta/kabel-zasilajacy-belden-19364-osemka-c7-ekranowany-7934718095

here is an example of one from Ali:
Screenshot_20200613-095720.png
 
Hi, any idea what's the MSDS or SS (material safety) code for SMSL M500? My shipper is asking me as I am posting my unit internationally...

Can you guys help @SMSL-Mandy @SMSL_Liu

Thanks
 
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Hi, any idea what's the MSDS or SS (material safety) code for SMSL M500? My shipper is asking me as I am posting my unit internationally... Thanks
No idea what is even that. I can try to help, but you need to tell me where I'm likely to find that. I doubt it's in the box, as it was very plain with not a lot on the outside.
 
No idea what is even that. I can try to help, but you need to tell me where I'm likely to find that. I doubt it's in the box, as it was very plain with not a lot on the outside.
Thanks my unit is at the customs and they are asking for this code. Maybe if you can check the box back side where Foshan etc is written. I checked the manual online and there's nothing...
 
A bit OT question, how do you compare Arya with HD800s?
Well...Arya is better sounding for sure but I listen to the 800S more as it's better built...just like the feel better that's makes me pick it up more. 800S lacks bass and you have to EQ it. Arya also benefits from EQ ... But doesn't need it....it's super balanced in all ranges. They both are almost equally open sounding albeit 800S presentation is a bit different...maybe not better but different! As for details, I feel Arya is more detailed just because it's a bit hotter in the upper end. Arya has more depth to sound... instrument separation is also maybe better on the Arya.

If you can get the 800S for US$800 used mint like I did...it's worth a shot! You won't regret it and you won't need another headphone if you EQ it. Buying new...go for Arya at US$1600 plus tax....oh! And one more thing beware of the Chinese HiFiMan quality... although I've not heard much complaints for their higher end gear like the Arya but that something you should bear in mind...mine has worked flawlessly and their customer service is one of the best in the world! If you are in to buying Chinese gear, I suggest Aoshida HiFi on AliExpress for DACs and other stuff ... for example I'm gonna buy my M500 V2 from them. Their customer service has been bullet proof till now and I've been using them for years and they always stand by their product sales going the extra mile to.make you happy! I feel Chinese stores are great at that...good luck with your purchase!

More info on your question is here:
 
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