SMSL M400 Balanced USB MQA DAC Review

[misterdog]

The big plus to me is that XLR interconnects have a grounded shield, I use quad core which has added twisted pair noise cancellation.
Because this cable is used by the pro industry, they manufacture thousands of miles of the stuff, so it costs peanuts - like..
Because I use monoblock amps I have 4Metre interconnects and they have to run parallel with mains cables.

So if anyone tells me that 'RCA might be better' my eyes are closed.

The M400 has no engineering shortcomings via XLR, and sounds superb through my Quad 989 ESL's, chosen for their lack of distortion.

I was quite shocked when I first plugged in my M400, it revealed each layer fed into the mixing desk with a clarity not heard before.

 

[Veri]

The M400 has no engineering shortcomings via XLR, and sounds superb through my Quad 989 ESL's, chosen for their lack of distortion.

I was quite shocked when I first plugged in my M400, it revealed each layer fed into the mixing desk with a clarity not heard before.

Congrats Sounds awesome.

 

[BAMCIS]

????????
Can you explain that? Because that makes completely no sense to me.....

Sure, I guess that was too vague an analogy. A sup par medium such as cassette tape and RCA outputs- both are inferior to the alternative (CD, SACD, hi-rez audio, XLR outputs)

 

[JohnYang1997]

Though if people need to chase the last 0.00001 SINAD they should be looking at something other than RCA, my 10 cents.

If RCA can reduce performance or collect external 'noise' of 0.00001 % then XLR is the way forward in my book and has been for the last 5 years in my system.

With XLR there is a measured difference with single and twisted pair geometry in cables, so RCA is hardly a pinnacle for audio engineering. ( though 'good enough' in the 1940's).

L30 has proven otherwise. It's when getting down below -140db and less than 0.2uV, the unbalanced connection is getting in the way.

 

[BAMCIS]

True, but we don't have an exact value for the output impedances. The sum would get us 1.2kΩ, which is about what is suggested. The 1611s on the unbalanced are clearly just creating an unbalanced from the balanced signal. But the 1612s should be otherwise the same drive capability.
It seems odd having so much resistance on the output. I guess they are current limiting the output. But odd none-the-less.
All I'm looking at is the specific suggestion that there is an explicit and unusual lack of output buffer that is characterised by the high output impedance. So far as I can see that output impedance is completely explained by the choice of passive components on the output. Whether this is a good idea is another matter.

Does using an XLR 'Y' splitter to feed an extra identical amplifier have a negative effect on the impedance / signal? I assume it halves the impedance? Sorry for the rookie question but I have always wondered about this since pre amps with dual XLR outs are so rare. The only DAC I've seen with dual XLRs is the Okto dac8 Stereo

 

[samdas]

Hi

i need help with SMSL M400 capacitors replacement, i cant find any tutorial.
Please help me.

 

[Francis Vaughan]

Does using an XLR 'Y' splitter to feed an extra identical amplifier have a negative effect on the impedance / signal? I assume it halves the impedance? Sorry for the rookie question but I have always wondered about this since pre amps with dual XLR outs are so rare. The only DAC I've seen with dual XLRs is the Okto dac8 Stereo

The impedance seen by the source is the two inputs in parallel. The general formula for this is the reciprocal of the sum of the reciprocals of the impedances. But assuming the input impedances are about the same, just assume half. In general there is more than enough padding built into the numbers that you need not worry. Maybe if you had a 10 way split you would start to see issues.

 

[Francis Vaughan]

Hi

i need help with SMSL M400 capacitors replacement, i cant find any tutorial.
Please help me.

That is a very wide ranging request. What capacitors and why replace? If this is some idea of improving the audio performance with high end capacitors, the answer is don’t. If you need to ask how you will almost certainly mess it up and wreck the device. If you do already know how, you would understand that it is a waste of time. It will just destroy any resale value and make no difference to the sound.

 

[samdas]

That is a very wide ranging request. What capacitors and why replace? If this is some idea of improving the audio performance with high end capacitors, the answer is don’t. If you need to ask how you will almost certainly mess it up and wreck the device. If you do already know how, you would understand that it is a waste of time. It will just destroy any resale value and make no difference to the sound.

Hi Francis,

Thanks for your answer please see the post regarding the capacitors from the manufacturer post.

https://www.audiosciencereview.com/...-usb-mqa-dac-review.13732/page-19#post-469606

 

[Francis Vaughan]

Ugh. I had forgotten about all that. The device is all surface mount. You need developed soldering skills and reasonable quality soldering tools before you think about going anywhere near that. Preferably a hot air rework station, but with care it could be done with a conventional iron. That said, it would appear that the intent is to change a couple of capacitors in the output filter. Given there are no markings on the capacitors on the existing PCB it is impossible to know what the design has currently chosen, and what might be correctly substituted. Unless the manufactuer actually decided to honour the promise to provide the needed infomation (and I very much doubt taht they will) you are on your own. OTOH, the defect is trivial. I would simply ignore it.

 

[James. B. Lansing]

Have any of you actually listened to the M400, it is better than topping's D90 and peoples attempts to discredit are disappointing.

It is one of the best DACS I have every listened to and I have plenty of DACS to compare it with.

 

[Jimbob54]

Have any of you actually listened to the M400, it is better than topping's D90 and peoples attempts to discredit are disappointing.

It is one of the best DACS I have every listened to and I have plenty of DACS to compare it with.

How does it compare to the DAC in the chromecast audio?

 

[James. B. Lansing]

How does it compare to the DAC in the chromecast audio?

That's my reference!

 

[MakeMineVinyl]

Because we already have an XLR interface with very good performance, we hope that the RCA interface is more musical, this is a design based on sound adjustment, and I hope this interface is more analogous! There is no problem! Just like the normal SLOW type of digital filter will also have a great attenuation in the high-frequency range!

If the parameters data need to be better, we only need to change the output capacitance value.
View attachment 75673
We can provide tutorials and tools, which will be updated later, you can contact the seller to get capacitors and tools for free.

I am potentially purchasing this DAC. Could you please tell me the value of the capacitors and resistors in the RCA's low pass filter. I would like to eliminate the droop at 20kHz on the RCA output. I have these parts at my disposal - I just need the values to use.

 

[MakeMineVinyl]

Has been explained before. It affected by capacitance. The original RCA design is more musical. So a higher capacitance value is used.

If your mind, we can provide tools and accessories for replacement. We can also provide more DIY solutions, which can be adjusted according to personal preference. E.g. low impedance Because every consumer’s preferences are different and different usage scenarios. As the manufacturer, on the one hand, it will pay attention to the actual situation of use, on the other hand, keep high parameters.

Hope you can try its RCA output, comment based on actual usage. Thanks.

Could you please provide us with the values of the resistors and capacitors used in the passive filter on the RCA outputs? I'm an engineer, and can calculate the values needed for flatter response, but I need to know what's there now. I want the RCA output to be flat not 'musical'.

 

[misterdog]

I want the RCA output to be flat not 'musical'.

Max Richter might disagree.

I now tend to roll off a lot of the high end in the electronics in my music, and this makes them sound very vintage-like.

With close on 6 million views he must do something right.

 

[ShiZo]

Then let it me mastered into the music...

 

[MakeMineVinyl]

Max Richter might disagree.

With close on 6 million views he must do something right.

If I want to roll off the highs, that's what tone controls are for. I don't want somebody (especially someone I've never heard of), making these calls, no matter how many 'views' they may have.

 

[misterdog]

I don't want somebody (especially someone I've never heard of), making these calls, no matter how many 'views' they may have.

I suspect he is not the only mixing engineer/producer/artist to do such.

How many complain of high frequency fatigue in digital. Usually those who have heard good quality vinyl reproduction.

 

[MakeMineVinyl]

I suspect he is not the only mixing engineer/producer/artist to do such.

How many complain of high frequency fatigue in digital. Usually those who have heard good quality vinyl reproduction.

It really depends on the individual recording. Of course some rock recordings can sound like trash, but honestly I've not run into this problem with recent releases of all genres. At any rate, if a recording has an excess of high frequencies, that can be easily remedied by the tone controls.