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SMSL M400 Balanced USB MQA DAC Review

misterdog

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I already wrote here a year ago mfrs could be tempted to make whatever it takes in order to solely achieve the measurements in detriment of whatever other parameters, as seen here. Now finally it happened, doesn't surprise me.

Which 'other parameters' would you focus on if you were a DAC designer ?

Does not reducing the SINAD mean that more music is available ? Whether that is useable to you in your system is entirely driven by the other components in your audio chain.
 
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Googolbyte

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Sorry,don't have that price ever. Please don't talk nonsense

You're right, it was nonsense :facepalm: I was deciding between the SU-9 and the M400 and I ended up getting the SU-9, which is actually at $400. My wife pointed out the mistake to me earlier to day.

My bad!
 

ethanhallbeyer

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can someone explain how the high output impedance impacts you in the real world? say you have a dac, preamp, and amp in your chain.
 

MakeMineVinyl

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As long as the input impedance of the gear you're hooking the DAC to is 10,000 ohms or more there won't be any difference. The output impedance of the DAC is not all that high in the grand scheme of things.
 

Nango

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JohnYang1997

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Screenshot_20201022-131713.jpg

Stop. Just stop.
 

Nango

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So, is it not true the mfr voided (without notice!) the output stage in order to gain +1/2 dB in SINAD terms making its DAC less compatible with other market amps? Because, thats what I read from the msgs I posted. Thanks ASR a device got less versatile and usable than it was before, isn't it?
 

JohnYang1997

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So, is it not true the mfr voided (without notice!) the output stage in order to gain +1dB in SINAD terms making its DAC less compatible with other market amps? Because, thats what I read from the msgs I posted. Thanks ASR a device got less versatile than it was before, isn't it?
Quite the opposite. It's called competition. ASR didn't do its favor by measuring at 4V instead of the full output voltage which gives extra 2dB performance boost.
Just stop with your nonsense.
 

JohnYang1997

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Non "standard" voltage has been implemented by many other companies as well. One of them is Chord, product is Mojo having 3V output. Chord is then again not a Chinese company but is from UK. This won't be an issue tho as you can always change level. It's not a dac that always output full level without a volume control.
Also there was no standard to begin with. It's just that recent years many companies seem to use 2V/4V a lot than else. If you look before that it's rare to see these "standard" voltages.
 

Nango

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I dont call it competition, I call it opportunistic behaviour. Dont know if Chord discloses what they do in order to gain an additional 0,5dB to rank first, SMSL did certainly not, until ASR got them. Not really talking about the specs, get the clue!
 

JohnYang1997

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I dont call it competition, I call it opportunistic behaviour. Dont know if Chord discloses what they do in order to gain an additional 0,5dB to rank first, SMSL did certainly not, until ASR got them. Not really talking about the specs, get the clue!
You can think whatever you want. But don't just be judgemental because you could assume something out of seemingly evidence. Competition between SMSL and Topping has been happening since about a decade ago. If you want to continue, you can go ahead. Everyone else around here already got a clear picture.
 

Nango

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As long as the input impedance of the gear you're hooking the DAC to is 10,000 ohms or more there won't be any difference. The output impedance of the DAC is not all that high in the grand scheme of things.
Thats exactly the point. I never paid attention to that figure while searching for an amp, but now it is becoming essential and key (OTOH I might have soon 130,5 dB instead of "only" 130dB and my DAC ranks first on ASR tables where 120 dB is the end of the hearing threshold, .... happy!!!).

Only few mfr do disclose such figures. The Atom is btw just that 10k. Heresy is 25k.
 
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MakeMineVinyl

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Thats exactly the point. I never paid attention to that figure while searching for an amp, but now it is becoming essential and key (OTOH I might have soon 130,5 dB instead of "only" 130dB and my DAC ranks first on ASR tables where 120 dB is the end of the hearing threshold, .... happy!!!).

Only few mfr do disclose such figures. The Atom is btw just that 10k. Heresy is 25k.
It is very difficult to find an amplifier who's input impedance is below 10k; the vast majority have input impedances far above this. The manufacturers don't state this spec because its always high enough so the amp is unlikely to load any upstream component you're likely to use with it. Its simply a non-issue in the real world.

As I posted earlier in this thread, I have the SMSL M400 and I bought it specifically because of the passive output filter. Adding a buffer stage is always going to degrade performance, even if a very slight amount. A passive filter is always going to be cleaner than an active filter. If active circuitry can be eliminated without compromising performance in other areas, it is always better to eliminate it. My background in designing large multi-channel audio mixing consoles made this point obvious; less is cleaner.
 
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Nango

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Again, it is primarily not a question of specs. You learnt (probably) from ASR the issue with no stage output and were free to decide to buy it. That's fine. And it seems from the labeling in your profile you are a mfr so you understand better than others why it is a non-event or not. But it may condition - to a lesser or not extent - the use of other gear. Gaining 0,5 dB in SINAD terms by sacrifying whatever else, no matter it is senseful or not, is not really a step forward in science .... it is more like "robbing Peter to pay Paul". But lets end here this issue. Thanks.
 

MakeMineVinyl

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Gaining 0,5 dB in SINAD terms by sacrifying whatever else, no matter it is senseful or not, is not really a step forward in science .... it is more like "robbing Peter to pay Paul". But lets end here this issue. Thanks.
Could you tell me specifically what is being sacrificed by the passive output? 1,200 ohms is not all that high an output impedance, and as a designer myself for a relatively large audio manufacturer, I see and use buildout resistors all the time on the output of line stages; it is standard practice. Generally its done so that muting relays can short the output during bootup so pops and other noise don't manifest themselves, but its also done for other reasons. All that is taking place in this DAC is that they are using the IV stage (itself a high quality opamp) as the 'output stage' and combining the tasks of buildout resistors and filtering together. A rather smart move I would say. If I were designing a DAC for my own use, this is the way I would handle the output.
 

Nango

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If this is such a brilliant move I would have emphasized to ASR even more!!! But they preferred to hide "the great discovering". Anyway, its ok. Again, it is not about specifically 1.200 or 2.200 ohms.
 
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