SMSL M400 Balanced USB MQA DAC Review

[wargreymon]

I just got a reply from SMSL that their output impedance is 470ohm while Topping D90 having 100ohm for unbalance and 200ohm for balanced output.

Having hard time decide between these 2

 

[777]

I just got a reply from SMSL that their output impedance is 470ohm while Topping D90 having 100ohm for unbalance and 200ohm for balanced output.

Having hard time decide between these 2

You can put over 470ohm resistors an 33uH (DCR few ohm's) 0804 smd package coil.

 

[amirm]

Can we get a zoomed in version of the SINAD chart of the far left, showing only the top 10-20 or so? Otherwise the chart is unreadable..

Thanks...

It is a full resolution chart. Click on it and it will show the original. Be forewarned though that the horizontal axis is approaching 4,000 pixels! So you need to scroll left and right to see it all.

 

[JohnYang1997]

I just got a reply from SMSL that their output impedance is 470ohm while Topping D90 having 100ohm for unbalance and 200ohm for balanced output.

Having hard time decide between these 2

Thats definitely not 470. I just measured it it's 609 per side. So 1218 for balanced output.

 

[Francis Vaughan]

I tend to think the SMSL design - even though it is almost exactly the datasheet example circuit is a bit odd.
As noted, they have ignored one half of the DAC. There are two channels of output that are not used. The Topping design uses all 4 channels and sums pairs. This should lead to less noise and generally a small increment in accuracy.
The AKM datasheet depicts summing all 4 outputs for a mono DAC. I can't see why a designer would not go for summing pairs. It is a few cents on the BOM. (Maybe AKM offer a secret cheap part when one half doesn't meet spec )
Output buffer is a curious question. I had not twigged that the 100Ω and 510Ω resistors were part of the output filter. They are mixed in with the mute transistors on the PCB. In principle an output impedance of about 1kΩ is no big deal. It simply forms a potential divider wit the input impedance of whatever it feeds. So feeding a 10kΩ input means you get 91% of the output voltage going into your device. A 100Ω output impedance would see 99%. Where it might start to be noticeable is feeding devices with unusually low input impedances. In the extreme, say 1kΩ input, you get only 50% of the input voltage.
If you used cables with noticeable capacitance you might get a just perceivable roll off in the high end. Certainly there was evidence that the golden eared could use different cables as tone controls, and ascribe the subtle change in sound to the special qualities of the unobtainium eye-wateringly expensive design.
But connecting the output filter, unbuffered, straight to the outside world does bother me. Maybe it is fine. It just bothers me. I can't help but feel that AKM were stretching for the best possible measurements on a reference design.
IMHO the Topping is a much nicer design all round. OTOH, I am more than happy with DX3 Pro and D50s. So I'm not going to be springing for any of these ultra high performance DACs. We have already reached peak DAC.

 

[Veri]

In principle an output impedance of about 1kΩ is no big deal. It simply forms a potential divider wit the input impedance of whatever it feeds. So feeding a 10kΩ input means you get 91% of the output voltage going into your device. A 100Ω output impedance would see 99%. Where it might start to be noticeable is feeding devices with unusually low input impedances. In the extreme, say 1kΩ input, you get only 50% of the input voltage.

Thanks for explaining

 

[wargreymon]

Thats definitely not 470. I just measured it it's 609 per side. So 1218 for balanced output.

Manufacturer claims are bias

I tend to think the SMSL design - even though it is almost exactly the datasheet example circuit is a bit odd.
As noted, they have ignored one half of the DAC. There are two channels of output that are not used. The Topping design uses all 4 channels and sums pairs. This should lead to less noise and generally a small increment in accuracy.
The AKM datasheet depicts summing all 4 outputs for a mono DAC. I can't see why a designer would not go for summing pairs. It is a few cents on the BOM. (Maybe AKM offer a secret cheap part when one half doesn't meet spec )
Output buffer is a curious question. I had not twigged that the 100Ω and 510Ω resistors were part of the output filter. They are mixed in with the mute transistors on the PCB. In principle an output impedance of about 1kΩ is no big deal. It simply forms a potential divider wit the input impedance of whatever it feeds. So feeding a 10kΩ input means you get 91% of the output voltage going into your device. A 100Ω output impedance would see 99%. Where it might start to be noticeable is feeding devices with unusually low input impedances. In the extreme, say 1kΩ input, you get only 50% of the input voltage.
If you used cables with noticeable capacitance you might get a just perceivable roll off in the high end. Certainly there was evidence that the golden eared could use different cables as tone controls, and ascribe the subtle change in sound to the special qualities of the unobtainium eye-wateringly expensive design.
But connecting the output filter, unbuffered, straight to the outside world does bother me. Maybe it is fine. It just bothers me. I can't help but feel that AKM were stretching for the best possible measurements on a reference design.
IMHO the Topping is a much nicer design all round. OTOH, I am more than happy with DX3 Pro and D50s. So I'm not going to be springing for any of these ultra high performance DACs. We have already reached peak DAC.

Guess the output impedance is kinda neglectable since most of the input is quite high.

Seem like D90 is the more convincing one to go with. I have a harder time to convince myself to get M400 than D90

 

[Abodh]

I tend to think the SMSL design - even though it is almost exactly the datasheet example circuit is a bit odd.
As noted, they have ignored one half of the DAC. There are two channels of output that are not used. The Topping design uses all 4 channels and sums pairs. This should lead to less noise and generally a small increment in accuracy.
The AKM datasheet depicts summing all 4 outputs for a mono DAC. I can't see why a designer would not go for summing pairs. It is a few cents on the BOM. (Maybe AKM offer a secret cheap part when one half doesn't meet spec )
Output buffer is a curious question. I had not twigged that the 100Ω and 510Ω resistors were part of the output filter. They are mixed in with the mute transistors on the PCB. In principle an output impedance of about 1kΩ is no big deal. It simply forms a potential divider wit the input impedance of whatever it feeds. So feeding a 10kΩ input means you get 91% of the output voltage going into your device. A 100Ω output impedance would see 99%. Where it might start to be noticeable is feeding devices with unusually low input impedances. In the extreme, say 1kΩ input, you get only 50% of the input voltage.
If you used cables with noticeable capacitance you might get a just perceivable roll off in the high end. Certainly there was evidence that the golden eared could use different cables as tone controls, and ascribe the subtle change in sound to the special qualities of the unobtainium eye-wateringly expensive design.
But connecting the output filter, unbuffered, straight to the outside world does bother me. Maybe it is fine. It just bothers me. I can't help but feel that AKM were stretching for the best possible measurements on a reference design.
IMHO the Topping is a much nicer design all round. OTOH, I am more than happy with DX3 Pro and D50s. So I'm not going to be springing for any of these ultra high performance DACs. We have already reached peak DAC.

What was your SAT score?

 

[ShiZo]

Topping D90 has a secondary windings for all 7 stereo op-amps with only 0,1A. So, it has a output buffer but it has not enough current. The sound is faint, without contrasts, 2D, without transients.
So, Topping or SMSL are the same...... They care only about the measurements, not about the sound. It is just a marketing strategy to kill the western audio companies.
If you want a good sound, you have too look elsewhere.

M400 is the best dav ive ever heard. That's compared to rme adi 2 dac v1 and v2, schiit jotunheim (yuck), d50s, e30, v35, all played through my hpa4.

Do you have some evidence to back up that claim. Does it frustrate you that chinese companies are making sota dacs affordably. And this is coming from a fanboy of german manufacturing.

 

[Veri]

Do you have some evidence to back up that claim. Does it frustrate you that chinese companies are making sota dacs affordably. And this is coming from a fanboy of german manufacturing.

I think it's clear user 777 has some kind of agenda or at least a significant bias...

 

[pinky-me]

Can anybody who has the DAC check if volume can be controlled via USB? Especially with DSD input?

 

[Jimbob54]

I think it's clean user 777 has some kind of agenda or at least a significant bias...

We had one of those not long ago. Didn't he use numbers for a handle?

 

[SMSL-Mandy]

Thats definitely not 470. I just measured it it's 609 per side. So 1218 for balanced output.

Topping has bought our M400? For compared? So soon.

 

[ShiZo]

Now that we have both topping and smsl representatives here... Any reason for the lack of attenuating to remove ultrasonics? Is it just considered inaudibe so not a concern?

 

[SMSL-Mandy]

I just got a reply from SMSL that their output impedance is 470ohm while Topping D90 having 100ohm for unbalance and 200ohm for balanced output.

Having hard time decide between these 2

The output impedance has nothing to do with the DAC, the main decision is the output impedance of the low-pass filter circuit, here 4 balance and 2 single both are 470.

As a signal source, this impedance is normal and has no impact on performance.

 

[dropbear]

A plexi top? I hope it is appropriately marked and highlighted in marketing materials as ScratchCatcher™, PC market tought us that it is not really that much more expensive to go with a full-fledged tempered glass. At this price point and with all what we can get for even 1/4 of a price of this device I find even this "detail" gaining a status of a point of consideration.

 

[ShiZo]

I actually like the top of my smsl m400, little bit of a fingerprint magnet. But that seems common for most audio devices lol. I dont like glass, it shatters and doesn't seem as strong. I'd take metal before glass.

 

[misterdog]

I prefer wood, but then I'm a cabinet maker.

 

[777]

I think it's clean user 777 has some kind of agenda or at least a significant bias...

No. I love China, I love chinese people. The problems are very punctual at Topping and SMSL. This problems are not at Denafrips, Gustard, Halo,etc... I have three of D90 dac's, one of mine and the other two from my friends. Did you like how they treat that high voltages at the connector ?

 

[ShiZo]

No. I love China, I love chinese people. The problems are very punctual at Topping and SMSL. This problems are not at Denafrips, Gustard, Halo,etc... I have three of D90 dac's, one of mine and the other two from my friends. Did you like how they treat that high voltages at the connector ?

Just spit it out then. If you have problem with topping or smsl why not just voice it. I'm not really understanding your problem with their devices but i definitely don't have the technical knowledge others do in this forum.