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Review and Measurements of SMSL VMV D1 DAC

bennetng

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"Higher those are moved, more the DAC's analog filter manages to cut those out and less ultrasonics there are going out to the amplifiers and loudspeakers. "

Is this what we're affraid of? That ultrasonic garbage may cause instability within the amp or burn the coils in the tweeters?
Hey, the point of interest is only the graphs, not those explanations. I am also not convinced when someone shows me a graph up to 5MHz but only has less than 50 pixels are below 20kHz. If you have further questions, better go to CA and talk with Miska, not me.

I myself have never encountered any so-called ultrasonic problems.
 

gvl

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Likely a simplification, but the bulk of the filtering is done digitally these days, the signal gets upsampled and the digital filter removes frequencies above source Nyquist. The analog filter downstream of the DAC chip only needs to suppress above oversampled Nyquist. With 8x redbook upsampling it is > 352.8kHz/2 = 176.4kHz. Delta-Sigma is different but similar principle applies, more or less anyway. Any accidental HF junk below that frequency will end up on the outputs.
 
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Krunok

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. Any accidental HF junk below that frequency will end up on the outputs.

Ok, but the question remains - why make fuss about the out of band garbage as neither the speakers/headphones can reproduce them nor we can hear them?
 
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amirm

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Ok, but the question remains - why make fuss about the out of band garbage as neither the speakers/headphones can reproduce them nor we can hear them?
Many amplifiers will be happy to reproduce up to 100 kHz and beyond. And many tweeters go above 20 kHz as well.

Here is an example amplifier (Mark Levinson):

1536361186603.png


Any my Revel Salon 2 speakers:

1536361321428.png
 

RayDunzl

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Here at Neverland East...

Preamp:
Frequency Response
0.4 Hz-220 kHz ±0.1 dB (Main Zone)
0.1 Hz-1.5 MHz ±3 dB (Main Zone)

Amp:
Hz to 20 kHz +0 dB, -0.05 dB
0.1 Hz to 240 kHz +0 dB, -3 dB

My speakers claim 24khz, but the impedance is quite low there, and unknown above that.

1536363651187.png


(similar speaker, but not the same exact model)

And an old Acurus A250 here:

The A250's frequency response was very nearly a demonstration of the overworked term ruler-flat. From 20 to 20,000 Hz, the output varied a mere +/-0.02 dB, falling (if that is the word) to -0.5 dB at 110 kHz and -1.5dB at 200 kHz.
 
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Blumlein 88

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Yes, I was chained to my analyzer running tests for you all. :D

Going to shop for a new computer monitor. Long drive to Fry's as none of the other places have much to look at.....

Just saw this. If its not too late, get one of those Dell Ultrasharp calibrated monitors. They are pretty sweet and not that much more expensive.
 
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amirm

amirm

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Thanks. I wanted to get something that I could see in person. Alas, they didn't have the unit I bought on display. But I got it anyway. It is a Benq PD3200u. It is almost perfect albeit, pretty expensive at $750 (32 inch, 4K monitor).
 

helloworld

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Thanks. I wanted to get something that I could see in person. Alas, they didn't have the unit I bought on display. But I got it anyway. It is a Benq PD3200u. It is almost perfect albeit, pretty expensive at $750 (32 inch, 4K monitor).
I recommend you could buy parts and assemble by yourself. It typically costs less than half of the same monitor without the brand.
 
D

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Ok, but the question remains - why make fuss about the out of band garbage as neither the speakers/headphones can reproduce them nor we can hear them?

My Norma integrated amp specs:

1536397015795.png
 

Krunok

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My Norma integrated amp specs:

View attachment 15455

Ok, but since those amps are capable of such HF response the ultrasonic garbage we're talking about won't upset them - those signals will be amplified and sent to speakers. Most of the speakers won't go over 25kHz while some will reach say 45kHz. So, what would be the result in our ears? In my opinion, absolutely nothing.

I do however agree, that expensive DACs shouldn't be too noisy even in the out of band segment, if only to justify their price.
 

bennetng

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maverickronin

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Ok, but since those amps are capable of such HF response the ultrasonic garbage we're talking about won't upset them - those signals will be amplified and sent to speakers. Most of the speakers won't go over 25kHz while some will reach say 45kHz. So, what would be the result in our ears? In my opinion, absolutely nothing.

Wouldn't it be bad for the tweeters because of excessive bandwidth of those amps? Even if the transducer can't actually reproduce those frequencies it still has to dissipate that power. In extreme cases of ultrasonic garbage from the DAC could lead to power compression or straight up frying the voice coil.
 

Krunok

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Wouldn't it be bad for the tweeters because of excessive bandwidth of those amps? Even if the transducer can't actually reproduce those frequencies it still has to dissipate that power. In extreme cases of ultrasonic garbage from the DAC could lead to power compression or straight up frying the voice coil.

It would be dissipated in the tweeter coil, but as its level is at -110dB or below this is not the issue.
 

Jimster480

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Based on my communication with SMSL people past three days, they don’t know it. At first their react was kind of slow because their engineers are not good at English, Mandy has to translate every technical thing to the engineer and then the engineers do the test or give an explanation. Sometimes there are misunderstandings because Mandy is not an engineer and get confused with some special words we were talking here. They are taking it very seriously actually and yesterday their engineers had been holding a meeting for several hours to discuss these issues found here.They were a little bit quiet yesterday because they use a different analyzer Prism Sound dScope Series III and were trying to get one Apx555 to repeat all the tests in this review. They will respond as soon as possible when they finish all of the tests. @amirm actually they were thinking of directly contacting you to make sure their tests were identical to yours, but you know, language.....So discussion may go a little bit slow here but I am sure smsl will keep everyone updated.
ITs awesome to see them be so responsive and concerned.
It goes to show they actually care about the engineering and this isn't just some BS they are making like some other companies reviewed here.
 
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amirm

amirm

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FYI I have been in daily communication with them trying to figure out what is going on. The time zone difference limits us to just a couple of hours of overlap so progress is a bit slow but they are working on it.
 

Veri

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FYI I have been in daily communication with them trying to figure out what is going on. The time zone difference limits us to just a couple of hours of overlap so progress is a bit slow but they are working on it.
This just goes to show, what kind of positive change your presence on the internet via audiosciencereview is starting to be. Engineers willing to be involved in discussions about possible issues (or even oversight/mistakes). I'm loving it!
 

ofrappier

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This just goes to show, what kind of positive change your presence on the internet via audiosciencereview is starting to be. Engineers willing to be involved in discussions about possible issues (or even oversight/mistakes). I'm loving it!

too... :)
 
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