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Review and Measurements of SMSL VMV D1 DAC

amirm

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#1
This is a review and detailed measurements of SMSL VMV D1 DAC. It is on a kind loan from a forum member. It retails for USD $1,299 including free shipping on Amazon. It is a super hefty unit, far more than you can imagine from its small enclosure:

SMSL VNV D1 DAC review and measurements.jpg

The box on the left which is permanently attached is the power supply. The bottom of the unit must be made out of lead as the entire thing is heavy.

The heart of the unit is ESS' flagship DAC, ES9038 Pro. Each channel has its own dedicated ES9038 Pro which has 8-channels internally and paralleled for better signal to noise ratio.

The display and functionality thereof are almost identical to SMSL SU-8 which I reviewed recently. In this configuration, it is way too tiny and unfitting of a device this expensive. I appreciate them leveraging what they already had but they should have stepped this up.

As with SU-8, you can choose the usual filter settings and special ESS DSP functionality to emulate tube sound and such with distortion products.

A metal but rather cheesy looking remote comes with it in silver and sparkling finish.

There are both balanced and unbalanced outputs which is nice. No headphone output however as this is strictly a DAC.

The write-up from SMSL is sadly machine translated from Chinese. But it includes a bunch of references to higher quality components, etc:

1535912441058.png



Hopefully measurements match the stated performance.

Measurements
As usual, let's start with our Dashboard view. First up is unbalanced RCA out:
SMSL VNV D1 DAC Unbalanced 44 kHz sampling dashboard.png


We have nice, 2.1 volt output which exceeds the nominal required value of 2 volts RMS. Distortion is quite low resulting in SINAD (signal above distortion and noise) of 110 to 113 dB depending on which channel we look at. This is however at 44.1 kHz sampling. Upping the sampling rate to 192 kHz shows a problem:

SMSL VNV D1 DAC Unbalanced 192 kHz sampling dashboard.png


We have a sharp drop in SINAD due to large number of spikes at higher frequencies (see FFT top right). To find the cause, I turned off the feed to D1 DAC and got this:

SMSL VNV D1 DAC Unbalanced 192 kHz sampling no output.png


Yup, the noise is still there! To show that in "time domain," I set the levels to -70 dBFS and got this:

SMSL VNV D1 DAC Unbalanced 192 kHz sampling -70 dBFS Measurement.png


See the clear spikes on our sine wave! They were there at all sampling rates by the way. Lowering the sample rate lowered their repetition rate. They are not visible in my first dashboard view because the bandwidth was limited there to 22 kHz and hence all the high frequency components were filtered out. With these higher sample rates that filtering is at higher frequency allowing the spikes to intrude.

EDIT: SMSL sent me a new board which resolved this issue (and improved jitter). See: https://www.audiosciencereview.com/...surements-of-smsl-vmv-d1-dac.4375/post-118213

What is interesting is that the switching noise is only in unbalanced output. Balanced is completely clean!

SMSL VNV D1 DAC Balanced 192 kHz sampling dashboard.png


This is just a couple of dBs worse than 44.1 kHz which is normal (we have more noise bandwidth at higher sample rates).

So this is a clear design misstep with respect to unbalanced output. Something from the digital side is bleeding into the analog side and should have been fixable seeing how it doesn't occur in balanced output.

Anyway, putting the SINAD numbers in context of other DACs, we get this:

SMSL VNV D1 DAC SINAD Measurement.psd.png


Jitter and noise again shows lack of attention to unbalance output:

SMSL VNV D1 DAC Jitter and Noise Measurement.png


Unbalanced in red shows a number of spikes at 1 kHz increments that are absent in balanced output.

On positive news, I actually had to lower my scale to -170 dB to show the noise floor of the unit. Really good work has been put in to reduce random noise here.

Unbalanced dynamic range is good:

SMSL VNV D1 DAC Dynamic Range SNR Measurement.png


As is balanced:
SMSL VNV D1 DAC Dynamic Range SNR Balanced Measurement.png


Let's look at intermodulation distortion relative to level:

SMSL VNV D1 DAC Balanced Intermodulatino Distortion Measurement.png


We can see pretty large deviation between the two channels. I hope they use closer spec parts in the future. We also see the usual "ESS hump" where the distortion rises at mid-levels. It is not nearly as bad as we see in lower cost ESS based DACs but is still there. Notice that the Benchmark DAC3 (in red) does NOT suffer from this even though it also uses an ESS DAC chip. Above is for balanced. Unbalanced was similar.

Wideband harmonic distortion+noise again shows the issue with spurious noise in unbalanced output:

SMSL VNV D1 DAC Distortion vs Frequency Measurement.png


Balanced actually beats the DAC3!

Last but not least, everyone's favorite, the linearity graph:
SMSL VNV D1 DAC Linearity Measurement.png


Usually this measurement is very slow as the analyzer struggles to get stable values at -100 to -120 dBFS. No here. The variability was very small allowing the measurement to finish very quickly. Very well done!

Conclusions
The SMSL VMV D1 comes very close to nailing its goal of bettering all other Chinese desktop DACs and rivaling or beating other western designed products. Alas, two missteps in the form of switching noise and jitter/distortion in the unbalanced output keep it from getting there.

Performance in balanced output is strong and easily earns my recommendation if that is the output you use.

I hope SMSL finds and resolves the issue with unbalanced output at which point, they will have a winner on their hand.

EDIT: SMSL sent me a new board which resolved this issue (and improved jitter). See: https://www.audiosciencereview.com/...surements-of-smsl-vmv-d1-dac.4375/post-118213

-------------

As always, questions, comments, recommendations, etc. are welcome.

If you like this review, please consider donating funds to support these reviews using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
 
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helloworld

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#2
Does the ESS company talk anything about the ESS midelevel hump? Is it possible that SMSL sove the unbalance output problem in this test with a firmware update?
 

amirm

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#3
Does the ESS company talk anything about the ESS midelevel hump? Is it possible that SMSL sove the unbalance output problem in this test with a firmware update?
No. They also don't release their specs to public. Someone contacted them about it and they did not answer. I also tried to connect to one of their engineers via LinkedIn and he did not respond. If I see them at a show, I will be sure to ask them.

For now, we have an explanation from the designer of Benchmark DAC3 which doesn't have that problem. He said building the output buffer requires care and most people don't do that and cause that problem. There was not enough detail in his answer to understand what the issue is, but the proof is there in DAC3 not having this problem.

I should say I have coined that phrase. :) It shows up in many of my measurements and so I thought I honor it with a name.

AKM based DACs don't have this issue by the way.
 

mindbomb

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#5
I'm taken aback by how good the performance on balanced here, especially after the su8 had high distortion at full scale. The only thing holding it back from being perfect were those IMD results - they weren't as good as the benchmark dac 3's, but still okay.
 
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#6
received_676463139399287.jpeg

I have the SMSL D1 connected to emotiva stealth 8's via balanced inputs. Thanks amirm for testing the unit, do you mind if I link this review in a Amazon review?
 

amirm

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#7
I have the SMSL D1 connected to emotiva stealth 8's via balanced inputs. Thanks amirm for testing the unit, do you mind if I link this review in a Amazon review?
Of course not. Please go ahead.
 
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#8
I was able to buy this unit for less than $1000, if anyone is interested I can forward them the store I purchased it from.
 
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#9
Capt....

Damned shame Emotiva cut those powered monitors out of the lineup. They were pretty darned good from what I've read, and they were on my hit list at one point.

Edit: I digress. I just checked their website, and the 8's are in the lineup. Interesting.......
 

restorer-john

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#10
This is however at 44.1 kHz sampling. Upping the sampling rate to 192 kHz shows a problem:
Is it actually caused by upping the sampling rate of the data being fed in, or is it just the FFT display extending up to 100KHz whereas it was only displaying up to 20KHz before? The harmonic spray has basically the same characteristics on each plot up to 20KHz.

Why not feed it 24/44 and show the FFT up to 100KHz to see what is really going on out of band?

I see the AP's waveform display at 192KHz is showing the jumps in sample steps/values too.
 
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amirm

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#11
Is it actually caused by upping the sampling rate of the data being fed in, or is it just the FFT display extending up to 100KHz whereas it was only displaying up to 20KHz before?
The latter. Problem is there at all sample rates.
 
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#13
@amirm

Up till now that “ESS mid level hump” has only been there with your measurements on the ESS chips for portable devices. I haven’t seen that hump on the top of the line PRO. If you go to the OPPO 205 that has the same ESS 3098pro chip, it doesn’t seem to display this hump! Yet the OPPO 205 has a single chip!
So my question is what is SMSL doing, or what feature is turned on for the ESS3098pro when enabled gives this mid level hump?
 

amirm

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#15
@amirm

Up till now that “ESS mid level hump” has only been there with your measurements on the ESS chips for portable devices. I haven’t seen that hump on the top of the line PRO. If you go to the OPPO 205 that has the same ESS 3098pro chip, it doesn’t seem to display this hump! Yet the OPPO 205 has a single chip!
So my question is what is SMSL doing, or what feature is turned on for the ESS3098pro when enabled gives this mid level hump?
I don't have a lot of insight more than you all. But I can see some amount of this hump potentially even in Oppo 205:

1535954355569.png


I have drawn that black line to demonstrate it. Now this could be measurement error too but may also indicate the same issue.
 

amirm

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#19
@amrim,

Can you place the Topping D50, SMSL D1, OPPO 205 on the same scale please.
The D50 was tested with my old analyzer. So i can't overlay it. Here it is from the old measurement:

Topping D50 DAC SMPTE Intermodulation Measurement.png


Here are the other two:
1535956010898.png
 

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