This is a review and detailed measurement/comparison of SMSL SU-8 DAC and Topping D50. It is on a kind loan from a member who had it drop shipped to me from Massdrop. Since there has been so much interest in this product, I decided to test it immediately.
Overall, the first impression is quite positive. Package is very nice and the unit has quite a heft and quality feel to it. It is a far more substantial unit than the Topping D50 due to inclusion of mains power supply and balanced outputs:
The display is kind of tiny but does the job. It came with a remote which is a great bonus (I did not unpack it). The only minor gripe is the very short AC cable. I think it is 2 feet or something as opposed to typical 6 foot. So like me, you may need to supply your own.
The retail price is $249 with free shipping on US Amazon right now. I am assuming Massdrop price was lower. The Topping D50 is also $249 so if the SMSL SU-8 matches its performance, it is quite a bargain. Let's see how it did in measurements (all done with default filter setting).
Measurements
Let's start with Topping D50 so we have a good reference:
As noted, I powered the D50 using a Samsung charger I had laying around. Let's compare that to SMSL SU-8 using its unbalanced output:
We see fair bit of power supply noise at 120 Hz and other harmonics of mains 60 Hz. We take a 4 to 5 dB hit in SINAD (signal above distortion+noise). Still, this is respectable performance with healthy output of over 2.1 volts.
There is fair bit of interest in balanced outputs of the unit so let's see how that did:
Distortion climbs unfortunately reducing SINAD to 86 dB. As you see in this IMD graph, this is due to the output stage saturating:
The balanced output in red clearly starts to saturate the output stage with distortion climbing past -7 dB or so. I guess if you keep the volume control down, you can reduce the impact of that.
Other than that, the performance of SMSL-8 SU-8 unbalanced output is pretty similar to Topping D50, both suffering from that mid-level "hump" courtesy of the ESS DAC chip used. Topping has slightly lower noise and distortion which we had seen in better SINAD numbers before.
Here is the spectrum of THD+N versus frequency:
This is done at 0 dBFS like the dashboard so obviously the balanced output does poorly with tons of distortion that gets worse with higher frequencies. I ran it again (not shown) at -5 dB and it was still worse than unbalanced (in red) but much more manageable.
The topping in green is well behaved with again, showing a bit less noise and distortion.
Here is a fun little graph/table I have started to show where each device lands with SINAD at 1 kHz:
We see a bucket of state-of-the-art on the left, then a mid-tier, and then the bottom on the right. Please remember that THD is not a very good measure of audibility so don't worry about small differences.
Finally, everyone's favorite measurement, linearity:
Here, tables turn and the balanced output of SMSL SU-8 (green) does much better than unbalanced (red). The Topping D50 as with other Topping products nails this test with perfect score.
Finally, here is the jitter and noise test:
Not much to note other than power supply noise in SMSL SU-8 on the left in red. And some USB packet noise in Topping D50 at multiples of 1 kHz and a couple of tones at 16 and 16.5 kHz. All inaudible due to their low level and our very high threshold of hearing at low and high frequencies.
Conclusions
The SMSL SU-8 seems to be a competently design DAC with superb feature set at an amazing price of $250. Some lack of hygiene exists which brings its measurements slightly below Topping D50. The other issue is the saturation of balanced output.
Overall, I am recommending this SMSL SU-8 to anyone who needs balanced output and in-built volume control with remote. It would make an excellent pairing with a couple of powered speakers like JBL 305.
-------------
As always, questions, comments, recommendations, etc. are welcome.
If you like this review, please consider donating funds for these types of hardware purchases 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).
Overall, the first impression is quite positive. Package is very nice and the unit has quite a heft and quality feel to it. It is a far more substantial unit than the Topping D50 due to inclusion of mains power supply and balanced outputs:
The display is kind of tiny but does the job. It came with a remote which is a great bonus (I did not unpack it). The only minor gripe is the very short AC cable. I think it is 2 feet or something as opposed to typical 6 foot. So like me, you may need to supply your own.
The retail price is $249 with free shipping on US Amazon right now. I am assuming Massdrop price was lower. The Topping D50 is also $249 so if the SMSL SU-8 matches its performance, it is quite a bargain. Let's see how it did in measurements (all done with default filter setting).
Measurements
Let's start with Topping D50 so we have a good reference:
As noted, I powered the D50 using a Samsung charger I had laying around. Let's compare that to SMSL SU-8 using its unbalanced output:
We see fair bit of power supply noise at 120 Hz and other harmonics of mains 60 Hz. We take a 4 to 5 dB hit in SINAD (signal above distortion+noise). Still, this is respectable performance with healthy output of over 2.1 volts.
There is fair bit of interest in balanced outputs of the unit so let's see how that did:
Distortion climbs unfortunately reducing SINAD to 86 dB. As you see in this IMD graph, this is due to the output stage saturating:
The balanced output in red clearly starts to saturate the output stage with distortion climbing past -7 dB or so. I guess if you keep the volume control down, you can reduce the impact of that.
Other than that, the performance of SMSL-8 SU-8 unbalanced output is pretty similar to Topping D50, both suffering from that mid-level "hump" courtesy of the ESS DAC chip used. Topping has slightly lower noise and distortion which we had seen in better SINAD numbers before.
Here is the spectrum of THD+N versus frequency:
This is done at 0 dBFS like the dashboard so obviously the balanced output does poorly with tons of distortion that gets worse with higher frequencies. I ran it again (not shown) at -5 dB and it was still worse than unbalanced (in red) but much more manageable.
The topping in green is well behaved with again, showing a bit less noise and distortion.
Here is a fun little graph/table I have started to show where each device lands with SINAD at 1 kHz:
We see a bucket of state-of-the-art on the left, then a mid-tier, and then the bottom on the right. Please remember that THD is not a very good measure of audibility so don't worry about small differences.
Finally, everyone's favorite measurement, linearity:
Here, tables turn and the balanced output of SMSL SU-8 (green) does much better than unbalanced (red). The Topping D50 as with other Topping products nails this test with perfect score.
Finally, here is the jitter and noise test:
Not much to note other than power supply noise in SMSL SU-8 on the left in red. And some USB packet noise in Topping D50 at multiples of 1 kHz and a couple of tones at 16 and 16.5 kHz. All inaudible due to their low level and our very high threshold of hearing at low and high frequencies.
Conclusions
The SMSL SU-8 seems to be a competently design DAC with superb feature set at an amazing price of $250. Some lack of hygiene exists which brings its measurements slightly below Topping D50. The other issue is the saturation of balanced output.
Overall, I am recommending this SMSL SU-8 to anyone who needs balanced output and in-built volume control with remote. It would make an excellent pairing with a couple of powered speakers like JBL 305.
-------------
As always, questions, comments, recommendations, etc. are welcome.
If you like this review, please consider donating funds for these types of hardware purchases 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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- is the deviation from "linearity" because of actual deviation from linearity or is it from noise?
