Topping D50 III Balanced DAC with EQ ASR Review
This is a review and detailed measurements of the Topping D50 III balanced stereo DAC with support for parametric equalization.
Sorry for the quality of the picture/display. It is quite dim compared to my photography light and when I tried to brighten it, it brought out the chromatic aberrations in my lens. While tiny, it is very sharp and clear white color. Back panel shows the innovation of using 1/4 jacks to bring balanced output in such a small enclosure:
The remote is bluetooth so you don’t have issues with how you point it. If you are using it as a USB DAC, you can plug that cable to the one labeled USB-C and be good to go. That is how I tested it using the hub in my monitor as I do with all DAC tests. There is auxiliary power input as well if you are not using USB but the S/PDIF options. I *think* you can also use that for higher quality power if your USB is not such.
What distinguishes the D50 III is what is inside: support for up to 10 filters of different types. The app, called Topping Tune, even has nice features like overlaying a target curve. Focus is on headphone use though as there is no way to assign separate EQ to each channel as you would need for Room EQ. You could use it to correct speaker flaws but would be harder to do so for room effects. I hope the company adds per channel capability.
If you are not familiar with my DAC measurements, I recommend this video tutorial on how I test audio DACs:
Topping D50III DAC Measurements
As usual we start with our usual dashboard. Max output defaulted to 5 volts so I used -1.5 dB of attenuation to get it down to nominal 4 volts:
We expect state of the art performance from Topping and that is precisely what we get here, easily landing the D50 III in our silly top 20 DACs as far as noise and distortion:
Distortion is vanishingly low at -140 dB so we are dominated by noise, which seems to be mostly from my analyzer. Fellow member @Rja4000 measured it with an RME audio interface and managed a SINAD of 124.6. Difference is academic as we are well past point of transparency either way.
RCA performance is a bit worse as usual:
But still verifiably transparent.
Here is the performance at lower output levels:
Dynamic range even measured with my analyzer is superb:
Multitone performance is stunningly good with extremely low and frequency independent distortion:
Jitter is super despite “dirty” computer power:
Linearity is naturally perfect:
IMD distortion is extremely low with tiniest, immaterial hit of “ESS IMD Hump” in one channel:
For compatibility with stereophile measurements, here is 50 Hz spectra until 600 ohm load:
Great example of how excellent engineering covers all bases seeing how I recently started to run this test with little opportunity for companies to optimize for it.
Wideband THD+N again lets Topping flex its muscles when it comes to superb engineering:
We have the usual filter settings (I have optimized this measurement a bit to make it more clear):
Mode 3 has the best attenuation without any ringing in out of band noise. Here is the impact on frequency response:
Topping D50 III Equalization Measurements
It is difficult to test impact of EQ on our measurements as the mere fact of changing the frequency response impacts the parameters used in the test. As an extreme example, if I put a notch filter at 1 kHz, SINAD test would just show garbage as the main tone is now filtered. To get around this, I programmed two filters in Topping Tune but left them at 0 dB. Here is the outcome:
As you see, it made no difference. I then set them to -5 dB with another 5 dB of pre-amp negative gain:
The high frequency filter makes no difference but the low frequency one showed variable noise around the 100 Hz frequency of the first filter:
That part of the graph would change shape and sometimes go down to no noise only to start again. At no time it rose above -120 dB so completely immaterial audibly. I usually would take the time to give this feedback to the company but in the interest of getting the review out, I figured I go ahead and post it.
BTW, I *think* you can’t play and change the EQ settings. I had to stop the analyzer from feeding the DAC before changing the settings. This may be wise as changing filters dynamically can cause glitches.
It also took me a bit to realize that making changes in Topping Tune are immediately communicated to D50 III. I kept looking for a “send” or “update” button and by accident discovered that changes are automatic.
Overall, I was very impressed with fit and finish of the Topping Tune seeing how this is their first attempt at software development. On great addition there would be to be able to update the firmware in the DAC.
