Topping D90SE Measurements (DAC) State Of The Art.

Topping D90SE Measurements (DAC)

Hi folks,

I just got my hands on the mighty Topping D90SE and wanted to share my objective analysis. Some might wonder what would be the point to post this, when we already have a complete test at ASR, with our host’s skills and his APx555… Well, at least three reasons, I would say:

1) I need an undisputed reference to set the benchmark for my further gears analyses.
2) That way, I am curious to find if I may reach the limits measurable by my ADC (no doubt I should).
3) In any case, repeatability is always a good thing ! This should remove some doubts about Amir receiving a cherry-picked product from the manufacturer… In case you’re wondering, this unit is brand new from Amazon FR in March 2022, so nine months after Amir tested it. By today, MSRP is 899€.

Disclaimer: Measurements you are about to see are not intended to be as precise or extensive than what you get from a 30k€ AP. There is obviously both hardware and software limitations here, so not quite apples to apples comparison with Amir’s testing. For example, I estimated SINAD (AKA THD+N) to be usually 5 to 6dB worse with my measurements rig, when compared to ASR reviews of the exact same products. Still, this data is enough to have a pretty good idea if the gear is bad or not, stellar, broken, or sub-par…

– ADC : E1DA Cosmos (Grade B), set to 4.5Vrms input for measuring XLR, or 2.7Vrms for RCA. Minimum phase filter.
– Software : RMAA 6.4.5 PRO and Multitone Loopback Analyzer 1.0.13.
– Method : 8 runs for each test, then I chose the closest to the average. All tests are running 24bits / 44.1Khz.
– Topping D90SE : Fixed XLR outputs (4.2Vrms) and USB input for most tests, unless specified otherwise.

RMAA Summary

Test	Results	RMAA rating
Frequency response (from 40 Hz to 15 kHz), dB	+0.04, -0.02	Excellent
Noise level, dB (A)	-125.0	Excellent
Dynamic range, dB (A)	124.5	Excellent
THD, %	0.00005	Excellent
THD + Noise, dB (A)	-115.7	Excellent
IMD + Noise, %	0.00031	Excellent
Stereo crosstalk, dB	-125.9	Excellent
IMD at 10 kHz, %	0.00023	Excellent

Wow. Both THD and THD+N are the best I’ve measured so far and would translate, per my own estimations, to at least 120dB SINAD in a proper measurements rig. Needless to say, RMAA’s rating is somehow outdated to evaluate this stunning level of performance. We reach -125dB Noise, which is the limit of my Cosmos ADC (Grade B)… at least in Stereo Mode. It is now pretty clear that I have to set my Cosmos in Mono Mode to find out the real D90SE abilities. To push the Cosmos to its absolute limits, I also measured the “5V mode” (really 5.2Vrms):

Test	Topping D90SE XLR	Topping D90SE XLR (Mono)	Topping D90SE XLR 5V (Mono)
Frequency response (from 40 Hz to 15 kHz), dB	+0.02, -0.02	+0.02, -0.02	+0.02, -0.02
Noise level, dB (A)	-125.0	-127.4	-127.7
Dynamic range, dB (A)	124.5	126.6	126.7
THD, %	0.00005	0.00004	0.00003
THD + Noise, dB (A)	-115.7	-117.7	-119.3
IMD + Noise, %	0.00031	0.00028	0.00027
IMD at 10 kHz, %	0.00023	0.00019	0.00016
Stereo crosstalk, dB	-125.9	/	/

I have no words. With setting to 5V, THD is simply out of this world at only… 0.00003% (-130dB!), but the biggest surprise was to realize that, yes, I can measure up to 119dB SINAD at home… About 127dB for both SNR and DR are still the limitations here, being the absolute limits of my Cosmos. Before setting back to Stereo/4V, for a more apples to apples comparison with others DACs, let’s have a look at this masterpiece:

THD + Noise (at -3 dB FS)

…Now, let’s run the usual bunch of tests :

Frequency response

	Left	Right
From 20 Hz to 20 kHz, dB	-0.03, +0.03	-0.04, +0.01
From 40 Hz to 15 kHz, dB	-0.02, +0.02	-0.03, +0.01

Noise level

	Left	Right
RMS power, dB	-122.9	-123.8
RMS power (A-weighted), dB	-124.5	-125.5
Peak level, dB FS	-87.1	-87.1
DC offset, %	-0.0	-0.0

THD + Noise (at -3 dB FS)

	Left	Right
THD, %	0.00005	0.00005
THD + Noise, %	0.00019	0.00017
THD + Noise (A-weighted), %	0.00017	0.00016

Dynamic range

	Left	Right
Dynamic range, dB	+123.1	+124.0
Dynamic range (A-weighted), dB	+124.1	+124.9
DC offset, %	-0.00	+0.00

Intermodulation distortion (swept tones)

	Left	Right
IMD + Noise at 5000 Hz,	0.00024	0.00022
IMD + Noise at 10000 Hz,	0.00024	0.00020
IMD + Noise at 15000 Hz,	0.00025	0.00021

Intermodulation distortion

	Left	Right
IMD + Noise, %	0.00032	0.00030
IMD + Noise (A-weighted), %	0.00021	0.00018

Stereo crosstalk

	Left	Right
Crosstalk at 100 Hz, dB	-127	-126
Crosstalk at 1000 Hz, dB	-126	-124
Crosstalk at 10000 Hz, dB	-124	-116

What about RCA outputs? I expect a logical drop in performance (whatever E1DA says, Cosmos ADC is not optimal for single ended measurements), the question is : by how much? Let’s find out:

THD + Noise (at -3 dB FS)

XLR VS RCA

Test	Topping D90SE XLR	Topping D90SE RCA	Topping D90SE RCA 5V
Frequency response (from 40 Hz to 15 kHz), dB	+0.02, -0.02	+0.02, -0.02	+0.02, -0.02
Noise level, dB (A)	-125.0	-121.6	-122.0
Dynamic range, dB (A)	124.5	121.6	121.6
THD, %	0.00005	0.00007	0.00007
THD + Noise, dB (A)	-115.7	-112.5	-113.2
IMD + Noise, %	0.00031	0.00039	0.00038
Stereo crosstalk, dB	-125.9	-116.5	-116.5

Apart from crosstalk being logically inferior, I am pleased to see that THD is still exceptionally low at 0.0007%. Using 5V Mode (2.6Vrms), THD+N is still 6dB better than my Matrix Mini-i Pro 3’s balanced outputs, which is quite an accomplishment! For my future measurements of unbalanced DACs, I am finally glad to know the reference being that high !

USB VS S/PDIF

Test	Topping D90SE USB	Topping D90SE S/PDIF
Frequency response (from 40 Hz to 15 kHz), dB	+0.02, -0.02	-0.00, -0.03
Noise level, dB (A)	-125.0	-124.4
Dynamic range, dB (A)	124.5	123.9
THD, %	0.00005	0.00005
THD + Noise, dB (A)	-115.7	-115.8
IMD + Noise, %	0.00031	0.00031
Stereo crosstalk, dB	-125.9	-124.7

Performance seems to drop by a little using S/PDIF. Ignoring run-to-run variations and averages, I would call both results to be similar. In any case, nothing to worry about.

Multitone Analyzer (100 tones, 5 averages)

RCA

XLR

XLR 5V

Multitone test of unbalanced outputs, while not perfect, is still a hair better than (again) my Matrix balanced. XLR performance is by far the best I saw in this test. I set back the D90SE to 5V for the last run and got this stellar picture you see above.

One last thing…

When running my first measurements, I noticed quite a few variations in overall frequency response. I then realized that I accidentally changed the filter with the remote. The D90SE has 7 filters called “Modes” from 1 to 7 (default is Mode 3).

None of them measured the same as far as FR is concerned (44.1Khz). Mode 1, in particular, is acting weird, really… My recommendation is for Mode 5 (Fast roll off linear), being the flattest :