Sabaj A20d 2023 DAC & HP Amp Review

[amirm]

This is a review and detailed measurements of the 2023 edition of Sabaj A20d balanced DAC and headphone amplifier. It was sent to me by the company and costs US $420.

As with last generation, the A20 comes in gorgeous packaging that completely sets it aside from its competitors. The display is ultra clear and very responsive and I like the large volume level indicator. Back panel shows what you expect:

The labels were a bit hard to read but that is a one-time aggravation.

The 2023 revision switches from ESS DAC to AKM AK4499EX.

Sabaj A20d 2023 DAC Measurements
When I first started to test the unit, I was getting high harmonic distortion, sinking expected SINAD by some 15 dB. It took a bit of looking but then found four "sound color" settings with all but the first one causing such distortion. I turned that off to get proper results:

This is excellent performance, easily landing the A20d in our top 20 best DACs ever measured:

Unbalanced RCA performance is almost as good:

Output was actually higher than the above and performance improves a bit if you let it go to the max:

You need exceptional noise performance to land in our top 20 list and A20d naturally delivers:

Linearity is perfect:

Multitone distortion is vanishingly low:

In order to make our tests more comparable to what is published elsewhere, I added a test of 50 Hz tone driving into a very low impedance of 600 ohm as used by Stereophile:

As a way of comparison, here is how the dCS Rossini Apex ($32,800) performed in the same test:

The A20d beats the worst case harmonic of Rossini by 7 dB yet costs nearly 80 times less!

IMD performance is excellent:

Jitter test shows a bit of internally generates spurious tones but otherwise is excellent:

We have the usual set of filters:

Here is our wideband noise+distortion vs frequency:

Sabaj A20d 2023 Headphone Amplifier Measurements
We have both 1/4 inch and 4.4 mm jacks but both convey the same signal so let's go with the latter:

These are extremely clean with good bit of power to drive just about any headphone. Despite lack of ultra low (negative) gain, noise performance is excellent at just 50 mv:

Conclusions
The 2023 revision of A20d brings excellence in every category from look and feel to performance across the board. It leaves nothing to complain about.

I am happy to recommend the Sabaj A20d DAC and headphone amplifier.

Manufacturer Specifications

Name	Sabaj A20d 2023
Input	USB. Optical, Coaxial. Bluetooth
Output	6.35mm/4.4mm headphone, RCA. XLR
Output level	RCA 2.3Vrms. XLR 4.6Vrms
HPA power	2W*2(160) 1W*2(322)
HPA gain	LOW OdB. HIGH +8dB
THD+N	HPA 0.0001% (-120dB) . DAC 0.00006% (-123dB)
Dynamic range	RCA 126dB. XLR 131dB
SNR	RCA 126dB. XLR 131dB
Output impedance	HPA NEAR 0Q, DAC 1000
Bluetooth	BT 5.0 (support apt-X HD, LDAC, apt-X, AAC, SBC)
USB transmission	Asynchronization
USB compatibility	Windows 7, 8, 8.1. 10, 11, Mac OS X 10.6 later, Linux
Bit width	USB 1bit~ 32bit, Optical/Coaxial 16bit~ 24bit
Sampling rate	USB 44.1~ 768kHz DSD64-512, Optical/Coaxial 44.1~ 192kHz DoP64
Power Consumption	<20W
Size	200×60×210 (W×H×D)
Weight	1500

----------
As always, questions, comments, recommendations, etc. are welcome. Click here if you have some audio gear you want me to test.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[Michael Fidler]

Just superb! Looks beautiful too, they've done a great job with this one. It would be interesting to know what the 'sound color' settings do in more details but I'm guessing that they're there to simulate the low-order distortion effects of discrete and valve type gear. Undesirable to have them on by default in any case as these types of distortions have always sounded bad to me at least.

Does the coax/TOSLINK input have some sort of FIFO/averaging type system to do away with incoming jitter?

 

[amirm]

Does the coax/TOSLINK input have some sort of FIFO/averaging type system to do away with incoming jitter?

There is always buffering but the incoming clock must be used from Coax/S/PDIF and that extracted clock can have jitter. USB is different in that the DAC clock is the master and USB is used for data transfer.

 

[Michael Fidler]

There is always buffering but the incoming clock must be used from Coax/S/PDIF and that extracted clock can have jitter. USB is different in that the DAC clock is the master and USB is used for data transfer.

I guess what I'm asking is does the clock have a sort of averaging internal locked loop with very low jitter that eliminates the (short term at least) effects of jitter on the S/PDIF input?

 

[amirm]

I guess what I'm asking is does the clock have a sort of averaging internal locked loop with very low jitter that eliminates the (short term at least) effects of jitter on the S/PDIF input?

There is a phased locked loop that filters out high frequency jitter. The corner frequency is implementation dependent but is usually a few Kilohertz. If the filtering is too strong, lock time (to a new sample rate) increases, causing user annoyance. For this reason, some implementations have programmable bandwidth for the PLL. This unit doesn't have that.

 

[diddley]

Nice that you made the comparison with Rossini, shows who's the boss.
Nice review as always, thanks Amir.

 

[gvl]

Rossini looks better IMO, the 3rd harmonic is same level or lower and there are no high order harmonics present unlike in the Sabaj. Harmonics decay monotonically.

 

[GianDi]

is there life (or sound) at -130 db?
they are always the same devices; few integrate an hdmi in/out, or a digital coax out.
on decent analog volume control and one or two aux inputs they might lose a few sinad db, to become flexible digital preamps.
thanks to Amirm, who tirelessly publishes Friday evening measures.....

 

[gvl]

Not sure I like the front handles. They are not pretty and clutter the small face, not very useful, and I’m sure add to the cost some.

 

[amirm]

Rossini looks better IMO, the 3rd harmonic is same level or lower and there are no high order harmonics present unlike in the Sabaj. Harmonics decay monotonically.

THat's not the case. The noise floor in my FFT is lower and hence shows the extra harmonics. Stereophile tests simply hide those.

 

[gvl]

THat's not the case. The noise floor in my FFT is lower and hence shows the extra harmonics. Stereophile tests simply hide those.

Fair enough, still the Sabaj seem to be more odd and high order harmonics happy than the Rossini, at the microscopic level anyway.

 

[respice finem]

The identical looks of the 2022 and 2023 models are IMHO not a good idea. Unless you are vigilant (and the vendor writes the model year correctly), one may get the 2022 version instead, and not even notice.

 

[F1308]

Voted great, but antennas are to be placed
inside, as it happens in any smartphone...

 

[polmuaddib]

Thanks for the review. It is a great performing DAC with an ok industrial design, but it does not compare to dCS's industrial design, which is more monumental, luxurios and ovarall, nicer.
I don't care it sounds the same.

 

[amirm]

Voted great, but antennas are to be placed
inside, as it happens in any smartphone...

You get better range with external antenna.

 

[DuncanTodd]

It would be interesting to know what the 'sound color' settings do in more details but I'm guessing that they're there to simulate the low-order distortion effects of discrete and valve type gear.

Interested to read more about these too.

 

[respice finem]

Voted great, but antennas are to be placed
inside, as it happens in any smartphone...

A smartphone tends not to have a metal case

 

[tree]

I understand the need to pursue good engineering but I do think that putting it above all other design goals, considering that most home noise floor is way above these numbers, can be a hindrance. Where is the trigger. Topping and the likes understood and introduced this feature in latest models. When I bought my DAC this is one of the base features I was looking for. Who has the power to go hunting for all these remotes or have a remote with endless macros.

 

[ohnonotagain]

Thanks Sabaj for sending another product to Amir for review. Now could you please send the A30a to him, so that all the owners and fans of it on this forum can finally find out whether it is as good as we think it is?

 

[somebodyelse]

A smartphone tends not to have a metal case

Or parts of the metal case _are_ the antenna - hence the iPhone "you're holding it wrong" problem.