[wushuliu]

I'm not sure how the design partnership works between different China-direct companies like SMSL, Topping, LoxJie et al. - to my ears their gear seems to have roughly the same sound signature - but Sabaj doesn't appear to share their sensibilities. Their Da3 stood out to me when I first got hold of one a couple years ago not only for it's bargain pricing but for the fuller more mid-centric presentation compared to the other ESS-based Chi-fi offerings.

A year later they released the desktop D5, which followed through on the promise of the DA3 but with the flagship 9038Pro chip and larger enclosure and better power. I found the D5 to be surprisingly warm, smooth, and laid back (YMMV of course). Unfortunately it was known to have power supply overheating issues and I reluctantly decided to return it. After that I focused my attention on rehabilitating my Soekris 1021. The budget DAC market had plateaued by that point into the same old budget combos and brands vying for measurement approval while R2R/Multibit made inroads in the mid and high end range. Sabaj doesn't appear to have the same rapid turnaround on products as the rest so the D5 was the best they had. That is, until the recently released A20d.



In terms of standard features, the A20d at first glance appears largely the same as the D5. 9038Pro chip, ES9311 low noise power regulator, XLR, I2S, Coax etc etc. It does not come with a headphone amplifier but does come with bluetooth. Build quality is decent, but the knob is still a bit too wobbly for my taste. The XMOS USB input has been upgraded to the XU 216. Perhaps to avoid the issues of the D5, power is now externally provided by a 15v SMPS. This voltage is not as convenient for battery purposes but there are still multiple low noise PS options, so I consider this a plus over an internal PS at this price class. Speaking of price, it's ~$420 but on Amazon it's ~$377. If you're diligent you can snag a lightly used one on Amazon for an additional $35 cheaper.

How does it sound?
Through my Asgard 3 and HD6XXs, I think it sounds excellent. The bass is taut but forceful. Low end is well defined. It's not bass-shy. Mids are clear and balanced, not too forward or recessed. Treble and upper frequencies are resolving without edginess. Next, the imaging and separation is superb (keep in mind I'm listening single-ended not balanced). Instruments and vocals occupy distinct spaces with body and resonance and texture. All this compounds to an element of realism that I would normally associate with R2R/Multi-bit and/or tube amplification. For instance with Heart's 'Silver Wheels' - an acoustic guitar instrumental - I get a more distinct sense of mic placement. I get not only the inner detail of Ann Wilson's low level inhalation and breath but the texture as well. The Egg's 'Fat Boy Goes To The Cinema' is an electronica track with a hot top end DACs have a hard time handling. The A20 does a superb job allowing articulation of the cymbals without the sizzle. Snare hits on Yes' 'Rhythm of Love' have snap and impact and you can differentiate the weight and imprecision (vs. Pro-tool looping) of Alan White's drumming. This is by no means a budget sounding DAC. With this kind of performance it becomes difficult to describe the nuances of presentation, so I'll use some comparisons to clarify.

vs. Topping E50
Compared to the E50 I wrote about a few days ago, the A20d comes off as more composed with a weightier low end. The A20d also has more observable separation and spaces between notes/instruments. The A20d also has an edge with its many filters and DPLL options to help dial in performance. However, the A20d doesn't quite have the E50's infectious PRaT (not a fan of the term but it's the most applicable), falling somewhere between the E50 and the DO200 below. But as good as the E50 may be (I could happily live with it if I had nothing else), the A20 is a more 'mature' sounding DAC.

vs. SMSL DO200
The DO200 is SMSL's newest comparable DAC to the A20d. It sports dual 9068ES chips and otherwise very similar specs and features. Priced at ~$480. It's gotten very good reviews as a resolving DAC that punches well above its weight. IMO the DO200 did sound very resolving, very refined. Low end was comparable to the A20d. However, I found the mids too recessed. Vocals lacked presence. Perhaps this would sound differently in a 2-channel speaker setup but I have my doubts. The upper frequencies were a step forward from the typical SMSL sizzle. The DO200 is certainly a step forward in the right direction. Ultimately, it still has the clinical unengaging 'flat' quality that has plagued some of these brands. The A20d shows more life, texture, and better mids if not the ultimate low noise/black background of the DO200.

I find myself using the word 'texture' in regards to the A20 vs. these and other dacs. I think that's the defining feature for me. More palpable could be another way to describe what I'm hearing. In some respects this is similar to my (heavily modded) Soekris setup and the A20d I would say is a step up for sure (Soekris has improved his DACs since mine though). Not bad for <$400.

IMO the A20d has a couple features that contributed to the level of performance I experienced: the digital filters and the DPLL function. Unlike most DACs the A20 comes with seven filter options, not just the bog standard three of minimum phase, fast roll-off, etc... The A20 also has apodizing and hybrid filters, both of which I found to improve top end transients. The DPLL options allows you to improve jitter performance. I was able to dial all the way down to 1 (out of 15, default is 5 IIRC). I have used this function on other dacs and the difference is audible. The lower you go the smoother and warmer the playback. Downside is you can get stutter if your source can't match the low latency required. Makes you wonder how many ESS dacs have been hampered by ignoring this setting or wanting to err on the side of compatibility vs. sound quality.

Lastly, a reminder that I use my PC as a source. I still believe that this provides more latitude in getting the best out of a DAC. Between ASIO, Kernel Streaming, and XMOS' own bit and buffer settings you can finesse better sound from my experience. So I can't say what you will hear from a plug and play source. But with my setup I am very impressed with the A20d and odds are I will keep it.

I do have one last wild card DAC coming though. It belongs more in the 'DAC for Peanuts' category and I doubt it will come close, but I'm intrigued nonetheless.

I don't know if Sabaj's house sound is by chance or by design. They certainly don't seem as focused (or well-funded?) on self-promotion as the more well-known China-direct brands. Whatever the case may be they remain IMO the best of the bunch in terms of dac sound quality price/performance ratio.

[Sparky14]

I did not know the D5 had power supply issues. Luckily mine has performed flawlessly.

[mresseguie]

Like Sparky14, I didn't know about the power supply issues in the D5. Fortunately, mine hasn't had this issue <yet>. Of course, mine sits in a box for 6 to 8 months each year. I'll keep an eye on it the next time I use it.

I'm glad you mentioned it, wushuliu. 

[genjamon]

Thanks for the review and comparisons!  What kind of power supply were you using for the 15v?

[wushuliu]

Thanks for the review and comparisons!  What kind of power supply were you using for the 15v?

First the stock and then I hooked up an old GPS-1850D bench power supply (rated at <500uV noise when current is under 3A - not bad).

[genjamon]

I decided to give this a try, and it just arrived yesterday.  Set it up, but couldn't find the right cable to connect to the variable voltage output from my HDPlex power supply.  So I decided to try the fixed 12v output instead, since I did have the right cable for that output.  It works on 12v!

I had a suspicion it might, as the particular circuits in computer/network/digital devices often run at much lower voltages served by various voltage step-down devices along the way.  I figured the 15v input might be that particular voltage simply because the A20d is designed to pair with the A20a amplifier, which uses a 15v input and has a matching 15v output to run the matching DAC, making it very convenient for those who want both units and plan to stack them or use side-by-side.  A 15v input makes much more sense for an amplifier, which is more demanding of power than a DAC.  But just because it's designed to be paired with an amplifier in such a way, it doesn't mean the internal circuits of the A20d actually need 15v themselves.  And sure enough, 12v works just fine.

Just thought you folks might be interested to know this fact, as it opens up a whole other range of low noise power supplies.  I haven't tried any lower voltages than this yet, but may eventually do so.  I also don't know if the device draws more current at 12v than at 15v, which could potentially be the case. 

In general, I don't think trying lower voltages is dangerous or potentially damaging to the device.  It would be voltages above 15v that would be the problem there. 

[wushuliu]

I decided to give this a try, and it just arrived yesterday.  Set it up, but couldn't find the right cable to connect to the variable voltage output from my HDPlex power supply.  So I decided to try the fixed 12v output instead, since I did have the right cable for that output.  It works on 12v!

I had a suspicion it might, as the particular circuits in computer/network/digital devices often run at much lower voltages served by various voltage step-down devices along the way.  I figured the 15v input might be that particular voltage simply because the A20d is designed to pair with the A20a amplifier, which uses a 15v input and has a matching 15v output to run the matching DAC, making it very convenient for those who want both units and plan to stack them or use side-by-side.  A 15v input makes much more sense for an amplifier, which is more demanding of power than a DAC.  But just because it's designed to be paired with an amplifier in such a way, it doesn't mean the internal circuits of the A20d actually need 15v themselves.  And sure enough, 12v works just fine.

Just thought you folks might be interested to know this fact, as it opens up a whole other range of low noise power supplies.  I haven't tried any lower voltages than this yet, but may eventually do so.  I also don't know if the device draws more current at 12v than at 15v, which could potentially be the case. 

In general, I don't think trying lower voltages is dangerous or potentially damaging to the device.  It would be voltages above 15v that would be the problem there.

Good to know! Opens up some possibilities indeed. I can try out different voltages with my bench supply and see if current load increases...

[genjamon]

Excellent!

[genjamon]

Another question - how much have you played around with the different filters, and do you have a preference for one over the others?

[wushuliu]

Another question - how much have you played around with the different filters, and do you have a preference for one over the others?

So far I've settled on filters 5 and 6, hybrid and apodizing. DPLL set to 1.

Also, current does increase with reduced voltage.

[genjamon]

Hmm, interesting regarding current increase.  Do you know if it increases proportionate to the voltage drop?  I.e. 12v is 80% of 15v, so current is 1.25x at 12v vs at 15v (1.25=1/0.8 )?

[wushuliu]

Hmm, interesting regarding current increase.  Do you know if it increases proportionate to the voltage drop?  I.e. 12v is 80% of 15v, so current is 1.25x at 12v vs at 15v (1.25=1/0.8 )?

Correct.

A quick peek inside reveals a 2A rectifier and a DC-DC downconverter most likely for 5v. Haven't tried yet but minimum voltage probably 7-9v.

EDIT: Minimum is 6.5v or so. Current rises to 600mA.

[genjamon]

Cool, thanks!

[wushuliu]

FYI, new post added in the 'DAC for Peanuts' thread.

[wushuliu]

FYI, one last surprise entry in the peanuts thread wraps things up for now. Sabaj may be headed back to Amazon.

[Sparky14]

Like Sparky14, I didn't know about the power supply issues in the D5. Fortunately, mine hasn't had this issue <yet>. Of course, mine sits in a box for 6 to 8 months each year. I'll keep an eye on it the next time I use it.

I'm glad you mentioned it, wushuliu. 

My D5 averages 6 hours of use per day in the 19 months I have owned it. No problems.

[genjamon]

I’ve had the Sabaj in my TV system for the past couple weeks. It gets 5-6 hrs of use per day between the family. Should have enough hours to be past early burn in. I run it with the optical out from my TV, and have to set the DPLL to 2 to avoid dropouts. Understandable, given a cheap tv optical signal as source.

It’s powered by a 12v Vinnie Rossi ultra capacitor power supply - so completely overkill there.

I like the overall look/feel and functionality of the unit. It has added a very important remote volume control to the system. Prior to its arrival, I was increasingly having to get up and adjust volume multiple times per day, given different volume levels of different apps, and also dialing in nighttime levels after the toddler has gone to bed. Now I just set my Acurus preamp volume to the loudest I would want it with the Sabaj at full output, and then use the Sabaj software attenuation as needed.

Sound wise, it’s a good fit in the TV room. It’s playing through the cheap and cheerful Pioneer speakers by Andrew Jones, which appreciate the detail and separation of the ESS sound. And the Acurus preamp warms up the sound a touch.

In my big rig, it initially impressed with detail retrieval, but I quickly observed that instruments sounded a bit threadbare. Not a clinical sound, just not natural or realistic instrument tones. This is compared with my dB Audio Tranquility SE with updates as of 2018 no and Jupiter copper foil output caps. It’s a hyper optimized circuit around an old R2R DAC chip, so very different than the Sabaj hyper modern chip approach. Also a very different price point, with used price at around 2.5-3x the cost of the Sabaj new.

So I think I’ll keep the Sabaj in the TV system where it’s working well. It’s cleaner and clearer than the Schitt Modi Multibit I’ve been using there for several years, even if the Schitt does have a bit more natural and laid back tone. A bit more pep and detail can be more welcome at the expense of natural tone when watching movies and shows, IMO. And I get the remote volume to boot.

But I could easily live with the Schitt and save the $400 if I had an easier remote volume option. 75% of its job is playing cartoons, so not exactly critical to extract all the details.

[wushuliu]

I’ve had the Sabaj in my TV system for the past couple weeks. It gets 5-6 hrs of use per day between the family.

Thanks for sharing your experience with it. Were you using the coax input in the main system? What kind of source (cd player, streamer, etc)?

[genjamon]

I used the USB input in the main system. Streaming Qobuz.  Fed by a Sonore Ultrarendu endpoint, using the Uptone USPCB adapter instead of a USB cable. And a Buffalo switch with the same board as the high end Melco switch. All units fed by Uptone LPS 1.2 ultra capacitor regulated power supplies. So it’s a very clean and isolated network, except for the modem and router. But I also have fiber internet, so at least were only dealing with noise internal to my house and those two units.

[genjamon]

I suppose it’s possible the USB input needed more burn in, since it hasn’t been used at all prior to the comparison.