Sabaj A30a announced

[GiBo61]

The feedback has nothing to do with it. As can be read in the Rel article, it’s the grounding scheme that is “messed” it up. They blame the amps, yet all they have to do is make sure that they don’t reference the high-level input to ground. Nowadays a great many amps are like this.

Those sub inputs are high impedance, they won’t influence any feedback loop, digital or otherwise.

That means that using the trick indicated by REL one can use a subwoofer high-level connection even with the Sabaj A30a?

 

[GiBo61]

I just unboxed my new Sabaj A30a and I was getting ready to apply the firmware update. Unfortunately I cannot reach the Sabaj website, I tried both from PC and Mac, using different browsers and I always get the same message:

Service Unavailable​

---

HTTP Error 503. The service is unavailable.

It's only me or is a common problem?

By the way I went on the HiFi express website and the Sabaj A30a seems to be sold-out (even selecting the delivery from China).

 

[voodooless]

That means that using the trick indicated by REL one can use a subwoofer high-level connection even with the Sabaj A30a?

I suspect so.

 

[PeterOo]

I just unboxed my new Sabaj A30a and I was getting ready to apply the firmware update. Unfortunately I cannot reach the Sabaj website, I tried both from PC and Mac, using different browsers and I always get the same message:

Service Unavailable​

---

HTTP Error 503. The service is unavailable.

It's only me or is a common problem?

[…]

It’s not just you. Sabaj.com.cn appears to be offline.

Sabaj.com.cn down? Current problems and status. - DownFor

Sabaj.com.cn won't load? Or, having problems with Sabaj.com.cn? Check the status here and report any issues!

downforeveryoneorjustme.com

 

[SidiousX]

I just unboxed my new Sabaj A30a and I was getting ready to apply the firmware update. Unfortunately I cannot reach the Sabaj website, I tried both from PC and Mac, using different browsers and I always get the same message:

Service Unavailable​

---

HTTP Error 503. The service is unavailable.

It's only me or is a common problem?

By the way I went on the HiFi express website and the Sabaj A30a seems to be sold-out (even selecting the delivery from China).

For years I have been yearned to register, at last you have given me no excuse to delay it any longer.
To all users especially @Toku, thanks for all your contribution.
Here is your firmware:

Private file

Zippyshare.com - Free File Hosting

www98.zippyshare.com

I'm happy to help.

 

[Toku]

Why connecting to high-level output from a30a is a no-go?

Class D amplifiers come in multiple types of output formats, including SE, BTL, PBTL, and PSE.
Of these, only the SE (single-ended) type and PSE (parallel single-ended) type are capable of high-level input through speaker output.
In the case of SE output, the negative side of R-ch and L-ch is connected to the ground, and the + terminal is 0V with no voltage applied, so there is no need to worry about short circuits.

The Sabaj A30a uses a BTL type amplifier. The BTL method obtains a large output by differentially driving two amplifiers.
The speaker is connected between the + side outputs of the two amplifiers, and the voltage between the speaker terminals is 0V, but the voltage between the speaker terminals and GND is half the power supply voltage.
Therefore, if a wire other than the speaker is connected to a BTL amplifier, the amplifier may be short-circuited and damaged due to overcurrent.
If A30a is connected to the high level input of SW, a short circuit condition may occur inside SW and destroy A30a.

For this reason, a general speaker switch cannot be used in a BTL amplifier. You must have one that supports the BTL method.

 

[antcollinet]

That means that using the trick indicated by REL one can use a subwoofer high-level connection even with the Sabaj A30a?

It depends on the exact archtechture of the input. Which might be different with different subs. I'd expect it to work, but not possible to be certain.

 

[ModDIY]

The Sabaj A30a is sold out on Hifi-express !!!

 

[SlamTaz]

The Sabaj A30a is sold out on Hifi-express !!!

for those in the U.S., it's available at amazon for $499.99 w/ free over-night shipping and free returns until Jan 31, 2023 for prime members.

 

[GiBo61]

Unboxing and installing my new Sabaj A30a

 

[GiBo61]

After unboxing I really appreciated the high built quality of the device, everything is well made and feels nice and solid, maybe with the exception of the rotary control wheel that feels a little bit wobbly on its axis. This is likely due to the fact that it not only rotates but also acts as a selection button. Although it's made of metal it feels very light, which I don't really like.
I initially connected the Sabaj A30a to a Chromecast Audio device using the analog input of the amplifier. The speakers are the Dali Zensor 3, they are honest and pretty entry level boxes, I would say neutral (boring?), as most speakers not particularly exciting at low volumes. The mid frequencies (voices) are a little bit recessed and the bass frequencies too lean for my taste. They were highly prised in a number of reviews both from experts and users. On the other side of the room I have the gorgeous and satisfying (and 4 times more expensive...) Elac Vela BS403 connected to a modern (i.e. not vintage) and quite infamous Denon DRA 800H 2.1 stereo AV receiver.
Everything worked fine at the first connection, however from the menu structure shown on the (nice and clear) display I realized that the Sabaj was NOT updated to the latest firmware release. The sound was nice and similar to the one I get when using my vintage Marantz amp. I could ear no audible background noise coming from the analog input. Then I switched a digital connection using a Mini TOSLINK-to-TOSLINK optical cable: once connected to the optical input of the Sabaj…. I’ve got no sound from the device. Before panicking I decided to apply the latest firmware update to the amplifier. This turned out to be non an easy task considering the the Sabaj web site last Saturday was down for several hours. Thanks to the help of a couple of the members of this thread I was able to get a copy of the zip file. The update procedure was not particularly complicated, HOWEVER it is something that can be done with confidence only by someone with a familiarity with electronic and Windows devices (most if not all of my friends will never consider to do this procedure by themselves). I HIGHLY recommend Sabaj to ship their devices with the latest firmware already installed.
After applying the update I connected again my Chromecast Audio via the optical cable and I had to adjust the "SPDIF Sense” level (now available in the menu after the firmware update) at 7 to get the sound out of it. Question: is it better to set this parameter at the minimum working threshold or rather to set it to a higher value (in my case 8 or 9), to be on the safe side? Later on I connected a Wii Mini streamer to the same optical input and it worked fine with every SPDIF Sense level value I tried (even with 1). I'm wondering if the issue with the Chromecast Audio device is related to the Mini TOSLINK-to-TOSLINK optical cable I used (I have no other one to test).
Using the Sabaj with a digital source connected with an optical cable results in an improvement in perceived sound quality. I'll post my first impressions later.

 

[ModDIY]

I received mine, works well I tested xmos, Bluetooth and is correct. I will install the firmware and get back to you with my impressions. Everything seems solid except for a handle which is a bit loose.

 

[ModDIY]

The A30a is available again on hifi-express.

This morning I start listening on my new speakers Focal Chora 826.

 

[vuittion]

So whats your verdict on the amp.

 

[pym]

Class D amplifiers come in multiple types of output formats, including SE, BTL, PBTL, and PSE.
Of these, only the SE (single-ended) type and PSE (parallel single-ended) type are capable of high-level input through speaker output.
In the case of SE output, the negative side of R-ch and L-ch is connected to the ground, and the + terminal is 0V with no voltage applied, so there is no need to worry about short circuits.

The Sabaj A30a uses a BTL type amplifier. The BTL method obtains a large output by differentially driving two amplifiers.
The speaker is connected between the + side outputs of the two amplifiers, and the voltage between the speaker terminals is 0V, but the voltage between the speaker terminals and GND is half the power supply voltage.
Therefore, if a wire other than the speaker is connected to a BTL amplifier, the amplifier may be short-circuited and damaged due to overcurrent.
If A30a is connected to the high level input of SW, a short circuit condition may occur inside SW and destroy A30a.

For this reason, a general speaker switch cannot be used in a BTL amplifier. You must have one that supports the BTL method.

Thanks for the explanation and the warning! I was planning to use a Dynavox Amp-S MKII speaker selector with a class D amplifier (audiophonics mpa-s250nc - BTL method). The dynavox has a "zero" position that you must go through when you select an amplifier. Is it useful to avoid short circuits?

 

[Zek]

I was planning to use a Dynavox Amp-S MKII speaker selector with a class D amplifier

You have to check if that selector separates the (-) pole as well or only the (+) one.
For class D amplifiers, it must be separated (-) pole to avoid a short circuit that can destroy the amplifier.

 

[Piopio]

Very interesting article.

 

[GiBo61]

Subjective mini review of the Sabaj A30a full-digital amplifier

First listening impressions of the Sabaj A30a using as a source a Wiim Mini streamer connected via TOSLINK. Dali Zensor 3 speakers in a 30 square meters room with no sound treatments.
The Dali Zensor 3 have been so far connected to a 1984 Marantz PM 550 DC amplifier and a few times to a (24 kg!!) Rotel RSX-1067 and a Denon DRA 800H.
Here is a partial list of tracks I used to test the system mostly at a 44 kHz sample rate and at 16 bit depth from Tidal HiFi Plus:
- David Brubeck: Take Five
- Aldo Romano: Cité Soleil
- Patricia Barber: What a Shame
- Tom Rizzo: Lonesome Cowboy
- Dire Straits: So far Away
- Dire Straits: You and Your Friend
- Eagle: Hotel California
- Nils Lofgren: Keith Don’t Go
- The Who: Pinball Wizard
- Steve Winwood: Higher Love

I’m not one of those audiophiles who is able to describe the sound of a device or a system using fancy terms. What I can say is that with the Sabaj I did not notice any particular difference in the reproduction of the low frequencies of my Dali Zensor 3, maybe they are a little bit more controlled than with my previous amplifier (I read somewhere that the SMSL VMV A2 twin device has an insanely high dumping factor of 4000). On the other hand the mid and high frequencies seems to be more alive and in general the music reproduction is more detailed and engaging. Although I would not bet my left kidney, I would say that I also noticed an improvement in the imaging and soundstage likely due to the very limited crosstalk between the two channels. I did not know what to expect from my first class D amplifier, in summary I would say that the sound is detailed, natural and not fatiguing at all.
I live in a condo so I could only test the system at low and medium volume (no more than 50-55 on the digital display) so I can’t comment about the power reserve of the amplifier that however seems more than enough to create irreversible problems with my neighbors. Even after 2 or 3 hours of listening at medium-low volume I would describe the temperature of the chassis as lukewarm. I never heard any noise coming from the cooling fan (either is very quite or has never been spinning). I also never heard any hum or hissing coming from the speakers (however I did not put my ear near the tweeters)
I only briefly played with the different equalisation settings available and I found at least a couple of them (Rock and Soft) that I could considered in the future when listening to music at low volume. I’m not sure I like any of the several loudness eq settings available beside the ones up to 4..
I then decided to connect to the Sabaj to my Martin Logan Dynamo 700w subwoofer. I really appreciate the availability of a combined low pass and high pass filter although the lower cutoff setting available (70 Hz) could be limiting in some setups. Considering that my Dali Zensor 3 are not exuberant on the low frequencies, the use of the subwoofer (with a cutoff at either 80 or 90 Hz) significantly improved the final quality of the sound.
I did also BRIEFLY connected the Sabaj to my Elac Vela BS403 (that I usually drive with my Denon DRA800 H stereo receiver) and I cannot say I detected a significant improvement over the Denon (maybe the bass are a little bit more tight with the Sabaj than with the Denon). However this is a very preliminary analysis considering that I had to move the Velas on the other side of the room to connect them to the Sabaj.

To summarize

PROS
- The Sabaj A30a looks a solid and well made device
- No need for a DAC to feed the amplifier
- Natural and not fatiguing sound with very nice mids
- The device is silent when no music is playing
- Nice to have a combined low pass and high pass filter for the SW output
- Minimalist design although not everyone will like the gold Sabaj logo and the handles on the front plate
- The display is small but nice and easy to read
- Nice speaker connectors on the back plate
- The device runs cool at low-medium volume (I did not test it at high volume)
- No hums of hiss when no music is playing (I didn't investigate the matter at length by cranking the volume all the way up)
- I did not have the possibility to push it but it seems to have a vast reserve of power
- Due to the new Axign-Full Digital Amplification technology it can probably compete with AB class amplifiers that cost 3 to 5 times more

CONS
- I was expecting more punchy bass, however I must say that the Dali Zensor 3 speakers I used for my test are rather poor in that department
- The volume knob is wobbly and very light
- There is no led that indicates if the device is on. When the display is dimmed and no music is playing is impossible to say if the amplifier is on or off.
- It would be nice to have an eco-friendly automatic shutdown when the amplifier is not in use after a certain amount of time
- The firmware update procedure is mostly only for computer or audio geeks
- It would be extremely useful to have the possibility to set a cut off frequency lower than 70 Hz for the SW output
- It would be also useful to have the possibility to have as an option a full frequency range output for the SW
- The instruction manual should be more detailed
- It’s ridiculous to have 20 or so EQ settings without knowing their effect on the frequency response

That's all Folks

 

[GiBo61]

The A30a is available again on hifi-express.

This morning I start listening on my new speakers Focal Chora 826.

View attachment 245324

View attachment 245325

Nice setup and gorgeous cat! I'm curious to ear how does the Sabaj play with your new Focals...

 

[paoloc]

interesting paper on Adc impact