Sabaj A30a announced

[Tonton_ZEeD]

I have an observation about the 'sub-out' output. I have no way of confirming this with measurements, but judging by ear (using both test tones and music) I get the impression that the volume curve of the subwoofer output is different from that of the main speakers. I have configured the subwoofer at volume 40 and at this level it is perfectly linear (the 'sub off' setting does not change the overall feel of the bass volume compared to the cut-off at 70Hz, only its downward extension), whereas at a much lower overall volume there is too much bass and similarly, at significantly higher volume levels, there is not enough bass. In both cases by changing the subwoofer gain I can get back to linear bass.
I tested this on all digital inputs with identical results. Perhaps the fact that I am using a wireless RCA signal transmitter, similar to the svs soundpath, is relevant here.
Could someone please try to reproduce this in their 2.1 system?

I've noticed the same behaviour.

 

[ModDIY]

I have an observation about the 'sub-out' output. I have no way of confirming this with measurements, but judging by ear (using both test tones and music) I get the impression that the volume curve of the subwoofer output is different from that of the main speakers. I have configured the subwoofer at volume 40 and at this level it is perfectly linear (the 'sub off' setting does not change the overall feel of the bass volume compared to the cut-off at 70Hz, only its downward extension), whereas at a much lower overall volume there is too much bass and similarly, at significantly higher volume levels, there is not enough bass. In both cases by changing the subwoofer gain I can get back to linear bass.
I tested this on all digital inputs with identical results. Perhaps the fact that I am using a wireless RCA signal transmitter, similar to the svs soundpath, is relevant here.
Could someone please try to reproduce this in their 2.1 system?

I configured in 2.1 and I muted the sub out at 70hz on the A30a. My sub doesn't have LFE, so I chose the highest cutoff frequency around 180hz, and the sub volume (not sub level on the A30a) at -3db, don't trust the value because it is a pot with printed indicator.

I tested at different powers and I did not feel a difference in level.

My Focal Chora 826 speakers have an impedance of 8ohm (2.9ohms at its lowest), 91db of efficiency and 250w maximum. I "tried" when listening to electronic music and a lot of bass to push the A30a to a very high level and it was already way too loud for my living room.

I'm going to do some more testing, but I didn't feel what you're describing.

On the other hand with some bad recordings, the tonal balance is not good, always occurs with studio recordings which I consider sloppy and made for radio or budget audio channels.

While on just about all good recordings, it stays balanced at all volumes.

 

[Mixed_Messages]

Does anybody have the problem that the A30a just wont switch on ? 4 or 5 times now I have given power to the unit (I can hear a click from within the unit) but it
wont power up. Generally after half an hour and a few goes it switches on. This is the response I had from HiFi-Express "We had this happen on our end once, it was multiple a30a's all doing this, then we changed the drain plug and it was fine. It was caused by insufficient power to the plug. Sometimes it would wait twenty minutes after plugging in before it would turn on that time." Not sure what this means..

 

[cyponn]

I've noticed the same behaviour.

Same behaviour on 2.1 setup on my side.

 

[Toku]

I tried turning it on and off several times with the power switch on the back, but the display turned on in about 4 seconds with the sound of the relay, and it was ready for operation.

 

[titilandus]

Does anybody have the problem that the A30a just wont switch on ? 4 or 5 times now I have given power to the unit (I can hear a click from within the unit) but it
wont power up. Generally after half an hour and a few goes it switches on. This is the response I had from HiFi-Express "We had this happen on our end once, it was multiple a30a's all doing this, then we changed the drain plug and it was fine. It was caused by insufficient power to the plug. Sometimes it would wait twenty minutes after plugging in before it would turn on that time." Not sure what this means..

Or maybe you're in service mode. Like for software update. Try connecting your a30a to your computer. Maybe there will be a connection. Alternatively, perform a software update as described by Toku here you have the link

 

[Mixed_Messages]

I tried turning it on and off several times with the power switch on the back, but the display turned on in about 4 seconds with the sound of the relay, and it was ready for operation.

I get the sound of a relay and then no display. I left it unplegged from the mains for about 10 mins. THen plugged it in again and it same on last night.

 

[Mixed_Messages]

Or maybe you're in service mode. Like for software update. Try connecting your a30a to your computer. Maybe there will be a connection. Alternatively, perform a software update as described by Toku here you have the link

Surely it would be in this mode every time I switch it on ? This is only an intermittent occurence..

 

[titilandus]

Will be. I put mine in service mode. After shutting down, he continued to work in it. Nothing was visible on the screen. I didn't know how to get out of it. I did a firmware update. When finished, the screen lit up and the amp went back to normal mode.

 

[ModDIY]

Same behaviour on 2.1 setup on my side.

I've noticed the same behaviour.

I have an observation about the 'sub-out' output. I have no way of confirming this with measurements, but judging by ear (using both test tones and music) I get the impression that the volume curve of the subwoofer output is different from that of the main speakers. I have configured the subwoofer at volume 40 and at this level it is perfectly linear (the 'sub off' setting does not change the overall feel of the bass volume compared to the cut-off at 70Hz, only its downward extension), whereas at a much lower overall volume there is too much bass and similarly, at significantly higher volume levels, there is not enough bass. In both cases by changing the subwoofer gain I can get back to linear bass.
I tested this on all digital inputs with identical results. Perhaps the fact that I am using a wireless RCA signal transmitter, similar to the svs soundpath, is relevant here.
Could someone please try to reproduce this in their 2.1 system?

Do you have the latest firmware update?

I seem to have read in this thread that there was a problem on the sub side with the first version.

I made several listening with the sub and this with several listening levels and at low, medium and high volume I do not hear more or less bass at different levels, it always remains homogeneous as long as the sub is good configure .

If I hear any defaults, I'll get back to you, but so far all is well with the A30a and sub.

 

[robbbie]

Do you have the latest firmware update?

I seem to have read in this thread that there was a problem on the sub side with the first version.

I made several listening with the sub and this with several listening levels and at low, medium and high volume I do not hear more or less bass at different levels, it always remains homogeneous as long as the sub is good configure .

If I hear any defaults, I'll get back to you, but so far all is well with the A30a and sub.

Thank you for the information.

I have the latest firmware installed on mine. I updated it right after the package arrived from China so I haven't had a chance to compare it with the original firmware.

I did some heavily unscientific measurements yesterday at the listening spot using the best tool at my disposal which is a Samsung s22 phone and various sweeps for low frequencies. The results, while not very precise, give food for thought and are far less spectacular than the initial impressions:
Listening at a volume setting of 25 (15 less than the reference 40 for me) makes the 40-60Hz region about 3-5dB louder than 80-120Hz. Conversely, a volume of 55 makes the lower bass about 2.5dB quieter than the higher bass.

So it seems to me that the phenomenon I observed is more a matter of room acoustics and the specifics of connecting the subwoofer via a "sub-out" output with a high-pass filter for the main speakers.

With previous amplifiers and subwoofers, I always used a high-level full-range connection for the speakers, which made the setup more difficult but, with the effort put in, repaid with more even bass distribution in the room and ideal volume (at least to my ears).

I would love to see what the situation would be like if it were possible to feed the full range to the "sub-out" while not cutting the bottom end from the main speakers...

Other than that I must admit that I'm pretty impressed with the sabaj, even though not flawless, it's still great little equipment for the price

 

[ModDIY]

Thank you for the information.

I have the latest firmware installed on mine. I updated it right after the package arrived from China so I haven't had a chance to compare it with the original firmware.

I did some heavily unscientific measurements yesterday at the listening spot using the best tool at my disposal which is a Samsung s22 phone and various sweeps for low frequencies. The results, while not very precise, give food for thought and are far less spectacular than the initial impressions:
Listening at a volume setting of 25 (15 less than the reference 40 for me) makes the 40-60Hz region about 3-5dB louder than 80-120Hz. Conversely, a volume of 55 makes the lower bass about 2.5dB quieter than the higher bass.

So it seems to me that the phenomenon I observed is more a matter of room acoustics and the specifics of connecting the subwoofer via a "sub-out" output with a high-pass filter for the main speakers.

With previous amplifiers and subwoofers, I always used a high-level full-range connection for the speakers, which made the setup more difficult but, with the effort put in, repaid with more even bass distribution in the room and ideal volume (at least to my ears).

I would love to see what the situation would be like if it were possible to feed the full range to the "sub-out" while not cutting the bottom end from the main speakers...

Other than that I must admit that I'm pretty impressed with the sabaj, even though not flawless, it's still great little equipment for the price

It may be a sensitivity issue of the subwoofer versus the main speakers. Because the subwoofer has its own amplifier which can react differently from one to another, which also complicates it is to marry well with the main amplifier and the speakers.

Yes it would be nice to be able to send the full audio track without cutting the bass from the speakers. Would be ok for testing.

I agree, the A30a is not perfect but even at twice the price it would still be a bargain, but at this price I don't think you can get better.

 

[Tonton_ZEeD]

Do you have the latest firmware update?

I seem to have read in this thread that there was a problem on the sub side with the first version.

Lastest firmware version, but this behaviour occurs since the second firmware.
I don't mind it, i change the SW volume a lot according to my listening sistutation, time of day, content played (background music while working, gaming etc etc)

 

[ModDIY]

I currently don't have time and my A30a is not in my office/workshop to easily take measurements. If I have time, I will take action with REW. I could measure the sub combined with the main speakers and at different power levels. Nothing very complex, but would measure the level of the sub vis-à-vis the speakers and compare.

 

[Jungstar]

A30a sure looks interesting, but why there is a dac? I don't want to pay extra for it, as I already own superb standalone D300.

The way the amp is made is that it IS a DAC... Most class D actually samples the analoge into what can be thought as a digital sampling.

 

[ZeljkoS]

I read the pages around SABAJ 30Aa and only on the last one did I notice major problems, which today in the "global world" is not a problem, except for physical packages at the post office. China is still far from my home. That's why I've been waiting for the New Year to buy.
Discussion about questions and claims; "it does not need a DAC" I read carefully - it is not a DAC or - it has a different technology for the same effect. However, I would like to hear experiences comparing the A30a with DAC devices it can deal with in terms of performance: better - worse - about the same!
My experience with stand-alone DAC is little: SMSL SU-6. Enough to get me started for the better. Greetings from Croatia

 

[vuittion]

I have had my SABAJ 30Aa for over a week and can honestly say it does not need an external DAC. The only thing that bothers me are the ridiculous EQ settings all of which sound awful to my ears, I leave the EQ setting off/flat. I purchased my SABAJ 30Aa from Amazon UK and have until the 31st Jan 2023 to evaluate it.

 

[ModDIY]

Please note that there are no major problems.

Subwoofer story and control can and will happen with almost most amps. It's been documented many times on forums that arranging a sub with main speakers is very tricky.

Then I have u no other supposed "problem". Everyone who bought A30a, most of them are very satisfied with it.

The other supposed problem of the Zero 2 is not one... this week I tested another software with my Raspberry PI 4 and NO problem with the Xmos of the A30a.

On the other hand, there is a small detail that I would like Sabaj to fix, when you press the button to navigate in the menu, the only way to get out of this display is to press a button such as the volume on the remote control... in the end not much.

An automatic fade out like with the Sabaj A20a 2019 would be welcome.

About the EQ choices, I don't use any because it's not good enough, we would like Sabaj to tell us the applied EQs. For my part just the tone controls are adequate, as lowered or raised a few DB low and high.

 

[Toku]

The way the amp is made is that it IS a DAC... Most class D actually samples the analoge into what can be thought as a digital sampling.

The A30a does not have DAC functionality. The A30a generates a PWM signal that outputs directly to the speaker from the input digital signal. So, in theory, it can output a purer audio signal to the speaker than traditional analog amplifiers or Class D amplifiers because it doesn't use an external DAC.
My prediction is that full digital amplifiers like the A30a and A2 will emerge in the future.

 

[roog]

My prediction is that full digital amplifiers like the A30a and A2 will emerge in the future.

Indeed, I am looking forward to this, as above with powerful DSP for room correction / EQ and 100W per ch ultralow distortion drive for my speakers.

Perhaps it is inevitable that such a scheme will end up being a part of an active speaker set. I guess it already is in some expensive active speakers?