Dual Merus MA12070 Amplifier Sabaj A20 fully balanced : pictures inside )

[Toku]

improved but not eliminated....?

I'm sorry, I don't understand the meaning.

I haven't received any detailed information yet.
I know it's just a power supply issue.

 

[AntGom]

i mean that the issue has fixed or the noise has merely reduced...

 

[Toku]

improved but not eliminated....?

It cannot be said that it was solved without the former.
Once you have the improved A20a, test it and report it.

 

[fluxcapacitor]

Hi amigos,

Just received the new Sabaj A20. This a brand new class D amp made with a dual Infineon Merus MA12070 and fully balanced.
This is my second amp based on this chip. I had already reviewed a fully symmetrical dual Mono MA12070 that I had built a few months ago.

The amp is made in an aluminum case, it feels sturdy and beefy. The front of the amp has a mirror front and the volume controller has a dual function (volume and selector). When you press a few seconds on it , it powers ON / OFF. The amps also comes with a remote control.
The design really looks like the SMSL AD18.

You have the possibility to adjust the bass / treble, the amp also has some presets, I'm not a fan of it, I left it in "direct" mode.

What we found inside :

- Dual Merus MA12070 chips
- OPA1678 op amps
- NJW1194 digital volume chip
- A great Meanwell SMPS PSU 300W
- RCA inputs
- XLR inputs
- Sub out
- Banana speakers



Pictures :

can you tear it down and show us all internal boards? thanks

 

[ad_fletch]

Hope someone can send an A20a to Amir for testing. I would if I lived in the US. Relay issue aside, it seems to have all the ingredients in place for a great lower-cost alternative to a Hypex amp.

I have a question for the experts (or maybe @peterwen ) - why does this amp and similar ones offer a digital low pass filter when almost every subwoofer amp in existence already has a LPF built in? Surely the thing people really want in a 2.1 system is an adjustable high pass filter to blend in the sub...?

Having a HPF would make these amps very attractive to those who have been hesitating over the expense of a MiniDSP solution.

 

[peterwen]

Hope someone can send an A20a to Amir for testing. I would if I lived in the US. Relay issue aside, it seems to have all the ingredients in place for a great lower-cost alternative to a Hypex amp.

I have a question for the experts (or maybe @peterwen ) - why does this amp and similar ones offer a digital low pass filter when almost every subwoofer amp in existence already has a LPF built in? Surely the thing people really want in a 2.1 system is an adjustable high pass filter to blend in the sub...?

Having a HPF would make these amps very attractive to those who have been hesitating over the expense of a MiniDSP solution.

A10d and A10h have been dispatched to Amir. There hasn't been any review yet. It's possible that we'll have to wait for Amir. Amir might be occupied. More items are available for testing, and we are willing to send them out.

 

[Zek]

Has the clicking problem on A20a been solved?

 

[peterwen]

Has the clicking problem on A20a been solved?

Yes, the customer who have the problem can connect me and we will send a new power supply. Thanks

 

[peterwen]

Or connect with the seller where your order from.

 

[Moosi]

Do you have to screw both sides of the amp open in order to have access to the power supply or can you pull it out after opening the back?

why does this amp and similar ones offer a digital low pass filter when almost every subwoofer amp in existence already has a LPF built in? Surely the thing people really want in a 2.1 system is an adjustable high pass filter to blend in the sub...?

Doing so would probably require an additional module, which would have to be of high grade not to degrade output quality. However, in a 2.1 system you could use a DSP to lower the db of lower frequencies, giving your speakers some room, while turning the Sub up a little to make up for the loss. Usually the sub is far too powerful for the systems balance anyway.

 

[Benji L]

It cannot be said that it was solved without the former.
Once you have the improved A20a, test it and report it.

Is the new power supply as powerful as the original one in the earlier A20a? Does anyone know what change has been made?

 

[Toku]

Is the new power supply as powerful as the original one in the earlier A20a? Does anyone know what change has been made?

We know that there is a problem with the power supply unit, but no further specific improvement measures have been disclosed. Of course I don't know either.
I will get the improved A20a again when it is distributed.
Sabaj will also take appropriate action for products that have already been sold. So wait for additional information from Sabaj!

 

[fluxcapacitor]

Or connect with the seller where your order from.

if i buy from Aliexpress and has that issue, will you send me a new psu? Aliexpress sellers usually asks for return of items which take a month in my case. I had two SMSL DA9, returned 1st one due to frozen at smsl logo, and will return 2nd one due to pop noise. I dont want to return my 3rd purchase. thanks for confirming

 

[Toku]

I'm waiting for a new version of the A20a, but before I got it, I was curious about the AO200 and bought it first.
I posted the test report in the DA-9 thread, so please take a look.
The AO200 completely eliminates the problems experienced with the DA-9 and A20a.
At last I was able to know the power of the Infineon MA12070 double tip. Wonderful.

https://www.audiosciencereview.com/...nd-see-or-solid-buy.21927/page-41#post-850180

 

[Toku]

I apologize to everyone!
I promised a test report when I received the A20a with the problem improved, but I still haven't received the A20a. Therefore, I abandoned the follow-up survey of A20a.
The AO200 that is already in use has been operating stably without any problems so far.

 

[Pavko]

I apologize to everyone!
I promised a test report when I received the A20a with the problem improved, but I still haven't received the A20a. Therefore, I abandoned the follow-up survey of A20a.
The AO200 that is already in use has been operating stably without any problems so far.

Do you have any hiss noise in your AO200 when power is on? I just received mine yesterday (today I'll get speakers) and I tirn onw power jist to check how it works and I hear hiss. Is it normal?

 

[Toku]

Do you have any hiss noise in your AO200 when power is on? I just received mine yesterday (today I'll get speakers) and I tirn onw power jist to check how it works and I hear hiss. Is it normal?

Normally, I don't feel any hiss noise at all. You can detect it slightly by bringing my ears close enough to the speaker unit. But that's the smallest level I've ever experienced. It's really quiet.

 

[Moosi]

I wonder if the AO200 uses the same psu as the DA-9. If so, it should be slightly inferior to the one in the A20a. 140/225W vs. 200/350W.

 

[Toku]

I wonder if the AO200 uses the same psu as the DA-9. If so, it should be slightly inferior to the one in the A20a. 140/225W vs. 200/350W.

Yes, as you say, the DA-9 and AO200 are the same power supply unit.
A larger unit is used for the A20a. However, this caused the A20a to have major defects.

 

[milan616]

However, this caused the A20a to have major defects.

I wouldn't call the relay clicking a major defect, though annoying to be sure. We'll see how the replacement PSU is.