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

Moosi

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There is only two kinds of people on this planet who don't like the Japanese. a)People who love whales b)Chinese :p
 

Toku

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There is only two kinds of people on this planet who don't like the Japanese. a)People who love whales b)Chinese :p
Thank you for pointing out.
Sure, whale lovers hate the Japanese, but people who live closer to Japan hate the Japanese more. I don't understand why this happens.

When I was a kid, whale meat saved my life. Whale meat was the cheapest food available in poverty. Whale meat is a lifesaver for those who have experienced post-WWII poverty.

When eating, Japanese people put their hands together in front of their chest according to Buddhist teachings. And we pray for gratitude for all the living things that have become food. This is the meaning of "Itadakimasu" that Japanese people say when they eat.
 

Moosi

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When I was a kid, whale meat saved my life. Whale meat was the cheapest food available in poverty.
I'm glad you got your life saved as a kid and I respect and cherish the glorious and rich Japanese tradition. However, the second highest developed creature on this planet being "the cheapest food available" tells you a lot about our perception of value as a society. Whales are not swimming cows, but let's not go there.
people who live closer to Japan hate the Japanese more.
Nobody lives close to Japan. You're an island. After the whales and besides putting pixels over your genitals that's the primary reason why your're being hated. The British know this and found a solution to the problem. They don't give a f**k and built a powerful navy.
 

Doodski

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The British know this and found a solution to the problem. They don't give a f**k and built a powerful navy.
The Japanese have a long history as having one of the best navies. They have that covered from what I read about it. Sue they are a peace keeping navy but they are still seamen/seapeople. :facepalm:
 

Moosi

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The Japanese have a long history as having one of the best navies.
No doubt about that. But they haven't conquered and held as many parts of the world with it as the British. Their naval tradition does not include that kind of rulership over vast parts of the globe. From Japanese perspective there is probably not much need to do that. If I would inherit Japan, I wouldn't go for Korea either. I'd rather exploit the vast ocean right of me. They actually have access to half the freaking planet. It's just underneath the water.
 

Moosi

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^
"Signal-to-noise and distortion ratio (SINAD) is a measure of the quality of a signal from a communications device."

There is no automatism that connects SINAD to amplifiers and DACs only. Since all navies do communicate via radio/satellite frequency, we can assume that they're somehow dealing with SINAD too. And since navies are packed with measurement devices of all sorts, I strongly assume they can measure distortion in their signalling pathways somehow. However, I don't think we can have a frigate shipped to Amir.
 

ModDIY

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Hi, I opened my Sabaj A20a, I notice the hp cables are further away from the JRC preamp. So I doubt that the problem comes from there with the RCA, because no noise for XLRs, which also go through the same signal path to the preamp.

I noticed that the 15V DC output at the back, the connection pins is right next to the RCA input.
 

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ModDIY

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Hi,

as many know here, on the RCA input with maximum volume there is a hiss, while it is complete silence with XLR input.

Yesterday I therefore moved the A20a from my main chain in the living room and installed on my chain in my workshop, wow it's complete silence on the RCA input with maximum volume.

My workshop bookshelf, I designed them with measurements and simulation with PC, the tweeter is a ribbon with medium sensitivity, so the ear close to the tweeter, it is complete silence as with my bi-amplification system on my main channel.

I am pleasantly surprised and will continue my tests.

For now I love the sound of the Sabaj A20a, the power is enormous, and I will add an Energy sub, in addition there is a tone control which is very practical, finally I do not regret my purchase.
 

Moosi

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Yesterday I therefore moved the A20a from my main chain in the living room and installed on my chain in my workshop, wow it's complete silence on the RCA input with maximum volume.
Very interesting, but what exactly do you think makes the difference here? Is it now silent because of the other bookshelf speakers from the workshop or is it silent because in the workshop there is a difference in how the amp is powered?

I'm not even sure 15V DC is that much of a deal in terms of radiated EMI. For me the biggest improvement to the RCAs was achieved by "cleaning up" the AC-cable with the N30 ferrite ring. AC should by definition produce a lot more EMI, because of the swichting phases in 50h/60hz and because there is a lot more volts passing.
 
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ModDIY

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Very interesting, but what exactly do you think makes the difference here? Is it now silent because of the other bookshelf speakers from the workshop or is it silent because in the workshop there is a difference in how the amp is powered?

I'm not even sure 15V DC is that much of a deal in terms of radiated EMI. For me the biggest improvement to the RCAs was achieved by "cleaning up" the AC-cable with the N30 ferrite ring. AC should by definition produce a lot more EMI, because of the swichting phases in 50h/60hz and because there is a lot more volts passing.
This is not because of the bookshelfs, they are quite, efficient and the ribbon tweeter lets all noise past. I would say the electrical power workshop is superior ... I don't know.

In my living room, on the small shelf I have several items of equipment. to sum up, my sound columns are normally bi-amplified by 1 pair of class AB amplifiers. So obviously there are 2 pairs of wires per speaker so a potential problem with EMI emissions from the cables. I can remove a pair of wires and so just have one pair of wires coming from the amplifier per speaker, I'm going to do that, matter of time and energy because I'm a technical guy and I like to know the why of this that it happens.

On the other hand, my health is bad and doing this test by changing the wiring takes time, a day or my pain leaves me alone. So in addition there are a lot of nearby equipment ...

For the nearby 15vdc, okay I take note. I bought and tested the N30 ferrite and put on the AC cable (Canada 120v ... to be taken into account because voltage 2 times lower than in Europe and elsewhere), so the N30 gave no difference in the living room room. In the workshop either.

This is the first time that this has happened and I haven't said my last word, I want to understand. In the workshop I used a TPA3255 which did the job well, but when changing to the Sabaj A20a, OMG it's amazing the sound of this amplifier.

I started repairing an old Energy sub to add it with the SUB output.

here it works and also with XLR total silence. In addition to SUB output and remote control and form factor that I like a lot.

Edit: The Energy sub is for the workshop of course.
 
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After few month of waiting, the fixed PSU board (non-clicking at heavy ohmic load) I was promised to receive free of charge is now in transit. (They ran out of stock somewhen in 2021-09 with the fixed boards I guess). Thank you, hifi-express for keeping your word.
 
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elak

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Hi, is there some universal remote control for Sabaj a20a? I can buy this amp much cheaper without remote.
 
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Hi, do you guys think that sabaj a20 will have any problem playing with that dac as preamp?
Not at all. But as neither the A20a can work as a power amplifier nor the one you mentioned can work as a pure DAC there is always two volume controllers in a row the signal runs through. That does not make a lot of sense. Just if feeding the A20a is not the only purpose...well...why not.
 

AntGom

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Not at all. But as neither the A20a can work as a power amplifier nor the one you mentioned can work as a pure DAC there is always two volume controllers in a row the signal runs through. That does not make a lot of sense. Just if feeding the A20a is not the only purpose...well...why not.
i am confused now....:p
 

Moosi

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A20a
DAC: none
Amp: [email protected]
Preamp: [email protected] (60 steps digital)

UDA38pro
pure DAC: none
DAC+Preamp: 58 steps digital, probably NJW119X or similar

Most (better) DACs
pure DAC: bypassing Preamp, handing signal without altering it
DAC+Preamp: something similar with digital steps

With the A20a you would want a DAC running in "pure DAC" mode to ensure best performance. This way the signal only gets degraded (ever so slightly) by the volume controller once in the chain. Since you can't turn the Preamp off in the A20a, you need to turn it off in the DAC.
 

AntGom

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A20a
DAC: none
Amp: [email protected]
Preamp: [email protected] (60 steps digital)

UDA38pro
pure DAC: none
DAC+Preamp: 58 steps digital, probably NJW119X or similar

Most (better) DACs
pure DAC: bypassing Preamp, handing signal without altering it
DAC+Preamp: something similar with digital steps

With the A20a you would want a DAC running in "pure DAC" mode to ensure best performance. This way the signal only gets degraded (ever so slightly) by the volume controller once in the chain. Since you can't turn the Preamp off in the A20a, you need to turn it off in the DAC.
Thanks...so maybe i should looking for alternatives of the little dac that i have. Could you link some of your choices?
 
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