There are only two SUB settings, SUB CUTOFF and SUB VOL.
The SUB CUTOFF setting has no effect on the speaker output, so I don't think there is a HP function.
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The SUB CUTOFF setting has no effect on the speaker output, so I don't think there is a HP function.
pickyAudiophile
Active Member
I see. Meanwhile until you receive a response hopefully tomorrow, would you like telling us about the idle noise level a little? Compared to the A300 (MA5332MS) or - if you still have them - Merus MA12070 based builds like 2020 series by Sabaj (e/g A20a highly appreciated), or Loxjie, SMSL.
It's warmly welcome!
BTW what about the fan characteristics?
I put my ear close to the speaker unit and check it, but I can hardly feel the noise when the A30a is silent. The noise level is lower than AO200. On the A300/A20a 2022 I can feel the noise, albeit at very low levels.
Looking at the block diagram of the A30a, the ASRC DIR part common to all inputs is suspicious. As you pointed out, setting the buffer size in this part may be the problem.
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they don't test it before releasing it for production/sale? strange that you noticed it after a while of testing and they didn't get to it during production. Is it possible to update the system from the amp menu?
I wonder if in this case it is possible to change the buffer size at the software level?
I agree with your doubts about quality control.
I used to be a development engineer for a Japanese manufacturer, so I have a very strict view of the quality inspection of finished products.
Therefore, every time I encounter such a problem, I have doubts about the state of the Chinese production system.
In today's China, the division of labor system is progressing, and even if the design and development is done at Sabaj or SMSL, the actual manufacturing of the product is outsourced to another manufacturing company.
However, even if the product is properly designed, the parts may be changed without permission at the factory.
In the past, an op amp of a certain manufacturer's amp product was replaced with an inferior product at the manufacturing factory.
The A30a has a USB input so I would expect the FW update to be done via USB.
However, there are some FW that can be done by the user and others that can only be done at the factory. I think that MCU (CPU) FW could only be done at the factory.
I have already sent a report of the situation to Sabaj, so I will wait for a reply.
I think the A30a will be a great amp once this issue is resolved.
Regarding the operation of the cooling fan attached to the bottom, the current temperature in Japan is very hot at 35℃, and the room temperature is set to 27℃, but the A30a case is quite warm.
The cooling fan seems to be spinning, but it doesn't bother me much because the sound is low and faint. But that doesn't mean it's silent.
pickyAudiophile
Active Member
I think the update will be via PC- USB-c using something like this: driver from sabaj website.
I further hope that it is some random problem, on the promotional video from youtube, it lasted almost 2 minutes
In general the situation worries me, I don't see myself sending the equipment back "God knows where" and still at my expense?
that is what i was afraid of, thank you for your confirmation
Would you elaborate how the sound quality of this one is "wins in all aspects"? Thanks
Weird all these chinese amps have some kind of issue. My late SMSL DA9 didnt turn on properly, my new MX5 has noise issues when turned off, the exceptional PA5 seems to stop working after a few months und my new contender A30a comes with its own kind of issues...
Cant they just make a unit that measures great and just works properly for years to come? Is that too much to ask?
Cant they just make a unit that measures great and just works properly for years to come? Is that too much to ask?
OP
- Thread Starter
- #112
Because of the new digital feedback technology, the A30a will be hotter when it is static, but it will not be hotter at high power.
No, in order not to affect listening to music, the fan will only work when the temperature is above 60 degrees, and the amplifier will not be interrupted when it is very hot.
The A30a uses a wide voltage design. In the case of 100-240v, please ask the voltage of your home, whether there will be insufficient voltage.
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Your a30a is already with you and you confirm the problem described above?Weird all these chinese amps have some kind of issue. My late SMSL DA9 didnt turn on properly, my new MX5 has noise issues when turned off, the exceptional PA5 seems to stop working after a few months und my new contender A30a comes with its own kind of issues...
Cant they just make a unit that measures great and just works properly for years to come? Is that too much to ask?
Hi everyone, additional report.
Half a day after turning off the A30a, I ran another repro test. At this time the A30a is cold enough.
The speaker output interruption that occurred immediately after playback started yesterday no longer occurs and two songs played normally.
After that, from the middle of the third song, the output suddenly fluctuated and gradually decreased, and finally I could not hear it.
It takes only 3 to 4 seconds from the occurrence of symptoms until the speaker output stops. This behavior was the first anomaly I noticed after receiving the product yesterday.
The case was a little warm at this point, but the fans weren't spinning yet.
The situation after that is the same as the previous report.
From this situation, I suspect not only the buffer size problem, but also "heat protection function worked" or "abnormal operation of the circuit".
Half a day after turning off the A30a, I ran another repro test. At this time the A30a is cold enough.
The speaker output interruption that occurred immediately after playback started yesterday no longer occurs and two songs played normally.
After that, from the middle of the third song, the output suddenly fluctuated and gradually decreased, and finally I could not hear it.
It takes only 3 to 4 seconds from the occurrence of symptoms until the speaker output stops. This behavior was the first anomaly I noticed after receiving the product yesterday.
The case was a little warm at this point, but the fans weren't spinning yet.
The situation after that is the same as the previous report.
From this situation, I suspect not only the buffer size problem, but also "heat protection function worked" or "abnormal operation of the circuit".
The most important thing for Chinese manufacturers today is product quality control. In a society with a different social system, I don't think you have yet understood its importance.Weird all these chinese amps have some kind of issue. My late SMSL DA9 didnt turn on properly, my new MX5 has noise issues when turned off, the exceptional PA5 seems to stop working after a few months und my new contender A30a comes with its own kind of issues...
Cant they just make a unit that measures great and just works properly for years to come? Is that too much to ask?
Based on my experience living in China for a short period of time, it seems that it will take time for them to acquire the quality we want.
OP
- Thread Starter
- #116
In order not to affect listening to music, the fan will only work when the temperature is above 60 degrees, and the amplifier will not be interrupted when it is very hot.
To reproduce the situation, in the same batch. We've been using it today and it's up to temperature without any hiccups.
The A30a uses a wide voltage design. In the case of 100-240v, please ask the voltage of your home, whether there will be insufficient voltage.
What speakers are used?
pickyAudiophile
Active Member
Did I get that right the "official" answer is "out of voltage range" kind of speculation? Sometimes I feel sorry for people in Japan who face these problems with poorly designed power adapters more than anybody else, as they're closer to lower limit of power adapter's usual voltage range with the common 100V provided.
What's your take on that, @Toku? To me that sounds less cooperative than I expected. Therefore I am worried a little.
@m8kbv Lets see how it works with 232V at 50 Hz in Europe then.
What's your take on that, @Toku? To me that sounds less cooperative than I expected. Therefore I am worried a little.
@m8kbv Lets see how it works with 232V at 50 Hz in Europe then.
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Thank you for your concern.
This symptom is never caused by the power supply voltage. My house power line is 103V, but I've also tested it with a voltage stepped up to 115V.
Symptom occurs in common with all of USB/OPT/COAX/BT/AUX. My opinion so far is that the thermal factor is a big factor.
I have had many discussions with Sabaj regarding products such as the A20a and A8, and they have always treated me as a gentleman, and I trust Sabaj.
The A30a is new and just launched. Based on my experience so far, I knew there was a certain amount of risk before purchasing. So I am never in a hurry. I have already sent the video footage documenting the symptoms to Sabaj. I hope they find the cause based on my report.
I am also waiting for information on whether the same symptoms have occurred in the A30a purchased by another person.
Seriously we were the only ones who threw ourselves into buying this amplifier I only have the information that "shipped", after the tracking number of the package I only have the information that it is in the process. So I am waiting.
I only have the information that "shipped", after the tracking number of the package I only have the information that it is in the process. So I am waiting.Is the shop you ordered from HFi express?Seriously we were the only ones who threw ourselves into buying this amplifier
I also ordered from HiFiexpress, but I only received an order confirmation email.
It said "I'll let you know when it's shipped", but I didn't hear anything after that.
However, the product suddenly arrived a week after ordering.
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