The most recent traditional (large, heavy) amp I had in the main system was an Adcom GFA-5400. I listen at moderate volumes and always felt like the 100wpc+ amps I used were largely wasted on me. As someone who enjoys trying different things I grew to dislike moving large amps around, not to mention the shipping hassles and expense of buying and selling them. In all of these ways these little amps are hopefully the future. Small, inexpensive, well-performing, easy to ship and receive, easy to move around.
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Aiyima A07 Max Amplifier Review
- Thread starter amirm
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Regarding the large power gap between the left and right channels of A07 MAX that everyone has been concerned about recently, our company has also conducted internal tests.
The reason why A07 Max has this problem is that the input sensitivity is 1V, while the input sensitivity of V3 is 2V.
First of all, we need to know the input sensitivity. The higher the input sensitivity, the greater the amplification factor, and the noise floor will also be amplified accordingly. However, with the same input signal, greater power can be output, which means it can be compatible with more audio sources, such as Use a mobile phone without a preamp as a sound source, because we know that the maximum output amplitude of the mobile phone is only 0.35V.
A low-sensitivity power amplifier has a small amplification factor, so parameters such as noise floor will not be amplified to a large extent, which also means that a larger signal preamp is needed to push. Under normal circumstances, human ears cannot hear the difference in such a small power, so we chose to make the whole machine more powerful.
If you increase the volume of the A07 Max to the maximum, the gap between the left and right channels will become smaller. In this experiment, we also tried to change the input sensitivity of the A07 Max to 2V, but the engineer tested the volume and sound quality and found that it was lower than when the input sensitivity was 1V. In order to better retain the original sound quality changes of the original tpa3255, we believe that keeping the input sensitivity adjustment is the best way to present the A07max to the audience.
The reason why A07 Max has this problem is that the input sensitivity is 1V, while the input sensitivity of V3 is 2V.
First of all, we need to know the input sensitivity. The higher the input sensitivity, the greater the amplification factor, and the noise floor will also be amplified accordingly. However, with the same input signal, greater power can be output, which means it can be compatible with more audio sources, such as Use a mobile phone without a preamp as a sound source, because we know that the maximum output amplitude of the mobile phone is only 0.35V.
A low-sensitivity power amplifier has a small amplification factor, so parameters such as noise floor will not be amplified to a large extent, which also means that a larger signal preamp is needed to push. Under normal circumstances, human ears cannot hear the difference in such a small power, so we chose to make the whole machine more powerful.
If you increase the volume of the A07 Max to the maximum, the gap between the left and right channels will become smaller. In this experiment, we also tried to change the input sensitivity of the A07 Max to 2V, but the engineer tested the volume and sound quality and found that it was lower than when the input sensitivity was 1V. In order to better retain the original sound quality changes of the original tpa3255, we believe that keeping the input sensitivity adjustment is the best way to present the A07max to the audience.
Please, keep us updated so that we don't need to wait for folks opening up their amps to check out. Thanks.
(PS: it would be great if you make those caps available for people willing to do the change themselves. 0.1 uF 63V smd electrloytics are difficult to find
)You start this post suggesting you are going to explain the difference in the left and right channel. But your explanation does not answer why there is a difference in the left and right channel. It does not even make sense for the input sensitivity to cause this, and it doesn’t make sense why a comparison to the v3 is relevant.
So in the end, are you saying that the test results are not a result of a defective unit? Because I presumed that was the most reasonable explanation when I saw Amir’s measurements. A decibel here and there can happen, chips aren’t perfect, manufacturing isn’t perfect, defects are part of life. Now your explanation here you don’t necessarily say it was defective, and instead seem to double down on the results.
High gain causes channel imbalances? I think you misunderstood your engineers there
I was thinking it might have been a slightly off-spec volume potentiometer, maybe even just a one off problem. If i where you, i would send Amir a second unit.Maybe it's something you already did?... look at your website: https://www.aiyima.com/products/aiyima-a07-max?_pos=1&_sid=7e8223577&_ss=r&variant=46847926239508
The 50V Rubicons have been replaced by new 63V Nichicons... right?
Will new orders from your website send this new upgraded version?
The discussion you are quoting is about the SMD capacitors. These (or whatever the ones at the voltage of the PSU, I don't know exactly which they are):Maybe it's something you already did?... look at your website: https://www.aiyima.com/products/aiyima-a07-max?_pos=1&_sid=7e8223577&_ss=r&variant=46847926239508
The 50V Rubicons have been replaced by new 63V Nichicons... right?
Will new orders from your website send this new upgraded version?
The bigger ones you mention have already been changed for 63V rated ones.
Guddu
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1v input sensitivity causing channel imbalance in A07 Max??? Don't know about others but I think you should revisit this with your technical team.
I cannot identify this channel imbalance while listening music and so not worried about it, but it has been seen in measurements and some would surely seeking some logical explanation.
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Talisman
Major Contributor
In Italian we call this thing "supercazzola" a series of phrases and terms that have a semblance of sense but which then collected in a speech mean nothing. We started from a defect with an obvious difference in the channels, then compared with the v3 and through a series of not very sensible observations we arrived at a presumed better audio quality with an input sensitivity of 1Volt (thus suggesting that it was a choice " better" than v3...." Congratulations for the imagination
The channel imbalance remains an issue but now intermingled by the Aiyima poster with something I've seen complaints about re the Fosi V3. I've seen a number of posts in several forums about it 'being too quiet'. When queried, the complainants are typically feeding the V3 a small signal from a device like a cell phone, or are not familiar with a Taper A volume control. The V3 needs a 2V signal to provide its best and the user needs to be comfortable cranking the volume knob.
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Do you know if receivers like a Denon x3800h pre outs are sufficient to output a 2v signal to make the most of a V3?
Guddu
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Yes, receivers pre-outs are normally pretty close to 2v.
Star Trek "technobabble" comes to mind. Explains whatever, sounds reasonable, except if you think about it.
However, @AIYIMA, we appreciate you communicating what your team said to us and we are aware that there is room for translation errors and of course that your expertise might not be theirs. Cheers anyway.
frabor
Active Member
Shame that Aiyima does not fix their unreliable pots, as they have brought imbalances to their units. they should consider something like an active baxandal volume control that is more tolerant of inferior pots
frabor
Active Member
I am still puzzled at the choice of s 2 Volt input sensitivity in a world that most dac meet or exceed 2.0V. l
The cell phone crowd that uses their phone as a site will probably not use this unit but another one with Bluetooth, much more convenient as you do not need to be thetered. I see this unit being used more often with dacs and streamers, most of them 2.0V compliant.
IMHO, when it comes to d class, I rather have a high sensitivity, to give me more headroom to avoid the dreadfull 10 per distorsión. Most d class have to be treated and loose some of the power envelope to be kept, optimally, below the 1 per cent distorsión Mark. Even manufacturers publish the 1 and 10 percent specs for you to understand how far they can be pushed.
It's really a step backwards to have a 1.0 V sensitivity.
The cell phone crowd that uses their phone as a site will probably not use this unit but another one with Bluetooth, much more convenient as you do not need to be thetered. I see this unit being used more often with dacs and streamers, most of them 2.0V compliant.
IMHO, when it comes to d class, I rather have a high sensitivity, to give me more headroom to avoid the dreadfull 10 per distorsión. Most d class have to be treated and loose some of the power envelope to be kept, optimally, below the 1 per cent distorsión Mark. Even manufacturers publish the 1 and 10 percent specs for you to understand how far they can be pushed.
It's really a step backwards to have a 1.0 V sensitivity.
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