AIYIMA A07 TPA3255 Review (Amplifier)

[antcollinet]

It just show how all over the place this manufacturer is. Every single one of those units have different caps and other components...

What makes you say that?

Electronics manufacturers have been living in a world of component shortages for at least 3 years now. It is common to need to change components used in a design in order to keep production going.

Of course - they could be sourcing any old shit, and just dumping it in the product. More likely (since they are still in busuiness, and the "dumping it in" apporach tends to get expensive fast) the design team evaluates the alternate components and signs off that the product will still perform to spec.

 

[notsodeadlizard]

What makes you say that?

Electronics manufacturers have been living in a world of component shortages for at least 3 years now. It is common to need to change components used in a design in order to keep production going.

Of course - they could be sourcing any old shit, and just dumping it in the product. More likely (since they are still in busuiness, and the "dumping it in" apporach tends to get expensive fast) the design team evaluates the alternate components and signs off that the product will still perform to spec.

He is right.
All these pseudo-branded billions of the nearly same Chinese devices are manufactured by the hierarchy of microscopic cooperatives.
Those from whom you buy a device, did not design this device themselves in 99.9999% of cases, and may not understand what they are assembling at all.
In this world there is no maintenance, no documentation, nothing but the principle of "assembled and sold".
There is no backstory, no inventors, absolutely nothing, emptiness, only poverty and a fierce desire for money.
Are you so naive that you didn't know that?

 

[grogi.giant]

What makes you say that?

Electronics manufacturers have been living in a world of component shortages for at least 3 years now. It is common to need to change components used in a design in order to keep production going.

Of course - they could be sourcing any old shit, and just dumping it in the product. More likely (since they are still in busuiness, and the "dumping it in" apporach tends to get expensive fast) the design team evaluates the alternate components and signs off that the product will still perform to spec.

I don't mind sourcing different components, as long as they are to similar specs. It still can be slightly shady though - customers often depend on tests and measurement (like on this site) and such replacement might influence the quality of the product you're getting.

However, changing PCB and external dimentions? That is intentional.

He is right.
All these pseudo-branded billions of the nearly same Chinese devices are manufactured by the hierarchy of microscopic cooperatives.
Those from whom you buy a device, did not design this device themselves in 99.9999% of cases, and may not understand what they are assembling at all.
In this world there is no maintenance, no documentation, nothing but the principle of "assembled and sold".
There is no backstory, no inventors, absolutely nothing, emptiness, only poverty and a fierce desire for money. Are you so naive that you didn't know that?

I wouldn't go as far as that.

There are people who work on that - there is someone responsible for making Amazon listings for Fosi or Aiyima. Someone maintains the doukaudio.com, www.aiyima.com or www.fosiaudio.com websites etc. Someone made a deal with Walmart to sell the amps there. But there is no consistent vision, there is no long-term care for the brand. It's "sell now, we'll see tomorrow."

Even more recognized Chinese players, such as Topping or SMSL, aren't clear what they want to do. Well actually they are - produce as many as possible almost-identical units and, at least with Topping - exp. PA5 - with questionable reliability.

 

[trungdtmc]

i research Ti document about post filter feed back and found something. A07 and almost another tpa3255 boards using old parament with componet of LC filter and Zobel network, addition A07 operating at 600khz, like tpa3251. i plane change some thing and add post filter feed back here

 

[antcollinet]

He is right.
All these pseudo-branded billions of the nearly same Chinese devices are manufactured by the hierarchy of microscopic cooperatives.
Those from whom you buy a device, did not design this device themselves in 99.9999% of cases, and may not understand what they are assembling at all.
In this world there is no maintenance, no documentation, nothing but the principle of "assembled and sold".
There is no backstory, no inventors, absolutely nothing, emptiness, only poverty and a fierce desire for money.
Are you so naive that you didn't know that?

You can speculate all you like about how a particular industry works.

But here, on ASR - if you are going to disparage a particular company like that - you'd better come with some actual evidence that applies to that particular company.

 

[JeffGB]

I think many people are using too high a voltage power supply for the capacitors used in the Aiyima a07. From the TI data sheet:

"The voltage of the decoupling capacitors should be selected in accordance with good design practices. Temperature, ripple current, and voltage overshoot must be considered. This fact is particularly true in the selection of the 1μF that is placed on the power supply to each full-bridge. It must withstand the voltage overshoot of the PWM switching, the heat generated by the amplifier during high power output, and the ripple current created by high power output. A minimum voltage rating of 100 V is required for use with a 51-V power supply. The large capacitors used in conjunction with each full-bridge, are referred to as the PVDD Capacitors. These capacitors should be selected for proper voltage margin and adequate capacitance to support the power requirements. In practice, with a well designed system power supply, 1000 μF, 80 V supports most applications. The PVDD capacitors should be low ESR type because they are used in a circuit associated with high-speed switching."

Using a 48v to 51v power supply with capacitors that are rated for 63v is not necessarily adequate and may result in failure.

 

[Jacob8275]

The “A07 PRO” is coming

Neohipo DA300 Amplifier Review. A Bluetooth Version of the Aiyima A07?

I came across this mini amplifier on Aliexpress that looks almost identical to my Aiyima A07, which I purchased a year ago but is now spoilt. The specs shown online are also very similar, so I bought one for around $75 and put it to the test. First Impressions The amplifier comes packaged with...

www.audiosciencereview.com

 

[Bruce Morgen]

Using a 48v to 51v power supply with capacitors that are rated for 63v is not necessarily adequate and may result in failure.

Yeah, but the odds are that even a 50v cap of decent quality will hold up just fine at anything short of 48v. You can't trust the marked rated max. voltage of a generic electrolytic from an unknown mfr., but a genuine Nichicon or Rubycon part rated at 50v will most likely survive for decades at 48v.

 

[conradj]

ok, i had serious brain fade when ordering caps, need some advice. Those 4 10uF caps between the heatsink and the op amps, i checked my order form and realized i ordered ones that're 8mm diameter instead of 5mm.


Now i don't want to re-order since it'll be $20CDN shipping for $2 of parts, so ... The PCB does have space for the 8mm caps if i make longer legs for them as well as take care that they're insulated from the SMD bits, plus a dab of adhesive in the bottom of each cap, and my question is; will long legs to the caps be bad, operationally, sonically, etc.?

 

[Dmaumau]

The A07 has a 3.5mm jack that can be used either for input or output. i'm using it as an output; connect the sub to it.

I don´t think it can be used as an Input. It´s an output without volume control, like to a recorder or to relay audio for another A07.

 

[fieldcar]

I don´t think it can be used as an Input.

It does work as an input. See the note in this image.

 

[Dmaumau]

Have been tinkering with my A07 and it´s 48V 10A PS. Swapped the 1200 uF caps with Nichicon Muse 4700 uF 80V and the improvement was very noticiable, specially in the bass. And on the PS swapped all major caps for Epcos (had Rubycongs ) and tripled-ish the capacitance in the rectifier.

Sounding pretty sweet.

Next step will be an Alps potentiometer and maybe a remote volume controller.

Having fun with this cheapo toy.

Yeah, an AWFUL pic. Seems like it was taken with a potato... LOL

Will replace it tomorrow.

 

[Bruce Morgen]

I don´t think it can be used as an Input. It´s an output without volume control, like to a recorder or to relay audio for another A07.

The TRS input jack is wired in parallel with the RCA jacks, so it's essentially an alternate input -- this essentially implements a built-in stereo "Y adapter," which is why you can use whichever input not in use as such as a fixed line level stereo output for (i.e.) an active subwoofer or to connect a second amplifier.

 

[trungdtmc]

PFFB test

 

[Dmaumau]

PFFB test View attachment 269188

Tell us more...

 

[trungdtmc]

Tell us more...

Done but need more time to say, haha

 

[Dmaumau]

Done but need more time to say, haha
View attachment 269251

View attachment 269255
View attachment 269252

Sometimes the haha part is just for the fun of tinkering, despite the actual results. That´s why I love these cheap bastards. We probably would not try any of that on an Accuphase.

 

[Dmaumau]

Some of my "developing stages"

 

[Dmaumau]

And now better pics with a nicer finish

 

[Ungeduld]

I am not an expert, but I believe I am an audiophile. I just received this little amp, delivered with the 32v power supply.

I was a bit skeptical, but I was not disappointed. What strikes me, at first, is the purity and the clarity of the sound. No perceptible distortion, even at high volume.

The bass is tight, well defined and surprisingly energetic. It's exciting to listen to. One could, at the limit, reproach a certain lack of infrabass, for the "bass heads". The midrange is magnificent, unfolding with great naturalness. The highs are impeccably clear - some might find them a bit aggressive. This is not my case.

I paired it with the Fiio E10K-TC DAC, another great deal, and the result is simply amazing. My old Yamaha amp is simply outclassed. Contrary to what some people say, who have not disassembled the unit, the components are obviously of good quality.

In short, it's a bargain. I've been listening to it for two days, and I'm happy with my purchase. I'm just surprised that such a cheap amp sounds so good.





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