Aiyima A07 Max - Aiyima's new TPA3255 amplifier with mono/stereo output

[Guddu]

Do you think just one in stereo would be enough for 80wpc or is two in mono a must? I know it's advertised as 300wpc but I don't trust that to be true.

I have tried A07 Max in stereo to Yamaha TSR700 front pre-out, and it has worked fine without any concerns.
Which front speakers you have? I would say any 8ohm speakers with 86+ sensitivity should be absolutely fine.
And later you can convert mono setup adding another one, if you feel the need.
While integrating with AVR, I would say keep volume at max on A07 Max.

I would day its more like 50-60wpc with 32-36v psu, probably around 80-100wpc with 48v psu, for 8ohm load.

 

[dr_mick51]

I measured power draw of my AVR during high volume stereo listening (which I do sometimes enjoy) and found it drew ~60-80 wpc more than at idle. Some of this may be lost to heat rather than going to the speakers, since it's a Class AB. Will two A07 Max's in mono config provide the power I need for the front speakers?

Hello. Measured how?. At the power outlet? It does not mean that's the power delivered to the speakers. You need to consider losses at the power supply section and the class AB.
Probably a 20W is what each speaker might be receiving.
You should be OK with the A07 MAX even in stereo mode.
What's the speakers impedance?
Remember to use a decent DAC with a decent output signal, remember music is not the same as test tones at 0dBFS. Music runs at least at 4 times lower voltage.

 

[space_duck]

Hello. Measured how?. At the power outlet? It does not mean that's the power delivered to the speakers. You need to consider losses at the power supply section and the class AB.
Probably a 20W is what each speaker might be receiving.
You should be OK with the A07 MAX even in stereo mode.
What's the speakers impedance?
Remember to use a decent DAC with a decent output signal, remember music is not the same as test tones at 0dBFS. Music runs at least at 4 times lower voltage.

Yes, at the wall outlet. Specifically, I measured the power strip that has my AVR and media streamers connected. ~20W with AVR in standby, ~100W with AVR on but silent, and 180-250W while playing loud music, which gives me 40-80WPC. Is AB really so inefficient that only 20W would go to the speakers?

They're KEF Q500, 8Ohm rated 87dB, I sit about 2.5m away from them. I do like to listen quite loud so I'd prefer to have some headroom. I have calculated that at my normal listening level I would rarely need more than 10-15W, but I don't want to risk any damage by pushing the amp too hard during really loud movie scenes.

I have tried A07 Max in stereo to Yamaha TSR700 front pre-out, and it has worked fine without any concerns.
Which front speakers you have? I would say any 8ohm speakers with 86+ sensitivity should be absolutely fine.
And later you can convert mono setup adding another one, if you feel the need.
While integrating with AVR, I would say keep volume at max on A07 Max.

I would day its more like 50-60wpc with 32-36v psu, probably around 80-100wpc with 48v psu, for 8ohm load.

That high, really? I think I will wait for the new edition with better capacitors and order one with the 48V PSU, then. Any idea when that will be available?

Sidenote, the small chi-fi amps I have now play a very loud jingle and say AUX MODE when I turn them on, which is rather annoying. Is that a thing with all chi-fi amps?

 

[Guddu]

They're KEF Q500, 8Ohm rated 87dB, I sit about 2.5m away from them. I do like to listen quite loud so I'd prefer to have some headroom. I have calculated that at my normal listening level I would rarely need more than 10-15W, but I don't want to risk any damage by pushing the amp too hard during really loud movie scenes.


That high, really? I think I will wait for the new edition with better capacitors and order one with the 48V PSU, then. Any idea when that will be available?

Sidenote, the small chi-fi amps I have now play a very loud jingle and say AUX MODE when I turn them on, which is rather annoying. Is that a thing with all chi-fi amps?

I understand your position about 48v psu because of caps rated @50v but I don’t think it should be an issue, I haven’t had any issues and no one else has reported anything as well.
However, I think you should go with 36v psu for peace of mind which should give you enough power in your case.
8R 87db speakers won’t be trouble for this amplifier.
Regarding aux mode selection thingy, it’s not applicable in case of A07 Max. That’s for the amps which run Bluetooth mode by default and requires manual selection like that.
A07 Max is straight forward RCA input amplifier.

 

[Mitusi]

Our fellow @robertospeed shared this picture:

If both amp are one on top of the other then you can use a single RCA cable to connect to each amp Left RCA

I have confusion in my mind.
If I use 2 A07 Pro (or V3) without bridging, each A07 get input from only one RCA source, either left or right, then each amplifier connects to it corresponding L/R speaker just as usual, then it should be same as the above Aiyima suggested bridge connection, so why should we need bridge mono mode from Max? Or do I miss something.

 

[dr_mick51]

I have confusion in my mind.
If I use 2 A07 Pro (or V3) without bridging, each A07 get input from only one RCA source, either left or right, then each amplifier connects to it corresponding L/R speaker just as usual, then it should be same as the above Aiyima suggested bridge connection, so why should we need bridge mono mode from Max? Or do I miss something.

The difference I understand is that on A07 MAX you configure the chip to work in mono mode and hence you get more power from that single channel (both channels working at the same time)
If you use 2 A07 PRO or 2 V3 and connect a single RCA cable to each amp, then you only get power from one channel from each amp, while the other channel is never used. I don't see the point of doing that.
Being honest I would not bother with the mono configuration, you can get plenty of power from a single amplifier in normal/stereo mode.

 

[Guddu]

I have confusion in my mind.
If I use 2 A07 Pro (or V3) without bridging, each A07 get input from only one RCA source, either left or right, then each amplifier connects to it corresponding L/R speaker just as usual, then it should be same as the above Aiyima suggested bridge connection, so why should we need bridge mono mode from Max? Or do I miss something.

It will work but you aren't using both the amps to their full potential, bridged mono should also provide more output power (technically).
Another aspect could be the design usage and impact to overall quality and longevity, long term impact of using a stereo amp with one channel in operation.

 

[Jeromeof]

The difference I understand is that on A07 MAX you configure the chip to work in mono mode and hence you get more power from that single channel (both channels working at the same time)
If you use 2 A07 PRO or 2 V3 and connect a single RCA cable to each amp, then you only get power from one channel from each amp, while the other channel is never used. I don't see the point of doing that.
Being honest I would not bother with the mono configuration, you can get plenty of power from a single amplifier in normal/stereo mode.

I have 2 of the A07 MAX setup in mono configuration and I think its works great - subjectively I think its provide cleaner sound, obviously no worries about channel crossover within the amp etc - but I also agree a single one of these Amp provides tremendous power with the right power supply.

 

[T&T]

I have 2 of the A07 MAX setup in mono configuration and I think its works great - subjectively I think its provide cleaner sound, obviously no worries about channel crossover within the amp etc - but I also agree a single one of these Amp provides tremendous power with the right power supply.

So sounds cleaner but not better?

 

[Joe Smith]

This is a mini-review of the A07 MAX from my "average Joe" perspective. Aiyima was gracious enough to send me a unit for review and evaluation.

I found the amplifier to be a lot like the Fosi V3 - apart from the noted Stereo/Mono feature, which I have not made use of.

While I think the Mono capability is an interesting addition, to me it's kind of a halfway step to true small monoblock Class D amps without integrated volume pots. The mono capability would seem to me to be most useful to people with a medium sized listening space with medium to high efficiency speakers who want to use the 48v power supply option to get medium to loud volume levels. You could do this in a smaller room or desktop setup, but why? Even with the 36v power supply I can get to very loud levels in my workroom with my 87db efficient KEFs.

During the past week, I have switched back and forth between the older Aiyima A04 and A07 amps, the Fosi V3, and the new A07 MAX amp, and varied between use of the Fosi 32v 5a power supply and the Aiyima 36v 6a power supply. All gave good sound and satisfactory volume levels. No noticeable power on or power off pops. Using a variety of sources, I did not detect any truly notable differences between the amps. I like that the V3 and MAX amps are vented, and I believe this should help add to the product longevity. This is even more important for users who are making use of the 48v supply to get to higher volume levels. With the 32v and 36v power bricks, none of these amps get very warm to the touch at all. All of these amps can get higher volume than my SMSL AO100 amp, which I like for the dining room (remote and integrated bluetooth) where I don't need high volume levels at all.

I am using the V3 and MAX amps with the supplied 5332 op-amps. I had changed out both of the older Aiyima amps to 4562s.

I like the very clean and simple appearance of the A07 MAX. Aiyima has made a nice case and clearly designed the product to compete with the V3. The lack of top case holes might be a plus for some users as a) it makes it less prone to liquids or other dust entering the case and b) it makes it stackable. But since Aiyima has no matching components, that's not a huge consideration. I especially like that the Stereo/Mono switch is well recessed from the case so it cannot be bumped accidentally. Good design work there.

It's a little thing, but given how close all these amps are, little things matter...IMO the knob is not as nice to use as the Fosi V3. It's just a little bit smaller, and in my sample, it mutes to about the 3rd volume marking. Because the Fosi knob is larger, it's easier to grip and quickly change a volume level over my shoulder, which is how my setup is arranged. If you are looking right at the amp on one's desk or shelf, that's less important - but I still think that Fosi wins the ergonomics award for the knob. It's got a little better control to set a low volume level easily.

Another feature of the A07 MAX is the offset speaker jacks. Yes, they are of higher quality and thickness than the Fosi. They stick out more in the back, and the best way to connect safely is still with banana plugs. The provided jacks don't make connecting with bare wire easier or advisable IMO. So it's kind of a difference that makes no difference, save perhaps for the users with very wide or angle-type plugs - (probably same users who are using the amps as mono units?).

All of these amps do the basic job of amplification for small to medium setups and in a nice way. I think for me personally, the V3 still is the nicest to use and has the most attractive appearance.

I think the next logical step is for one of the Chinese manufacturers to a) solve the noted load dependency issue for frequencies above 10k; b) create an attractive and good-component built true monoblock option (with the power supply in-case with the amplifier) that would compete with the Hypex amps but at a lower cost; c) create a matching solid state preamp for the monoblocks with a high-quality volume control, 2-3 inputs, and a remote.

It's great to have so many good choices right now in these compact amps. I am glad that Aiyima is continuing to develop some solid state, clean, "no frills" units along with their tube and more steampunk looking options. The A07 was the first small amp I'd bought since my decade-old SMSL SA-50s, and it was an improvement, which the A07 MAX takes further still.

Postscript: I tried to open up the MAX case, was thinking of testing with different Op-Amps (4562s) - could not figure out how to open the case, gave up. I loosened all of the 3 back plate screws, the screws on the bottom would not loosen with my wrench, they are in super tight - so I gave up. If Aiyima markets the MAX as having replaceable Op-Amps, it should be easier to change those out, as was true for the original A07 and A04 amps, which was very easy. This would also be a good competitive feature versus the Fosi V3, which I also did not attempt because of owner reports that it was pretty hard to get in to change the Op-Amps out.

 

[Jeromeof]

So sounds cleaner but not better?

Well cleaner is better - but obviously this is very subjective. My point is you might not need the power of 2 monoblocks especially as a single A07MAX is very powerful (as is a Fosi Audio V3) but there are other advantages to monoblocks

 

[T&T]

Well cleaner is better - but obviously this is very subjective. My point is you might not need the power of 2 monoblocks especially as a single A07MAX is very powerful (as is a Fosi Audio V3) but there are other advantages to monoblocks

So someone have to take measures in mono and stereo to see what really happens...maybe nothing?

 

[Joe Smith]

Also, a follow up - just now , I tried to open up the MAX case, was thinking of testing with different Op-Amps (4562s) - could not figure out how to open the case, gave up. I loosened all of the 3 back plate screws, the screws on the bottom would not loosen with my wrench, they are in super tight - so I gave up. If they market the MAX as having replaceable Op-Amps, it should be easier to change those out, as was true for the original A07 and A04 amps, which was very easy. This would also be a good competitive feature versus the Fosi V3, which I also did not attempt because of owner reports that it was pretty hard to get in to change the Op-Amps out.

 

[NoMoFoNo]

I changed the op amps in my V3 to LME49720s. Getting into the case was easy enough. The 5532s were pretty tightly set into the blocks but they came out without too much trouble. Did they change the sound? Not that I could identify in a DBT. It was fun to change them though.

 

[Meloman]

Very hot with 48V 5A, you can switch on only amplifier not listen the music its warm up in bypass mode.You can fried eggs on it. The shame for manufacturer. I am disappointed.Testing with 32V 5A , the volume the same, but no crazy heat. I want return amplifier i think.

 

[dr_mick51]

Very hot with 48V 5A, you can switch on only amplifier not listen the music its warm up in bypass mode.You can fried eggs on it. The shame for manufacturer. I am disappointed.Testing with 32V 5A , the volume the same, but no crazy heat. I want return amplifier i think. View attachment 325024

Well, I think that what you should return is the 48V power supply, because it is pointless. I doubt you need more than 10W. Right now I'm listening at higher than regular volume and it's not consuming more than a single watt (above idle). The unit consumes 4.5W ON and no music playing.
What is your opinion on the audio performance?. I find strange that you just created an account to trash on the amplifier and show your "disappointment".
No TPA3255 is meant to run with a single 48V power supply. Even the V3 gets really hot.
The TI TPA3255 design is meant to work with 2 independent power supplies. One 12V which is used for Auxiliary functions on the chip and another power supply (up to 53V) for the audio output(output swing voltage). The problem is that these Chinese manufacturers are using a simplified design with voltage regulators to produce the required 12V. And not all voltage regulators are meant to "regulate" from voltages way higher than the target voltage. This causes the voltage regulator to heat up too much and not being able to regulate properly, causing that instead of 12V, a higher voltage is provided to the TPA3255 breaking havoc.
So people, please stop using 48V power supplies. It's not needed. Power-wize 50w is way more than enough. And you risk burning your voltage regulators and probable your chip amp.

 

[Meloman]

Ну, я думаю, що вам потрібно повернути блок живлення 48V, тому що це безглуздо. Я сумніваюся, що вам потрібно більше 10 Вт. Зараз я слухаю на вищій за звичайну гучності, і це не споживає більше одного ватта (вище, ніж у режимі очікування). Пристрій споживає 4,5 Вт і музика не відтворюється.
Що ви думаєте про якість звуку?. Мені дивно, що ви просто створили обліковий запис, щоб викинути підсилювач і показати своє «розчарування».
Жоден TPA3255 не призначений для роботи з одним джерелом живлення 48 В. Навіть V3 стає дуже гарячим.
Конструкція TI TPA3255 призначена для роботи з 2 незалежними джерелами живлення. Один 12 В, який використовується для допоміжних функцій на мікросхемі, і інший джерело живлення (до 53 В) для аудіовиходу (вихідна напруга коливання). Проблема полягає в тому, що ці китайські виробники використовують спрощену конструкцію зі стабілізаторами напруги для отримання необхідних 12 В. І не всі регулятори напруги призначені для "регулювання" напруг, значно вищих за цільову напругу. Це призводить до того, що регулятор напруги занадто сильно нагрівається і не може належним чином регулювати, в результаті чого замість 12 В на поломку TPA3255 подається вища напруга.
Тож люди, будь ласка, припиніть використовувати джерела живлення 48 В. Це не потрібно. Power-wize 50 Вт більш ніж достатньо. І ви ризикуєте спалити ваші регулятори напруги та, ймовірно, свій мікросхемний підсил

Why Aiyima sell with 48V PSU? I by it for recommendation, people's says its better for sound not for loudness, now i think what need to do, return PSU i think imposible, dont ask me how i get it from Ali, i living in Ukraine, and shipping fee i think be very expensive.About sound, it's better then fosi v3, it's have a bright sound, if you don't have neutral speakers you must go around this amplifier. With my AE 109-2 and Topping DAC E 30 the sound perfect, detailed, with quality low mid and high frequencies.I think its sound better then vintage amps or denon PMA600.

 

[dr_mick51]

With the volume knob at 12 o'clock only 10% of the input signal passes through. If you have a 2V DAC at 0dBFS, then the same DAC produces 0.5V with mus8c at -12dBFS. This means that only 0.05V reaches the amplifier. And assuming 29dB gain or x30 amplification then the output voltage is a mearly 1.5V which translates to 1.5^2/4= 0.56W per channel. That's all the music power the amplifier is producing at 12 o'clock with a "good signal" from a "decent" DAC. Under this same situation but using a 48V power supply you will not get more power from this amp. The only way is using a preamp to double the input signal, so instead of 0.5V rms with music, now we get 1V. Which at 100% volume translates to 30V at the output. A 48V power supply can provide voltage swings of 48V×0.707=33.39Vrms or 33.39^2/4=240W per channel. And that 48V power supply will need at least 10A to produce that power.
All the values are related. Input signal, output voltage, power supply voltage and power supply current. You cannot get more power if you don't increase input signal as well.

 

[dr_mick51]

Why Aiyima sell with 48V PSU? I by it for recommendation, people's says its better for sound not for loudness, now i think what need to do, return PSU i think imposible, dont ask me how i get it from Ali, i living in Ukraine, and shipping fee i think be very expensive.About sound, it's better then fosi v3, it's have a bright sound, if you don't have neutral speakers you must go around this amplifier. With my AE 109-2 and Topping DAC E 30 the sound perfect, detailed, with quality low mid and high frequencies.I think its sound better then vintage amps or denon PMA600.

The only possible explanation to why people say those amplifiers sound better with a 48V power supply(and I believe that probably some specific power supplies from specific brand and model) is because the power supply might produce a cleaner power, and not because of the higher voltage.
I particularly use a SMPS filter board from DIYAudio, so different brands of power supplies should not affect much.

Here in the US, Amazon only sells the A07 Max with 36V power supply.

I assume Aiyima provides the option for 48V with this amp just because people ask for it and the competition is also doing it.

 

[Toku]

The only possible explanation to why people say those amplifiers sound better with a 48V power supply(and I believe that probably some specific power supplies from specific brand and model) is because the power supply might produce a cleaner power, and not because of the higher voltage.
I particularly use a SMPS filter board from DIYAudio, so different brands of power supplies should not affect much.

Here in the US, Amazon only sells the A07 Max with 36V power supply.

I assume Aiyima provides the option for 48V with this amp just because people ask for it and the competition is also doing it.

The only difference between a 36V and 48V power supply for a class D amplifier like the AIYIMA A07 Max is that you get more power.
You can get a bigger output by turning the volume knob even more than when you set it to 36V.
There is almost no change in sound quality between 36V and 48V, and the only difference is the maximum output that can be obtained.
However, many audiophiles mistakenly believe that it means better sound quality.
However, increasing the voltage also has disadvantages. The power loss of the main unit will increase and the case temperature will rise significantly.
I tested several Class D amplifiers equipped with my TPA3255. I think they can be used safely and with confidence at 40V or less in an indoor environment of 28℃ or less. The A07 Max uses a capacitor with a withstand voltage of 50V in the power line, so 40V is the limit that can be safely used. Selling a set with a 36V power supply on Amazon is electrically correct.