AIYIMA A07 TPA3255 Review (Amplifier)

[Deleted member 46664]

Summer Parties, playing loud in the garden I guess. He is not an audiophile

Yep, that'll likely kill the Aiyima ... pushing it that hard will surely trigger thermal and overcurrent shutdowns.

Maybe grab a used Pro-Amp someplace ....

I'm sorry but I seriously doubt the Aiyima A07 is a good choice in that case.

 

[oslosl]

Any ideas ? Solution has to include 2 amplifiers (real 2-300W) and trafo/psu and be cheap.

 

[Deleted member 46664]

Any ideas ? Solution has to include 2 ampliers (real 2-300W) and trafo/psu and be cheap.

Why not just buy a used pair of powered speakers, that work?

I got no ideas beyond what I've already suggested.

 

[RHO]

I believe the stock op amp is the NE5532. Any reason you want the LM4562 instead?

Either way, I'd be looking at somewhere like Mouser Electronics.

Audiophonics sells them with LM4562. That's how mine is configured.
(I didn't even know when I ordered it since I care very little about the actual opamp type, but the LM4562 is very nicely spec'd one.)

 

[Palladium]

I ordered one for my pair of Wharfedales 4 inchers left forgotten in a box for 7 years.

Fingers crossed.

 

[robot34]

How big difference is there between say Aiyima a07 and some 300-500$ new/used class a-b amplifier?

 

[antcollinet]

How big difference is there between say Aiyima a07 and some 300-500$ new/used class a-b amplifier?

Well the A07 has been reviewed here - all you need to do is use the review database to find a reveiw of a 3-500$ amp, and compare the measurements.

 

[robot34]

Well the A07 has been reviewed here - all you need to do is use the review database to find a reveiw of a 3-500$ amp, and compare the measurements.

Measurements will tell me how much audible difference there is?
I'm mostly curious how good A07 is when compared to something in 3-500$ range, is it a huge night and day difference or is it minimal?

 

[RHO]

Measurements will tell me how much audible difference there is?
I'm mostly curious how good A07 is when compared to something in 3-500$ range, is it a huge night and day difference or is it minimal?

If you hear a night and day difference between 2 amplifiers, at least 1of them is broken.

 

[robot34]

If you hear a night and day difference between 2 amplifiers, at least 1of them is broken.

So not much difference between lepai 2020 and high end yamaha power amp apart from how loud they get?

 

[RHO]

So not much difference between lepai 2020 and high end yamaha power amp apart from how loud they get?

Depends on how they measure. But no night and day difference, no. Or one would be broken (a design can be broken too, but still the difference should not be night and day.)

 

[robot34]

Depends on how they measure. But no night and day difference, no. Or one would be broken (a design can be broken too, but still the difference should not be night and day.)

So the measurements are mostly to check for distortions and noise and all that unwanted stuff? And power ofcourse. But if those are fine no reason to spend a lot more money on an amplifier? I see cheapaudioman changed opamps on Aiyima A07 and said some slight differences he notices like soundstage and whatnot, so I'm guessing speakers count for 90% of the sound and difference between amplifiers is about 10%(apart from distortion/noise)? I never tested/tried different setups so I'm probably wrong, but am I close with that approximation?

 

[RHO]

So the measurements are mostly to check for distortions and noise and all that unwanted stuff? And power ofcourse. But if those are fine no reason to spend a lot more money on an amplifier? I see cheapaudioman changed opamps on Aiyima A07 and said some slight differences he notices like soundstage and whatnot, so I'm guessing speakers count for 90% of the sound and difference between amplifiers is about 10%(apart from distortion/noise)? I never tested/tried different setups so I'm probably wrong, but am I close with that approximation?

I would say the most important factors are speakers, room and EQ.
There's not much to gain with regards to audio quality between 2 well designed amplifiers. It would be a challenge to tell the 2 apart in a blind test. With regards to audio quality, the Aiyima A07 is a well designed amplifier. So, if the one you want to compare it to is too, you will not hear a big difference, if any difference at all.
I would disregard anything cheapaudioman says about swapping opamps. If anything those expensive things he put in the amp would have made performance worse, not better. Changing opamps does nothing with regards to soundstage, or there would have been a major channel imbalance or something, which is more likely to happen in the opamp modules he used than in an integrated circuit.

There are also the factors of aesthetics, ergonomics, reliability and build quality. Those also have an impact on price.
For some amps none of the above play a role in the price setting and it is purely based on brand-name and all the marketing speak around it.

 

[antcollinet]

So the measurements are mostly to check for distortions and noise and all that unwanted stuff? And power ofcourse. But if those are fine no reason to spend a lot more money on an amplifier? I see cheapaudioman changed opamps on Aiyima A07 and said some slight differences he notices like soundstage and whatnot, so I'm guessing speakers count for 90% of the sound and difference between amplifiers is about 10%(apart from distortion/noise)? I never tested/tried different setups so I'm probably wrong, but am I close with that approximation?

Most likely the difference he "heard" from changing the op amp was not really there. Our ears/brains are notoriously bad at comparing sound from electronics when we are looking for or expecting a difference.

And there is NO sound difference, apart from distortion, noise and frequency response - all shown by measurements. They are the only things that can create a difference.

 

[robot34]

Did anything new come out that's better than Aiyima A07 for the price?

 

[dr_mick51]

Hello! I have a 2.0 audio system with Aiyima A07 amplifier. I would like to add an active subwoofer (Jamo S810), however I'm not sure if it will be possible. Can I connect the active subwoofer with only 1 LFE input to the AUX 3.5 output on Aiyima A07?

Sure, bass is usually mono, so it does not matter if you connect the left RCA or Right RCA. You can use an RCA to 3.5mm Jack adapter and plug one of those RCA into the sub

 

[dr_mick51]

Hello! I would like to buy the Aiyima A07 to power my tower speakers (impedance: 8 ohms, RMS power: 120W, sensitivity: 91 dB). Will the the standard Aiyima power supply (32V 5A) be enough to play music loud (105dB at 1m) without clipping? Do I need to buy additional power supply (36V 6A or 48V 7.3A)? May be it's better to get another amplifier?

You need 32W per channel to achieve 106db with your speakers. That means you need a total of 64w from the amplifier. Basically 2A at 32V.
Dude, you really don't need a huge power supply, you need a "clean" power supply. Try getting a low noise and ripple power supply, less than 20mV P-P

 

[dr_mick51]

Gave A07 some ventilation View attachment 206824

Nice, but what about EMI/EMF?

 

[dr_mick51]

According to specs Less than 250mV peak to peak .

There are videos on YouTube where they tested those psus and verified the specs.

I installed an extra capacitor of low esr 1000uF 63V Japan brand Rubycon on the voltage rail near the amp DC input to lower the ripple even More

Try installing multiple bypasses for each capacitor at 1% of the capacitor you are bypassing.
For example. You said you used a 1000uF Electrolytic capacitor, then use another 10uF and then another 0.1uF Film capacitor preferably. This way you filter a bigger range of frequencies. Remember noise and ripple occur at different frequencies.

 

[dr_mick51]

Most likely the difference he "heard" from changing the op amp was not really there. Our ears/brains are notoriously bad at comparing sound from electronics when we are looking for or expecting a difference.

And there is NO sound difference, apart from distortion, noise and frequency response - all shown by measurements. They are the only things that can create a difference.

An Operational Amplifier is indeed a "Voltage" amplifier. It increases the amplitude/gain of the input audio signal. But on the Aiyima it also creates an "Inverted Audio Signal" from the original input. That's why there are two dual Opamps. The first stage amplifies the input signal and the second stage inverts the amplified signal for each channel. They are daisy-chained.
The TPA3255/3251 are differential amplifiers. That's why they need two identical signals out of phase 180°. So in theory you could add a balanced input signal and bypass the opamps.

Ok, so all the opamps sound the same?. Of course not. The same way not all amplifiers sound the same. The same way not all the DACs sound the same. The same way not all speakers sound the same. There are special characteristics that make each component unique.
Do you think all capacitors sound the same? Then I invite you to mod one of your speakers( change capacitors, at least the one in series with the tweeter for a better quality Film capacitor and leave the other stock. Then configure your amplifier or your player to Mono and then play with the Balance back and forth. But first leave the modded speaker running for a couple of hours before doing the comparison. You can use this test to compare different speakers as well. You can use this test to compare different opamps in the Aiyima ( because it uses one for each channel, you can try 2 different Opamp at the same time) if you use windows then you can use Foobar and a down mix to Mono addon and then play with the Balance from windows audio settings.
If you try this and they sound the same so be it. But it is very likely you will be surprised.
But no amplifier, preamplifier or Opamps will take a poor signal and make it something out of this world. Distortion accumulates during the audio chain. It is the square root of the sum of the square of each individual distortion, if expressed as %. If expressed as dB it's more complicated than that because you need to use Logarithmic operations.
If your input signal is 0.1% THD and goes into a amplifier with 0.0001% THD you total THD will be 0.10000005%, so better pay attention to your sources. But ultimately we don't listen amplifiers, we listen to speakers. And if your speakers have 0.6% THD then...