AIYIMA A300 Review (Stereo Amplifier)

[levimax]

Tough crowd here. With 90 watts of plenty clean enough for audio power, good headroom, balanced inputs, built is PS, and tone controls (which most people will find way more useful than an extra 10 or 20 dB of SINAD) for under $180 I don't see how this review could be considered poor. To me it looks like it deserves a "fine" panther.

 

[P_M]

giving it a poor rating only because of the rising HF response as early as 10khz for a 8 ohm load. Speaker impedances may be low in the mid frequencies but it is usually higher in the high frequencies. Its a rising curve.
Not sure if amir did any listening impressions or not but I would imagine it would be an undesirably bright presentation.

 

[whazzup]

It depends on what you care about. A lot of people are sensitive to hiss when no signal or low level signal is present. The key metric here is residual noise at the speaker terminals, this amplifier has high residual noise.

13 bit source material is fine because you are likely applying some attenuation using a decent digital or analog volume control which will reduce the source noise floor. You have no such option with a high residual noise amplifier, the noise is always present.

I will say that once music is playing noise floor is often very difficult to hear unless there are quiet parts.

You asked earlier about other sub-$200 options. They are DIY but I would look at IcePower modules such as the 125ASX2 and 200AS2 (also TPA325x based). You get more power and better noise performance. You still have some frequency dependent response but I think overall they are a better option.

Michael

Wait, how do you know this amp has high residual noise? You have one?

 

[mdsimon2]

Wait, how do you know this amp has high residual noise? You have one?

From the measurements. You can convert the dynamic range measurement to residual noise. You can also add in the contribution from your DAC to get a feel for what the total residual noise at your speaker terminals looks like. In this case because of the poor amplifier performance residual noise will likely be dominated by the amp not the DAC.

Here is an example.

Let's say we have a pretty decent DAC that has 115 dB dynamic range at 2 V output.

residual noise at DAC output = dac_vout x 10^(-DR/20) = 2 x 10^(-115/20) = 3.56 uV

Now multiply that by the amplifier gain, assuming 29 dB we get...

DAC residual noise at amplifier output = dac_noise x 10^(gain/20) = 3.56 x 10^(29/20) = 100 uV

Now let's look at the amplifier. We have 76 dB dynamic range at 5 W in to 4 ohms. First we need to calculate the amplifier output voltage at 5 W.

amp output voltage = sqrt(P x R) = sqrt (5 x 4) = 4.47 V

Now we can convert the output voltage to residual noise.

amp residual noise = amp_vout x 10^(-DR/20) = 4.47 x 10^(-76/20) = 708 uV

Now calculate total noise from DAC / amplifier combination at speaker terminals.

total noise = sqrt(amp_noise^2 + amplified_dac_noise^2) = sqrt(708^2 + 110^2) = 715 uV

Again I've done measurements at the speaker terminals of my own system and correlated them with whether or not I have audible hiss. For me that threshold is around 150 uV. This thread has more details -> https://www.audiosciencereview.com/...m-china-with-topping-performance.24768/page-2.

Michael

 

[NiagaraPete]

Great set of features. If the SINAD had been anywhere in the green I would have been an owner.

 

[t$$]

It depends on what you care about. A lot of people are sensitive to hiss when no signal or low level signal is present. The key metric here is residual noise at the speaker terminals, this amplifier has high residual noise.

13 bit source material is fine because you are likely applying some attenuation using a decent digital or analog volume control which will reduce the source noise floor. You have no such option with a high residual noise amplifier, the noise is always present.

I will say that once music is playing noise floor is often very difficult to hear unless there are quiet parts.

You asked earlier about other sub-$200 options. They are DIY but I would look at IcePower modules such as the 125ASX2 and 200AS2 (also TPA325x based). You get more power and better noise performance. You still have some frequency dependent response but I think overall they are a better option.

Michael

Totally agree!

I have a cheap Monoprice subwoofer that was making me crazy in my bedroom because of 60hz hum (power supply or shielding, not ground loop) and some sizzle when turned on. You can't really notice it during the day, but it is distracting in an otherwise quiet room at night.

The other annoying thing about that subwoofer is that its auto-power circuitry is not sensitive enough to turn on the subwoofer unless you have the volume cranked.

I ended up using a zwave switchable outlet and setting up an automation to turn on the SW whenever I am playing music to the streamer in the bedroom, and that approach would work for some people with this amp too, but of course that adds $30 and integration time that probably is otherwise better spent on improved quality product rather than band-aids.

 

[Joe Smith]

I will stick with my a04 and a07 units for now, very happy with those. I have no need at present for balanced inputs. And I'd rather have no tone control than a "meh" one. But for folks needing a bit more power than the a07, I understand this may have a place.

 

[Joe Smith]

I'd much rather have the in built power supply.
Far, far, far more convient.
Dealing with integrating high powered external power supplies is not for any newbs either and could pose a danger to them.
Totally decent product.
Nobody who bought or buys this is getting state of the art of course, but it fits in it's price class reasonably well.
Typical use cases will likely gain no meaningful benefit with a slightly better amp or even a much better one.
Comes down to price and convience.
Eecks out a "fine" vote from me.

Hey, remember when a Lepai T-amp was getting "Wow's"? We've come a long way.

 

[TimW]

I'd just like to remind everyone about the 3e-Audio SY-DAP2002 which is pretty similar to this in functionality, price, and performance. Instead of input switching and tone controls though you get DSP which is a big plus IMO.

 

[amirm]

@amirm was it tested in "direct" or "tone" mode? I believe "tone" mode may introduce some performance impact.

Direct.

 

[ROOSKIE]

I'd just like to remind everyone about the 3e-Audio SY-DAP2002 which is pretty similar to this in functionality, price, and performance. Instead of input switching and tone controls though you get DSP which is a big plus IMO.

It is actually less $$.
Definitely a big plus to have DSP, no sub out though.
Just need to combine both of these as tone are essentially for the content and DSP is fixed and for addressing speaker issues discovered in anechoic or Klippel data and for especially room correction at and below transfer to the room.
So still could use those tone controls, and deff sub out is a big plus.
Oh well. Eventually the whole package will arrive.

 

[mdsimon2]

Is the sub out low pass filtered? I tried to find a manual for this online and didn't see anything.

Michael

 

[anphex]

Hey, at least it's second harmonics!
I like this thing, and respects to the manufacturer for taking the initiative to allow third party measurements. Trust earned.

 

[acetogen]

The multitone test for the A300 here seems to outperform the Aiyima a05 that @Amir tested last year. I've read on the Amazon user reviews about another TPA3255 based amp that leaving the tone controls flat made the amplifier sound non-neutral. In other words, the tone controls are really restoring a neutral sound rather than adding bass/treble. Seems strange.

 

[pseudoid]

Why do some people jump into almost every review thread and harass Amir about whether this was tested or that was tested? Just be happy that someone has taken the time to test anything for you, for free and show some gratitude.

I used to run the FFT to see the switching frequency. Not sure how useful it is so I don't always run it.

Thank you for the review.
I guess if all the equipment was optical connections the need for stretching out plots to >90kHz, would be useless.
imo: as long as we continue to use copper connections (analog or digital), any noise spectra above the audible region is a worthy concern.
Thanks again for all the work that you do, Sir amirm.

 

[Rottmannash]

@amirm Nice to see the addition of Peak Power.

Speaking of...don't most Class D amps have little to no increase in Peak power vs RMS?
2nd question: Would the SINAD improve appreciably with an external PS?

 

[pseudoid]

2nd question: Would the SINAD improve appreciably with an external PS?

Unit picture and per @amirm, it is an AC input.
I hear power generators are quite noisy; unless you generate your own pure 50/60Hz...

 

[amirm]

Speaking of...don't most Class D amps have little to no increase in Peak power vs RMS?

This is almost always the case although I have seen some that do have higher peak power.

 

[amirm]

2nd question: Would the SINAD improve appreciably with an external PS?

As noted above, power supply is internal so no messing with that.

 

[AIYIMA]

We actually want to make a good product, so we send it to Amirm for testing. We want to find problems through Amirm's professional tests, and know what you think through more professional comments and replies, so as to optimize our products. As you said, the results of the test were very poor and actually had a lot of negative impact on sales. But we believe that a professional and high-quality product will have good sales, so temporary problems will not stop us. We've always wanted to make a better amplifier.
So currently we are optimizing the A300 based on the test results.