This is a review and detailed measurements of the 3e Audio A5 Stereo class D amplifier. It was sent to me by the company and costs US $229.99.
Despite its simplicity, the A5 has very well thought out features. Clipping indicators are provided for each channel. And selection of inputs is made through volume control push action. Hold it in for more than 2 seconds and it will shut off the unit. The volume control can be bypassed using a switch and that is how I tested it:
Also nice is selectable gain for RCA. As is inclusion of 12 volt trigger for automatic turn on based when you power on a source with the same output. For the sources that lack that, the A7 uses signal detection on the inputs to power itself on and off. Very nice.
In use, the unit was robust, barely getting warmer than ambient temperature. Pushing it into clipping was no big deal as it would automatically and quickly reset to working condition.
There are two square holes underneath to expose the op-amps and let you replace them (I highly suggest that you do not). There are large air slots all around to provide good circulation.
"PFFB" is implemented so the amplifier should be load independent.
If you are not familiar with my measurements, please watch my tutorial on what the tests are and what they mean:
3e-audio A5 Measurements
Let's start with our dashboard using XLR input with volume fixed:
Distortion spikes are below threshold of audibility so noise sets our SINAD, ranking the A5 as one of the best amplifiers tested regardless of price:
RCA performance is almost as good which is a nice bonus:
Here is high gain:
Low gain is sufficient for full power with typical DAC providing 2 volts:
XLR gain is fixed but fortunately it too provided max power below 4 volts that DACs produce:
Frequency response as expected, is essentially load independent, with nary a resonance above 20 kHz:
Crosstalk was exceptionally good:
Multitone shows very respectable performance:
Distortion rises at high frequencies though so our 19+20 kHz suffers some:
Fortunately you are never going to play music with this kind of spectrum so mostly academic.
The low noise and distortion shows up in our power sweeps:
EDIT: it should say 122 watts, not 92.
We almost achieve the specified power rating at 4 ohm and 1 kHz:
New in my amplifier tests, is power rating at 40 Hz which represents the reasonable low frequency for vast majority of users of audio systems:
So you give up about 14 watts so not bad at all.
My reactive load box locks up if I test a BTL amplifier on its right channel. So here are the results of that but for only left channel driven:
Nice to see it continue to "double down" as impedances halve and halve again, albeit with one channel.
Edit: other measurements:
Here is the warm up test:
Conclusions
The A5 amplifier is very well thought out small amplifier with excellent feature set and performance to back it. I love features such as clipping indicator to tell you whether you are exhausting all of its power. Measurements show one of the most implementations of this architecture with no weak point other than perhaps, high frequencies. All of this for a reasonable price. I am good at finding faults but I am without words when it comes with the A5.
I am happy to recommend the 3e-audio A5 stereo amplifier.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Despite its simplicity, the A5 has very well thought out features. Clipping indicators are provided for each channel. And selection of inputs is made through volume control push action. Hold it in for more than 2 seconds and it will shut off the unit. The volume control can be bypassed using a switch and that is how I tested it:
Also nice is selectable gain for RCA. As is inclusion of 12 volt trigger for automatic turn on based when you power on a source with the same output. For the sources that lack that, the A7 uses signal detection on the inputs to power itself on and off. Very nice.
In use, the unit was robust, barely getting warmer than ambient temperature. Pushing it into clipping was no big deal as it would automatically and quickly reset to working condition.
There are two square holes underneath to expose the op-amps and let you replace them (I highly suggest that you do not). There are large air slots all around to provide good circulation.
"PFFB" is implemented so the amplifier should be load independent.
If you are not familiar with my measurements, please watch my tutorial on what the tests are and what they mean:
3e-audio A5 Measurements
Let's start with our dashboard using XLR input with volume fixed:
Distortion spikes are below threshold of audibility so noise sets our SINAD, ranking the A5 as one of the best amplifiers tested regardless of price:
RCA performance is almost as good which is a nice bonus:
Here is high gain:
Low gain is sufficient for full power with typical DAC providing 2 volts:
XLR gain is fixed but fortunately it too provided max power below 4 volts that DACs produce:
Frequency response as expected, is essentially load independent, with nary a resonance above 20 kHz:
Crosstalk was exceptionally good:
Multitone shows very respectable performance:
Distortion rises at high frequencies though so our 19+20 kHz suffers some:
Fortunately you are never going to play music with this kind of spectrum so mostly academic.
The low noise and distortion shows up in our power sweeps:
EDIT: it should say 122 watts, not 92.
We almost achieve the specified power rating at 4 ohm and 1 kHz:
New in my amplifier tests, is power rating at 40 Hz which represents the reasonable low frequency for vast majority of users of audio systems:
So you give up about 14 watts so not bad at all.
My reactive load box locks up if I test a BTL amplifier on its right channel. So here are the results of that but for only left channel driven:
Nice to see it continue to "double down" as impedances halve and halve again, albeit with one channel.
Edit: other measurements:
Here is the warm up test:
Conclusions
The A5 amplifier is very well thought out small amplifier with excellent feature set and performance to back it. I love features such as clipping indicator to tell you whether you are exhausting all of its power. Measurements show one of the most implementations of this architecture with no weak point other than perhaps, high frequencies. All of this for a reasonable price. I am good at finding faults but I am without words when it comes with the A5.
I am happy to recommend the 3e-audio A5 stereo amplifier.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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