This is a review and detailed measurements of the A7 / "A7 Mono" stereo power amplifier with balanced inputs. It was sent to me by the company. I have no idea what it costs in US. Audiophonics lists it for 379,00 €tax incl.
While the A7 may look like its competitors, it has a heft to it that I don't recall others not having. It really feels like it is filled with lead or something! A nice volume control in the middle adjusts the gain but it can also be bypassed using a switch in the back. Pushing the volume control quickly switches between XLR balanced and RCA. Two thoughtful clipping indicators are provided, making me wish it would be a standard feature on any amplifier. A minor nit: LED colors indicating which input is active is red and clipping in green. I think based on convention, the latter should be red.
Back panel shows nice set of features:
Trigger input is provided as is the aforementioned combo TRS/XLR balanced inputs. Low and high gain switch is provided but I focused on low gain as that is fully compatible with current audio products outputting 2/4 volts. Yes, there is that monster GaN power supply! It can of course be purchased with other options. The input connector says max is 48 volt but per designer, the mono configuration, which is just using the left channel, can go up to 52 volts. He said I could test in stereo just the same and that is what I did. I found no issues.
FYI, I was impressed with the secure way the power supply input accepts the plug. There is a lot of current and power involved here so good to see a tight fit.
One nice feature, beside trigger, is auto-shut off in case of no input signal. I left it on by accident and was pleasantly surprised when I came back and it had gone to sleep.
3e audio A7 Amplifier Measurements
Let's start with low gain, volume control set to (volume bypass didn't make a difference), and XLR as inputs:
Very nice. Well above average in performance with distortion below threshold of hearing:
RCA input as usual loses a bit, but not much, scoring 100 dB with again, inaudible distortion:
SNR is the limit here, which is quite good actually:
At full power, it provides transparency for practically all music produced!
The A7 uses post filter feedback (PFFB) so it is essentially load (speaker) independent:
Crosstalk while much better than average, is a bit worse than 3e audio A5:
As is typical here, above 1 kHz, distortion does climb:
This is one powerful little amplifier, easily besting its nicely mentioned specs:
Edit: forgot to include the power vs frequency sweep:
Power is more or less sustained across the full audible band:
Its distortion goes from 0.05% to huge amount as it clips so I could not test it at 1% THD at higher frequency. So I searched for power point at just 0.05% which disadvantages this amp a bit.
My reactive loadbox still doesn't like these bridged amplifiers so I could only test the left channel (although per above, stereo and mono performance were the same):
You have to keep reminding yourself that this much power is coming out of this little box, no bigger than the old CD cases!
Finally, the amplifier is rock solid on power up:
Oh, too much on my mind so I forgot to run the power up/down glitch test.
Conclusions
If my memory serves me right, 3e audio was the first company to bring us high performance TI TPA3255 class D amplifiers with PFFB. While they have more competition now, it is clear they intend to stay on top of this game, squeezing every bit of performance out of this architecture, while providing nice feature set. We are talking high performance, high power amplifiers that are tiny yet deliver what people need in most cases.
I am happy to recommend 3e audio A7 / A7 Mono stereo audio amplifiers.
------------
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/
While the A7 may look like its competitors, it has a heft to it that I don't recall others not having. It really feels like it is filled with lead or something! A nice volume control in the middle adjusts the gain but it can also be bypassed using a switch in the back. Pushing the volume control quickly switches between XLR balanced and RCA. Two thoughtful clipping indicators are provided, making me wish it would be a standard feature on any amplifier. A minor nit: LED colors indicating which input is active is red and clipping in green. I think based on convention, the latter should be red.
Back panel shows nice set of features:
Trigger input is provided as is the aforementioned combo TRS/XLR balanced inputs. Low and high gain switch is provided but I focused on low gain as that is fully compatible with current audio products outputting 2/4 volts. Yes, there is that monster GaN power supply! It can of course be purchased with other options. The input connector says max is 48 volt but per designer, the mono configuration, which is just using the left channel, can go up to 52 volts. He said I could test in stereo just the same and that is what I did. I found no issues.
FYI, I was impressed with the secure way the power supply input accepts the plug. There is a lot of current and power involved here so good to see a tight fit.
One nice feature, beside trigger, is auto-shut off in case of no input signal. I left it on by accident and was pleasantly surprised when I came back and it had gone to sleep.
3e audio A7 Amplifier Measurements
Let's start with low gain, volume control set to (volume bypass didn't make a difference), and XLR as inputs:
Very nice. Well above average in performance with distortion below threshold of hearing:
RCA input as usual loses a bit, but not much, scoring 100 dB with again, inaudible distortion:
SNR is the limit here, which is quite good actually:
At full power, it provides transparency for practically all music produced!
The A7 uses post filter feedback (PFFB) so it is essentially load (speaker) independent:
Crosstalk while much better than average, is a bit worse than 3e audio A5:
As is typical here, above 1 kHz, distortion does climb:
This is one powerful little amplifier, easily besting its nicely mentioned specs:
Edit: forgot to include the power vs frequency sweep:
Power is more or less sustained across the full audible band:
Its distortion goes from 0.05% to huge amount as it clips so I could not test it at 1% THD at higher frequency. So I searched for power point at just 0.05% which disadvantages this amp a bit.
My reactive loadbox still doesn't like these bridged amplifiers so I could only test the left channel (although per above, stereo and mono performance were the same):
You have to keep reminding yourself that this much power is coming out of this little box, no bigger than the old CD cases!
Finally, the amplifier is rock solid on power up:
Oh, too much on my mind so I forgot to run the power up/down glitch test.
Conclusions
If my memory serves me right, 3e audio was the first company to bring us high performance TI TPA3255 class D amplifiers with PFFB. While they have more competition now, it is clear they intend to stay on top of this game, squeezing every bit of performance out of this architecture, while providing nice feature set. We are talking high performance, high power amplifiers that are tiny yet deliver what people need in most cases.
I am happy to recommend 3e audio A7 / A7 Mono stereo audio amplifiers.
------------
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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