3e Audio A5 Stereo Amplifier Review

[somebodyelse]

Thanks, I've looked at this table so many times, but apparently I've never read up to point 5.

You're not the only one. I'd probably be making some inline attenuators so I could turn it up to where it matches better.

 

[Roland68]

You're not the only one. I'd probably be making some inline attenuators so I could turn it up to where it matches better.

Yes, that's my plan B too.
I don't need that for my regular DAC, which has a perfectly equal analog volume control for each channel.
For everything else, I'll build myself a set of RCA and XLR cables with voltage dividers in the connectors.

 

[jareinertson]

That’s true -but does it actually matter? -And is it audible?

All designs account for some degree of component drift -they have to. Even brand-new components typically have a +/- 10% tolerance, yet the performance is expected to remain consistent within that range.

This built-in tolerance works in our favor. It's part of the reason why so many 30-year-old amplifiers still perform just as well as they did when new -and many of those haven't even been serviced. That’s pretty impressive, isn’t it?

And if a few capacitors need replacing due to leakage, or the unit needs a bit of cleaning and attention to switches or pots, so be it. Once that’s done, the amp usually runs solidly again. That's minor work for a quality product.

Indeed! My 35year old ML No 29 was completely serviced and recapped in 2024 for about 20% of its 1990 purchase price. Working great and ready for another 30 years. A great value in my opinion.

 

[ianovic69]

The primary system amp is also class D - a Nord Acoustics Hypex NC252 - which I think is always going to be a step up from this 3E A5 amp, great as it is at the price. The Nord cost around 3x more.

I'm considering buying the Nord, just wondering if a 3eA7 will do the job just as well?
I don't know enough about all this to make a decision, it's all a bit confusing tbh.
Would you be able to direct me to the best place here to post related questions?

 

[Roland68]

I'm considering buying the Nord, just wondering if a 3eA7 will do the job just as well?
I don't know enough about all this to make a decision, it's all a bit confusing tbh.
Would you be able to direct me to the best place here to post related questions?

The question is how much power you need.
We've blindly compared two different Hypex NC252 amplifiers with the PA5 II, A7, and A5, and these three TPA3255/51-based amplifiers were preferred by all.
The sound reproduction was simply a touch more transparent.

The A7 has roughly the same power output as the standard Hypex NC252 amplifiers and is absolutely stable at 2 ohms.
The maximum continuous power is lower, but unless you're constantly running your speakers at well over 120 watts, you'll just be spending more money.
Even a friend with impedance-sensitive and inefficient 83 dB speakers hasn't been able to push the A7 to its limits, and that's in a 28 square meter room.

 

[magreen]

The question is how much power you need.
We've blindly compared two different Hypex NC252 amplifiers with the PA5 II, A7, and A5, and these three TPA3255/51-based amplifiers were preferred by all.
The sound reproduction was simply a touch more transparent.

I’d love to hear more about these blind comparisons.

 

[VientoB]

The question is how much power you need.
We've blindly compared two different Hypex NC252 amplifiers with the PA5 II, A7, and A5, and these three TPA3255/51-based amplifiers were preferred by all.
The sound reproduction was simply a touch more transparent.

The A7 has roughly the same power output as the standard Hypex NC252 amplifiers and is absolutely stable at 2 ohms.
The maximum continuous power is lower, but unless you're constantly running your speakers at well over 120 watts, you'll just be spending more money.
Even a friend with impedance-sensitive and inefficient 83 dB speakers hasn't been able to push the A7 to its limits, and that's in a 28 square meter room.

Really? Show us the blind test.

 

[ianovic69]

The question is how much power you need.
We've blindly compared two different Hypex NC252 amplifiers with the PA5 II, A7, and A5, and these three TPA3255/51-based amplifiers were preferred by all.
The sound reproduction was simply a touch more transparent.

The A7 has roughly the same power output as the standard Hypex NC252 amplifiers and is absolutely stable at 2 ohms.
The maximum continuous power is lower, but unless you're constantly running your speakers at well over 120 watts, you'll just be spending more money.
Even a friend with impedance-sensitive and inefficient 83 dB speakers hasn't been able to push the A7 to its limits, and that's in a 28 square meter room.

Thanks for replying.

The question is how much power you need.
We've blindly compared two different Hypex NC252 amplifiers with the PA5 II, A7, and A5, and these three TPA3255/51-based amplifiers were preferred by all.
The sound reproduction was simply a touch more transparent.

The A7 has roughly the same power output as the standard Hypex NC252 amplifiers and is absolutely stable at 2 ohms.
The maximum continuous power is lower, but unless you're constantly running your speakers at well over 120 watts, you'll just be spending more money.
Even a friend with impedance-sensitive and inefficient 83 dB speakers hasn't been able to push the A7 to its limits, and that's in a 28 square meter room.

120 watts continuous will at times be probable, if not more. My concern there is peaks, particularly at low bass frequencies.
The A7 appears to be the best cheaper alternative, and I'll do more research into it.
Nord is still my preference, they appeal to me on multiple levels.

 

[Roland68]

Thanks for replying.

120 watts continuous will at times be probable, if not more. My concern there is peaks, particularly at low bass frequencies.
The A7 appears to be the best cheaper alternative, and I'll do more research into it.
Nord is still my preference, they appeal to me on multiple levels.

May I ask which speakers you intend to use with it?

 

[Roland68]

I’d love to hear more about these blind comparisons.

Really? Show us the blind test.

These are simple, completely blinded comparisons, always between only two devices.
Short excerpts of music, 10-20 seconds long, are played.
Both devices run 5 times per trial, for a total of 10 times per trial. The only criteria are better, worse, and the same.
Switching occurs automatically and randomly, so that a device runs a maximum of two times consecutively. Therefore, no one knows which device is currently running during the trials. The first evaluation takes place after 3 trials.

With 3 consecutive trials, where one device scores at least 7/10, a small/marginal, but audible difference can be assumed.
At 8/10, we assume an audible difference.
At 9/10, we assume a definite audible difference.
At 10/10, the audible difference is significant.

 

[ianovic69]

@Roland68
No idea other than the largest floor standing I can find at a used price I can afford.
If I had to buy new then I like the look of the Linton, Fyne 501e, Quad S4 or S5, that kind of thing.
That price range for used, so whatever comes up that matches the amp on spec and passes the wife test.

I could do with suggestions so if anyone has them please do feel free to chip in with your recommendations, I would be very grateful.

 

[Roland68]

@Roland68
No idea other than the largest floor standing I can find at a used price I can afford.
If I had to buy new then I like the look of the Linton, Fyne 501e, Quad S4 or S5, that kind of thing.
That price range for used, so whatever comes up that matches the amp on spec and passes the wife test.

I could do with suggestions so if anyone has them please do feel free to chip in with your recommendations, I would be very grateful.

For something like this, it makes sense to start a separate thread.
But you wouldn't need anywhere near 120 watts of continuous power for any of these speakers. However, it makes more and more sense to buy the speakers first and then the amplifier.

As a large floorstanding speaker, I could also recommend the Heco Aurora 1000, but it depends on which country you live in, as many speakers are only readily available on certain continents or in certain countries.

 

[VientoB]

These are simple, completely blinded comparisons, always between only two devices.
Short excerpts of music, 10-20 seconds long, are played.
Both devices run 5 times per trial, for a total of 10 times per trial. The only criteria are better, worse, and the same.
Switching occurs automatically and randomly, so that a device runs a maximum of two times consecutively. Therefore, no one knows which device is currently running during the trials. The first evaluation takes place after 3 trials.

With 3 consecutive trials, where one device scores at least 7/10, a small/marginal, but audible difference can be assumed.
At 8/10, we assume an audible difference.
At 9/10, we assume a definite audible difference.
At 10/10, the audible difference is significant.

Can't be volume matched accurately enough though, can they?

 

[Roland68]

Can't be volume matched accurately enough though, can they?

We've been doing this in a project for over 25 years and know what we're doing. Absolutely identical volume, both between devices and between channels, has been a given from the start.
Three decimal places for low-level signals and HPA, and two decimal places for amplifiers, should be sufficient for the voltage.

 

[RandomEar]

We've been doing this in a project for over 25 years and know what we're doing. Absolutely identical volume, both between devices and between channels, has been a given from the start.
Three decimal places for low-level signals and HPA, and two decimal places for amplifiers, should be sufficient for the voltage.

Would you mind reporting in more detail on your tests in a new thread? They sound well done and clearly, with the measurements suggesting that the differences between the Hypex and TPA325x devices are small, this would be an interesting thing to explore. Also, on ASR, I would expect a... lively discussion about such results

 

[lunaria]

We've blindly compared two different Hypex NC252 amplifiers with the PA5 II, A7, and A5, and these three TPA3255/51-based amplifiers were preferred by all.

Did you perform a precise level matching? How did you verify that?

Did you verify that the frequency response was identical between all amps (measured at the speaker)? All of them should be load-independent and completely flat in the audible range.

The input impedance of the PA5 and 3e Audio amps is much lower than the NC252 and depending on the source, there could be an audible impact.

I find your report of audible differences being detectable in a blind test very, very surprising. IMO, it's far more likely that there are issues with the test setup (that could be easily measured) rather than audible differences between the amps (assuming a source with low output impedance is used and levels are precisely matched).

 

[Roland68]

Did you perform a precise level matching? How did you verify that?

Did you verify that the frequency response was identical between all amps (measured at the speaker)? All of them should be load-independent and completely flat in the audible range.

The input impedance of the PA5 and 3e Audio amps is much lower than the NC252 and depending on the source, there could be an audible impact.

I find your report of audible differences being detectable in a blind test very, very surprising. IMO, it's far more likely that there are issues with the test setup (that could be easily measured) rather than audible differences between the amps (assuming a source with low output impedance is used and levels are precisely matched).

As I already mentioned, we measure the voltage to 2-3 decimal places, usually more precisely.
We use two highly impedance-linearized loudspeakers with 4 and 8 ohms. If an amplifier can't handle this, the manufacturer has made a mistake.
We ensure that the output impedance of the source is at least 20 times lower. We also have a 20-ohm source.
We conduct these tests because opinions are of no help to us, nor are theories about what is audible and what isn't.

Of course, our measurement setup can have errors and has been continuously optimized over more than 25 years. We also paid a high price in the first 5 years and later had to repeat many comparisons, as more factors have an influence than many people realize.
However, we have several people from measurement technology and development involved, including two application developers from measurement technology. The setup has also been reviewed by manufacturers and other developers.

 

[pieterv1]

Literally finished my DIY NCx252MP build yesterday, for practicality and better looks, only for this guy to come in and say there's a clear difference :')

 

[Roland68]

Literally finished my DIY NCx252MP build yesterday, for practicality and better looks, only for this guy to come in and say there's a clear difference :')

Please don't take this out of context.
Marginal difference.

Besides, you're talking about the newer NCx252MP, which have just been released. They're a new, further developed generation and have better measured values. I haven't had them in my hands yet, so I can't say anything about them.

Furthermore, past experience has shown that the input buffer in these amplifiers can have a significant influence on the overall performance.

However, it's important to remember that, regardless of whether it's the NC252, NCx252MP, A5, A7, Mini 300, PA5 (II), etc., they are better than almost anything that existed 10 years ago, and also better than most so-called high-end amplifiers that cost many times more.

 

[peng]

Please don't take this out of context.
Marginal difference.

Besides, you're talking about the newer NCx252MP, which have just been released. They're a new, further developed generation and have better measured values. I haven't had them in my hands yet, so I can't say anything about them.

Furthermore, past experience has shown that the input buffer in these amplifiers can have a significant influence on the overall performance.

However, it's important to remember that, regardless of whether it's the NC252, NCx252MP, A5, A7, Mini 300, PA5 (II), etc., they are better than almost anything that existed 10 years ago, and also better than most so-called high-end amplifiers that cost many times more.

Did you keep a score sheet, am interested to know if people could id the dut better than 7 out of 10 times? Thank you.