3e audio A7/A7 Mono Amplifier Review

[SMen]

Thanks for these numbers - indeed, even with the A5, I would assume , it would rarely go to half power or more.
However, in terms of longevity of the amp, would it not be better to regularly use a more powerful amp at 20%, than a less powerful one at 35%?

I have read that the A5 has a slightly warmer sound - is this from a few purely subjective anecdotal accounts? Given that class D is supposed to produce a transparent colourless sound in general..

I have both the A5 and A7 and I would take 'warmer sound', if you are referring to A5 vs the A7, with an enormous pinch of salt - put it down to bias.

They have different gain, which might lead to perceived differences


Post edit ... purely subjectively - I felt a slight sense ease with the A7 over the A5 even through efficient speakers - so bias or not it is the A7 that has stayed in.

 

[Decisionmaker]

I have both the A5 and A7 and I would take 'warmer sound', if you are referring to A5 vs the A7, with an enormous pinch of salt - put it down to bias.

They have different gain, which might lead to perceived differences


Post edit ... purely subjectively - I felt a slight sense ease with the A7 over the A5 even through efficient speakers - so bias or not it is the A7 that has stayed in.

Yes, I found it hard to believe there would be an marked difference. It is still odd that the manufacturer splashes on their main product comparison/marketing chart that the less powerful model is higher quality audio, giving the A7 Stereo a modest 4/5! Although they claim the A7 Mono is 5/5 on power and audio! Just trying to make life difficult for decision makers!
What kind of speakers are you driving?

 

[SMen]

Still trying to hear some differences between the NC502MP and the A7 but it seems impossible, frustrating…, can’t wait to get someone else to try, hopefully soon.



View attachment 505541

We already conducted similar comparisons between the NC502MP and the well-measuring TPA3251/55 some time ago, and the differences, if they exist at all, are marginal and barely audible. If anything, the chances are slightly higher with the TPA3251.

You can also include the Sabaj A30a and SMSL VMV A2 in the test; the results will be the same.

It is useful to read about no audible differences / or barely if they exist at all.

 

[SMen]

Yes, I found it hard to believe there would be an marked difference. It is still odd that the manufacturer splashes on their main product comparison/marketing chart that the less powerful model is higher quality audio, giving the A7 Stereo a modest 4/5! Although they claim the A7 Mono is 5/5 on power and audio! Just trying to make life difficult for decision makers!
What kind of speakers are you driving?

I'm using a pair of Triangle Titus speakers which are 90 db. Directly coupled (cross-overless main driver).

I can't help but think that they would complain about an amplifier (or source) given the slightest chance !

 

[Roland68]

Yes, I found it hard to believe there would be an marked difference. It is still odd that the manufacturer splashes on their main product comparison/marketing chart that the less powerful model is higher quality audio, giving the A7 Stereo a modest 4/5! Although they claim the A7 Mono is 5/5 on power and audio! Just trying to make life difficult for decision makers!
What kind of speakers are you driving?

It is useful to read about no audible differences / or barely if they exist at all.

What distinguishes the TPA3251 from the 55 is the slightly higher (potential) resolution of the TPA3251, assuming equally good implementation.
We're talking about marginal differences here, not worlds apart, but depending on the quality of the music material and the imaging capabilities of the speakers, it can make a small difference.

However, I've never noticed a difference in tone/warmth between these two amplifier ICs.

 

[Roland68]

Thanks for these numbers - indeed, even with the A5, I would assume , it would rarely go to half power or more.
However, in terms of longevity of the amp, would it not be better to regularly use a more powerful amp at 20%, than a less powerful one at 35%?

I have read that the A5 has a slightly warmer sound - is this from a few purely subjective anecdotal accounts? Given that class D is supposed to produce a transparent colourless sound in general..

Actually, it would be the other way around.
In such devices, only capacitors and relays fail due to wear and tear, both of which are easy and inexpensive to replace.
What causes the capacitors to age in Class D amplifiers is primarily the high switching frequencies. Temperature also plays a role, but that's secondary, especially since a certain amount of heat is desirable.

The A5, however, has both a lower voltage (38V instead of 48V) than the A7, and a 2-2.5 times lower idle power consumption (idle temperature), which is why the A5 is probably more durable under the same load. But in my experience with Class D amplifiers, even this difference is marginal and shouldn't be a deciding factor when buying.

 

[TurtlePaul]

The A5, however, has both a lower voltage (38V instead of 48V) than the A7, and a 2-2.5 times lower idle power consumption (idle temperature), which is why the A5 is probably more durable under the same load. But in my experience with Class D amplifiers, even this difference is marginal and shouldn't be a deciding factor when buying.

That all depends if they used the same capacitors in both models. There is a chance that the A5 uses some caps with a lower voltage or temperature ratings, but I just don't know.

 

[Mort]

Still trying to hear some differences between the NC502MP and the A7 but it seems impossible, frustrating…, can’t wait to get someone else to try, hopefully soon.

No thank you, life isn't long enough...

 

[Roland68]

That all depends if they used the same capacitors in both models. There is a chance that the A5 uses some caps with a lower voltage or temperature ratings, but I just don't know.

Due to my profession, I'm quite familiar with capacitors in many application areas.
I'm also familiar with the types used in the devices, and my statement is based on that.

But again, temperature is absolutely secondary for Class D amplifiers, as long as it doesn't continuously exceed approximately 50°C. The high switching frequencies have a much greater impact on lifespan. And that's precisely what the capacitors are designed for.

 

[Decisionmaker]

In such devices, only capacitors and relays fail due to wear and tear, both of which are easy and inexpensive to replace.
What causes the capacitors to age in Class D amplifiers is primarily the high switching frequencies. Temperature also plays a role, but that's secondary, especially since a certain amount of heat is desirable.

The A5, however, has both a lower voltage (38V instead of 48V) than the A7, and a 2-2.5 times lower idle power consumption (idle temperature), which is why the A5 is probably more durable under the same load. But in my experience with Class D amplifiers, even this difference is marginal and shouldn't be a deciding factor when buying.

Thanks for the detailed technical info. 2 - 2.5 x lower idle power use seems significant - though I'd probably just keep it turned off.
I can actually get both models for the same price.
In that instance would you still get the A5?

 

[peng]

No thank you, life isn't long enough...

Understood, I just meant to wait for one of my friend (who has excellent hearing/discerning vs me) to come over to do it. I already know I don't have the ability to discern whatever minute differences there may be so like you, not going to waste time. When he's here, I'll let him compare it to a class AB amp as well.

 

[Roland68]

Thanks for the detailed technical info. 2 - 2.5 x lower idle power use seems significant - though I'd probably just keep it turned off.
I can actually get both models for the same price.
In that instance would you still get the A5?

In fact, the two ICs draw 1 watt and 2-2.5 watts respectively, but of course, the idle power consumption of the other components also needs to be considered.
Personally, I would choose the A5 in such a case, but I already mentioned that. That's simply my personal preference for detail over power.
However, it's your decision, and your preferences might differ.
If you decide to add a subwoofer in the future—an 18" or two 15" subwoofers would be a good fit—then the A5 should be sufficient for 121dB .

Understood, I just meant to wait for one of my friend (who has excellent hearing/discerning vs me) to come over to do it. I already know I don't have the ability to discern whatever minute differences there may be so like you, not going to waste time. When he's here, I'll let him compare it to a class AB amp as well.

Then make sure that he neither knows nor can see which device is currently running.

 

[peng]

In fact, the two ICs draw 1 watt and 2-2.5 watts respectively, but of course, the idle power consumption of the other components also needs to be considered.
Personally, I would choose the A5 in such a case, but I already mentioned that. That's simply my personal preference for detail over power.
However, it's your decision, and your preferences might differ.
If you decide to add a subwoofer in the future—an 18" or two 15" subwoofers would be a good fit—then the A5 should be sufficient for 121dB .


Then make sure that he neither knows nor can see which device is currently running.

will do. This person was able to pick out my 4B SST from the A21 the majority of the times (don't remember the score, not more than 7/10 for sure), still not that reliable, but he did better than me for sure. Again, not that I care at all, just that its all wire up so we may as well have some fun out the exercise. I definitely feel people should not even think about which one (A7 vs A7 Mono, A7 SE, A5, A5 SE etc.) to choose based on SQ, or a couple of difference in their SINAD score, but just based on their voltage/current needs as those amps are all very transparent.

 

[r-36m2]

Speaking of power, my 17-square-meter room has homemade speakers with a sensitivity of around 88-89 dB, connected to an old 3e Audio SY DAP1002 amplifier with a TPA3250 chip, which puts out around 40 watts per channel into 8 ohms.
Guys, that's very loud. I very rarely watch rock concerts or movies at max volume (even though I love it), because the volume is sufficient even at low frequencies, considering my speakers are sealed enclosures, which have a weak bass response.
I have a subwoofer, but it's covered in dust.
I'm currently considering the A5se, which is more powerful than my amplifier, and its power will be more than enough for me.
I think the A7 is worth considering for compression speakers with low sensitivity or for very large rooms.
In most cases, the A5 will cover all the needs of a home.

 

[SanojS]

Most A/B amplifiers can't match the A7's measured performance. Add to that weight, size, the potential need for servicing on used units, and power consumption, especially at idle.

With Purifi/Hypex, you'd have to go for the higher-end models, which are often quite expensive even used.

I would only buy the B100 once you've decided on your speakers, as it has relatively low power and is sensitive to speakers with a minimum impedance below 4 ohms.

The V3 Mono amplifiers aren't on par with the A7 in terms of quality or measured performance.

If you're not placing the monoblocks directly next to the speakers, you could use a single A7 instead of two A7 Mono amplifiers. It offers the same power output and measured performance as two A7 Mono amplifiers (the A7 is essentially two A7 Mono amplifiers in one unit).

By the way, I like the ideas of monos - have done that in the past with Vincent about 25 years ago - I believe that keeping things segregated is always better to keep signal as clean as possible on the power stage. So it's not only about power but about having true mono separates to minimize the possibility of interference.

I also like that the power brick is outside the mono stage - more separation can only be good!

It might not be audible but my adhd brain likes the idea :-D

 

[r-36m2]

I personally don't pay any attention to the crosstalk between channels in modern amplifiers using a shared power supply -115 dB versus -121 dB with separate power supplies. Because, in my opinion, sound reflections in the room create such a mess of channels before the sound even reaches your ear that even a supercomputer with a stack of reference microphones wouldn't be able to discern whether there's crosstalk between channels in the amplifier or not.
Besides the fact that we hear the right speaker with our left ear and the left with our right ear, we hear a million reflections, and we're constantly moving our heads.
Using monoblock amps is certainly possible because it suits the overall design/is convenient/it's Feng Shui/it's kosher, and for other reasons, but being able to hear crosstalk at levels well beyond -100 decibels is fantastic.
However, the confidence that you have done everything possible often adds to your satisfaction with life, and that is the main thing!)

 

[SanojS]

I personally don't pay any attention to the crosstalk between channels in modern amplifiers using a shared power supply -115 dB versus -121 dB with separate power supplies. Because, in my opinion, sound reflections in the room create such a mess of channels before the sound even reaches your ear that even a supercomputer with a stack of reference microphones wouldn't be able to discern whether there's crosstalk between channels in the amplifier or not.
Besides the fact that we hear the right speaker with our left ear and the left with our right ear, we hear a million reflections, and we're constantly moving our heads.
Using monoblock amps is certainly possible because it suits the overall design/is convenient/it's Feng Shui/it's kosher, and for other reasons, but being able to hear crosstalk at levels well beyond -100 decibels is fantastic.
However, the confidence that you have done everything possible often adds to your satisfaction with life, and that is the main thing!)

Yes I know and agree. This is only in my engineering brain, that I think it's better (perceived), not that it is factually better
It makes me think I have done all I can do on my end to make the signal as good as possible.

 

[Bleib]

Thought this was rather funny, Fosi:fied

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[harkpabst]

Thought this was rather funny, Fosi:fied

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View attachment 506150

I find these fans more funny than the orange knob.

 

[Chaos01]

lol, what a picture

By the way the A7 and mono seem to be now permanent available on Amazon official from 3e (for Germany, so also EU i guess)