3e audio A7/A7 Mono Amplifier Review

[welwynnick]

Since the power vs. distortion test uses resistive 8 and 4 ohm loads, one likely can’t assume it will deliver the same disclosed power under reactive load conditions with both channels driven -considering the shared 52V, 9A power supply.

See post #38 above

 

[1066]

How audible is the distortion in higher frequencies and would that become more audible at levels higher than 5 watts?

 

[howard416]

How audible is the distortion in higher frequencies and would that become more audible at levels higher than 5 watts?

If anyone can ever come up with a peer-reviewable methodology of testing that could prove this level of distortion is audible in any form of actual music, … that’d probably be a world first.

You may find it informative to look at distortion measurements of state of the art dome tweeters and compression drivers to see how they stack up against the performance of this amp in HF.

 

[Chaos01]

Well, 3e audio A7‘s low gain is other people’s (Topping B100) high gain! And the 2 Ohms stability is simply astonishing!
3e audio delivers exactly in the areas where it really matters for amplifiers:
View attachment 444236

Hopefully Topping will shoot back with something discrete and ultrastable at 2 Ohms (Maybe 675 Watts /channel @ 4 Ohms and 1.300 Watts / channel @ 2 Ohms), so that nobody, even @restorer-john can complain!

Something like the Hypex ncx500? Topping just would have to make it cheaper, could be difficult because a pair of the topping 200w monos is yet at the same price Like a audiophonics ncx500 or more :/

 

[SMen]

They are sold as different products. But internally, just using the left channel of stereo version is the same as mono dedicated unit. I know, it took me a while to wrap my head around that too. Saved the company from having to send me extra stuff.

This is actually a missed selling point for 3eaudio ... you (@3eaudio ) should point this out and maybe tempt A7 owners with a second unit...

I wonder if this topology is the same for the A5? Maybe 3e could answer this.

Great to see this reviewed. Delighted with my A5.

 

[antcollinet]

How audible is the distortion in higher frequencies and would that become more audible at levels higher than 5 watts?

Components at -90dB at 20kHz. Not audible at all. Look how the sensitivity of your hearing drops off above 5kHz.

Auditory Sensitivity Function – Introduction to Sensation and Perception

pressbooks.umn.edu

(figure 5.5.1)

In order for those -90dB components to reach the threshold of auibility you'd have to have the music up at more than 110dB.

But then they'd only be audible - to someone with perfect hearing - if the room was dead silent. Not having music blasted into it at 110dB

Basically you are talking about hearing a feather land on the back of a kitten while listening to music at loud club levels

 

[1066]

Components at -90dB at 20kHz. Not audible at all. Look how the sensitivity of your hearing drops off above 5kHz.

Auditory Sensitivity Function – Introduction to Sensation and Perception

pressbooks.umn.edu

(figure 5.5.1)

In order for those -90components to reach the threshold of auibility you'd have to have the music up at more than 110dB.

But then they'd only be audible - to someone with perfect hearing - if the room was dead silent. Not having music blasted into it at 110dB

Basically you are talking about hearing a feather land on the back of a kitten while listening to music at loud club levels

Thank you. I will have a read through

 

[Matt_Holland]

Thanks Amir.

You can buy this amp based only on this data:

 

[Old_School_Brad]

See post #38 above

I’m not sure how that’s relevant.

What I’m pointing out is this:

Power vs. distortion tests:
– Done with 8 and 4 ohm resistive loads
– Both channels driven

Reactive load tests:
– Done with only one channel

So assuming it can deliver the same performance shown in the reactive load test with both channels running is unlikely, especially considering the power supply is 52V at 9A.

 

[antcollinet]

So assuming it can deliver the same performance shown in the reactive load test with both channels running is unlikely, especially considering the power supply is 52V at 9A.

While true, it doesn't really matter for real world use cases.

Power at that level is only going to be sustained for the briefest of transients - which are unlikely to exist in both channels simultaneously.

 

[daniboun]

Well, 3e audio A7‘s low gain is other people’s (Topping B100) high gain! And the 2 Ohms stability is simply astonishing!
3e audio delivers exactly in the areas where it really matters for amplifiers:
View attachment 444236

Hopefully Topping will shoot back with something discrete and ultrastable at 2 Ohms (Maybe 675 Watts /channel @ 4 Ohms and 1.300 Watts / channel @ 2 Ohms), so that nobody, even @restorer-john can complain!

Funny you're surprised ) The 3E Audio 480-1-29A module tested in 2023 by Amir already showed superb performance @2ohms

 

[Old_School_Brad]

While true, it doesn't really matter for real world use cases.

Power at that level is only going to be sustained for the briefest of transients - which are unlikely to exist in both channels simultaneously.

I'm simply aiming for a fair comparison and suggesting that expectations should be tempered before taking the graph’s numbers at face value. When both channels are driven simultaneously, the power output will likely decrease -potentially by half at certain points, because the power supply may not be able to sustain the required current.

It’s also important to note that transients, especially from drums and electronic beats, commonly occur in both channels at the same time, placing real-world demands on the amplifier that may not be reflected in single-channel testing.

That said, the performance is still impressive given the compact form factor, just keep in mind that the published power figures are measured over short durations (5–10 seconds for the left bar graph, 20 ms for the CEA test and 10s of ms in the sweeps), and continuous performance may differ.

I definitely miss seeing he more "FTC-like" 1 min. continuous power test we got with the Topping B200 amplifier, for example.

Spoiler: Topping B200 - "FTC-like" test

 

[1066]

If anyone can ever come up with a peer-reviewable methodology of testing that could prove this level of distortion is audible in any form of actual music, … that’d probably be a world first.

You may find it informative to look at distortion measurements of state of the art dome tweeters and compression drivers to see how they stack up against the performance of this amp in HF.

Thank you Howard. I couldn’t find easy way to compare amp high frequency distortion and tweeter distortion for my knowledge level.

I looked up what resembles the tweeter in revel f206 I have. I can see freq response. That’s all I can understand.

 

[Spkrdctr]

As a public service announcement for the USA people reading this and loving it, the price will double in the next month or so, if you want one, buy now like in the next week or so. Tariffs have not hit yet but they will fairly quickly. Good Luck on your purchases.

 

[HalSF]

Basically you are talking about hearing a feather land on the back of a kitten while listening to music at loud club levels

 

[antcollinet]

Course there is.

Just like there is a chance all the atoms of your body line up with all the atoms of the earth, and you sink to planet's core.

 

[Crook]

At this price why not just buy a Hypex amp.

Agree 100%. It is really overpriced on Audiophonic's. €100 more for NC252MP! Buying Chinese products directly is much cheaper, but you run the risk if it goes pop.

 

[antcollinet]

Agree 100%. It is really overpriced on Audiophonic's. €100 more for NC252MP! Buying Chinese products directly is much cheaper, but you run the risk if it goes pop.

All that warranty and after sales stuff costs real money.

 

[DSJR]

As by EU law the mandatory 2 years warranty on faulty goods is covered by the dealer, sure. Dunno if this applies for Brexit folks too.

I can't remember, but it's got to be cheaper and quicker than shipping expensively to China, surely, in the event of failure?

 

[Ajax]

Which one offers similar performance for the price...?
The UCD's have lower sinad and generally lower power handling for low impedance speakers or low frequency output afaik.

The Buckeye NC252MP measures very close for an extra $100 (cost = US$575). I have one and can vouch for its performance from a subjective viewpoint. When hooked up to a Benchmark DAC2 driving a pair of B&W AM01 outdoor speakers the sound is extremly clean with plenty of power. I've had it for about 3 years and it gives me great pleasure.

Buckeye NC252MP Stereo Amplifier Review

This is a review and detailed measurements of the Buckeye NC252MP balanced stereo class D amplifier. It was kindly drop shipped to me by a member and costs US $575. The amp is almost the size of a loaf of bread and literally weighs nearly as much! Amazing how far amplification technology has...

www.audiosciencereview.com

Also it is assembled in the US with parts from the Netherlands and Malaysia so it is not as exposed to future tarrifs as are the 3e products. I'm not trying to be controversial or political just stating how I see things from an Australian viewpoint.

The reality is that whatever happens the front end of the audio chain, streamers, DACs and power amps, have never performed better nor been more affordable. It's my belief prices have fallen by nearly 90% in the past 10 years. There are plenty of products available today that will provide a SOTA front end that is audibly transparent, while producing over 100 watts into 8 ohms, all for under $1K ... just add speakers.