3e audio A7/A7 Mono Amplifier Review

[RandomEar]

It looks like the roll starts at 20k hz, so you might be able to.

See for yourself, test a level difference of 0.2 dB and report back (the actual value for the Emotiva is about -0.15 dB @ 20 kHz). Sadly, this test isn't at 20 kHz, where you couldn't hear it anyway...

 

[jlx]

It looks like the roll starts at 20k hz, so you might be able to.

??????
How would this be possible?
That graph indicates a roughly 1/8dB roll off at 20k Hz and starting at somewhere above 10k Hz depending upon the speaker impedance.
IIRC, a normal human loses the ability to hear above 19khz typically around the age of 20.
Beyond that, real music has exceedingly minimal content above 15k Hz and humans lack the ability to discern differences much below 1dB under the best of testing conditions with specific test tones, never mind in complex actual material.
Of course if anyone here has a bat or a dog as a parent, my statements may not apply to you and I'll have egg on my face. But I'm feeling lucky today

 

[Ropeburn]

Yes indeed... and when we look at the A7 here:

If anything, there's a slight emphasis around 10kHz, however completely inaudible because it's 0.1dB at best. No "rolloff" whatsoever. @TreyHaynie there are two main possibilities here: 1) what you're hearing is something else, or more likely 2) an illusion. Happens all the time because of that highly biased and hallucinatory brain between our ears. Such things reliably disappear in a properly controlled blind test.

Unless of course you're this guy:

 

[Ruediger]

From info within this thread about gain of the A7:

RCA: 26 dB (LOW) or 29 dB (HIGH), input sensitivity 1.75V
XLR: 20 dB, input sensitivity 3.5V

As I understand it using XLR also bypasses the opamp.

Does anyone use a RCA-to-XLR connection with voltages 1.75V or lower, not for a nearfield setup but for home theater room?

I wonder if it makes even sense to try that cabling.

 

[john61ct]

Could you explain, why?

Short distance, not much EMI/RF?

You mean something basic like this?

Are you a human?

www.newegg.com

 

[Ruediger]

Could you explain, why?

Short distance, not much EMI/RF?

You mean something basic like this?

Are you a human?

www.newegg.com

Basically for reasons of slightly better shielding.

I have RCA-to-XLR cables made according to Hypex/Purifi recommendations.

But I need a good range of volume incl. very loud. By very loud I mean stereo poweramp consumes around 150W.

 

[antcollinet]

Basically for reasons of slightly better shielding.

I have RCA-to-XLR cables made according to Hypex/Purifi recommendations.

But I need a good range of volume incl. very loud. By very loud I mean stereo poweramp consumes around 150W.

well 1.75V is 6dB lower than 3.5V (half) so if you go in with this to the XLR input, you'll only be able to drive to around 1/4 of full power (power is related to the square of voltage) - so it looks like you would not achieve your 150W target.

 

[Ruediger]

well 1.75V is 6dB lower than 3.5V (half) so if you go in with this to the XLR input, you'll only be able to drive to around 1/4 of full power (power is related to the square of voltage) - so it looks like you would not achieve your 150W target.

Thanks for adding the math to this.

Yes, looks a bit slim this way. I'll better stick to RCA.

 

[LambdaCDM]

A7 Stereo. Are there any real reasons to replace the stock 48V 10A PSU with the MeanWell HRP-600N3-48? Won't it be worse in terms of noise?
In what cases or with what speakers might such a current be needed (13A continuous, Peak+350%(2kW) up to 5sec), given a continuous SPL of around 80 dB and a peak SPL of around 95 dB in a sweet spot 2,5m distance? Google AI says there's no point. And i agree. But could it be missing something?
I hate snake oil, but in this case, I'm just curious from a scientific perspective.

 

[Dave TR3A]

A7 Stereo. Are there any real reasons to replace the stock 48V 10A PSU with the MeanWell HRP-600N3-48? Won't it be worse in terms of noise?
In what cases or with what speakers might such a current be needed (13A continuous, Peak+350%(2kW) up to 5sec), given a continuous SPL of around 80 dB and a peak SPL of around 95 dB in a sweet spot 2,5m distance? Google AI says there's no point. And i agree. But could it be missing something?
I hate snake oil, but in this case, I'm just curious from a scientific perspective.

I suspect that you would be worse off with the Meanwell PS than with the PS that comes with the A7.

I was unsuccessful using a Meanwell LRS-600-36 power supply with my Aiyima A07 amps. The Meanwell PS introduced too much ripple and noise --- far more than the PS that came with the amps.

I run tri-amped Klipsch La Scalas. I had wanted to use the Meanwell supply to consolidate the 3 PS that came with my amps. I went back and forth with Meanwell's support group but was never able to get the Meanwell PS to quiet down. Here's a screen shot showing some the noise on the Meanwell's output:

I tried (and loved) 3e Audio's A7 amps. Unfortunately, I had to send them back because -- at the volumes I was listening at -- the autosense would turn off the amp driving my tweeters. By my calculations (extrapolated from this post), I believe it very unlikely that you would need 13A for the amps.

From my testing (using the PS that came with the A7), the A7 starts to clip at about 27 VRMS when driving a 4 ohm load. That would require about 6.4 amps.

I should point out that the volume at 27 VRMS would have been deafening (my speakers are about 105 dB @ 1W @ 1m). Given the SPL levels you cited, I can see no reason that you would need 13A, even if your speakers are very low impedance (2 ohms or less).

I would recommend that you stay with the PS that came with the A7.

 

[LambdaCDM]

I suspect that you would be worse off with the Meanwell PS than with the PS that comes with the A7.
I was unsuccessful using a Meanwell LRS-600-36 power supply with my Aiyima A07 amps.

I saw your post.
But it's different model, HRP with active PFC, and, afaik, has less ripple and noise. But nevermind. I may use the slightly more expensive Hypex SMPS1200A180 instead.
But for now, we seem to agree that such power will remain highly excessive and the stock PSU is more than sufficient in most real use case.

 

[somebodyelse]

But nevermind. I may use the slightly more expensive Hypex SMPS1200A180 instead.

That's an odd choice - it's got a -ve supply rail that you won't be using with an A7.

 

[john61ct]

The stock 5A will get you to 95% and nothing at all will improve on the 10A.

Unless you tweak voltage to say 51Vdc (danger Will Robinson)

which might get you up to another 5%.

Are you SURE your SPL needs are that demanding?

If so consider buying an amp actually designed to get up to say 50% or more above the A7

 

[LambdaCDM]

-ve supply rail

Oh, thanks. I didn't notice that.
By the way, do you share the opinion that a PSU over 10A is excessive? Or is there potential benefit, since the implemented PBTL can easily handle transients of 10A per channel.

 

[LambdaCDM]

The stock 5A will get you to 95% and nothing at all will improve on the 10A.

I already have a 48V 10A power supply. I'm wondering if a higher current rating makes sense? Everything suggests there's no point.

Are you SURE your SPL needs are that demanding?

Sure not. But maybe I'm missing something, that's why I came here with this question.

 

[john61ct]

I already have a 48V 10A power supply.

Then stop move on to other, real issues.

> I'm wondering if a higher current rating makes sense?

100% certainly not.

> that's why I came here with this question

question answered

 

[Ruediger]

I think the A5 or A7 with the 48v/10a GaN psu - not the cheap non-GaN ones to be found on Ali - bundled by audiophonics or sold by brands like Aiyima is optimal. Nothing to gain from other psu options.

The A5 could use more than the small 48v/5a psu provides on paper - but I don't know how real that is. Don't people get the A5 because they don't need the power of the A7? I would get the better 48v/10a GaN psu nonetheless, it's also good for other amps.

 

[antcollinet]

Oh, thanks. I didn't notice that.
By the way, do you share the opinion that a PSU over 10A is excessive? Or is there potential benefit, since the implemented PBTL can easily handle transients of 10A per channel.

Probably the 10A PSU can also. 10A is a continuous rating. It will almost certainly be capable of higher transient peaks - even for some time.

 

[antcollinet]

I think the A5 or A7 with the 48v/10a GaN psu - not the cheap non-GaN ones to be found on Ali - bundled by audiophonics or sold by brands like Aiyima is optimal. Nothing to gain from other psu options.

The A5 could use more than the small 48v/5a psu provides on paper - but I don't know how real that is. Don't people get the A5 because they don't need the power of the A7? I would get the better 48v/10a GaN psu nonetheless, it's also good for other amps.

GAN is not a quality indicator. You can get nasty gan power supplies just as you can nasty PSUs with conventional power switches. Gan just buys you higher efficiency and/or smaller size.

Just make sure the PSU is a quality device from a reputable supplier - whether GAN or not.

 

[somebodyelse]

I think the A5 or A7 with the 48v/10a GaN psu - not the cheap non-GaN ones to be found on Ali - bundled by audiophonics or sold by brands like Aiyima is optimal. Nothing to gain from other psu options.

The A5 could use more than the small 48v/5a psu provides on paper - but I don't know how real that is. Don't people get the A5 because they don't need the power of the A7? I would get the better 48v/10a GaN psu nonetheless, it's also good for other amps.

I think the A5 uses 36V due to TPA3251 (lower power, slightly lower distortion). Buy the A5 if you don't need the extra power of the A7, and buy the se version if you don't have very low impedance speakers ~2R.