3e audio A7/A7 Mono Amplifier Review

[Ruediger]

They're barely warm after a normal sub 80dB session and auto power off / on works perfectly.

I see the A7 getting a good bit warmer than handwarm when having to do the bass too. I probably would not stack these amps over each other, just like in your rack.

 

[metal4ever]

I have the Klipsch Heresy IV. 3e A5se or A7 and which power supply? Also have WIIM Ultra

 

[Ruediger]

I have the Klipsch Heresy IV. 3e A5se or A7 and which power supply? Also have WIIM Ultra

Very high sensitivity and also high impedance.

Any amp from the lineup will work.

It depends on your listening levels how much power you need / want. They take a max. of 100w continuously, which would be ear-bleeding level.

 

[metal4ever]

Very high sensitivity and also high impedance.

Any amp from the lineup will work.

It depends on your listening levels how much power you need / want. They take a max. of 100w continuously, which would be ear-bleeding level.

I ordered the A7, should be here tomorrow. I mostly listen at reasonable levels but like to turn it up a bit occasionally but nothing crazy.

 

[Bernard23]

I ordered the A7, should be here tomorrow. I mostly listen at reasonable levels but like to turn it up a bit occasionally but nothing crazy.

What is a reasonable level for you? I'm going to try to find the clipping point of mine when I get the chance to establish whether I really DO need the 10A PSU or just that I think I do. Like buying an SUV when you live in a crowded city.....

 

[Dave TR3A]

What is a reasonable level for you? I'm going to try to find the clipping point of mine when I get the chance to establish whether I really DO need the 10A PSU or just that I think I do. Like buying an SUV when you live in a crowded city.....

I did some tests of the A7 with a 5A power supply in this thread. There was some very good discussion over the next few pages of the thread (which, among other things, made clear that I had misunderstood the definition of input sensitivity). I summarized what I learned in this post.

I found that the clip indicator on the A7 was sensitive enough that it would light before I could discern clipping when watching the signal on my oscilloscope.

The A7 with the 5A power supply was almost too powerful for my system. This post explains the volumes that the A7 could (in theory) drive my speakers to. For my system, getting the 10A power supply would have been unnecessary.

 

[Ruediger]

The 48v 5a psu they bundle for 10 € (amazon difference vs. no psu) is from the same brand as the big one and also GaN.

 

[metal4ever]

What is a reasonable level for you? I'm going to try to find the clipping point of mine when I get the chance to establish whether I really DO need the 10A PSU or just that I think I do. Like buying an SUV when you live in a crowded city.....

I would say around 75db to 85db and occasionally push it to 90db. I'm just wanting to move on from my tube amp and stumbled on the A7 review. I ordered the A7 (which will be here today) then I noticed they had a A5se with only 70watts per channel into 8ohms. I guess I'm just hoping it will sound better.

 

[john61ct]

The 48v 5a psu they bundle for 10 € (amazon difference vs. no psu) is from the same brand as the big one and also GaN.

Worth adding, resale value is higher so even if never needed

 

[john61ct]

I ordered the A7 (which will be here today) then I noticed they had a A5se with only 70watts per channel into 8ohms. I guess I'm just hoping it will sound better.

A7 is "better" IMO if priced the same, but I'm always chasing Watts.

If A5se is lots cheaper then that's a subjective judgment call

 

[Bernard23]

The 48v 5a psu they bundle for 10 € (amazon difference vs. no psu) is from the same brand as the big one and also GaN.

Amazon UK currently has the bundled version cheaper than the one without the psu, but that's because the bundled ones are used like new condition. I bought two of them and they look like they've not even been opened let alone used.

 

[Aimarketingbot]

Worth adding, resale value is higher so even if never needed

By the time you sell it a GaN psu will be common as mud and as cheap as they should be. 5A is enough for almost every use case.

I run a dual 3255 on 350W 48V/7.3A driving 200W 8ohm towers, they have enough for the peaks between capacitance in a decent PSU and the amp. It pushes 4x6" bass drivers at 89dB/W to x-mech with ease.

 

[Ruediger]

My point was to not order without that added psu because it is a good one for next to no money. A backup is never bad.

The 10a version has it's price everywhere.

 

[Bernard23]

By the time you sell it a GaN psu will be common as mud and as cheap as they should be. 5A is enough for almost every use case.

And hopefully GaN FET class D amps will be the new de facto standard, though they might not see the full benefit of the low cost of the FET devices pull through to the amp unit prices. That's after the new tech premium price wave has passed.

 

[john61ct]

The 10a version has it's price everywhere.

Costing more than most TPA3255 amps in fact.

 

[Ruediger]

I could swear it was different a week ago, but maybe it's my mind.

Price difference on amazon is 20 € no-psu vs. the 48v 5a GaN psu. Same thing for the A7 mono and stereo.

 

[Roland68]

And hopefully GaN FET class D amps will be the new de facto standard, though they might not see the full benefit of the low cost of the FET devices pull through to the amp unit prices. That's after the new tech premium price wave has passed.

GaN-FET power supplies definitely offer advantages, even if they aren't as significant when used for amplifiers compared to other applications.

But what advantages do GaN-FET amplifiers offer in audio applications?
1% better efficiency, perhaps?

 

[Bernard23]

GaN-FET power supplies definitely offer advantages, even if they aren't as significant when used for amplifiers compared to other applications.

But what advantages do GaN-FET amplifiers offer in audio applications?
1% better efficiency, perhaps?

They're huge. Much faster switching speed and almost no dwell time. Efficiency is greater than 1% too, more like 8-10% better. It's not inconceivable that you could have 500W+ per channel in a box the size of the A7 and it won't get overly hot.

 

[somebodyelse]

They're huge. Much faster switching speed and almost no dwell time. Efficiency is greater than 1% too, more like 8-10% better. It's not inconceivable that you could have 500W+ per channel in a box the size of the A7 and it won't get overly hot.

On paper maybe, but can you point to an actual amp showing these benefits?

 

[Roland68]

They're huge. Much faster switching speed and almost no dwell time. Efficiency is greater than 1% too, more like 8-10% better. It's not inconceivable that you could have 500W+ per channel in a box the size of the A7 and it won't get overly hot.

That just goes to show how easily people fall for marketing hype.
GaN FETs really shine in high-power—and, above all, constant-power—applications. And what is the one thing an audio amplifier *doesn't* have? Exactly: constant power output.
Furthermore, the advantages are usually cited in comparison to standard applications; yet amplifiers like the 325X series—as well as those from Purifi and Hypex—are already highly efficient switching amplifiers, operating at 90–93% efficiency.
On top of that, the operating parameters required for GaN FETs impose various design constraints.
Given these circumstances, a 1% efficiency gain over current switching amplifiers is actually substantial, while a 2% gain is pure fantasy.

There is a reason why none of the current manufacturers of GaN FET amplifiers show genuine efficiency measurements taken under real-world conditions in comparison to other switching amplifiers. They might not even be any better.

Which would you prefer: an amplifier optimized for audio reproduction, or one optimized for a specific technology?
Current GaN FET amplifiers don't convince me—partly due to reliability issues and their measured performance.
There will certainly be further, improved developments in the future, though the technology might well be overtaken by something else entirely.