3e audio A7/A7 Mono Amplifier Review

[Roland68]

The monos give around ~480W at 2ohm per Channel at the Same time, while the stereo gives max. ~ 240w at 2ohm per Channel at the Same time. As Long as you use the 48V 10A Power supplys.
So dont know of youre speakers need that much at 2ohm and the content needs it at the Same time, depends.
8 and 4 Ohm W should be identical +-10W, right?
Maybe better Channel seperation but the A7 stereo got already very good seperation.
Less Gear with the Stereo
EDIT: maybe the monos have better Heat dissaparion? Not shure about that.
Happy Christmas

Thanks!
And happy Christmas!

Please excuse me for disagreeing, but that's incorrect information.
The A7 and A7 Mono have exactly the same power output per channel across all impedances. Both amplifiers are built identically, but the A7 Mono is missing half of the stereo circuitry/components; technically, it's an A7 with only one channel populated.

Amir's measured power output per channel applies to both the A7 and A7 Mono.

 

[somebodyelse]

Please excuse me for disagreeing, but that's incorrect information.
The A7 and A7 Mono have exactly the same power output per channel across all impedances. Both amplifiers are built identically, but the A7 Mono is missing half of the stereo circuitry/components; technically, it's an A7 with only one channel populated.

Amir's measured power output per channel applies to both the A7 and A7 Mono.

The difference is in the power available from the PSU - whether it's all available to one channel or split between two. Whether it makes a difference will depend on the details of the test - how long does the power need to be produced for, what are the overload capabilities of the PSU etc. The 240W / 480W argument appears based on the nominal power output of the PSU so long term power output, but I'm suspicious the amps will run into heat issues - the mono again has an advantage here.

Will this matter in a real audio system? Probably not, except in an unusual combination of circumstances - like powering 2R subs during that ~5 minute sequence in Interstellar where the LFE runs near max output.

 

[Chaos01]

Yes, thats why i wrote "per Channel at the Same time"... The 48V * 10A = 480W Power supply is the Limit.

 

[TurtlePaul]

Yes, thats why i wrote "per Channel at the Same time"... The 48V * 10A = 480W Power supply is the Limit.

Realistically the difference is just about 140 watts per channel with a 40V10A PSU with stereo amp and just about 240 watts per channel with a mono amp on the same supply. With the 48V10A on the A7 mono, the limitation becomes the TPA3255 chip itself, which is not able to use 480 watts.

edit: it is actually hard to find a test with the A7 stereo and 48V10A supply, but the difference isn’t nearly double.

 

[Deleted member 88178]

So... for most case scenarios in a 20 square meter living room the stereo one is more than enough, right? even with speakers that dip down to 2Ω at certain frequencies, right?

 

[TurtlePaul]

So... for most case scenarios in a 20 square meter living room the stereo one is more than enough, right? even with speakers that dip down to 2Ω at certain frequencies, right?

Yes, my room is about this size and I have no trouble with the 48V5A power brick on an A7 stereo. The sensitivity of your speakers also matters. Another way to think about it is that 200 watts is enough to bottom out speakers with a single 5” or 6.5” woofer. Tower speakers with multiple large woofers per cabinet are required to actually reach peak power.

 

[SMen]

So... for most case scenarios in a 20 square meter living room the stereo one is more than enough, right? even with speakers that dip down to 2Ω at certain frequencies, right?

I think that I am correct in saying that voltage sets the ceiling - so it is 48V in both scenarios: mono or stereo. I could not vouch for all speakers but I think the answer is a simple 'yes' and @TurtlePaul has pointed out about the limitation being the chip itself ... with stupidly difficult speakers I am guessing that both the mono and stereo would cut out at the same time!

 

[SMen]

Yes, my room is about this size and I have no trouble with the 48V5A power brick on an A7 stereo. The sensitivity of your speakers also matters. Another way to think about it is that 200 watts is enough to bottom out speakers with a single 5” or 6.5” woofer. Tower speakers with multiple large woofers per cabinet are required to actually reach peak power.

So... for most case scenarios in a 20 square meter living room the stereo one is more than enough, right? even with speakers that dip down to 2Ω at certain frequencies, right?

I also got the 48V5A initially on Ali Express, and then later on got the 48V10A. I have absolutely no problems with the 5A and just luxuriate with the 10A placebo effect . The A7 is quite expensive on Audiophonics especially when available on sale on Ali Express ... so no harm in trying the 5A first either.

Post edit: actually just checked ... only during sale periods!

 

[GiBo61]

I also got the 48V5A initially on Ali Express, and then later on got the 48V10A. I have absolutely no problems with the 5A and just luxuriate with the 10A placebo effect . The A7 is quite expensive on Audiophonics especially when available on sale on Ali Express ... so no harm in trying the 5A first either.

Post edit: actually just checked ... only during sale periods!

You mean that in normal usage you do not feel a difference between the 48V 5A and the 48V 10A power supplies?

 

[TurtlePaul]

You mean that in normal usage you do not feel a difference between the 48V 5A and the 48V 10A power supplies?

The difference in PSUs is just a math problem. These class D amps with switching power bricks are pretty clean right up until they run out of power.

Here is the napkin math in my room:
87 dB/2.83V is the 1 meter sensitvity of F206 speakers
- 3 dB to convert 2.83V to 1 watt for 4 ohm speakers
+ 3 dB for two speakers (both channels driven)
- 9 dB because I listen at 2.5 - 3.0 meters
= 78 dB at my listening position with 1 watt per channel

Amir tested the e3 A5 with 38V5A PSU to reach 92 watts x 2 channels. log10(92 watts) x 10 dB/bel = 19.6 dB. An e3 A5 can reach 78 + 19 dB = 97 dB in my room.

In this review Amir tested an A7 mono with 52V9A PSU (468 watts) to reach 208 watts. log10(208) x 10 =23.2 dB. 78 + 23 =101 dB in my room.

A 48V5A PSU comes right in between at around 99dB in my room. For music with 14 dB dynamic range, I can play at 85 dB. I live in an apartment so reality is much below this.

 

[SMen]

You mean that in normal usage you do not feel a difference between the 48V 5A and the 48V 10A power supplies?

I never compared with a proper blind test or anything like that, so I think the best way for me to answer your question is to say that I never felt a lack of power with the 48V 5A. In fact the small form factor (it is significantly smaller than the 10A) would make it a sensible choice for many on those grounds. It is not at my location so I can't compare currently.

 

[somebodyelse]

I think that I am correct in saying that voltage sets the ceiling - so it is 48V in both scenarios: mono or stereo.

It depends in the impedance of the speakers. For speakers that don't drop much below 8R the voltage will be the limitation. For speakers around 2R the current will be the limitation.

 

[Urtica]

Hello,

I am considering using the 3e Audio A7Se with Wharfedale Linton 85th Anniversary speakers and would like to ask for advice.

The Lintons are rated at 6 ohms nominal, but measurements show impedance dips to around 3–3.5 ohms in the bass. The A7Se is specified as stable down to 4 ohms and offers high output power, but I am interested in real-world experience with this pairing.

The listening room is approximately 20 m², and listening levels would be moderate, with occasional louder sessions.

Do you think the 3e A7Se provides sufficient current, stability, and control for the Linton 85th in this room size?
Any practical impressions, measurements, or long-term usage experiences would be appreciated.

Thank you.

 

[ziggurcat]

Hello,

I am considering using the 3e Audio A7Se with Wharfedale Linton 85th Anniversary speakers and would like to ask for advice.

The Lintons are rated at 6 ohms nominal, but measurements show impedance dips to around 3–3.5 ohms in the bass. The A7Se is specified as stable down to 4 ohms and offers high output power, but I am interested in real-world experience with this pairing.

The listening room is approximately 20 m², and listening levels would be moderate, with occasional louder sessions.

Do you think the 3e A7Se provides sufficient current, stability, and control for the Linton 85th in this room size?
Any practical impressions, measurements, or long-term usage experiences would be appreciated.

Thank you.

It's probably fine, but you can get the A7 (not the SE version) with the 10a power supply, and be stable down to 2ohms if you really want to be sure.

 

[Urtica]

It's probably fine, but you can get the A7 (not the SE version) with the 10a power supply, and be stable down to 2ohms if you really want to be sure.

I bought a 3e A7Se to compare it with my vintage Sansui AU-D7. I’m curious to hear how a Class D amp performs in my setup. Honestly, when I ordered it on AliExpress, I didn’t even notice those last two letters


It’s already on the way, and I can’t wait to test it. I’m a little concerned about the 4 Ω – 16 Ω rating of the A7Se, though—hope it won’t be an issue.

 

[ziggurcat]

I bought a 3e A7Se to compare it with my vintage Sansui AU-D7. I’m curious to hear how a Class D amp performs in my setup. Honestly, when I ordered it on AliExpress, I didn’t even notice those last two letters


It’s already on the way, and I can’t wait to test it. I’m a little concerned about the 4 Ω – 16 Ω rating of the A7Se, though—hope it won’t be an issue.

It won't be an issue.

 

[peng]

Yes, thats why i wrote "per Channel at the Same time"... The 48V * 10A = 480W Power supply is the Limit.

Just minor technical point, 48 V*10A = 480 VA not 480 W. I don't like using watts for power amp outputs, but that's the way it has been for too long so it will never change I guess.

 

[peng]

I bought a 3e A7Se to compare it with my vintage Sansui AU-D7. I’m curious to hear how a Class D amp performs in my setup. Honestly, when I ordered it on AliExpress, I didn’t even notice those last two letters


It’s already on the way, and I can’t wait to test it. I’m a little concerned about the 4 Ω – 16 Ω rating of the A7Se, though—hope it won’t be an issue.

Just curious, why would you be concerned? The speakers are rated 6 ohms, 3.5 ohms minimum. The Sansui is not even rated for 4 ohm speakers but it should be fine with the Linton 85 as long as you don't push them to the limit, so if the Sansui amp has been doing fine for you, then the A7Se with the 48 V 10A PS should do even much better in terms of current delivery capability. The Sansui amp would like run warm because of the phase angle in the 65-180 Hz range so overall I would predict the little 3eA7e would be a better amp to use with the Linton 85.

You will enjoy the setup, and if you find it sounds not as good as the Sansui, then try to do blind listening comparison and the difference would likely disappear.

Wharfedale Linton 85th Anniversary Speaker Review

Wharfedale Linton 85th Anniversary Review

www.erinsaudiocorner.com

 

[Urtica]

peng, Thans for info.
A small correction: the power supply is the 48V / 5A version.


Overall, I am very happy with the Sansui, but I don’t really have a wide point of comparison. That’s why I decided to try a Class D amplifier.


To be honest, this was a bit of an impulse purchase, and I bought the 3e A7Se thinking it was the 3e A7. If it turns out that, in my conditions, there is no significant difference between them, then I unknowingly saved quite a bit of money

 

[NJ coffee roaster]

The B100 is actually class C with super massive negative feedback.

is it true that the negative feedback reduces dynamics etc?