3e Audio A5 Stereo Amplifier Review

[chervokas]

There is something that users of the A7 or A7 Mono should be aware of. When using a 48V 10A GAN adapter, ground loop noise occurs when using the RCA input. The solution is to block the grounding port of the adapter’s power cable.

FWIW, I have an A7, use the RCA inputs from a subwoofer HPF, use a 48V 10 A GAN adapter, and have no ground loop hum or buzz. Might not be an inherent ground loop problem in the A7 or the power supply but something local to your signal/power chain.

 

[gaston312]

If I set 800 mVrms, it will sound even quieter...

Care to share what your speakers are? And also, what was your previous amp?

 

[SMen]

FWIW, I have an A7, use the RCA inputs from a subwoofer HPF, use a 48V 10 A GAN adapter, and have no ground loop hum or buzz. Might not be an inherent ground loop problem in the A7 or the power supply but something local to your signal/power chain.

There is something that users of the A7 or A7 Mono should be aware of. When using a 48V 10A GAN adapter, ground loop noise occurs when using the RCA input. The solution is to block the grounding port of the adapter’s power cable.

The power supply that 3e supplied (to me anyway) is two pin from the mains, rather than three.

 

[Mario_Primo]

Care to share what your speakers are? And also, what was your previous amp?

One more time.My speakers are 4 ohms,89 db,the recommended amplifier power is 150 watts. Before that, it was the Smsl ao300.

 

[harkpabst]

The WiiM Ultra's line output level can be set to either 500 mV or 800 mV in the settings. Yours needs to be switched to 800 mV.

Actually, 2 Vrms should be the best setting with the 23 dB gain setting. Also, bypass mode has nothing to do with it, the A5 doesn't offer more voltage, power or gain with bypass not enabled.

When I got my a5, I was surprised by its weak power.In bypass mode, my wiim ultra doesn't sound that loud at 100% volume. I should have bought an a7...

The A7 would have made little difference. The A5 is not low on power. 250 W over 150 W into 4 ohm just means 2.2 dB higher SPL.

Selectable gain on the A5 is 23 or 26 dB and on the A7 26 or 29 dB, so the A7 will sound slightly louder at the same volume setting on the Ultra, but not significantly.

If you're not getting the desired volume level with the Ultra set to 100%, check the following:

1. Is the Line Out Level of the Ultra set to 2 Vrms? It should be.
2. Is the Volume Limit of the Ultra set to a value lower than 100%? Only when using EQ (e.g. for rom correction) you should reduce the Volume Limit by 1 percentage point for each 0.6 dB of EQ boost. If you don't use EQ, just leave it at 100%.
3. What are your sources? The phono input is relatively low in level. Many TVs do never put out a signal close to 0 dBFS, so the TV input may also be very low. Old CDs or recordings used for streaming have a very big safety margin towards 0 dBFS. You can compensate for low level sources using the Pre-Gain feature, if you are sure the source level the reason for low sound. Compare the loudness to a source like the included Radio Paradise music service, even if you don't intend to listen to it later on. It's free and a good example of average loudness modern sources.
4. If you still don't get the desired SPL.from your speakers, set the gain switch to 26 dB.

 

[stigger]

Sorry for a yet another kind of off-topic question, but I don't really have a feeling for it, so here goes: A7 with the 48V5A power supply, subwoofer crossed over at ~80hz, Canton Ergo 690 DC speakers (4-8 Ohm, 88.3 dB at 2.83V/1m). Is it correct to assume that since the amp does not have to deal with the bass, there should not be any difference between the 48V5A and the 48V10A power supplies?

 

[Deleted member 72219]

Sorry for a yet another kind of off-topic question, but I don't really have a feeling for it, so here goes: A7 with the 48V5A power supply, subwoofer crossed over at ~80hz, Canton Ergo 690 DC speakers (4-8 Ohm, 88.3 dB at 2.83V/1m). Is it correct to assume that since the amp does not have to deal with the bass, there should not be any difference between the 48V5A and the 48V10A power supplies?

Correct.

-Ed

 

[Mario_Primo]

set the gain switch to 26 dB.

If I do this, will there be any audio degradation ?

 

[harkpabst]

If I do this, will there be any audio degradation ?

It's a tradeoff between gain and noise. Increasing the gain means a little more noise. Can you hear any noise even with your ear close to the tweeter? I doubt it.

Getting the gain structure right is the important thing. For every single stage get the output voltage as high as possible without over-driving the next stage's input. If you cannot get your speakers to play as loud as you want to with any change upfront, increasing the power amp's gain is the final step.

 

[Mario_Primo]

It's a tradeoff between gain and noise. Increasing the gain means a little more noise. Can you hear any noise even with your ear close to the tweeter? I doubt it.

Getting the gain structure right is the important thing. For every single stage get the output voltage as high as possible without over-driving the next stage's input. If you cannot get your speakers to play as loud as you want to with any change upfront, increasing the power amp's gain is the final step.

Okay, I get it.Thank you for the detailed answers, you helped me a lot.

 

[Roland68]

Okay, I get it.Thank you for the detailed answers, you helped me a lot.

However, to increase the volume, you always need to amplify the signal somewhere, whether in the device before the amplifier or in the amplifier itself.
Simply adding more power to the amplifier won't increase the volume.

 

[gaston312]

Ok, recently i got the A5. However, before plugging it i realized that they sent me the USA cord cable, which states 7a 125v. I bought the European plug, because i live in Uruguay and here we have the same sockets, and 220v outlets…. So, should I buy a new proper power cord? Or will it be fine if I use the 125v/7a one(using the socket adaptor for 250v)?
One thing I don’t understand is that the cable in itself states “…2x18awg 105 ºc 300V…” but the tip of the cable (the 8 shaped) states 7A 125V~…
If anyone can help, much appreciated!

 

[Alannn]

Ok, recently i got the A5. However, before plugging it i realized that they sent me the USA cord cable, which states 7a 125v. I bought the European plug, because i live in Uruguay and here we have the same sockets, and 220v outlets…. So, should I buy a new proper power cord? Or will it be fine if I use the 125v/7a one(using the socket adaptor for 250v)?
One thing I don’t understand is that the cable in itself states “…2x18awg 105 ºc 300V…” but the tip of the cable (the 8 shaped) states 7A 125V~…
If anyone can help, much appreciated!

2x18awg 105 ºc 300V is the rating for the insulated wire only.
The plugs at the ends have a lower rating causing the fully assembled cable to be rated at 7A 125V.
Definitely shouldn't have 220V applied.
There have been other reports of 3eAudio shipping the wrong cord. They simply need to now ship you the cord you ordered. Tell them.

 

[gaston312]

2x18awg 105 ºc 300V is the rating for the insulated wire only.
The plugs at the ends have a lower rating causing the fully assembled cable to be rated at 7A 125V.
Definitely shouldn't have 220V applied.
There have been other reports of 3eAudio shipping the wrong cord. They simply need to now ship you the cord you ordered. Tell them.

Ok thanks! So, with the Wiim Ultra it would be the same thing (I bought it from USA, the power cord also states 125v), I should get a proper cord for my voltage, right?
I have cables that are 250v and 2.5A, I don’t know if it will be enough amperage (specially for the A5 ac adapter, it says for input 3.5A)

 

[JeremyFife]

However, to increase the volume, you always need to amplify the signal somewhere, whether in the device before the amplifier or in the amplifier itself.
Simply adding more power to the amplifier won't increase the volume.

I thought I was getting my head around gain / volume / power ...

Why doesn't adding more power (all other things remain unchanged) increase the available amplification and hence volume?

 

[Roland68]

I thought I was getting my head around gain / volume / power ...

Why doesn't adding more power (all other things remain unchanged) increase the available amplification and hence volume?

Because it's only about the voltage used to drive the motor. That doesn't change, whether it's 10, 100, or 1000 watts.

It's just like the speed and power in a car. If you're driving at 3000 rpm in a certain gear, your speed won't increase even if you add 1000 horsepower.

 

[JeremyFife]

Because it's only about the voltage used to drive the motor. That doesn't change, whether it's 10, 100, or 1000 watts.

It's just like the speed and power in a car. If you're driving at 3000 rpm in a certain gear, your speed won't increase even if you add 1000 horsepower.

Thanks for the reply - unfortunately I'm still not getting it! Can you share the maths that demonstrates this?

 

[jlx]

Thanks for the reply - unfortunately I'm still not getting it! Can you share the maths that demonstrates this?

Because it's only about the voltage used to drive the motor. That doesn't change, whether it's 10, 100, or 1000 watts.

It's just like the speed and power in a car. If you're driving at 3000 rpm in a certain gear, your speed won't increase even if you add 1000 horsepower.

I'm not exactly clear of your meaning here as on it's face this is incorrect.
2 engines, 6Krpm redline, one is 500hp the other 1000 hp with all else equal.
for both engines with the same output power curve, at 3000 rpm = XX percentage of max available power
the 500 hp engine at XX% = Z hp output vs
the 1000 hp at engine XX% = 2Z hp (so double). Here the 1000 hp engine will output 2 times more than the 500hp for any given rpm.

back to amps
the A5 and the A7 have the same sensitivity as they both need 1.75Vrms input for maximum power output, so with .5V rms signal applied to both amps the wattage output for the A7 will be greater.
The problem is that it will only be a little increase as I think the A7 output power is only 2.2db greater. For reference 10db output= roughly ONLY a doubling of perceived volume increase. So a 2.2db output bump is audible but it is not much of an increase

simplified example (% of max output is made up and not actual as I'm too lazy to look them up or do the math)
A5 at .5V= 20% of max output, so let's say 150W x .20= 30W
A7 at .5V= 20% of max output , so let's say 250W x .20= 50W
so an increase of 2.2db or so for the A7. It's something but it isn't really that much

 

[SMen]

I'm not exactly clear of your meaning here as on it's face this is incorrect.
2 engines, 6Krpm redline, one is 500hp the other 1000 hp with all else equal.
for both engines with the same output power curve, at 3000 rpm = XX percentage of max available power
the 500 hp engine at XX% = Z hp output vs
the 1000 hp at engine XX% = 2Z hp (so double). Here the 1000 hp engine will output 2 times more than the 500hp for any given rpm.

back to amps
the A5 and the A7 have the same sensitivity as they both need 1.75Vrms input for maximum power output, so with .5V rms signal applied to both amps the wattage output for the A7 will be greater.
The problem is that it will only be a little increase as I think the A7 output power is only 2.2db greater. For reference 10db output= roughly ONLY a doubling of perceived volume increase. So a 2.2db output bump is audible but it is not much of an increase

simplified example (% of max output is made up and not actual as I'm too lazy to look them up or do the math)
A5 at .5V= 20% of max output, so let's say 150W x .20= 30W
A7 at .5V= 20% of max output , so let's say 250W x .20= 50W
so an increase of 2.2db or so for the A7. It's something but it isn't really that much

Thanks for the reply - unfortunately I'm still not getting it! Can you share the maths that demonstrates this?

So my stepped attenuator increments in .5db increments, as indeed does the digital volume control on my DAC.

So the difference is about 4 clicks on the attenuator ... or four presses on the DAC volume control. So something, but indeed not that much.

Someone will maybe chip in about how it all relates to speaker sensitivity! Mine are 90db so A5 a safe choice (for me).

 

[Roland68]

I'm not exactly clear of your meaning here as on it's face this is incorrect.
2 engines, 6Krpm redline, one is 500hp the other 1000 hp with all else equal.
for both engines with the same output power curve, at 3000 rpm = XX percentage of max available power
the 500 hp engine at XX% = Z hp output vs
the 1000 hp at engine XX% = 2Z hp (so double). Here the 1000 hp engine will output 2 times more than the 500hp for any given rpm.

back to amps
the A5 and the A7 have the same sensitivity as they both need 1.75Vrms input for maximum power output, so with .5V rms signal applied to both amps the wattage output for the A7 will be greater.
The problem is that it will only be a little increase as I think the A7 output power is only 2.2db greater. For reference 10db output= roughly ONLY a doubling of perceived volume increase. So a 2.2db output bump is audible but it is not much of an increase

simplified example (% of max output is made up and not actual as I'm too lazy to look them up or do the math)
A5 at .5V= 20% of max output, so let's say 150W x .20= 30W
A7 at .5V= 20% of max output , so let's say 250W x .20= 50W
so an increase of 2.2db or so for the A7. It's something but it isn't really that much

Exactly, and yet with both motors at the same rpm, the same transmission, and the same gear, you will reach exactly the same top speed. Neither will be faster, even if it has 10 times the power.

And that's exactly the apt example for the A5 and A7.
The input sensitivity is the same for both devices. But the internal gain (the amplification factor in the small-signal processing before the TPA325x) is 3 dB higher. And thus, the achievable volume can also be higher if enough power is available. This is also the correct approach by 3e Audio.
And back to the example above, with the A7, it's as if you shift up a gear = higher speed.