3e audio A7/A7 Mono Amplifier Review

[ziggurcat]

Just to close the loop completely, and remove 100% doubt, I did try the A7 with my E50 DAC on my bedroom TV setup. The connection chain was:

Cable Box -- HDMI --> TV -- TOSLINK --> E50 DAC -- Balanced Out (TRS to TRS) --> A7

No issues whatsoever. As was expected based on information from the last series of tests. That's where the A7 is going to go, I think. Now it's fully a matter of what to do with my Mac, and how to mitigate the issue it's apparently causing, which I think is a problem for a different thread.

 

[howard416]

Appreciate your transparency throughout your troubles!

 

[Postlan]

Interesting but......

relative to what? which other similar amplifier are you relating it to for comparison?

As far as I could tell, the only other similar amplifier with similar performance is Topping PA7/PA7+ and A7 is relatively cheaper.


If the components are original or genuine, works fine and have performance that we are seeing then how does it matter what other brands are using?

Are you implying it uses sub-standard components with lower performance or life or ratings?

P.S. I know that you are knowledgeable but these comments aren’t helping.

You're completely forgetting about reliability. If the capacitors used here are just cheap Chinese fakes with a different label, they’ll almost certainly fail in a few years.

Given that it's been several years since Elna Silmic II was discontinued, it's not unreasonable to point out that this is likely the case.

 

[ziggurcat]

You're completely forgetting about reliability. If the capacitors used here are just cheap Chinese fakes with a different label, they’ll almost certainly fail in a few years.

Given that it's been several years since Elna Silmic II was discontinued, it's not unreasonable to point out that this is likely the case.

That was addressed months ago:

3e audio A7/A7 Mono Amplifier Review

Amirm: I suggest you contact either ELNA, MOUSER, DIGIKEY, FARNELL, TOPPING, or SMSL (your choice) to ask them this question ;) I don't need to do anything. You have to do your homework to prove the caps are fake. I ask again, are you confident that it is impossible to source these caps...

www.audiosciencereview.com

 

[Roland68]

You're completely forgetting about reliability. If the capacitors used here are just cheap Chinese fakes with a different label, they’ll almost certainly fail in a few years.

Given that it's been several years since Elna Silmic II was discontinued, it's not unreasonable to point out that this is likely the case.

And yet, that shouldn't matter at all and shouldn't affect the service life.

- These capacitors are only in the signal path as coupling capacitors and are subject to virtually no stress. Even cheap capacitors can easily last 25-30 years, and that's our experience, as counterfeit Silmics existed 25 years ago.
- Silmics have always been "labeled" standard capacitors, e.g., RJH, RFS, ARS, etc., sold for a high price as special audio capacitors.
- Often, the counterfeits contain much higher-quality (industrial) capacitors with significantly better measured values. Especially since the measurement technology for this is available to anyone for €15-40. Who complains about better products?
- 3E Audio will certainly have an incoming inspection and check such components for sufficient measured values. I prefer high-quality industrial capacitors to that Silmic nonsense.

 

[sebanow]

Question for A7 users, as I wait for mine to be delivered:

Which position of the volume bypass is which? I don't see any markings in photos on this thread, and it's not explained in the manual, as far as I can see. It would be better to know

Bought mine for $211+vat of 22%. There was a discount, maybe because of the tariff situation?

 

[ziggurcat]

Question for A7 users, as I wait for mine to be delivered:

Which position of the volume bypass is which? I don't see any markings in photos on this thread, and it's not explained in the manual, as far as I can see. It would be better to know

Bought mine for $211+vat of 22%. There was a discount, maybe because of the tariff situation?

The bypass on my unit was enabled, so I got a very loud jolt when I first set it all up because my D50 III is in DAC mode, which maxes out the gain/volume coming out of the DAC. With both devices at max volume, I nearly blew my speakers (I wouldn't be surprised if there was a little damage).

 

[harkpabst]

Question for A7 users, as I wait for mine to be delivered:

Which position of the volume bypass is which? I don't see any markings in photos on this thread, and it's not explained in the manual, as far as I can see. It would be better to know

Bought mine for $211+vat of 22%. There was a discount, maybe because of the tariff situation?

They are actually marked clearly (in theory) but it doesn't work out too well (in practice).

Many buyers seem to read the printing above the switch as "BYPASS VOL(ume control)" when it really means to say:
"BYPASS" [left position] and "VOL(ume control)" [right position]


You're not the only one. Sometimes I think that non-native speakers are less prone to fall for this. 3e Audio could probably improve this by changing the printing to something like:
BYPASS/VOL or BYPASS | VOL

 

[sebanow]

They are actually marked clearly (in theory) but it doesn't work out too well (in practice).

Many buyers seem to read the printing above the switch as "BYPASS VOL(ume control)" when it really means to say:
"BYPASS" [left position] and "VOL(ume control)" [right position]


You're not the only one. Sometimes I think that non-native speakers are less prone to fall for this. 3e Audio could probably improve this by changing the printing to something like:
BYPASS/VOL or BYPASS | VOL

Thanks! Now I get it.
Me thinks that this is a result of the other switch at the back labelled RCA GAIN, and that this switch uses two different lengths of markings. It would be much clearer, at least for me, if instead of using BYPASS VOL it used something like BYP . . VOL or BYPAS . . VCTRL, with wider spacing between the two.
Btw, I'm not a native speaker
Thank you again for your explanation.

Edit: using dots to avoid multiple spaces being compressed into just one.

 

[sebanow]

The bypass on my unit was enabled, so I got a very loud jolt when I first set it all up because my D50 III is in DAC mode, which maxes out the gain/volume coming out of the DAC. With both devices at max volume, I nearly blew my speakers (I wouldn't be surprised if there was a little damage).

Yeah, that's exactly why I've asked, because I've read your post.

 

[yavormoskov]

The bypass on my unit was enabled, so I got a very loud jolt when I first set it all up because my D50 III is in DAC mode, which maxes out the gain/volume coming out of the DAC. With both devices at max volume, I nearly blew my speakers (I wouldn't be surprised if there was a little damage).

I will receive the amp tomorrow. That's good information. I will pay attention. Thank you

 

[ziggurcat]

I know I've posted a lot about the A7 in my desktop system, and I might have found a configuration that "works." Under the following conditions, I have not been able to hear any popping from my normal seated position**:

D50 III DAC set to preamp mode in its settings menu. A7 volume bypass enabled. DAC is connected to the A7 via TRS. DAC is connected to my Mac Mini via USB-C. If I leave the DAC in preamp mode, and disable the A7's volume bypass, the popping becomes audible at the seated position once the volume knob on the A7 is at around the 9 o'clock position (or higher).

I know I have posted a lot of information about test conditions with the A7 amp in my desktop system, but I think I still need to understand why this configuration (mostly) doesn't exhibit the behaviour, while almost all other conditions results in those pops. I'm not blaming the amp, I just need to understand why.

**I don't hear any popping in the Right channel, but there's popping in the Left channel. It is not audible from my normal seated position, it is only audible if my ear is within 6 inches of the speaker drivers. This was not noticed in my last series of tests because I assumed that the popping was coming from both channels (which it is in every other instance), so I had only been listening for the pops on the Right channel.

 

[Roland68]

I know I've posted a lot about the A7 in my desktop system, and I might have found a configuration that "works." Under the following conditions, I have not been able to hear any popping from my normal seated position**:

D50 III DAC set to preamp mode in its settings menu. A7 volume bypass enabled. DAC is connected to the A7 via TRS. DAC is connected to my Mac Mini via USB-C. If I leave the DAC in preamp mode, and disable the A7's volume bypass, the popping becomes audible at the seated position once the volume knob on the A7 is at around the 9 o'clock position (or higher).

I know I have posted a lot of information about test conditions with the A7 amp in my desktop system, but I think I still need to understand why this configuration (mostly) doesn't exhibit the behaviour, while almost all other conditions results in those pops. I'm not blaming the amp, I just need to understand why.

**I don't hear any popping in the Right channel, but there's popping in the Left channel. It is not audible from my normal seated position, it is only audible if my ear is within 6 inches of the speaker drivers. This was not noticed in my last series of tests because I assumed that the popping was coming from both channels (which it is in every other instance), so I had only been listening for the pops on the Right channel.

As already mentioned, this is one of the most complex topics of all. Many experts and manufacturers have already bitten their teeth on it.
You can find some threads in the forum about ground problems and ground loops. You should also find plenty of information online, for example, at Rod Elliott/ESP.
It's also strange that you're having more problems with symmetrical cabling than with RCA/SE, but it could also be due to the higher gain.
You could also check the correct phase of your devices (power supply phase and neutral).
You could also try one of the tested high-speed USB isolators.

It would probably be better to explain this problem in a separate thread.

 

[ziggurcat]

As already mentioned, this is one of the most complex topics of all. Many experts and manufacturers have already bitten their teeth on it.
You can find some threads in the forum about ground problems and ground loops. You should also find plenty of information online, for example, at Rod Elliott/ESP.
It's also strange that you're having more problems with symmetrical cabling than with RCA/SE, but it could also be due to the higher gain.
You could also check the correct phase of your devices (power supply phase and neutral).
You could also try one of the tested high-speed USB isolators.

It would probably be better to explain this problem in a separate thread.

I'll do more searching, I guess. I am pretty certain that it has something to do with the higher gain. Apparently, I'm not the only one who has experienced this issue, though:

3e Audio A5 Stereo Amplifier Review

I planned on getting one from Amazon yesterday. Planning to use a RAW MDA1 for volume control. Ended up ordering a PA5 II instead. The turn off pop was a huge concern. My speakers are efficient, the tests indicated turn off pop is audible. Do you get a pop when turned off? The auto off was a...

www.audiosciencereview.com

That user had the same thing happen with an A5 amp, and posted about popping after they've paused/stopped audio (the link above is their response when I asked if it sounded like what I have experienced), so I at least know it's not completely unique.

If you have any recommendations on a USB isolator to try out, I'm all ears.

 

[harkpabst]

I'll do more searching, I guess. I am pretty certain that it has something to do with the higher gain.

To be clear about this:

The balanced inputs (XLR or TRS) has a lower gain than the unbalanced inputs (RCA). It's 20 dB for balanced and 26/29 dB (switchable) for single ended inputs.

 

[ziggurcat]

To be clear about this:

The balanced inputs (XLR or TRS) has a lower gain than the unbalanced inputs (RCA). It's 20 dB for balanced and 26/29 dB (switchable) for single ended inputs.

The input sensitivity is 1.75Vrms with SE, 3.5Vrms with Balanced, so that might factor into the equation?

 

[harkpabst]

The input sensitivity is 1.75Vrms with SE, 3.5Vrms with Balanced, so that might factor into the equation?

It's a strange case, so I won't rule out anything.

Balanced outputs are expected to put out twice the effective voltage compared to single ended. With a true balanced output the same signal is present on both hot wires, but with opposite polarity. The differential input stage will then - as the name implies - only amplify the differential signal and suppress any signal component in identical phase and magnitude (e.g. caused by RF interference, that affects both wires in the same way).

Should the signal source contain the noise, it's nature will be differential and there's nothing that could be suppressed.

I'm still struggling to understand how much of a Dela there is between stopping playback and the pop. Is is a tenth of a second? Or a couple of seconds? Is it always the same delay.or are there variations?

Good luck!

 

[ziggurcat]

It's a strange case, so I won't rule out anything.

Balanced outputs are expected to put out twice the effective voltage compared to single ended. With a true balanced output the same signal is present on both hot wires, but with opposite polarity. The differential input stage will then - as the name implies - only amplify the differential signal and suppress any signal component in identical phase and magnitude (e.g. caused by RF interference, that affects both wires in the same way).

Should the signal source contain the noise, it's nature will be differential and there's nothing that could be suppressed.

I'm still struggling to understand how much of a Dela there is between stopping playback and the pop. Is is a tenth of a second? Or a couple of seconds? Is it always the same delay.or are there variations?

Good luck!

In the audio file I provided -- and in every other test I've conducted -- there is about 1 second of a delay before the two pops occur after pausing/stopping. Every time.

Edit:

The main instances where it has changed was with an RCA connection. Looking at my original post with the RCA tests, I might have to do them again to nail down the details. I believe there were two pops with certain settings, but it is definitely different in that the tiniest, single tick happened in most of those tests, but you really do quite literally need to put your ear against the drivers to hear it. When I have time/energy I can repost clearer results of those test conditions. Then there's the condition of setting my DAC to preamp mode, and enabling the A7's volume bypass where no pops are in the right channel, but two fainter pops are in the left (the timing is exactly the same, though - around 1 second after audio has been paused/stopped).

 

[Punchy_Power_Cat]

3E Audio store on aliexpress has closed, no amp is buyable anymore? Does anyone know what is going on?

 

[Panelhead]

I was told that tariffs and shipping costs are making things hard for distributors. The true added costs are changing day to day.
Do not know if manufacturers are getting squeezed to make up the differences. From what I see prices to us have stayed constant. Someone is covering these costs.