3e Audio A5 Stereo Amplifier Review

[harkpabst]

The boards are definitely different. Even the amp configuration is. AFAIR, the 260-2-29A uses a single TPA3255, whereas the A5 uses dual 3251

Yep. Completely different layout. Different and supposedly superior output filter coils, too.

 

[capslock]

I guess we can compare the performance of the two now that Amir has tested both.

The coils are an interesting story. The PFFB should render differences insignificant, but it does not because there is not that much loop gain. Do we know if anyone has tried two pole compensation and the like to wrestle higher stable loop gain out of the chip?

 

[harkpabst]

The coils are an interesting story. The PFFB should render differences insignificant, but it does not because there is not that much loop gain.

If I remember correctly from the top of my head the original TI paper on PFFB shows the comparison of different coil types and the conclusion is: You can get the same performance out of cheaper coils or improved performance using the better coils. I would expect there to be further room for improvement over the reference design parts.

But as you say the improvement PFFB brings is noticeable but not earthshaking, due to limited open loop gain.

 

[Chaos01]

Any Updates on a A7 review?
But for me the Auto Trigger and missing 3,5mm headjack Trigger seems a Deal breaker...

3e Audio A7 [TPA3255 PFFB Stereo] Finished Amplifier - User Impressions | Owner's Thread

How was the volume of the A5 set when it switched off? You may try to reduce the volume on the A5 and compensate that with a higher volume on your source. This way, you have a better chance that auto On/Off will not trigger ... Hopefully ... BTW: I am still struggling whether to buy an A7 or...

audiosciencereview.com

There seems to be issues with Auto Off in Low Volume. My KefKF92 has also annoying Auto Off at low volumes. I would prefer a normal Trigger... :/

 

[Head_Unit]

Clipping indicators are provided for each channel.

OMG hallelujah! Finally! Haven't seen such in decades. I know the exact performance of the indicators (persistency and illumination etc) can be a rabbit hole but it's nice to be able to see if you are for instance into significant clipping. I kinda want to say if your amp never clips your speakers will 99.999% be fine...

What I would wish for is a more powerful version of this!
EDIT: I guess there are, even "480W" monoblock, I hope the price is still great...

 

[doc2c]

Did not work well for me. During gaming, it would auto-off on me, and when action happens it takes 2 seconds to turn on, completely ruining horror games. Rain and footsteps in games isn't enough to keep it on.

After some testing, I found that it will not auto-on with any frequencies above 4Khz.

Since there's no way to force the device on (unplugging and plugging power doesn't even work), it's unusable for me and I returned the device.

30 minute auto-off would have worked in this situation.

Did not work well for me. During gaming, it would auto-off on me, and when action happens it takes 2 seconds to turn on, completely ruining horror games. Rain and footsteps in games isn't enough to keep it on.

After some testing, I found that it will not auto-on with any frequencies above 4Khz.

Since there's no way to force the device on (unplugging and plugging power doesn't even work), it's unusable for me and I returned the device.

30 minute auto-off would have worked in this situation.

If you can clarify , is this with the A5 or the A7 ?
RCA or XLR ?

Thank you

 

[doc2c]

Does having 12v trigger connected bypass the faulty auto on-off on the a5/a7 that I’ve been hearing about

 

[Guddu]

Does having 12v trigger connected bypass the faulty auto on-off on the a5/a7 that I’ve been hearing about

Faulty?
It’s not faulty, it’s just to a lower level than some of the users need.

 

[doc2c]

Faulty?
It’s not faulty, it’s just to a lower level than some of the users need.

Whatever you want to call it.
we have users saying it turns off in quiet parts of games/movies. If you can’t bypass this behavior , I consider it a rather big oversight

 

[harkpabst]

Does having 12v trigger connected bypass the faulty auto on-off on the a5/a7 that I’ve been hearing about

There is no trigger input.

 

[howard416]

I wonder if a [crappy] workaround would be to inject DC on the signal.

Or even worse, run the interconnects alongside the power cord for a space heater, and put the space heater on a timer so that the 60 Hz EMI comes in (at a hopefully inaudible level lol)

@amirm can you show us photos of how the trigger input was implemented? Maybe we can figure out a way to add it to our production models ourselves.

 

[JuergenN]

You can see here (scroll down):
(the outside pictures are already without trigger, but the picture showing the PCB still has the trigger in the upper right corner)

3E AUDIO A7SE Amplifier

3E Audio, a recognized player in the DIY world, now offers a Class D Stereo amplifier incorporating audiophile Hi-Fi components. The A7se amplifier is based on a TI TPA3255 chips in BTL configuration, and two dual OPA1612A OPAs.

www.audiophonics.fr

 

[Chaos01]

When amirm had the Prototype A5 with a 12v Trigger to review, i am question now if this autotrigger could influence the thd, sinad and so on from the produktion model negative?

 

[harkpabst]

When amirm had the Prototype A5 with a 12v Trigger to review, i am question now if this autotrigger could influence the thd, sinad and so on from the produktion model negative?

If anything, I would expect the removal of the trigger input to improve the measurements.

Generally, this would be the last thing I would worry about when a pre-production sample has been reviewed ...

 

[JSmith]

It's really unfortunate TBH that 3e removed the 12V trigger... other amp companies have gone back to having a trigger in addition to auto on/off. For the same reasons a few have mentioned here... gaming and movies, where in quiet passages the unit is turning off.

3e should put it back for the next round of models... I think most would be happy to pay another $10 - $20 for this feature.


JSmith

 

[Bushellj]

You can see here (scroll down):
(the outside pictures are already without trigger, but the picture showing the PCB still has the trigger in the upper right corner)

3E AUDIO A7SE Amplifier

3E Audio, a recognized player in the DIY world, now offers a Class D Stereo amplifier incorporating audiophile Hi-Fi components. The A7se amplifier is based on a TI TPA3255 chips in BTL configuration, and two dual OPA1612A OPAs.

www.audiophonics.fr

If the socket for the 12volt trigger is still on the PCB it may be possible just to short out two of the pins to provide a permanent 12 volt trigger signal. This is of course if the functionality is still supported in the MCU software.

Maybe 3e Audio could confirm if this would be an alternative solution although it does of course require the user to open the box which for many users may not be desirable.

 

[somebodyelse]

It's really unfortunate TBH that 3e removed the 12V trigger... other amp companies have gone back to having a trigger in addition to auto on/off. For the same reasons a few have mentioned here... gaming and movies, where in quiet passages the unit is turning off.

3e should put it back for the next round of models... I think most would be happy to pay another $10 - $20 for this feature.


JSmith

Agreed. And if they make it more sensitive they will have complaints from other people about them never turning off, or turning on unexpectedly. There is no sensitivity that is correct for all situations unfortunately, which many other companies have run into when trying to implement automatic power on/off. An adjustable sensitivity should work for most people, but even then some with interference issues may have trouble finding an acceptable sensitivity. Some people need something like the trigger to override the automatic power control.

 

[harkpabst]

I think most would be happy to pay another $10 - $20 for this feature.

Honestly, not me.

... other amp companies have gone back to having a trigger in addition to auto on/off.

Not Fosi with their V3 Mono. I didn't follow what kind of problems people had with the sensitivity of these being to high, they just work as intended I both setups I tried them with.

The difference is that the V3 Mono have that three-way-switch, of course: On/Auto/Off.

 

[Angarato]

Aside from the 3e Audio A5/7 and the Fosi V3 Mono, are there many other amps with an auto on/off function within a similar price range?

In addition to that question, if someone wanted to build a system with DAC, headphone amp and speaker amp with 12V triggers, are there actually any DAC + headphone amp combos (2 devices or DAC with headphone amp) with 12V triggers for a reasonable price? Just looking at the DAC with headphone amps, the first one I can find is the Topping DX7 Pro+, which at €700 is far from cheap. Is there anything less than that? Combining a Topping L70 + E70 is only slightly less than that for example. How would you go about building such a system for a reasonable price?

 

[3eaudio]

If the socket for the 12volt trigger is still on the PCB it may be possible just to short out two of the pins to provide a permanent 12 volt trigger signal. This is of course if the functionality is still supported in the MCU software.

Maybe 3e Audio could confirm if this would be an alternative solution although it does of course require the user to open the box which for many users may not be desirable.

just share here
actually the components of trigger are not populated yet,so it is hard to do that,also making a hole on the back panel won't be so easy.
we do have a solution by remove 1 resistor to increase the sensitivity by 14dB,RCA down to 400uV and XLR down to 800uV,but this also need some skill of diy

3e Audio A7 [TPA3255 PFFB Stereo] Finished Amplifier - User Impressions | Owner's Thread

@3eaudio I found the Auto on/off feature of the A5 amp better than my SVS S1000 Pro subwoofer. When I set volume very low, my subwoofer goes to stand by, but amp remains on. For Sub, I use high level input using speaker out.

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