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

Did / could anyone test, how the A5/A7 reachts if it is connected to a switchable power supply?
If you switch off power with the amp being "on", will it then restart when power is switched back on?

Thanks - that is cool.

I my case, the Wiim Ultra will not reliably toggle a Master - Slave power strip, as the difference in power consumption between Standby and On is too low.

In cases where the auto On/Off of the A5/A7 does not work reliably, you could then use the 12V trigger of the source and connect that to a power switch, for example this: https://www.audiophonics.fr/en/diy-...v-230v-slave-power-supply-device-p-10661.html

thanks
Juergen

Basically A7 retains its state through main power ON/Off cycle.
If its in standby then it would retain standby state when mains is powered OFF and then powered ON. Likewise, if it is powered ON and then mains power is OFF and ON then it would retain to powered ON state.
I have smart plug on the main power for it and it has always worked like this without any failure.
On the other hand, I also had ZD3 DAC which always comes ON when mains id powered ON which annoyed me too much being on the same power distribution.
 
2 - 4 mV is too much. My amp with audio sense has a sensitivity of less than 1mV and works perfect for me, even to watch movies. The designer (member of ASR) says though that was not easy to make it so sensitive and avoid other issues like getting triggered when you switch on another appliance etc. like some claim the fosi do.
The Fosi v3 monos do switch on with light switches sometimes for me, but I would prefer that. Solution is indeed an off/on additional option.
 
Basically A7 retains its state through main power ON/Off cycle.
If its in standby then it would retain standby state when mains is powered OFF and then powered ON. Likewise, if it is powered ON and then mains power is OFF and ON then it would retain to powered ON state.
No, it should actually not retain its previous state but always start in power ON mode when applying the mains power. That's how @3eaudio explained it and that's how it works with my A5 (just tested one of them).
 
No, it should actually not retain its previous state but always start in power ON mode when applying the mains power. That's how @3eaudio explained it and that's how it works with my A5 (just tested one of them).
I just have A7 (stereo), so can only tell what I see on this one.
Personally, I think it's doing what it should because it would power up (auto-ON) if the audio signal is coming in when the mains power comes up.
If there is no input audio signal then it being retaining standby state on mains power ON isn't bad in my view.

On the other hand, if @3eaudio says it should power up when mains power is switches ON no matter what was previous state then I am seeing and reporting different operation.

P.E. @harkpabst - Is your input signal ON when you are testing this? What if your input signal is OFF while testing the state on mains power switched ON?
 
Hey, my 2 A7 monos (vol bypass, -<XLR -<fosi ZD3) also have the same unwanted behavior of switching off at lower listening levels (still reasonable) that I need and want to be able to use. Not absolute levels of course but switching off at ZD3 vol setting 28-35 depending on input (speakers spec'd 88 db/w). Also disappointed with this, particularly as they sound very good when they are on -- but I've had to remove them from my system.
In your setup one solution (at least for now) would be to disable volume bypass and slightly reduce the volume on the A7 Monos for such low level listening sessions. Not perfect, but it will work. THD+N might increase slightly with bypass disabled, but not down in this low power range. Even if it did, you wouldn't be able to hear the difference.

I just have A7 (stereo), so can only tell what I see on this one.
Personally, I think it's doing what it should because it would power up (auto-ON) if the audio signal is coming in when the mains power comes up.
If there is no input audio signal then it being retaining standby state on mains power ON isn't bad in my view.

On the other hand, if @3eaudio says it should power up when mains power is switches ON no matter what was previous state then I am seeing and reporting different operation.

P.E. @harkpabst - Is your input signal ON when you are testing this? What if your input signal is OFF while testing the state on mains power switched ON?
That's interesting. My A5 definitely comes up ON, regardless of the previous state. I was referring to this post, back in November:

amp will power on from OFF state when AC power provided(the idea here is to eliminate user manual press the power key again if he want to use it, either it will auto off if just leave there don't use it ) ,auto audio sense on off is for standby state and On state,sorry for the confuse,hope this is clear for you @Inertiaman

Doing all that with an analog circuit is quite a challenge. Low power uC with some proper analog front end is much more convenient and may even result in lower BOM cost.
According to @3eaudio the A5/A7 amps do employ an MCU. They should be able to make changes at least to newly produced units rather easily. I agree it won't be able to find one solution that fits everybody's needs.

It's probably mostly the standby power off threshold that would benefit from some tweaking.
 
@harkpabst
Personally, I think it's doing what it should because it would power up (auto-ON) if the audio signal is coming in when the mains power comes up.
If there is no input audio signal then it being retaining standby state on mains power ON isn't bad in my view.
Correction after some more testing
I just tested specifically tested this and A7 does not come UP when mains power is turned ON even if audio signal is coming in. So it has to be turned ON with potentiometer after a mains power cycle when previously in standby state.
If this isn't how it is supposed to work and other A7 units are operating as powered ON after mains power cycle then it might just be some setting with my pre-production unit.
 
@Guddu can you please try this:

  1. un-plug AC when unit is on, this is to make sure there is any no power existing the unit to maintain MCU still in On status
  2. then re plug AC power then the unit should will auto on.
the auto power on only happen when unit is in previous OFF status, not standby.
 
@Guddu can you please try this:

  1. un-plug AC when unit is on, this is to make sure there is any no power existing the unit to maintain MCU still in On status
  2. then re plug AC power then the unit should will auto on.
Yes, it works this way. I mentioned is earlier as well that it powers on if the main the off while it was powered on previously.

the auto power on only happen when unit is in previous OFF status, not standby.
1) I powered off the unit by potentiometer and then removed power from wall socket. After plugging the cable back, it doesn’t power up automatically if I do it within a minute.
If I wait for few minutes before plugging it in then it powers up automatically.


2) If A7 goes to standby and then I power off from mains, then it doesn’t come back up automatically if powered on within a minute, just like above case.
Only option is to power ON by potentiometer.
However it powers up automatically if I wait for longer before power on from mains.

So I think we can conclude that it’s working as it is supposed to?

*** correction made after a few tests on standby mode
 
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that is normal because there still power existing for the MCU until 2-3 minutes roughly, there are big capacitors on both unit and power supply and also the MCU consume very little energy in standby mode.
 
that is normal because there still power existing for the MCU until 2-3 minutes roughly, there are big capacitors on both unit and power supply and also the MCU consume very little energy in standby mode.
I made correction on standby test statement above.
It powers ON automatically even when I power off from mains when it’s in standby mode but if I wait for few minutes before plugging power back in.

So it’s basically the residual power that’s coming in play.
 
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I made correction on standby test statement above.
It powers ON automatically even when I power off from mains when it’s in standby mode but if I wait for few minutes before plugging power back in.

So it’s basically the residual power that’s coming in play.
Thanks for all the testing.
So it looks we found an alternative for the missing 12V trigger.
Still, I would prefer the trigger.
@3eaudio : please check whether you can add the 12V trigger again for the next batch of units.
It would help a lot of people, and it would not hurt anyone who doesn't need it.

thanks
Juergen
 
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My two SY-DAP2002x are collecting dust as I cannot defeat the ASB. The SigmaStudio files for ASB can't be found online, and the ones I found will compile but no sound output...

So I was looking at this amplifier which looks great, just to find that it also has the same ASB :(

I need my power amplifier to stay on at all times! Please give us an option to defeat ASB :)
 
What happens when it's not?

There is no sound coming to my tweeters as I'm running an active setup.
Since the amp goes to standby when plugged in, I have to power it on manually. For it then to power off despite the user not triggering the power off, is too bad.
 
There is no sound coming to my tweeters as I'm running an active setup.
Since the amp goes to standby when plugged in, I have to power it on manually. For it then to power off despite the user not triggering the power off, is too bad.
Finding a modern device with no auto off will be rather hard. A trigger input would just hand over the responsibility for auto off up the chain. As long as a small company like 3e Audio has no plans to sell separate versions for countries where low poser standby is not legally required I don't see much hope for your request.

The A5/A7 series amps are not a direct replacement for the SY-DAP2002 anyway, you would need an external DSP. They do feature auto on, though.
 
Finding a modern device with no auto off will be rather hard. A trigger input would just hand over the responsibility for auto off up the chain. As long as a small company like 3e Audio has no plans to sell separate versions for countries where low poser standby is not legally required I don't see much hope for your request.

The A5/A7 series amps are not a direct replacement for the SY-DAP2002 anyway, you would need an external DSP. They do feature auto on, though.

Yeah the trigger would definitely be another way to do it. Perhaps I'll just have to design and buy a passive crossover so I don't have to have separate amps for woofers/tweeters, haha :)
 
3e Audio,
Is it possible next time to make a finished amplifier that would be easily upgradeable? So, when in future your company releases a next generation electronic board, we users would just buy this board alone and replace it in the amplifier ourselves without the need to buy the finished amplifier again.
Is it possible to do so?
 
Folks, my A5 is switching off automagically when I listen at night. Wiim Ultra volume level is at 10, and this is already triggering the auto-off mechanism. :/

A bit disappointing, TBH.
The problem is that it works with loudspeakers with a medium efficiency, but not with horn loudspeakers.
You want to listen more quietly and you can't. This is extremely annoying and a reason for me not to order the 3e products in their current form.
I once had the problem with the automatic switch-on and switch-off with a Yamaha subwoofer. Quiet listening was not possible there either and there was a volume range in which it switched on - switched off - switched on, etc. Horror
In general, I'm not a fan of an automatic system if it works in an area that I prefer to control myself, regardless of whether it's an amplifier or an automatic program on a camera.
If you can switch off the automatic and choose to set it manually, it's OK.
If not, it's a problem.
 
In your setup one solution (at least for now) would be to disable volume bypass and slightly reduce the volume on the A7 Monos for such low level listening sessions. Not perfect, but it will work. THD+N might increase slightly with bypass disabled, but not down in this low power range. Even if it did, you wouldn't be able to hear the difference.


That's interesting. My A5 definitely comes up ON, regardless of the previous state. I was referring to this post, back in November:




According to @3eaudio the A5/A7 amps do employ an MCU. They should be able to make changes at least to newly produced units rather easily. I agree it won't be able to find one solution that fits everybody's needs.

It's probably mostly the standby power off threshold that would benefit from some tweaking.
Hi, thx for taking the time to reply and offering your suggestion. I can see that thus would work but using the A7 monos vol bypassed as poweramps was the appeal in getting them and I'd rather not have to manually level-balance the 2 channels.
 
The preferred solution would be, obviously IMHO:
- physical power switch (even though one would ideally cut off the power to the SMPS brick for a real off state).
- standby/operate switch with several positions, on / off / 12-Trigger / signal-detect, the latter maybe with 2 or 3 different sensitivities.
 
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