3e Audio TPA3251 TPA3255 Finished Amplifier with PFFB is coming!

[3eaudio]

A typical speaker produces 87dBSPL at 2.83V, 1m. 30mV is about -40dB from that, so about 50dBSPL depending on distance and room gain.
That is still a bit higher than I would like the threshold to be.
And then there are speakers with high sensitivity.

note it down.
the threshold we set is base on some lesson learn from V3 Mono that some people feedback it is too high sensitive, now any case are good for us to know different user's criteria and mitigated a better solution in the future.

 

[olieb]

note it down.
the threshold we set is base on some lesson learn from V3 Mono that some people feedback it is too high sensitive, now any case are good for us to know different user's criteria and mitigated a better solution in the future.

I understand, use cases are different. My guess is that V3 mono is might be too sensitive when volume is tuned down far enough, which will be the case most of the time. which can happen with volume control. But with a volume bypass it is different. So either you could make the sensitivity adjustable or better still, make an off - auto - on switch (or a 12V trigger).

 

[harkpabst]

Just for the records: In my view the auto sensing sensitivity of the V3 Mono is just perfect (low gain RCA inputs) for what they are, mono power amplifiers, not desktop toys. Personally I wouldn't eve mind if some noise or pops turns them on in error. Doesn't happen in my use case.

I hope the A5 will allow low level listening in a typical home HiFi environment.

Edit:
And I agree with @olieb that an off - auto - on switch would be best.

 

[SMen]

@3eaudio I'd like to know when you are going to get in more monos ... without obligatory power supplies
Happy Christmas all.

 

[pieterv1]

off - auto - on

Maybe it could be:

Off (or 12v trig) - auto - on

Or just entirely bypass the three way power mode switch when a 12v trigger jack is inserted.

 

[shilent]

I'm trying to deal with the low sensitivity Auto-on, but I now find the Auto-off a problem. If I'm watching something then pause to use the bathroom or make a snack, I come back with no audio for a few seconds and have to rewind every time. It's a huge inconvenience.

I think the Auto on/off design was only with music in mind, I don't have an issue there. Looks like I'll have to return.

 

[Piotr]

Well, the good old, seasoned members were saying that the 12V trigger is the best, most solid option, but their voices were not heard. Often, the simplest, battle-tested solutions work best.

I understand the inclusive, greedy attitude because, in theory, it could lure marketing people to sell more products, but this is not the way.

The way is to funnel the community into buying a DAC with a trigger.

Anyways, my piece just landed . I think it will take a few days before it reaches my house. Enjoy Christmas time!

 

[harkpabst]

I am seasoned and I definitely don't like trigger cables and the additional hum potential they bring.

I ln particular for a power amp, always on and a switched power strip is all I need. Auto on comes as a bonus.

 

[MCH]

Just for the records: In my view the auto sensing sensitivity of the V3 Mono is just perfect (low gain RCA inputs) for what they are, mono power amplifiers, not desktop toys. Personally I wouldn't eve mind if some noise or pops turns them on in error. Doesn't happen in my use case.

I hope the A5 will allow low level listening in a typical home HiFi environment.

Edit:
And I agree with @olieb that an off - auto - on switch would be best.

The problem with the Fosi if I remember correctly, please correct me if I am wrong, was that some members reported the power consumption while in auto stand by mode was almost as much as when on, so why bother... I hope here it is a real, low power consumption stand by.

 

[Inertiaman]

As many of us feared, the auto-on/off implementation has problematic quirks. It seems like most of the problem cases could be mitigated with a 20-30 minute period rather than a 5 minute period. Still not as deterministic/reliable as 12V trigger, but would seem to resolve many of the initial complaints above, and at a very small "cost" (= a few watts a few times per day).

I don't know the specific sense/switch subsystem in the e3 amps, but surely its easily configurable to different time periods?? Although unfortunately I don't imagine a way to retrofit in the field.

 

[somebodyelse]

note it down.
the threshold we set is base on some lesson learn from V3 Mono that some people feedback it is too high sensitive, now any case are good for us to know different user's criteria and mitigated a better solution in the future.

As others have found before, there isn't a sensitivity or timeout period that works well for everybody. You could make it adjustable, but that confuses some people too.

 

[Piotr]

There are too many variables: sensitivity threshold, auto-off period, standby power usage, and switches. It seems it would be wise to at least have the option to disable the auto power-off feature / eventually postpone by 1h.

Can also be solved by instant power on / no pop noise / no delay - likely super challenging if possible.

 

[Joe0429]

I am seasoned and I definitely don't like trigger cables and the additional hum potential they bring.

I ln particular for a power amp, always on and a switched power strip is all I need. Auto on comes as a bonus.

A 12V trigger must always be electrically isolated.
Traditionally, relays were used (hence the 12V requirement).
Modern approaches employ optocouplers, allowing for lower operating voltages (e.g., 5V) in some devices.
If a 12V trigger function produces a humming noise, it is almost certainly a manufacturing defect.

 

[howard416]

My A5 arrived today and not more than about 15 minutes in, it starts making a randomly-occurring staticky popping noise. Happens just once or twice every now and then, and sometimes it just does machine-gun popping multiple times a second. It is also is very loud and also is not proportionate to the level of the input signal.

Update: left channel died (other than the popping noise). 3e audio reached out to me for support so let's see how this goes.

 

[3eaudio]

The problem with the Fosi if I remember correctly, please correct me if I am wrong, was that some members reported the power consumption while in auto stand by mode was almost as much as when on, so why bother... I hope here it is a real, low power consumption stand by.

correct,this is a REAL LPS mode which is <0.5W

 

[fiercekid84]

Update: left channel died (other than the popping noise). 3e audio reached out to me for support so let's see how this goes.

sorry to hear that. hopefully 3eaudio has good after sales support which is very importance for every company.

 

[3eaudio]

There are too many variables: sensitivity threshold, auto-off period, standby power usage, and switches. It seems it would be wise to at least have the option to disable the auto power-off feature / eventually postpone by 1h.

Can also be solved by instant power on / no pop noise / no delay - likely super challenging if possible.

want to cycle back here after discuss with our engineer.

1. the Auto on/off is can't be remove as it is FW set inside the MCU.
2. the sensitivity can be adjust but need one modification on the board which require diy experience,i will share more detail once they verified.
3. our original purpose with auto on/off is to mitigate trigger function and No-trigger DAC(still many of user own old device),and also the thermal issue complaints of TPA3255 is considered.

 

[fiercekid84]

want to cycle back here after discuss with our engineer.

1. the Auto on/off is can't be remove as it is FW set inside the MCU.
2. the sensitivity can be adjust but need one modification on the board which require diy experience,i will share more detail once they verified.
3. our original purpose with auto on/off is to mitigate trigger function and No-trigger DAC(still many of user own old device),and also the thermal issue complaints of TPA3255 is considered.

for the the thermal i have change to the paste i use on my computer kingpin KPX. works well.

 

[phoenixsong]

Update: left channel died (other than the popping noise). 3e audio reached out to me for support so let's see how this goes.

Slightly concerning- mine has also experienced interruptions 4x so far (sounds akin to playing bad vcds that get stuck but eventually resume playback). We'll see how it goes

 

[fiercekid84]

Slightly concerning- mine has also experienced interruptions 4x so far (sounds akin to playing bad vcds that get stuck but eventually resume playback). We'll see how it goes

popping noise by bad source should be ok. if popping noise by the amp itself without connecting to a source should be concerning