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

Digiface support was added to linux in kernel 6.12. Android might catch up in a release or two, but there's still every chance manufacturers won't include the driver for such an unusual device.
It's funny, it's 'an unusual device' and yet potentially so darn useful when you don't want a big cinema receiver with a stack of RCA outs.
 
Unfortunately both units are defective or at least they do not operate in my system.....

When I connect them to my DAC the signal gets dropped out intermittently with a really loud popping noise
I tried with RCA connection (both low gain and high gain), XLR connection, volume bypass, etc.
Then I tried with a different amp and my system just works fine
The issue is only happening with the two A7 Mono amps

See a video about the issue here:
You can see that the signal is intact (DAC showing sample rate) and when the amp is switched on the signal gets dropped out

Now let's see the same with my Fosi V3 Mono amp:
No issues, works perfectly

I have opened a ticket with Audiophonics, let's see.....
I am really disappointed I have to say
@3eaudio for your information, not sure if you have seen this type of issue before
 
Unfortunately both units are defective or at least they do not operate in my system.....

When I connect them to my DAC the signal gets dropped out intermittently with a really loud popping noise
I tried with RCA connection (both low gain and high gain), XLR connection, volume bypass, etc.
Then I tried with a different amp and my system just works fine
The issue is only happening with the two A7 Mono amps

See a video about the issue here:
You can see that the signal is intact (DAC showing sample rate) and when the amp is switched on the signal gets dropped out

Now let's see the same with my Fosi V3 Mono amp:
No issues, works perfectly

I have opened a ticket with Audiophonics, let's see.....
I am really disappointed I have to say
@3eaudio for your information, not sure if you have seen this type of issue before

I have disconnected everything, reconnected everything and now it seems to be working fine. This is really strange, I have never experienced anything like this before.
Tomorrow I will keep it on for the whole day and see what's going to happen

One other thing I have noticed: the amp keeps switching itself off
Can that be turned off? It is freaking annoying - it might actually render the amp useless if I need to stand up every 3 minutes, walk to the amp and turn it back on manually....
 
I have disconnected everything, reconnected everything and now it seems to be working fine. This is really strange, I have never experienced anything like this before.
Tomorrow I will keep it on for the whole day and see what's going to happen

One other thing I have noticed: the amp keeps switching itself off
Can that be turned off? It is freaking annoying - it might actually render the amp useless if I need to stand up every 3 minutes, walk to the amp and turn it back on manually....
Tomorrow, to keep them on, you will need to be playing something on repeat or they will switch off. Totally agree about an always on option. I've a Topping that kept on switching itself off and I had to fall back on that. Fosi Monos have always on option too ... though they click on with signal and only seem to click off with silence after 10 mins.

Hopefully you will get away with a low signal keeping them on ...
 
Tomorrow, to keep them on, you will need to be playing something on repeat or they will switch off. Totally agree about an always on option. I've a Topping that kept on switching itself off and I had to fall back on that. Fosi Monos have always on option too ... though they click on with signal and only seem to click off with silence after 10 mins.

Hopefully you will get away with a low signal keeping them on ...
I am afraid not..... the product simply cannot be used like this
They keep turning off every few minutes

I will need to send them back unless this 'feature' can somehow be turned off - this is definitely a showstopper for me
@3eaudio can you please let me know how this really annoying auto-off can be turned off?
Thank you
 
I want to know what is the relationship of the ready made models with the older, previous DIY boards ?
For ex. A7 mono vs 3E Audio 480-1-29A ? Which is better in terms of technical solution ?
 
The other thing I have noticed: the amp keeps switching itself off
Can that be turned off? It is freaking annoying - it might actually render the amp useless if I need to stand up every 3 minutes, walk to the amp and turn it back on manually....
Hate to bring it to you, but this feature/bug has been one of the main topics of discussion here. There has been talk of a diy solution to increase the sensitivity, but otherwise I'd suggest to return it while you can and wait for an updated model.
 
Hate to bring it to you, but this feature/bug has been one of the main topics of discussion here. There has been talk of a diy solution to increase the sensitivity, but otherwise I'd suggest to return it while you can and wait for an updated model.
I have missed that...... o_O:rolleyes:
This is so annoying....

Isn't there a jumper inside that could turn off this auto-off 'feature'? Or simple soldering? I am happy to do that, not worried about losing the warranty
 
I have missed that...... o_O:rolleyes:
This is so annoying....

Isn't there a jumper inside that could turn off this auto-off 'feature'? Or simple soldering? I am happy to do that, not worried about losing the warranty
If I understand correctly, it involves the removal of one (SMD) resistor, but I have not yet seen detailed instructions. Warranty would be my main concern actually. As good as the amps might sound, we're still a bit early in the lifecycle of the amps and their longevity is still a bit of an unknown. Granted, 3E's amplifier modules have been out there for quite a while now, without any issues it seems.
 
I have missed that...... o_O:rolleyes:
This is so annoying....

Isn't there a jumper inside that could turn off this auto-off 'feature'? Or simple soldering? I am happy to do that, not worried about losing the warranty
Contact 3e, I've had a bit of an email conversation with them and they have sent me details of a solution for the A7 monos of desoldering a resistor that will change the sensitivity of the auto on/off sensor. I havn't got myself organized/psyched up to try it yet with my amateur solder skills. I'd rather not have to do this but the A7 monos are not really usable as they are.
 
Contact 3e, I've had a bit of an email conversation with them and they have sent me details of a solution for the A7 monos of desoldering a resistor that will change the sensitivity of the auto on/off sensor. I havn't got myself organized/psyched up to try it yet with my amateur solder skills. I'd rather not have to do this but the A7 monos are not really usable as they are.
Thank you, I am already in discussions with him
In the meantime I have got some advice from @Audiophonics too, will try that also
I will post my findings here
 
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Thank you, I am already in discussions with him
In the meantime I have got some advice from @Audiophonics too, will try that also
I will post my findings here
OK I think this issue is resolved, at least in my case
I have received the following advice from @Audiophonics

- turn off Volume Bypass (to enable volume control on the amp)
- set the volume on the amp to 10 hours
- increase the input signal to match the SPL to how it was with the volume bypassed (in my case I had to add 15dB to the sub channels in Jriver)

It works fine, the amps do not shut down even at low volume
I also checked with some movies, I am still fine with regards to digital headroom/clipping

Not sure if others can do the same but it works fine for me - I am really glad to be honest
The amps run so cool btw that I cannot believe it! All my other PFFB amps (A30A, PA7 Plus, V3 Mono) run so hot that I apply active cooling to them but the A7 Monos stay cool all the way!
 
OK I think this issue is resolved, at least in my case
I have received the following advice from @Audiophonics

- turn off Volume Bypass (to enable volume control on the amp)
- set the volume on the amp to 10 hours
- increase the input signal to match the SPL to how it was with the volume bypassed (in my case I had to add 15dB to the sub channels in Jriver)

It works fine, the amps do not shut down even at low volume
I also checked with some movies, I am still fine with regards to digital headroom/clipping

Not sure if others can do the same but it works fine for me - I am really glad to be honest
The amps run so cool btw that I cannot believe it! All my other PFFB amps (A30A, PA7 Plus, V3 Mono) run so hot that I apply active cooling to them but the A7 Monos stay cool all the way!
I will try to see if it works for me to make this absolutely great otherwise power amplifier with high end external PSU works also at "really late night volume" thank you so much!!
 
@3eaudio when do you think the 2nd batch prod for A7 should be ready for retailers ?
 
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