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

[Le son des cimes]

Some more feedback after one week having the A7 in my setup.
The amp has been playing flawlessly at all kind of volumes, from late night wispers to houseparty levels: I already mentioned that I was pleased with low level listening behavior, and I discovered during the week that high volume playing with the A7 is even more satisfying because it induces no fatigue. I can just crank up the volume, and no nasty distorsion shows up,
What I like about the amp overall is that it has... no "sound" ! It is transparent, and just provides juice and control to the speakers when and where they need, without being the limitating element in hte chain. This is the first time I have such an amp in my system, and it is beautiful !
Cherry on the cake, I have run a fresh Dirac room calibration using the minidsp Flex, and the A7 is nicelly capable of filling the dips and taming the bumps in my room, and I get an in-room frequency response that is almost textbook, with a gently log-decaying dB vs frequency curve, which I could not achieve with my previous ARCAM amp. Fingers crossed for long term durability, but right now I am a happy man !

 

[antcollinet]

of course I'm not able and willing to argue against the qualified engineers here! I simply wonder why so many different equivalent OPAMP's are on the market? please give me a qualified hint.

For exactly the same reason that there are a million audiophile cables available. Snake oil sales for the scientifically ignorant obsessive audiophile.

Plus - line level audio is not the only application for op amps. Every single analogue application on (or off) the planet - from temperature sensors in washing machines to control, imaging, and comms systems on the James Webb space telescope use op amps. Many of those applications do need significantly different characteristics.

But line level audio frequency in an audio amp is amongst the most trivial applications of op amps there are. Those "fancy" discrete types aimed at specifically audiophiles *are* just the same snake oil as those million cables.

 

[SMen]

I think that the threshold with op amps is low. What I mean by that is that you would need to start with a pretty bad op amp!
I'm delighted my A5 came with TI OPA1656 ... but this is because 3e provided measurements for a number of alternatives - and for me it shows care in the overall design. They had no need to go with a 3251 either ...

I'm pretty sure I heard oscillation (or something like that) with Muses 02's in the Fosi v3 Mono ... so this seemed cynical to me. I'm pretty sure a jfet I preferred some time ago in another unit was because of where it slotted next to a volume control. But other than that I have not heard a difference - or so small I would have no idea if it was real or imagined.

Michael Fidler gives strong reasons (at length) for his choice of 5534 opamp as a front-end, followed by 5532 in his MM Pro and his active loading design.

This is what I want to hear ...

I don't have experience of Hypex or Purify etc. but while also extremely transparent, what comes through my A5 sounds natural as well as transparent. I will get to compare with my Fosi V3 monos in a few days.

Thank heavens for user impressions threads here!!

 

[antcollinet]

Michael Fidler gives strong reasons (at length) for his choice of 5534 opamp as a front-end, followed by 5532 in his MM Pro and his active loading design.

Phono pre-amps and Mic pre-amps are probably the only audio applications that have more stringent requirements than the line level circuits used on power amplification. This comes from the very high gain required, hence noise performance becomes critical. But also due to the source impedance of the different cartridges.

But if you try op amp rolling on these components - unless you are at least as skilled in low noise electronic design as the designer of that device, you will screw it up.

 

[SMen]

Phono pre-amps and Mic pre-amps are probably the only audio applications that have more stringent requirements than the line level circuits used on power amplification. This comes from the very high gain required, hence noise performance becomes critical. But also due to the source impedance of the different cartridges.

But if you try op amp rolling on these components - unless you are at least as skilled in low noise electronic design as the designer of that device, you will screw it up.

This is my point (although I think there is more to the active loading on the MMPro design than this).

"But if you try op amp rolling on these components - unless you are at least as skilled in low noise electronic design as the designer of that device, you will screw it up"

Sorry but if I do what exactly?

My point is (well exactly my point) ...

if someone were to try and swap op amps on the MM Pro they would be going against the designer's clearly stated design objectives and recommendations. ...

on the other hand if someone were to swap in a Muses02 into the Fosi v3 mono ... I mean heck they have been provided by the manufacturer ...!

my point ...

post edit :

 

[cfwotzka]

Many thanks to everybody who helped an old German engineer to understand in a better way that OPAMP swapping in most of the cases is contractionary to design objectives and changing of sound usually is due to unwanted effects.

talking 3e Audio: to my ears OPA1656 in my A7 monos is a perfect match
talking Fosi V3 monos: I tried the Muses02 delivered together with the amps but quickly return to the original NE5532

 

[SMen]

Many thanks to everybody who helped an old German engineer to understand in a better way that OPAMP swapping in most of the cases is contractionary to design objectives and changing of sound usually is due to unwanted effects.

talking 3e Audio: to my ears OPA1656 in my A7 monos is a perfect match
talking Fosi V3 monos: I tried the Muses02 delivered together with the amps but quickly return to the original NE5532

Yup ... me too with the Fosi's ... but no harm in trying (as I understand it) in this circuit.
Nobody has, as yet explained the extra op amp in the Fosi Monos. I postulate they do their feedback there, but it is just a guess. The 3e use one per paralleled channel, not too.

And beautifully put by 'an old German engineer'!!

 

[cfwotzka]

Yup ... me too with the Fosi's ... but no harm in trying (as I understand it) in this circuit.
Nobody has, as yet explained the extra op amp in the Fosi Monos. I postulate they do their feedback there, but it is just a guess. The 3e use one per paralleled channel, not too.

And beautifully put by 'an old German engineer'!!

since you got the Fosi's as well, my ears much more love the 3e's. this was already the case with some DIY mono's built on 3e Audio modules and with Micro-Audio PSU's. not to old engineer and still wide open mind and ear to follow the exiting technical developments in audio industry in recent years as well as this very interesting forum here.
it seems that very good listening experience is becoming affordable.

 

[SMen]

since you got the Fosi's as well, my ears much more love the 3e's. this was already the case with some DIY mono's built on 3e Audio modules and with Micro-Audio PSU's. not to old engineer and still wide open mind and ear to follow the exiting technical developments in audio industry in recent years as well as this very interesting forum here.
it seems that very good listening experience is becoming affordable.

I will reply back to you in a few days with my own comparison. I'll be most interested. I had an initial impression with the Fosi's that did not leave - fine, full bodied even, but somehow I wondered if more resolution was not possible ... of course that means my expectation bias is set ;-) - we shall see. 3e sounds great from my phone into a pair of old wharfedale diamonds!

 

[cfwotzka]

I will reply back to you in a few days with my own comparison. I'll be most interested. I had an initial impression with the Fosi's that did not leave - fine, full bodied even, but somehow I wondered if more resolution was not possible ... of course that means my expectation bias is set ;-) - we shall see. 3e sounds great from my phone into a pair of old wharfedale diamonds!

I can very good imagine you will be surprised...

 

[antcollinet]

since you got the Fosi's as well, my ears much more love the 3e's. this was already the case with some DIY mono's built on 3e Audio modules and with Micro-Audio PSU's. not to old engineer and still wide open mind and ear to follow the exiting technical developments in audio industry in recent years as well as this very interesting forum here.
it seems that very good listening experience is becoming affordable.

Any contols used in those comparisons? (Levels matched with multimeter, not knowing which amp was playing, statistically relevant number of attempts?)

 

[cfwotzka]

Any contols used in those comparisons? (Levels matched with multimeter, not knowing which amp was playing, statistically relevant number of attempts?)

of course not. it's my personal taste judging

 

[henel321]

Some more feedback after one week having the A7 in my setup.
The amp has been playing flawlessly at all kind of volumes, from late night wispers to houseparty levels: I already mentioned that I was pleased with low level listening behavior, and I discovered during the week that high volume playing with the A7 is even more satisfying because it induces no fatigue. I can just crank up the volume, and no nasty distorsion shows up,

We've used our A7 extensively for the past 10 days, everything from Tidal/Spotify to some TV and PS5. No issues with auto-off. it takes a few seconds for it to turn on though which is a little annoying coming from an integrated setup, but not a deal breaker in any shape or form. Also even after very long listening sessions it only gets a bit "warm", it doesn't by any means get hot which was a positive surprise.

I completely agree with your thoughts above. The sound is really good when at low levels, perfect for background listening, but at the same time still what impresses me is more high volumes. Likely because of the added power and that I am used to have the WIIM Amp without PFFB and its load dependence.

Still super happy with my purchase, and the combination with the Wiim Ultra is really great, very good fit.

 

[OdiusEX]

Something else

I don't know if you tried this, but you could keep your Fosi ZD3 in pre-amp mode, but have the volume attenuated in analogue using the Aiyima's. You may find that 95% to 100% on the digital control don't make such a difference ... and then you can dial in your two analogue controls ... enjoy that couch 10 % more

Good idea, I'll try it. Also, having to get up off couch so often----it's almost like a I have a Turntable again **)

 

[SMen]

I can very good imagine you will be surprised...

I have had a day or so now to listen and I am surprised indeed.

I bought the A5, and in comparison to the Fosi v3 Monos power is simply not an issue.

I am using efficient speakers (Triangle 90dB+) but, if anything, the A5 sounds more powerful.
Certainly more transparent to my ears. Very impressive. On amplifier performance terms I would not go back to the v3 monos.

I have to say though, that the lack of an on / off switch is annoying. @3eaudio have also got the auto on/off sensitivity wrong on this amplifier. Let's say I'm making dinner and playing music... 5 minutes can easily go by, and going through to the sitting room from my kitchen to restart some music, and then waiting for the amplifier to click back on ... well it could ruin my steak!

I joke, but it really is annoying.

My subwoofer tells me that the 3e "clicking in" should be imminent, but it is slow and not nearly as responsive as the Fosi v3 Monos.

I will suffer, given the improvement in amplification performance ... but it is annoying. An easy mistake to avoid, and it really needs to be fixed.

I have no issues when I am in the room having a listening session though. And, as I said, the transparency and sense of power is a joy.

 

[rvsixer]

Kind of eerie when a hot thread goes silent for two weeks . Maybe @3eaudio is using the time to cook up an AUTO ON/OFF fix, or better yet 12V trigger, so can order up a trio of A7 Mono's for LCR duty.

 

[niekos]

I was wondering the same thing But I really enjoy the A7 now for some weeks, maybe others are listening and enjoying it as well. It sounds really good, also at low volume levels, and no listening fatigue. I have no problems with the auto on/off so far. I replaced the opamps with SX52B. Not hearing much of a difference with these (still sounds great). I used it instead of my Dartzeel NHB-108 clone in my main system for a while, but the Dartzeel is really better (IMHO). So the A7 has moved to secondary system.

 

[cfwotzka]

I was wondering the same thing But I really enjoy the A7 now for some weeks, maybe others are listening and enjoying it as well. It sounds really good, also at low volume levels, and no listening fatigue. I have no problems with the auto on/off so far. I replaced the opamps with SX52B. Not hearing much of a difference with these (still sounds great). I used it instead of my Dartzeel NHB-108 clone in my main system for a while, but the Dartzeel is really better (IMHO). So the A7 has moved to secondary system.

I think the factory installed OPAMP's are a perfect match and in my case my dartzeel is collecting dust since I switched on the A7 monos the 1st time

 

[SMen]

I was wondering the same thing But I really enjoy the A7 now for some weeks, maybe others are listening and enjoying it as well. It sounds really good, also at low volume levels, and no listening fatigue. I have no problems with the auto on/off so far. I replaced the opamps with SX52B. Not hearing much of a difference with these (still sounds great). I used it instead of my Dartzeel NHB-108 clone in my main system for a while, but the Dartzeel is really better (IMHO). So the A7 has moved to secondary system.

I think the factory installed OPAMP's are a perfect match and in my case my dartzeel is collecting dust since I switched on the A7 monos the 1st time

Aha!! My V3 monos are gathering dust, but I'm going to switch them back in for the weekend to see if it's my imagination.

 

[rgruber]

Was just about to buy two ZA3s or a set of V3 monos but recently got wind of the 3e A7 monos and am reconsidering. Not sure if the auto on/off would be an issue for me just for listening to music and am a little leery of Ali Express but these seem like the best iteration of the 3255 chip.