• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

3e Audio A5 Stereo Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 5 1.7%
  • 2. Not terrible (postman panther)

    Votes: 11 3.8%
  • 3. Fine (happy panther)

    Votes: 50 17.1%
  • 4. Great (golfing panther)

    Votes: 227 77.5%

  • Total voters
    293
Simply put, an A7 Mono is exactly half an A7 with its own power supply.
A7 has 2 pieces of TPA3255, one per channel as PBTL, the A7 Mono has a TPA3255 as PBTL.
The advantage of completely mono is no crosstalk, no mutual interference and its own power supply.
And of course you can place it directly next to your speakers.
I'm slightly following on from your answer here, and a couple of questioners about the V3 Monos...
A 'half A7' would have one op amp (for output) in each unit. Audiophonics have an image which bears this out - just checked and pasted below.

I have always wondered about the two op amps Fosi use in each of the V3 Monos ...
Define "better". :)
And my question also slightly relates here too : better? Why have an extra op amp? Fewer for me would = better!


Does anyone have any thoughts on this?

1736549455933.jpeg
 
I'm slightly following on from your answer here, and a couple of questioners about the V3 Monos...
A 'half A7' would have one op amp (for output) in each unit. Audiophonics have an image which bears this out - just checked and pasted below.

I have always wondered about the two op amps Fosi use in each of the V3 Monos ...

And my question also slightly relates here too : better? Why have an extra op amp? Fewer for me would = better!


Does anyone have any thoughts on this?

View attachment 420150
I'm also surprised, because the V3 Mono has 3 operational amplifiers ;). They probably just copied the circuit from the normal V3 and the NE5532 is really cheap in quantities.

The A7 Mono has 2 dual operational amplifiers, which is at least necessary (SE and balanced input).

And better is always relative, it's just different.
 
I'm also surprised, because the V3 Mono has 3 operational amplifiers ;).
And Fosi claim you could/should replace any number of them. :p

And better is always relative, it's just different.
That's why I've been asking. It's easy to see that the 3e Audio A5 performs technically better in all measurements performed by Amir and @Archimago. But a set of V3 Monos provides higher max. power, of course. They also have the "always on" switch some are missing on the A5/A7. The binding posts on the A5/A7 are of much higher quality, as is the casework in general (if not as fancy looking as the Fosi).

Personally, I enjoyed listening with the A5 more than with a pair of V3 Mono, but this is a purely subjective impression, prone to all sorts of biases. I didn't even attempt a valid comparison. And it's valid in my environment only.

Overall I just like the 3e Audio product a lot better. It feels like the more serious amp. But that's just me.

PS:
Fosi provides an FAQ document explaining what the three op amps are supposed to do:

Unfortunately, the explanation for OP1 and OP2 doesn't make any sense.
The op amps in positions 2 and 3 are responsible for adjusting the tone.
:p
 
I'm also surprised, because the V3 Mono has 3 operational amplifiers ;). They probably just copied the circuit from the normal V3 and the NE5532 is really cheap in quantities.

The A7 Mono has 2 dual operational amplifiers, which is at least necessary (SE and balanced input).

And better is always relative, it's just different.
Yes ok :D - I kind of disregarded those single ended to balanced purposed ones as I am only using balanced inputs.

But I'm still curious about the 'extra' ones in the Fosi before the output. You are probably right about copying / varying the V3 circuit.
Even so, why have two when one does the job (though it sells fewer op amps)
 
And Fosi claim you could/should replace any number of them. :p


PS:
Fosi provides an FAQ document explaining what the three op amps are supposed to do:

Unfortunately, the explanation for OP1 and OP2 doesn't make any sense.

:p
Yes - sell more op amps.



The op amps in positions 2 and 3 are responsible for adjusting the tone.

And this is why this configuration (x2) has 'niggled' at me.
 
But I'm still curious about the 'extra' ones in the Fosi before the output.
I don't see an (replaceable) op amp towards the output, though. That would make no sense. The one closest to the output is just the single-ended to balanced converter (similar to what's found on the A5/A7).

Edit:
Forgot to mention: Fosi V3 Mono sold before August 2nd had inverted polarity. I won't discuss if absolute phase is perceivable or not, but at least this imposes a risk when replacing only one unit in a pair and mixing up old and new versions.

It's unclear if this affects all units sold through Kickstarter or not. Probably yes. I didn't find have the time to test my pair yet.
 
I don't see an (replaceable) op amp towards the output, though. That would make no sense. The one closest to the output is just the single-ended to balanced converter (similar to what's found on the A5/A7).
I think it's my language sorry.

The op amps in positions '2' and '3' in the Fosi v3 monos are the ones that always niggled at me. Never understood why two, and (from my position of complete circuit design ignorance :)) I much prefer that 3e have only one op amp per channel (disregarding the single ended to balanced).

I am sure the A5 will sound all the purer to me as a result ;)!
 
I don't like to buy items that must be returned to a different country. A dac I sent back for repair was $85 shipping to China from the USA. So, can these be 3e-audio amplifiers be bought anywhere in the USA besides Aliexpress and Audiophonics?

Also, the "sell more opamps" comments, are people buying the opamps from Fosi? You can get opamps lots of other places. I don't see that as a big income stream to a company. I think it's more of a fun feature like tube rolling, for people that think there are big differences in opamps these days. Maybe the Burson or Sparkos versions are made for a certain sound profile.
 
Define "better". :)
Objectively better in all the relevant measures in regards to an ideal amplifier: provably inaudible distortion, no load dependency, etc.
 
Objectively better in all the relevant measures in regards to an ideal amplifier: provably inaudible distortion, no load dependency, etc.
Easy then, Amir tested both, the 3e Audio A5 and the V3 Mono. Just look at both reviews and compare. :)

I had already given my interpretation of the data.
 
Easy then, Amir tested both, the 3e Audio A5 and the V3 Mono. Just look at both reviews and compare. :)

I had already given my interpretation of the data.
just found your take a few comments above haha, thanks!
 
???
This already exists, please take a look at 3E Audio A7 and A7se.
Thank you for the heads up .... from Archimago's review and the comments here I gained the impression that the A7 was available only in mono.

I found the A7 Stereo version, which 3e claim produces 140W into 8 ohms, on Audiophonics for just under US$400.


The advancement in performance in the electronics of the front end of systems is incredible. Combine th A7 with a miniDSP Flex and bit perfect streamer and you have SOTA with DSP for about US$1K .... just add speakers. Why would you spend more?
 
That would hardly qualify "continuous" power. I don't remember @amirm talking about this test in more detail but I think @Archimago mentioned that his power test lasts like 30 seconds or so. That's too long to be fed from the buffet capacitors.


That's all true, of course, but totally not the point here. :) And it's not just the change with frequency. We could go on and discuss at length how many amplifiers struggle to keep their output voltage into reactive loads (not the 3e Audio A5, which does remarkably well in this area). And we could talk about how and if EPDR is able to provide a better metric for compatibility.

But in this case the question was simply if the A5 could drive a certain speaker (Revel Performa3 F208) marketed as being nominally 8 ohm with a sensitivity of 88.5 dB. Truth is, that this is clearly not an 8 ohm speaker so its sensitivity should be stated at 2.0 V, Not at 2.83 V, which would make it look less attractive at 85.5 dB.


The next question is, if the A5 (PBTL, stable down to 2 ohm loads) or the A7s (BTL, stable.down to 4 ohm) was the better suited amp.

Personally, I'd.probably.still.pick the A5 or the A7, not the A7se. But we don't have any independent measurements if the A7se (or A5se for that matter) yet.
I can't imagine trying to drive my F208's w/ the PA5-or this amp if I had it. Never hooked it up to them, knowing it wouldn't be able to drive them to adequate loudness levels (that I listen to).
 
Last edited:
You know beforehand? Out of godly wisdom? ;)

What about the A7? Or A7 Mono?
The Purifis drive them well. Should I hook the PA5 up and let it strain? Nah. No point.
 
I can't imagine trying to drive my F208's w/ the PA5-or this amp if I had it. Never hooked it up to them, knowing it wouldn't be able to drive them to adequate loudness levels (that I listen to).
Worth measuring the power consumption on your existing amplifier with a simple smart plug or wattage meter. You might be totally right but why guessing and posting without facts!
 
Worth measuring the power consumption on your existing amplifier with a simple smart plug or wattage meter. You might be totally right but why guessing and posting without facts!
Power consumption? I'm talking about power production. I guess I will have to hook the little bugger up and see if it produces smoke to make u guys happy.
 
Power consumption? I'm talking about power production. I guess I will have to hook the little bugger up and see if it produces smoke to make u guys happy.
Why are you posting off topic to this thread at all? Just to show that you own a PA5 and a Purifi amp and just because of that you know how inappropriate the A5 is in your environment?

No need to make "us guys" happy. Just comment meaningful stuff or ... don't post. :)
 
Back
Top Bottom