3e Audio A5 Stereo Amplifier Review

[Bruce Morgen]

With two inputs, input selector, and gain knob, it's an integrated amp.

If that's true, then this 1970s classic was also "an integrated amp."

 

[ICIETDIYEUR]

@ Roland68:

I think that the 'PFFB' part cannot pose a problem of reliability.

For the BAL part. to SE, I think they hid the OP-AMPs used because they could very well have used 4 OP-AMP LT1028 rather than the usual 2 OP-AMP NE5532 at this level to get less noise on these inputs

 

[Ropeburn]

@ Ropeburn ->

View attachment 419358



I did better with an O-NOORUS D1: check out the post

View attachment 419361


The amplifier O-NOORUS D3 PRO which is about to be released has this 'MOD' as well as the 'filter' for PVDD

Yes, no load dependency. Where do you see any on that pic? It's useless for your point because there's no comparison between different loads. But here is one:

From this post:

Hypex UcD180HG HxR amplifier module analysis and review

Hypex UcD180HG HxR module analysis and review After buying and testing AIYIMA A07 amplifier (based on TPA3255 class D chip) in January 2021 I was quite disappointed with the frequency response modulated by speaker complex impedance and its audible consequences. This is, unfortunately...

www.audiosciencereview.com

So yes indeed, as you can see, no load dependency whatsoever. It was a solved problem 20 years ago. Companies using integrated class D amplifier chips have been playing catch up ever since.

 

[ICIETDIYEUR]

@ Ropeburn

I think our opinions are similar if you read my posts:

Bruno Putzeys certainly has nothing to learn from these Chinese companies (it's not pejorative), quite the contrary

But that doesn't take away from TOPPING's credit for their best achievements

 

[Multicore]

If that's true, then this 1970s classic was also "an integrated amp."View attachment 419368

Yes, I would say that's an integrated amp. I wonder how it got the label it has.

EDIT to add:

Assuming the gain control goes low enough to silence the speakers. It's reasonable for a power amp to have a gain control with a hot minimum, like on my Genelec 1029A.

 

[somebodyelse]

Yes, no load dependency. Where do you see any on that pic? It's useless for your point because there's no comparison between different loads.

It's from a later post in the same thread:
https://www.audiosciencereview.com/...-module-analysis-and-review.27852/post-969225
Comparing the resistive load plots and the plot with the Quadral speaker we see all three are ~0.6dB down at 20kHz, confirming the UcD180-HG is load independent for practical purposes, and refuting @ICIETDIYEUR's claim.

 

[Roland68]

@ Roland68:

I think that the 'PFFB' part cannot pose a problem of reliability.

If the same problem occurs under the potting compound as with the first PA5, then there will be a problem.
It has nothing to do with PFFB, only with the components under the potting compound, regardless of what they belong to.

 

[EXIF68]

Same Amp-Chip as used in WIIM Amp Pro as tested here a while ago.
And more or less the same technical specs,
For my part: My WIIM sounds really nice and so should this device be too.

 

[Bruce Morgen]

Yes, I would say that's an integrated amp. I wonder how it got the label it has.

To distinguish it from the actual integrated amp -- with the same DC-coupled output circuit -- in the Kenwood lineup, the KA-7002.

 

[Roland68]

Now I think these amps can bring more focus on having excellent power supplies that meet everyone’s desire for safety and longevity…could cost more, but I think people would pay for an encased but extra high quality unit?

That's exactly what doesn't work and the question comes up regularly in every thread about amplifiers with external power supplies.
It's not the manufacturer's focus that's wrong, but the focus on price. There are already enough amplifiers with internal power supplies, but they're in a higher price range for good reason, see below.

First of all, such power supplies have been in use for 20 years for workstation notebooks with significantly higher power (230 watts and more), without problems and under high continuous load. Defects are very rare and these power supplies are usually decommissioned after 7-10 years with the notebooks and then work for a few more years elsewhere. And we're talking about at least 8-10h/5d use, often even more.
So it's neither new nor untested.

In addition, such power supplies have an efficiency of around 94%, so that only a small watt range of waste heat can be generated and it doesn't heat up much during operation.

The big advantage is that you can connect any power supply, Mean Well, TDK, etc.

A larger housing with a built-in power supply would make the device significantly more expensive and require additional checks and tests, which would also have to be paid for by the buyers. Shipping costs would also increase significantly.
At the same time, the higher price would significantly reduce the number of units sold, so that the total costs would have to be spread over significantly fewer devices, which would make the device significantly more expensive.

 

[JustJones]

Yes, I would say that's an integrated amp. I wonder how it got the label it has.

Perhaps due to when the term "integrated amplifier " came to be used? McIntosh used to call their "integrated amplifiers " Pre-Amp - Amplifier

 

[ICIETDIYEUR]

@ Roland88

The building blocks of the PFFB are passive components.

The TOPPING PA5 had active components (OP-AMPS) in its coating in addition to the passive ones, which caused overheating problems: in the case of the 3eAudio the problem will therefore not arise

 

[ICIETDIYEUR]

If I could buy this Mac Intosch MA 6100 at the same price as the one asked by 3eudio for their amplifiers (even the most expensive) then I would run to the store even if I didn't have legs !!!

 

[Roland68]

@ Roland88

The building blocks of the PFFB are passive components.

The TOPPING PA5 had active components (OP-AMPS) in its coating in addition to the passive ones, which caused overheating problems: in the case of the 3eAudio the problem will therefore not arise

That's exactly where your mistake lies, the PA5 never had an overheating problem, that was a myth from heat hysterics.
I have now repaired over 10 pieces of PA5s without having to replace a single OPAmp, so much for the overheating problem.

The problem was due to improper use of the potting compound, nothing more and nothing less. And it can also occur with purely passive components.

 

[Bruce Morgen]

Perhaps due to when the term "integrated amplifier " came to be used? McIntosh used to call their "integrated amplifiers " Pre-Amp - Amplifier

View attachment 419379

Here's a McIntosh power amplifier from the same era as the MA-6100. Note the gain knobs, the speaker switch, and the headphone jack.

 

[ICIETDIYEUR]

That's why I didn't want MC 1000 mono blocks because there was no socket for the headphones ! (LOL)

 

[ICIETDIYEUR]

Very well Roland88. So let's hope that 3eAudio is less 'idiotic' than TOPPING....

TOPPING uses the 'laser' now so as not to identify the circuits...

 

[shilent]

Production models of these amps do not include the 12v trigger input - that was on early review samples only. The signal sensing on/off works well though. Price is also higher than stated as others have mentioned.

Did not work well for me. During gaming, it would auto-off on me, and when action happens it takes 2 seconds to turn on, completely ruining horror games. Rain and footsteps in games isn't enough to keep it on.

After some testing, I found that it will not auto-on with any frequencies above 4Khz.

Since there's no way to force the device on (unplugging and plugging power doesn't even work), it's unusable for me and I returned the device.

30 minute auto-off would have worked in this situation.

 

[phoenixsong]

Happy owner of the A5 here It easily powers my JBL A170 tower speakers to frightening levels (I still have relatively young and healthy ears). That said, I would have loved to see measurements on the resultant impact on sound quality when the bypass is disengaged

 

[Joe Smith]

That's exactly what doesn't work and the question comes up regularly in every thread about amplifiers with external power supplies.
It's not the manufacturer's focus that's wrong, but the focus on price. There are already enough amplifiers with internal power supplies, but they're in a higher price range for good reason, see below.

First of all, such power supplies have been in use for 20 years for workstation notebooks with significantly higher power (230 watts and more), without problems and under high continuous load. Defects are very rare and these power supplies are usually decommissioned after 7-10 years with the notebooks and then work for a few more years elsewhere. And we're talking about at least 8-10h/5d use, often even more.
So it's neither new nor untested.

In addition, such power supplies have an efficiency of around 94%, so that only a small watt range of waste heat can be generated and it doesn't heat up much during operation.

The big advantage is that you can connect any power supply, Mean Well, TDK, etc.

A larger housing with a built-in power supply would make the device significantly more expensive and require additional checks and tests, which would also have to be paid for by the buyers. Shipping costs would also increase significantly.
At the same time, the higher price would significantly reduce the number of units sold, so that the total costs would have to be spread over significantly fewer devices, which would make the device significantly more expensive.

No, you mistook me - I mean still separate SMPS supplies, like what Fosi and Aiyima and SMSL are doing now, but with ironclad certifications, excellent components and "hospital grade" or "Meanwell grade" quality. I'm ok with the current power supplies and only had a problem with one SMSL one years ago, but many buyers here seem concerned about the safety, lifespan and quality of the current bricks.