Any review on Apollon Purifi 1ET9040BA DM Dual Mono Stereo Amplifier?

[Ruediger]

Whatever brings the pleasure the actual owner/customer seek. I would however argue that sometimes (or quite often actually), the brand value / prestige value / aesthetics and so on may very well exceed the actual performance value. That's for just about anything an enthusiast within any area would purchase.

Are you saying people pay ridiculous prices for sub-par performance in hifi? Soldiers of fortune may have populated the area?

Actually I know no other area in life where you can spend kajillions and get bare pennies in return. It may exist, but I know only hifi devices/parts with that much distance between science/reality and prices.

I don't think Ascilab or Purifi fall under that label though. I know Ascilab also has some expensive models, but they aim to deliver. That's different from wooden unicorns with fantasy pricetags on them.

But it's a hobby. The one thing in life were no one needs to make compromises. My motto.

 

[Soundproof]

Are you saying people pay ridiculous prices for sub-par performance in hifi? Soldiers of fortune may have populated the area?

Actually I know no other area in life where you can spend kajillions and get bare pennies in return. It may exist, but I know only hifi devices/parts with that much distance between science/reality and prices.

I don't think Ascilab or Purifi fall under that label though. I know Ascilab also has some expensive models, but they aim to deliver. That's different from wooden unicorns with fantasy pricetags on them.

But it's a hobby. The one thing in life were no one needs to make compromises. My motto.

Noooo......

I don't believe HiFi is even close to be unique. Any area populated with enthusiasts who engage in it as a big hobby is exposed to the weaknesses of the flesh. Yachts - the 3 ft decease, litterature and collecting rare books, history/religion and collection, cars, watches, bicycles, guns, sports, art and what not.

For instance, road bicycles for people who don't participate in races. It may very well be that the latest and greatest have become more efficient. But if you are only in it for the activity and excercise, a less efficient bike will make your training more efficient. Or?

Another example: Wristwatches. To a large extent but not entirely, they are obsolete and mainly used as male jewellery. For the enthusiasts they are of HUGE significance, and specimens are paid for by tons of cash, despite being inferior to watches for beginners. But the watches and the technology is still largely obsolete and mostly insignificant to the wider audience apart from potential prestige.
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Purify and Ascilab falls within my range, thus I'd argue great and real value to many. Not really a hobby to me, just want decent quality and good sound to my taste and the music I play. But you guys have the competence I'm short of, and when I'm done I will most gratefully have benefited a lot from your competence. One can get good stuff stretching a budget, bad purchase and trading back and forth is what costs. Not possible to test and try a lot of gear hereabout, thus, with the aid of the ASR community I am more likely to get it right first time around.

 

[Ursulou]

I don't think Purifi Eigentakt-based amplifiers fall into the most expensive category; sure, they aren't $300 a unit, but they are cheaper than offerings from some luxury brands.
I always operate on the principle that "passion is always right": you stay sensible, save up, upgrade your system gradually, and—above all—listen to the music.
Looking back to when I bought my first system in 1990 (Cabasse Clipper 3, Yamaha, etc.) and the regular investments I've made since—acquiring gear bit by bit according to my means—I’ve arrived at my current setup without feeling financially strained. I don't drive a luxury car or travel the world on vacation... in short, it’s a choice, a passion, without needing to own a $30,000 rig!
I’ve listened to many systems and met many fellow enthusiasts, and I take great pleasure in simply listening to music—just like all of us here—whether it’s on my home system or outdoors with my little JBL Flip 5 speaker.

 

[Ursulou]

Hello,
Here is the reply from Boxem; notably, they do not address the issue of their units' sensitivity when placed near Radian 745DPB8 compression drivers and passive crossovers in my speakers:
I will try to answer all your questions at once.

"Expect to pay around €3,620 (incl. tax) for a pair of Arthur 5523/E1 units delivered to an urban area in France. Allow for an extra €30–€50 for delivery to very remote areas. I can provide an exact quote if you let me know the delivery city.
Below is a photo of the interior taken at the end of assembly.




You can find reviews of our products on HCFR, On-Mag, and ASR. I would like to point out that measurements for our products have consistently been impeccable, with SNR figures 2 to 3 dB better than competing products.
Our products comply with European and US standards regarding radiated electromagnetic emissions and immunity.
The 'Audiosense' feature can be disabled via an internal jumper. We can, of course, disable it during manufacturing if you wish, but I encourage you to test its effectiveness and disable it yourself if you aren't convinced."

 

[Ruediger]

Good info with the jumper and their offer to set it to off from the start.

Personally I wouldn't buy in this price class and as first thing open the case.

 

[boXem]

notably, they do not address the issue of their units' sensitivity when placed near Radian 745DPB8

It is exactly what we do when we state that our products comply to EM regulations. If the 74DPB8 also comply, no issue to be expected.

Personally I wouldn't buy in this price class and as first thing open the case.

Why would you do so?

 

[Ruediger]

Why would you do so?

"The 'Audiosense' feature can be disabled via an internal jumper."

 

[boXem]

"The 'Audiosense' feature can be disabled via an internal jumper."

So what? Not only we propose to disable it before shipment but none of our customers ever had to disable it by themselves for the simple reason that it is working as it should.

 

[Ruediger]

So what? Not only we propose to disable it before shipment but none of our customers ever had to disable it by themselves for the simple reason that it is working as it should.

What is it then, do you propose to disable it or are you sure it doesn't need to be disabled?

Maybe a bit more scientific: how sensitive is that autosensing feature?

 

[boXem]

What is it then, do you propose to disable it or are you sure it doesn't need to be disabled?

Question was "can it be disabled at production time?" Answer was "yes, there is a jumper allowing this". All the rest is you inventing non existing issues.

Maybe a bit more scientific: how sensitive is that autosensing feature?

Below -60 dBv.

 

[Ruediger]

Alright then.

 

[Ursulou]

Boxem demonstrates its professionalism by responding to technical inquiries, and the internal construction of its amplifiers is very neatly executed.
From a technical standpoint, how can amplifiers based on the same ET9040BA modules and power supplies yield slightly different measurement figures? (Differences in implementation, wiring quality, or terminal quality...?)
"A signal-to-noise ratio (SNR) 2 to 3 dB higher than that of competing products."

 

[boXem]

From a technical standpoint, how can amplifiers based on the same ET9040BA modules and power supplies yield slightly different measurement figures?

Input buffer design: feedback resistors have a huge impact on noise. The lower the better. But lowering them pushes the opamp to it's limits causing distorsion. Solution is to have a composite design allowing both low noise and distorsion.

 

[Ursulou]

Hello,
In your opinion, does this type of amplification require a specific break-in period when new?

 

[Ursulou]

Hello.
A pair of Audiophonics mono blocks equipped with ET9040BA modules underwent brief testing with a B&W 800 Matrix system, compared against Pass Labs 600.5 power amplifiers.
Unfortunately, a technical issue cut the testing short.
The listening assessment of the Audiophonics units cannot be considered definitive because the units were brand new (hence my question regarding the break-in period for this type of amplification).
The initial impression was a difference in bass control at low volumes: the Class A Pass amps performed better in this regard, whereas the Audiophonics ET9040AB units required a higher volume level to achieve proper tonal balance.
The liveliness of the amplification, the sense of scale at moderate volumes, and the clean transient response certainly seemed to be present with the Purifi-based amps.
Unfortunately, we cannot say more at this stage.
System configuration: Nubert streamer/DAC/preamp (preamp stage bypassed) -> Atma-Sphere MP-3 -> power amplification (Audiophonics or Pass Labs).

 

[Ruediger]

Something like this needs to be done level-matched and blind. Otherwise it's just that, an impression. Not a test. Impressions can be generated in every direction.

But the candidates are interesting as they are very different.

Can there be break-in without moving parts? Not warmup, actual change of molecules. I know there are people who offer burn-in service for cables. I think they are funny.

 

[Ursulou]

Thank you for your honesty and, above all, for your reply.
I thought you might be interested in this comparison of two amplification technologies—admittedly very different ones.
I won't get into the debate between "listening impressions" and sonic realism; after all, everyone has their own ears and appreciates what they hear in their own way.
The owner of this system has been a musician for 40 years; I am not, though I have attended countless live performances—from indoor and outdoor concerts to street music, jazz cellar sessions, and music heard in churches. Strangely enough, we find common ground when it comes to appreciating reproduced sound.
As for the break-in period for this type of Class D electronics, you seem to consider it just as unnecessary as that of a cable; am I to conclude that, in your view, breaking in these devices makes no difference at all?

 

[Ruediger]

Our accoustic memory has certain things it can and can not do. The setup of a proper test accounts for that.

Bias and expectation are very powerful. I kind of see both in your posting.

Just pointing out that an impression is not a comparison. Being tricked is very easy at this point. I know because I did it to myself many times (especially with amps). You can read more into this if you like, I'm no expert in explaining the science behind it.

As for the break-in, I don't think it is real for this kind of device. It is real for moving parts like speaker membranes. But probably overrated by many as this huge important period. But can they actually hear a difference?

Cable burn-in changing the molecules of the conductor - I think this is snakeoil territory and not worth further discussion. I just brought it up as a example about how fast things can turn to voodoo or audiofoolery. We see it with cables and other things all the time.

As for your interesting amps, are there reviews (with measurement) for the class A blocks?

 

[Ursulou]

Vincent:
Manufacturer specifications:
Measurement / Characteristic | Value / Data
RMS Power (8 Ω / 4 Ω) | 300 Watts / 600 Watts
Pure Class A Biasing | Up to 100 Watts (into 8 Ω)
THD (Manufacturer / Actual at 5W) | < 0.02% / ~0.004%
Signal-to-Noise Ratio | > 95 dB
Frequency Response | 10 Hz – 20 kHz (± 0.5 dB)
Damping Factor | 195
Input Sensitivity / Impedance | 2.0 V / 47 kΩ
Filter Capacitance / Transformer | 120,000 µF / 1500 VA
Dimensions (W x H x D) | 430 x 180 x 530 mm
Net Weight (per unit) | ~35 kg

My amplifiers have been fully serviced; actual Class A power output does not exceed 46 W into 8 ohms.

 

[Ursulou]

Passlabs X600.5
Measurement / Characteristic | Value / Data
RMS Power into 8 Ω | 600 Watts
RMS Power into 4 Ω | 1200 Watts
Bias | Pure Class A up to 80 Watts (peak)
Distortion (THD at 1 kHz, full power) | 1% (significantly lower at typical power levels)
Bandwidth (Low / High Frequency) | 1.5 Hz to 100 kHz
Damping Factor | 200
Slew Rate | ± 50 V/µs
Voltage Gain | 26 dB
Input Impedance (XLR / RCA) | 30 kΩ (balanced) / 20 kΩ (unbalanced)
Voltage for full power (@ 26 dB gain) | 3.46 V
Output Noise | 200 µV
Idle Power Consumption | 600 Watts
Dimensions (W x H x D) | 483 x 284 x 571 mm (19" x 11.2" x 22.5")
Net Weight (per unit) | ~60 kg (132 lbs)