Apollon 1ET6525SA ST Amplifier Review

[daniboun]

Am I missing something? This is supposed to be the successor to the 1ET400A but it’s down on power on that older model and on the newer 1ET6525SA spec?

E.g. NAD 298 1ET400A design: 187w into 8ohm, 345w into 4ohm

This unit: 158w 8ohm, 276w 4ohm, 367w 2ohm

1ET6525SA spec is 230/450/510w, respectively. Why is the Apollon so far off?

Relevant observation) I suppose that the NAD uses a proprietary PSU because the evaluation version gives more consistent results compared to the 1ET6525SA

Review and Measurements of Purifi 1ET400A Amplifier

This is a review and detailed measurements of the Purifi 1ET400A Class-D amplifier module. Company was kind enough to send me a complete, assembled kit consisting of two modules, power supply and case, ready to go. They have not disclosed the cost of the unit. Modules will be available to DIY...

www.audiosciencereview.com

 

[Haskil]

It is a magnificent piece of engineering, but there is one specific feature that would make it even more competitive.
I recently noticed that other new amplifiers on the market, such as the Buckeye Purifi 1ET9040BA, have started incorporating Signal Sensing Auto Trigger.
I strongly invite Apollon to consider adding this functionality. Many users, including myself, pair these high-end amplifiers with gear like MIDI keyboards, pro interfaces, or streaming DACs that lack a traditional 12V trigger output. Having the amplifier wake up automatically upon detecting an audio signal is a game-changer for usability in both studio and home environments.
Adding this would bridge the gap and make the Apollon an even more versatile and 'complete' choice compared to the competition.

Not really, because when the amplifier is turned on and starts playing sound, the music has already begun. You then have to stop playback, go back to the beginning to start listening, otherwise you miss the beginning... Unless you use Roon, which has the clever idea of sending a short chime that gives the amplifier time to warm up before the music starts playing.

 

[nothingman]

Relevant observation) I suppose that the NAD uses a proprietary PSU because the evaluation version gives more consistent results compared to the 1ET6525SA

Review and Measurements of Purifi 1ET400A Amplifier

This is a review and detailed measurements of the Purifi 1ET400A Class-D amplifier module. Company was kind enough to send me a complete, assembled kit consisting of two modules, power supply and case, ready to go. They have not disclosed the cost of the unit. Modules will be available to DIY...

www.audiosciencereview.com

Ok, what about this new Apollon unit coming in so under spec? The new design is expected to be more powerful.

Not really, because when the amplifier is turned on and starts playing sound, the music has already begun. You then have to stop playback, go back to the beginning to start listening, otherwise you miss the beginning... Unless you use Roon, which has the clever idea of sending a short chime that gives the amplifier time to warm up before the music starts playing.

Lord, do I detest auto-on. Everything should be on triggers to a preamp.

 

[Ropeburn]

I don't like autosensing and auto-off. It's too easy to get wrong and/or annoying. There are simply too many different use cases requiring different sensing levels and time settings for getting a one size fits all thing.

Trigger is way more reliable. It just works every time, so does manually switching. For example in a studio setting, I want the amp always on until I say otherwise. Not have it semi-randomly fuck around and be turned off when I come back from the toilet or something. Or making a break of whatever kind without sound.

 

[Matias]

Very nice amp. And specially interesting compared to Apollon NCx500, a nice trade of pros and cons between them.

Apollon NCx500ST Stereo Amplifier Review

This is a review and detailed measurements of the Apollon NCx500ST stereo class D amplifier based on Hypex NCOREx NCx500 modules. It was kindly drop shipped from the member and costs 1,090.00€ (US $1,168) with standard opamp. While the case is stamped aluminum, it is a heavily customized one...

www.audiosciencereview.com

 

[unmutual]

Glad to see this reviewed. I've used this model for well over 6 months in my setup, and have no complaints. Excellent cost/performance ratio.

 

[JayGilb]

Amir,
Thanks for another review.

 

[daniboun]

Ok, what about this new Apollon unit coming in so under spec? The new design is expected to be more powerful

In term of output power they are pretty close
Check attached file

 

[Redwine]

Guess it’s a choice between this one and Boxem (has autosensing and auto-off), in case you stay in Europe at least.

 

[VientoB]

Does it let you use single ended for one channel and balanced for the other? And different gain settings for each channel?

 

[Apollon Audio]

Does it let you use single ended for one channel and balanced for the other? And different gain settings for each channel?

Yes

 

[David_M]

@Apollon Audio, why doesn't the amp meet the 4 ohm specification of 425 Watts?

 

[Matt_Holland]

Another phenomenal amp for roughly a grand. Thanks for the review @amirm. Did you get data for the reactive load presentation as you did for the boXem A 4216/E2? Does the Apollon perform the same?

 

[Billy Budapest]

Yet another stellar product that is built around Purifi amp modules. Is the PS also from Purifi?

I second the idea by @F1308 to include an auto on/off (from standby) feature based on the audio signal input. It's very practical for the end user.

Hypex power supply. Purifi does not make their own.

 

[Apollon Audio]

@Apollon Audio, why doesn't the amp meet the 4 ohm specification of 425 Watts?
View attachment 503411

The measured output power can vary depending on the available mains input voltage. When the amplifier is supplied with a lower mains voltage (for example 110-120V), the Hypex 1200/A400 switched-mode power supply provides a correspondingly lower DC rail voltage, which results in a slightly reduced maximum output power.

This behavior is common to most SMPS-based power supplies, as their maximum available output power is directly influenced by the mains input voltage. At higher mains input voltages (such as 240-250V in Europe or 130 V on a high-line U.S. supply), the power supply delivers the nominal DC voltage required for the amplifier to reach its specified output of 425 W into 4 Ω. Here in Europe this amp measures slightly better.

 

[Apollon Audio]

@Apollon Audio congrats for the superb measurements. What is the opamp option installed on the DUT?

Thank you.

I think that the OPA1656 is installed in this amp.

 

[delta76]

Eternal debate debunked by Amir....

Exactly my point

 

[David_M]

The measured output power can vary depending on the available mains input voltage. When the amplifier is supplied with a lower mains voltage (for example 110-120V), the Hypex 1200/A400 switched-mode power supply provides a correspondingly lower DC rail voltage, which results in a slightly reduced maximum output power.

This behavior is common to most SMPS-based power supplies, as their maximum available output power is directly influenced by the mains input voltage. At higher mains input voltages (such as 240-250V in Europe or 130 V on a high-line U.S. supply), the power supply delivers the nominal DC voltage required for the amplifier to reach its specified output of 425 W into 4 Ω. Here in Europe this amp measures slightly better.

That makes sense ... would you be willing to offer a regulated MicroAudio power supply option?

 

[pickyAudiophile]

One more great alternative.
However, Boxem shouldn't be worried IMO when it comes to overall implementation and thought-out usability.

I don't like autosensing since that doesn't match my listening habits with plenty of breaks and resumptions at all. - That's the deal breaker to me.

And I know about that type of flimsy input switch very well... At least we did not receive a dip switch panel, that's the good news...
If you don't insert your tool, like a 3mm slotted screw driver super carefully and strictly vertical...with every switching operation that black hard plastic would get deformed just a little bit more, and over time it would really suffer from wear. - If you don't do a lot of swapping, switching and testing that's not an issue for sure...

 

[temujin44]

I guess with this kind of performance (and other purifi and hypex based modules) it’s end game, like we have it for DACs.
What more do we want? Let’s focus on speakers to reduce their distortion!

just hire musicians to play in your house