Apollon NCx500ST Stereo Amplifier Review

[antcollinet]

With that responsiveness cherry on top - this is certainly my way to go forward. Just looking for a DAC+preamp that has a configurable sub out and dirac that matches well with this now.

You'll be wanting a miniDSP flex then

 

[Matias]

People claimed that OPA1612 measured slightly better than OPA1656 in the DIY Audio thread I linked, but that people seem to prefer the sound of the 1656..

Either way, I believe both are more transparent than the NCx500ST, so besides subjective preference it shouldn’t matter.

Bruno Putzeys explains below at 33:04 time-stamp.

On paper the OPA1612 is better but the OPA1656 has higher and much more linear input impedance which in a number of applications performs better.

PS: boXem has been using OPA1656 since the beginning.

 

[Labjr]

Anyone buying the Soncoz over this?

 

[pablolie]

Bruno Putzeys explains below at 33:04 time-stamp.

On paper the OPA1612 is better but the OPA1656 has higher and more linear input impedance which in a number of applications performs better.

PS: boXem has been using OPA1656 since the beginning.

Are OpAmps the next tube swap fad?

 

[Matias]

Are OpAmps the next tube swap fad?

Have been for several years now.

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Several threads were created about this already.

 

[antcollinet]

Anyone buying the Soncoz over this?

Meters though.

 

[Dougey_Jones]

Have been for several years now.

Input Buffer for Hypex NC500 and Purifi Audio 1ET400A

CUSTOMIZABLE Input buffer for Hypex and Purifi Audio ✔ HOW IT WORKS ✔ Design Process ✔ Technical Specifications ✔ Spectral density

atm-audio.com

Several threads were created about this already.

Was going to say, this has been a thing for a few years, and very similar to tube rolling. I'm not quite sure whether to believe people are hearing a difference or wanting to hear something.

My configuration choice was to go with standard, I didn't want any color. I can add a tube line stage or any number of other noise makers later if I feel the need.

 

[Labjr]

Meters though.

“THE POWER OF ORIGINAL SOUND”

 

[pablolie]

Was going to say, this has been a thing for a few years, and very similar to tube rolling. I'm not quite sure whether to believe people are hearing a difference or wanting to hear something.
...

In which case, it seems a miss they don't offer "OpAmp rolling" upgrade options as a probably profitable revenue source? Is it really just a plug-in thing? Are there any dip switches one has to set up? Didn't see any documentation out there, so you gents are waaay ahead of me, and I am sorry if I am wasting your time with the question.

 

[TimF]

The photo posted by Tom22 shows the Apollon all in black with a simple grey or silver metalic edge around the front face. That silver/metalic edge is what I recommend NAD add to their NAD C298. I think such edge trim makes an improvement to otherwise large void appearance of the NAD C298. It gives the box dimensionality.

 

[Ajax]

Not bad! Now are there options for half the power at roughly half the cost with equivalent performance?

Have a look at the Buckeye NC252MP ... US$570.

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

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Archimago assembled one as a DIY project and then measured it and stated that in his opinion is it all you need for HiFi level performance. The distortion + noise is about 95db - down 20 db on this amp.

MEASUREMENTS: Hypex nCore NC252MP Amplifier (+ Subjective opinions around objective testing, and CES2020)

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

I have one and it is excellent

 

[AdamG]

In fairness to Amir, it might have been confusing for him to see it spelt correctly...


(I joke I joke, please don't come after me)

Al-Lu- minimum. What?

 

[peng]

Actually, all the measurements there are using burst mode now. This is compliant with CEA-2006/490A. Here is the description from AP manual:



The PowerCube has a rating of just 200 watts for continuous but jumps to 2 KW for burst and hence my modifications of the test to use this. This is the same measurement method I have been using on the right for each amp:

As you see, for class D amps it typically doesn't help the amplifier much but does ease the load on the dummy load.

Thanks, how about the regular 8 ohm, and 4 ohm continuous (so called) test, what would be the test duration? If user selectable, what's the test duration you would typically use for those so called continuous power output tests.

 

[xaxxon]

It'd be great to just lump amps built with commodity parts in one graph entry unless they're significantly different than reference.

The graph entry should just be the commodity part.

 

[pseudoid]

The graph entry should just be the COTS part.

Commercial Of The Shelf but with "features".
This Apollon checks both boxes.

Al-Lu- minimum. What?

My Nonna used to call it amulinium! But who cares about a typo. Right?

 

[Dougey_Jones]

It'd be great to just lump amps built with commodity parts in one graph entry unless they're significantly different than reference.

The graph entry should just be the COTS part.

Wish there were a thumbs down option for stuff like this.

Without reviewing each model, you can't verify that the reference design was implemented well, and you wouldn't have any remarks on the fit and finish or unique features added by the company.

 

[Music1969]

@amirm can you show 1.2Mhz bandwidth plot of switching noise?

Like you sometimes do

 

[xaxxon]

Wish there were a thumbs down option for stuff like this.

Without reviewing each model, you can't verify that the reference design was implemented well, and you wouldn't have any remarks on the fit and finish or unique features added by the company.

reviewing the model is fine. But when it's graphed it should be lumped for long-term clarity.

 

[thegeton]

reviewing the model is fine. But when it's graphed it should be lumped for long-term clarity.

Respectfully disagree. Let's keep the current format.

 

[pseudoid]

This made it easy to measure with PowerCube:

Results of those two PowerCube graphs @amirm provided speak for themselves.

On paper the OPA1612 is better but the OPA1656 has higher and much more linear input impedance which in a number of applications performs better.

Isn't the output of a powerAmp's linearity (being able to drive most loads) much more important than linear input impedance?