Hypex NCore NC500 build

[Malefoda]

We are adults. My UcD400HG HxR are good enough. Where can I buy the Purifi please?! =) just kidding.

 

[NATDBERG]

Nord take this a stage further using larger format discrete op amps normally found in studio gear.

I don't know, the best studio gear just use plain old op-amps, most of the best stuff using 5534s in the past.

Maybe boutique-style studio equipment ... who sell based on the idea of their gear having desirable "colour" to their sound.

 

[NATDBERG]

To be fair, Bruno designed UcD, then NC400 and NC500, the Purifi are his next generation product, so it's only natural to make that leap.

It's not necessarily a logical leap. There will surely be complications of who owns the designs.. If Putzey can no-longer use some intellectual properly currently owned by Hypex, then he will have to go re-invent some things and claim it's better tech.. It could be true to say it's his next generation of design... but caused by having some restriction placed upon him.

Likely none of us in this thread really know. We just have to trust or do the old subjective thing vs objective thing.

But certainly there is no point in making assumptions..

 

[Julf]

I don't know, the best studio gear just use plain old op-amps, most of the best stuff using 5534s in the past.

Exactly.

Maybe boutique-style studio equipment ... who sell based on the idea of their gear having desirable "colour" to their sound.

Yes, there is a lot of stuff used in the studio exactly for that reason - as effects and coloring. A bit like spices in cooking. You wouldn't want to ad ketchup to every dish you get in a Michelin star restaurant...

 

[barrows]

NO

It's not necessarily a logical leap. There will surely be complications of who owns the designs.. If Putzey can no-longer use some intellectual properly currently owned by Hypex, then he will have to go re-invent some things and claim it's better tech.. It could be true to say it's his next generation of design... but caused by having some restriction placed upon him.

Likely none of us in this thread really know. We just have to trust or do the old subjective thing vs objective thing.

But certainly there is no point in making assumptions..

Actually, both the subjective listening tests (see 6moons) and the objective measurements show the Purifi amps are better. Perhaps you should check out the available information before just making speculative posts like this. There is a lot of feedback both objective and subjective of the Purifi modules at this point.

 

[NATDBERG]

Yes, there is a lot of stuff used in the studio exactly for that reason - as effects and coloring. A bit like spices in cooking. You wouldn't want to ad ketchup to every dish you get in a Michelin star restaurant...

It's definately a valid place to go ... for creativity and for pleasing one's own tastes in sound. Just not for accurate reproduction. If someone wants to add ketchup to a Michelin star restaurant, then whose to stop them! It's their choice... but you're not then getting to taste what the chef intended. Same with music.

When I'm being creative with sound/music, I want colouration in certain places.

But then I want it all replayed back accurately, as recorded.

I guess, the ulitimate folly would be to take the Putzey BPBBP circuit and start adding Burson descrete opamps to it (to make up for the lack of boutique audiophile stepped attenuator/pot he was designing out ?)

 

[NATDBERG]

Actually, both the subjective listening tests (see 6moons) and the objective measurements show the Purifi amps are better. Perhaps you should check out the available information before just making speculative posts like this. There is a lot of feedback both objective and subjective of the Purifi modules at this point.

If you read my post again and check back to see the post I was responding to, you'll see that there is no speculation and you've kind of misunderstood the context of it.

The speculation would only be that the Purifi should almost automatically be thought of as being superior, simply on the basis of chronology.

As you say, whether it is or not can only be decided on measurement and listening... which is what I was alluding to also.

 

[barrows]

point being, this information is already available:

"As you say, whether it is or not can only be decided on measurement and listening... which is what I was alluding to also."

As well as Brono Putzeys' own reports of Purifi outperforming nCore by a significant margin (If one is at all aware of Mr. Putzeys positions, he is not one prone to exaggeration, or mincing words).

And, at least for any of the (decent) engineers I have worked with, the will always improve on a previous generation project when given another go at something.

 

[NATDBERG]

Great point! But not relevent to my post unfortunately.

My post was in direct response to https://www.diyaudio.com/forums/vendor-s-bazaar/281361-hypex-ncore-nc500-build-184.html#post5957373 (which is why I quoted it !).

Anyway, comparing the measurements on Audio Science Review between NC400 and 1ET400A they look much of a muchness in real life. The best choice will depend on other things like price and running temp (which the 1ET400A looks to have a big advantage with).

People's subjective opinions on comparisons in sound... well, I have no idea whom to believe, so I don't so much - just look at the general direction.

 

[daanve]

Bruno (finally) discovered the cause of the weak point of Ncore.
The poor hysteresis behavior of the output coil is responsible for what he calls a "granularity" in sound.
It is what I'd call a certain "cloudiness" in sound when listening to an Ncore based setup for longer times.
In a recent AES presentation he demonstrated what is going on (feed back not being able to "correct" hysteresis distortion).
Purifi Audio - A Straight Wire to the Soul of Music | audioXpress
In his Purifi amps the output coils will have better quality core material.
Maybe this will bring the quality of class d amps up to the level of the best class A/B amps.

 

[NATDBERG]

Can we change the output coils on our NC400s?

Over-consumption of the human race and all that, surely better to swap out the one component than start a whole new production run of new amplifiers..

 

[Armand]

Hypex NC1200: Quality of the implementations | Audio Science Review (ASR) Forum

In the EU, Apollon, Rouge Audio and atm I do not like Nord stereo implementations of Hypex modules.


I did not know about Vera Audio, I take note. Inside pictures? Only a drawing, of NC500. Buffer boards? Without wiring.

| Vera Audio |

An externally hosted image should be here but it was not working when we last tested it.

This an early rendered model of our product. More (and new) pictures will be updated on the web soon.

Key functions are:
* Selctable gain in very accurate 3dB steps from 12dB to 30dB
* Possibility to bridge the two modules
* Trigger input
* Cabinet without visible any seams and screws (except under)
* Microcontoller controlled fans
* RGB led in front indicates clipping (both current and voltage)

Key performance data:
* CMRR of at least 110dB@100Hz and better than 95dB@1kHz
* Very low noise of less than 15uV
* 680W into 4 ohm with less than 0,01%THD+N (stereo)
* S/N of more than 130dB (stereo)
* 1200W into 8 ohms with 0,01% THD+N (bridged)
* S/N of more than 132dB (bridged)

We have based our buffer on the newest opamps from TI on a four layer PCB with very short signal paths. This is mounted inside a separate compartment behind the XLR inputs for optimum shielding. A special arrangement of low noise operational amplifiers and differential amplifiers with 0,004% resistors provides a very robust input signal stage for both balanced and single ended inputs.
Voltage regulation for both the NC500 and the signal stage is done with state of the art regualtors providing 0,8uV noise.
Even class-D amplifiers needs cooling if pushed hard and we use very silent Noctua fans to keep the temperature under control even it hot environments if pushed hard. This amplifier is capable of delivering a continous sinewave with a power of 1200W into 8 ohms for hours without anything overheating. In that condition the fans will run at about 40% capacity and are virtually silent.
Under normal temperature conditions with music power up to several hundreds watts of power the fans will not start at all.

 

[maty tinman]

Very interesting.

Weeks ago I insisted Bruno to change two buffer resistances to better ones to increase the CMRR (PURIFI 1ET400A) but he did not seem to be very interested even though the cost increase is acceptable.

In the end it is the same as always, wanting to spare where it is not due, two resistor or NC500 coil. Or very cheap 85ºC big electrolytics of Hypex SMPS.

 

[troystg]

I think you guys are getting the wrong idea about the alternative input buffer boards for NC500. They are not using these to colour or create a house sound. The Hypex stock chip based op amp buffer certainly has a sound. The input boards from Hypex/Apollon use discrete op amps that are way more transparent. I use Sparko's versions in my bass amps for deeper bass and richer lower mids and Sonic Imagery versions in my Mid/Twt amps for detail and less forward top end. This is how they perform in my set up YMMV. I have also tried Burson V5, V6Vivid and V6Classic discrete devices. They all sound different, but are all better than the cheap and cheerful LM4562 in terms of improved detail and transparency. This is the goal of Nord/Apollon and the latest rev D boards from Nord take this a stage further using larger format discrete op amps normally found in studio gear. Not tried these yet, but there is a comparison of the two types on offer on hifi pig and I shall be upgrading my bass amps to the new Sparko's at some point for the "absolutely astonishing" bass. Nord NC500 Rev-D Input Buffer Board Upgrade | Hifi Pig

Wouldn’t that be the exact definition of house sound?

Putting in different input stages to “tune” the sound to your needs/tastes...

The nCore module is supposedly completely neutral. Why wouldn’t you want a neutral input stage? (Rhetorical question)

 

[Machismo]

I think it would be a better idea to make a separate 'distortion box' maybe with some additional EQ adjustments for 'hot midrange' etc than make changes to the amp itself.
So a similar device to a guitar effect pedal. For example if a more spacious sound is required, then something like this might work:

YouTube

Sounds amazing, huh? I think in the future, the more neutral the amplifiers become, the more people have to colorize them to make them sound right again.

 

[Julf]

Weeks ago I insisted Bruno to change two buffer resistances to better ones to increase the CMRR (PURIFI 1ET400A) but he did not seem to be very interested even though the cost increase is acceptable.

Could it possibly be that Bruno understands the issue slightly better than you?

 

[Julf]

Maybe this will bring the quality of class d amps up to the level of the best class A/B amps.

Maybe they already are...

 

[Julf]

As well as Brono Putzeys' own reports of Purifi outperforming nCore by a significant margin (If one is at all aware of Mr. Putzeys positions, he is not one prone to exaggeration, or mincing words).

He isn't, but even he has commercial interests.

And, at least for any of the (decent) engineers I have worked with, the will always improve on a previous generation project when given another go at something.

You can always improve on the measurements. That doesn't mean the improvements are audible.

 

[maty tinman]

My proposal, if I remember correctly, was to change two SMD resistor from 0.1% to 0.01% to improve the CMRR.

Key performance data:
* CMRR of at least 110dB@100Hz and better than 95dB@1kHz
* Very low noise of less than 15uV
* 680W into 4 ohm with less than 0,01%THD+N (stereo)
* S/N of more than 130dB (stereo)
* 1200W into 8 ohms with 0,01% THD+N (bridged)
* S/N of more than 132dB (bridged)

We have based our buffer on the newest opamps from TI on a four layer PCB with very short signal paths. This is mounted inside a separate compartment behind the XLR inputs for optimum shielding. A special arrangement of low noise operational amplifiers and differential amplifiers with 0,004% resistors provides a very robust input signal stage for both balanced and single ended inputs...

 

[maty tinman]

Review and Measurements of Purifi 1ET400A Amplifier | Page 15 | Audio Science Review (ASR) Forum

1ET400A has a own buffer with the OPA1612 if I am not wrong. This opamp has very good PSRR and CMRR.

Those 22 dB of difference in the CMRR measurement between the two modules are excessive, maybe these resistances have a tolerance of 5% or 10%.

As it is not yet in mass production phase in China?, I suppose that the cost of improving them will be minimal (two resistors with 0.1% tolerance). It would be necessary to make the calculations and the pertinent measurements.

Review and Measurements of Purifi 1ET400A Amplifier | Page 16 | Audio Science Review (ASR) Forum

Rod Elliott says:

http://sound.whsites.net/articles/balanced-2.htm

The bridge is most sensitive to small fractional impedance changes in one of its arms when all arms have the same impedance [ 7 ]. It is least sensitive when upper and lower arms have widely differing impedances. For example, if the lower arms have infinite impedance, no voltage difference can be developed across the line, regardless of the mismatch severity in upper arm impedances. A similar scenario occurs if the upper arms have zero impedance. Therefore, we can minimise CMRR degradation due to normal component tolerances by making common-mode impedances very low at one end of the line and very high at the other [ 8 ]. The output impedances of virtually all real line drivers are determined by series resistors (and often coupling capacitors) that typically have ±5% tolerances. Therefore, typical line drivers can have output impedance imbalances in the vicinity of 10 ohms. The common-mode input impedances of conventional line receivers is in the 10 k to 50 k ohm range, making their CMRR exquisitely sensitive to normal component tolerances in line drivers. For example, the CMRR of the widely used SSM-2141 will degrade some 25 dB with only a 1 ohm imbalance in the line driver.

Line receivers using input transformers (or the InGenius® IC discussed later) are essentially unaffected by imbalances as high as several hundred ohms because their common-mode input impedances are around 50 M ohms - over 1000 times that of conventional 'active' receivers...