Review and Measurements of Nord One NC500 Amp

[amirm]

Yeah okay, but it would be really easy to do:

Will have to check to make sure that heatsink is not hot. I don't think it would be prudent to check it with a voltmeter first.

 

[maty]

by PMD

https://www.audioshark.org/showthread.php?t=9369&p=279071&viewfull=1#post279071

Finally I have ordered today Nord One SE NC500DM MKII Dual Mono Stereo Amp in black, but with OP Amp Sparkos Labs SS2590 and version full grazing version: cabling Neotech UP-OCC Cu, network plus sockets Furutech FI-06 IEC & FP-S022N Mains Wire , outputs for columns WBT-0705Cu Copper Conductor Posts, inputs XLR - Furutech XLR FT-786 Rhodium, and bottle-free SYNERGISTIC SR BLUE FUSE 5A.

https://www.audioshark.org/showthread.php?t=9369&p=284516&viewfull=1#post284516

[ Because it has been tremendously busy lately, so I didn't have any time to share my impressions from listening to the warmed Nord. Meanwhile, it has over 600 hours in stock and I can't hear any further progressive changes in sound...

There was a question whether listen to the Nord is not tired in the long run. After proper heating, nothing like that happens. The last element that changed was the opening of the treble and with it the final smoothing of the sound. generally, Nord is neutral, has a flesh, does not embellish or round anything, do not improve the sound of the system with it to make it nicer, warmer or more pleasant (like e.g. McIntosh tube preamps will work). Nord will show you how your system sounds, but it is not thin or dry by itself, it does not brighten the system. It is very sensitive to the power cable, which I wrote about earlier, and it can be a surprising experience how very much you can model its sound by choosing different power cords. I tested 4 and each clearly influenced the presentation, so much that it makes matter with which it is combined. It can also be a reason for which a given sound may simply not be approached by someone. I will only add that my Pre (ARC Ref.5) is not beautifying or rounding. ARc is rather cool, resolving and precise. The elements that soften my habits can be only columns for me and maybe IC XLO Limited. No less resultant of the system allows for long relaxed listening sessions, adorned with lots of detail in the background... ]

It seems that PSRR is insufficient so that the quality of the power supply does not affect the sound, a very common problem that many try to solve by buying expensive power cables, some of which act as simple low pass filters. The logical and cheapest solution is to try first with a good RF / EMI filtering.

https://en.wikipedia.org/wiki/Power_supply_rejection_ratio

 

[boXem]

69

 

[laidick]

by PMD

https://www.audioshark.org/showthread.php?t=9369&p=279071&viewfull=1#post279071



https://www.audioshark.org/showthread.php?t=9369&p=284516&viewfull=1#post284516

[ Because it has been tremendously busy lately, so I didn't have any time to share my impressions from listening to the warmed Nord. Meanwhile, it has over 600 hours in stock and I can't hear any further progressive changes in sound...

There was a question whether listen to the Nord is not tired in the long run. After proper heating, nothing like that happens. The last element that changed was the opening of the treble and with it the final smoothing of the sound. generally, Nord is neutral, has a flesh, does not embellish or round anything, do not improve the sound of the system with it to make it nicer, warmer or more pleasant (like e.g. McIntosh tube preamps will work). Nord will show you how your system sounds, but it is not thin or dry by itself, it does not brighten the system. It is very sensitive to the power cable, which I wrote about earlier, and it can be a surprising experience how very much you can model its sound by choosing different power cords. I tested 4 and each clearly influenced the presentation, so much that it makes matter with which it is combined. It can also be a reason for which a given sound may simply not be approached by someone. I will only add that my Pre (ARC Ref.5) is not beautifying or rounding. ARc is rather cool, resolving and precise. The elements that soften my habits can be only columns for me and maybe IC XLO Limited. No less resultant of the system allows for long relaxed listening sessions, adorned with lots of detail in the background... ]

It seems that PSRR is insufficient so that the quality of the power supply does not affect the sound, a very common problem that many try to solve by buying expensive power cables, some of which act as simple low pass filters. The logical and cheapest solution is to try first with a good RF / EMI filtering.

https://en.wikipedia.org/wiki/Power_supply_rejection_ratio

How come an audio device is sensitive to power cord? Is that because the cord are badly constructed or what?
I am just curious... Thanks

 

[maty]

The power grid is much dirtier than years ago and is getting worse in urban concentrations.

https://en.wikipedia.org/wiki/Low-pass_filter

You can build a cable that works like an LPF but with very little attenuation with noise, interferences... at f > hundreds of kHz. If mains is very dirty, the difference will be noticed as long as the electronics are not well designed for the current reality, something too usual. The logical thing is to use professional solutions, of which we have measurements and graphs and not a modded cable.

PS: there is also more and more DC, but in this case it would not affect by the type of PSU used, switched.

 

[LTig]

by PMD

https://www.audioshark.org/showthread.php?t=9369&p=279071&viewfull=1#post279071



https://www.audioshark.org/showthread.php?t=9369&p=284516&viewfull=1#post284516

[ Because it has been tremendously busy lately, so I didn't have any time to share my impressions from listening to the warmed Nord. Meanwhile, it has over 600 hours in stock and I can't hear any further progressive changes in sound...

There was a question whether listen to the Nord is not tired in the long run. After proper heating, nothing like that happens. The last element that changed was the opening of the treble and with it the final smoothing of the sound. generally, Nord is neutral, has a flesh, does not embellish or round anything, do not improve the sound of the system with it to make it nicer, warmer or more pleasant (like e.g. McIntosh tube preamps will work). Nord will show you how your system sounds, but it is not thin or dry by itself, it does not brighten the system. It is very sensitive to the power cable, which I wrote about earlier, and it can be a surprising experience how very much you can model its sound by choosing different power cords. I tested 4 and each clearly influenced the presentation, so much that it makes matter with which it is combined. It can also be a reason for which a given sound may simply not be approached by someone. I will only add that my Pre (ARC Ref.5) is not beautifying or rounding. ARc is rather cool, resolving and precise. The elements that soften my habits can be only columns for me and maybe IC XLO Limited. No less resultant of the system allows for long relaxed listening sessions, adorned with lots of detail in the background... ]

It seems that PSRR is insufficient so that the quality of the power supply does not affect the sound, a very common problem that many try to solve by buying expensive power cables, some of which act as simple low pass filters. The logical and cheapest solution is to try first with a good RF / EMI filtering.

https://en.wikipedia.org/wiki/Power_supply_rejection_ratio

Uh huh

 

[NielsMayer]

So when's bruno going to update the NC400 to Gallium Nitride??
https://parttimeaudiophile.com/2019...oduces-the-114-new-gallium-nitride-amplifier/
https://epc-co.com/epc/cn/GaN技术杂谈/Post/13752/Gallium-Nitride-Brings-Sound-Quality-and-Efficiency-to-Class-D-Audio

 

[Matias]

He already answered about GaN in one of his Q&A. Google it.

 

[maty]

You know, very cheap caps in the Hypex SMPS1200.

https://www.pinkfishmedia.net/forum/threads/trouble-with-nord.233569/

To be honest I found Colin very unhelpful, he couldn’t tell me if the problem had been corrected. He said he was too busy to repair it. He just wanted to sell me some replacement boards. He also informed me that the amp was 2 years old and what do I expect.

I then contacted Hypex, they also informed me that they had had this issue. They asked me for me serial number on the power supplies...

I then contacted Hypex with the serial numbers. The responded saying mine was not one in the effected serial number range to have this problem.

To me this means this problem is endemic and could happen to every Hypex or Nord amp with this ps in. I don’t know what to do, I am the thick end of 2k down with nothing to show for it !

Hypex said replace C38 and C39 caps, but I am worried if I do I won’t have a leg to stand on when taking this further.

https://www.pinkfishmedia.net/forum/threads/trouble-with-nord.233569/page-2#post-3804680

by Nord

As above I have been in touch and will resolve the issue next week. I guess we are all human and we backed each other into a corner, a corner from which I apologize.

I would say its only affected a small % of early amps. The above amp was nearly 3 years old and the 72 we produced...

 

[maty]

https://www.pinkfishmedia.net/forum/threads/trouble-with-nord.233569/page-3#post-3807358

by droom3

Had a similar problem with a Hypex stuffed Audiotronics Audiophonics power amp. The French manufacturer declined to sell me a replacement for a blown module and only wanted to sell me a new amp.

Contact with Hypex directly did not resolve the matter and they wouldn't sell me a module either saying that they were OEM. I ended up getting a module from another source.

It was all unsatisfactory, a closed shop and really poor customer service all round.

 

[DKT88]

https://www.pinkfishmedia.net/forum/threads/trouble-with-nord.233569/page-3#post-3807358

by droom3

I wonder if its better to leave these Hypex amps on all the time to avoid inrush current.

 

[maty]

When not in use it is better to turn them off. Another thing is to turn them on for a while before listening to music, class A and class AB amps.

About two years ago I had a power surge because of some old power company cables, 400 Vac (Spain: 230 Vac / 50 Hz). The stereo was saved thanks to a varistor that I decided should have the DC blocker x4 ME (from the first DCB protototype). It also burned one of the two fuses.

[IMG, link] http://maty.galeon.com/WP-imagenes/hum/ATL-Hi-Fi-DC-Blocker-x4-ME-open-front-side-3.jpg

Other option is a DIY SMPS with much better components. Pinnocchio using them for the new amplifier you are mounting. Made by Cresnet.

https://www.diyaudio.com/forums/solid-state/312866-global-loop-amplification-post5973161.html

[IMG, link] http://maty.galeon.com/WP-imagenes/hum/Simpelstark-with-Cresnet-smps-by-pinnocchio.jpg

 

[Bear123]

What is the input voltage required to get rated power out of this amp? I have a Denon X3300 which I assume will perform about the same as the Denon X3500 tested on this site. I have considered getting the 3 channel version of this amp and I saw that the pre-outs at 2 volts measured 74 dB or so, while at 1 volt were much better at 95 dB.

Another question....does it matter? Will I hear the .02% distortion from a 2 volt signal being fed to this amp from my Denons pre-outs? Will I be able to say the .002% distortion sounds so much better? I've seen some opinions that it won't matter much for movies but this is a dual purpose system for both music and movies.

I've poked around but haven't been able to quite figure out how much voltage this amp needs to reach rated power....not that I need quite that much....my speakers are only rated for 200 watts.

 

[amirm]

What is the input voltage required to get rated power out of this amp? I have a Denon X3300 which I assume will perform about the same as the Denon X3500 tested on this site. I have considered getting the 3 channel version of this amp and I saw that the pre-outs at 2 volts measured 74 dB or so, while at 1 volt were much better at 95 dB.

If my math is correct, you need 2 volts to reach max power given the 27 dB gain.

 

[Bear123]

If my math is correct, you need 2 volts to reach max power given the 27 dB gain.

Amir, thank you so much. Based on rudimentary napkin math, this tells me I should be able to fully power my 6 ohm speakers(rated at 200 watts) with less than 1.5 volts which should yield better(than 74 dB) performance from my Denon's pre-outs. Figured it makes sense to ensure I'm not feeding a $1700 95 dB amp a dirty signal from a $600 AVR.

 

[BobPM]

Power or every last bit of distortion? I have been in the market for an amp and have been reading this website for the last couple of months and haven't really come to any conclusions on what to get. If I go with the Nord base NC500 amp I get more watts for my 86db efficient speakers that present a mostly 4 ohm load. If I go with the NC400 DIY, I get lower distortion but less power. I have also been considering the new Purify DIY, but don't think I am ready to move until someone puts together a decent kit and it has about the same power as the NC400.

I am inclined to the Nord so I can switch out buffer boards in the future and it has more power. Anyone have an opinion on whether the ultimate distortion measurement or the higher power output will have the most noticeable effect on the sound?

 

[Armand]

Vera Audio will release a new amp in february. Vera P150/600.

Same size cabinet and basically the same as Vera P400/1000 but without the fans.
https://www.vera-audio.com/product.php?product_id=1&fane=1
Very accurate gaincontrol in 3db steps (0,01dB channel accuracy on all steps).
Custom buffer with OPA1612 and INA1620 opamps with extremelsy low noise. (16-20uV depending on gain)
CMRR of minimum 89dB at 1kHz.
Balanced input only.
Bridgable.
3kW power supply.

Here is a sweep of the preliminary prototype. The jumps in THD+N is due to measurement gear changing scale invreasing its noise. The minimum is probably less than 0,0002% around 200-300W.
900W into 4 ohm with 0,0004% is impressive.

IMD both channels at 5W into 4 ohms.

Linearity:

SINAD 5W 4 ohm

Armand.
Vera Audio

 

[Samoyed]

Nice. Active cooling?

 

[Armand]

P400/1000 with active cooling yes.
Below 27 degrees celcius ambient and less than 300W music power the fans are not running at all. After that they start at 500RPM. Yes, 500. That is actually less than 0dB SPL.
Also note the aluminum cooling bar that cools the NC500 coils. Only Vera uses this solution which alone reduces the temperature 15 degrees celcius on the output coils.

The new Purifi model if more efficient, has less power and does not need extra cooling.

 

[Bear123]

Power or every last bit of distortion? I have been in the market for an amp and have been reading this website for the last couple of months and haven't really come to any conclusions on what to get. If I go with the Nord base NC500 amp I get more watts for my 86db efficient speakers that present a mostly 4 ohm load. If I go with the NC400 DIY, I get lower distortion but less power. I have also been considering the new Purify DIY, but don't think I am ready to move until someone puts together a decent kit and it has about the same power as the NC400.

I am inclined to the Nord so I can switch out buffer boards in the future and it has more power. Anyone have an opinion on whether the ultimate distortion measurement or the higher power output will have the most noticeable effect on the sound?

Personally, I would say you are better off going with more power. The NC500 has distortion so low that it is audibly transparent, so I'm not sure if it matters having distortion even lower than what can't be heard anyways. However, running out of power and clipping the amp will certainly be heard, so I personally don't see the reason to spend a lot more money for much less power and a little lower distortion(for the Puri or Benchmark). Nord's 3 channel I think comes to around $1700 shipped with a 10% code that is available. The other bang for the buck contender imo would be the Monolith 3/5/7+ channel. It doesn't have as much power as the Nord but if its more than you need, it is somewhat cheaper and seems to measure quite well(on Audioholics)