January 01, 2020

HiFi Pig Review of the Nord One UP NC500DMST Highly Recomended By Lionel Payne

Class D is gaining a good deal of momentum in the audio world. Lionel Payne listens to the the Nord One UP NC500 DMST stereo power amplifier costing £1409.

The Nord One UP power amplifier is the brainchild of Cheltenham based designer Colin North and designed around the Hypex nCore NC500 modules. Built within a three-quarter width all aluminium case, this Class D power amplifier is a true dual mono design. The 10mm front panel is available in standard black or silver, or for a relatively small cost premium, numerous exotic veneered finishes are available. Mine arrived with a very attractive American Black veneer which I felt easily warranted the small surcharge.  There is a solitary on/off button to the front fascia which is surrounded by a blue LED light and to each side of this are three parallel grooves. Above the power button lies the Nord logo badge. Around the back are solid brass gold-plated quality binding posts for 4mm banana plugs, spades or bare wire (up to 8mm) as well as an IEC socket, an on/off switch and XLR sockets (note : no RCA inputs here). The Nord One UP can deliver up to 400watts per channel at 8ohms resistance, 700watts at 4ohms and 550watts at 2ohms and despite the Class D generation of amplifiers being renowned for their efficiency and low running costs this power amplifier does run a little warmer than one would expect. However, the casework is well designed and allows airflow through vents on the bottom as well as the top panel. New casework has been announced.

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When I first received the Nord One UP it was in Revision B form and came to me with Burson V5 and Sparkos Labs SS3602 as alternative op-amps. These op-amps are interchangeable internally through an eight pin DIP socket and it takes literally a few minutes maximum to change over. I found the Burson op-amp very similar to my old feelings of Class D amplifiers; all being rather cold and clinical affairs , albeit with a fabulous tonality. I’m pleased to say that none of the old feelings arose when listening through the Sparkos op-amps as I now found the music took on an all new feeling of tremendous organic quality. A sound I have to say that really impressed me, particularly given the asking price.

A short time after receiving the amp I happened to bump into Colin North at a hifi show in the Midlands, and we had a good discussion about his product. He explained to me that the product’s design was still evolving and he had discovered an even better op-amp but unfortunately it was adding unwanted noise to the circuit. He explained that he felt the voltage regulation board was at fault and was working on improvements to make the circuit silent with this new op-amp. I suggested, if possible, that I would love to hear this new version of the product when he had cured its teething problems. A short time later the Nord was sent back to Cheltenham and returned to me in Revision C form with an upgraded (and, I’m told, more costly) voltage regulator with the new Sonic Imagery 994 op-amps installed. Colin had promised a similar sound but with more air around instruments and a much better soundstage with the trade-off being a slightly less fulsome bass response that the Sparkos  op-amps could provide. 

On being re-acquainted with the Nord One UP I immediately found that the soundstage had, indeed, improved with Revision C and the Sonic Imagery  994 op-amps (pictured above). Playing Sting’s “Live In Berlin” disc through the Acoustic Precision Eikos  CD player resulted in startling imagery as well as superb tonality and timing. I went on to play quite a few of my favourite and most well-known CD’s back to back. I loved the air around instruments and the 3D soundstage which was so much better than I remembered but something kept tugging at my consciousness to tell me something was missing, and try as I might, I didn’t immediately recognise the missing element. The amplifier appeared to be playing music with the same qualities it had shown before – namely, a superb tonality with great dynamics and a wonderful ability to shift scale and weight with tremendous athleticism. Crescendos are replayed with fabulous enthusiasm with the Nord. Listening to Nick Cave’s “Red Right Hand” caught me out one time as it followed a quietish acoustic track on my playlist and the opening bell on the track had me jumping out of my skin !

Unfortunately, when the amplifier was returned to me, the inclusion of the Sparkos Labs op-amps had been over-looked and I was left to ponder whether the missing element was linked to the Sonic Imagery op-amps. I contacted Colin for the Sparkos to be sent over and within a few tracks after swapping the op-amps I finally recognised the difference. To my ears, and your opinion may vary from mine, the difference was almost completely visceral. The Sonic Imagery op-amps are very good and I’m sure some will find that they prefer them in their system. However, I found the Sparkos op-amps to be more organic in quality and they would draw me far deeper into the emotion of the music.  There is a little more fullness to the lower regions with the Sparkos but it’s far from a chalk and cheese situation. In fact I found the Sonic Imagery to be perfectly acceptable in all areas of the sound spectrum, but emotionally I was drawn in by the Sparkos. This may be a result in my favoured genres of music that I prefer to listen to, as I prefer a good amount of acoustic material mixed mainly with Indie and rock music, although my overall collection is extremely eclectic.

I have to admit that this review has been quite a prolonged one, and that is partly due to how much I have enjoyed the Nord One UP within my system. It also proved to be a godsend as my own trusty Musical Fidelity Tri Vista 300 integrated amplifier blew a channel during the review period. This required an extensive repair (my grateful thanks to John Sampson of for a fantastic job) but while I had the Nord One UP I was never left wanting for more. In fact, as it is a very even-handed, neutral sounding amplifier it proved an invaluable asset during it’s time as my substitute reference.


Having this power amplifier within my system for so long has certainly allowed me plenty of time to analyse its strengths and weaknesses. I have also used it to drive a fair few pairs of loudspeakers, not all of them an easy drive, and I have to say it has proven to have the grip of an Olympic shot-putter on steroids ! It drove Shahanian Obelisks with ease and also, when partnered with PMC FB1+’s delivered a soundscape better than any other amplifier I had ever tried with them.

However, having superb grip and drive is not the only strength of  this power amplifier. When subtle is required, the Nord delivers with equal control and finesse. As previously stated it also has a wonderful control of differing dynamics within a mix and delivers crescendos with superb precision. I used even-handed as a description earlier in this review and that is exactly what you get with the Nord. To reveal any weaknesses is a difficult proposition as I feel it has none at all, and at this price point must resemble extremely good value for money. Another selling point is the opportunity to try different op-amps which can tailor the sound to your tastes. It is even an economical amplifier in use, using far less electricity than most other amplifiers with this quality.

What’s not to like? If you are looking for a new power amplifier in this area of expense, get this one on your audition list!



Wonderful soundstage

Even-handed with all types of music

Sound can be tailored with differing op-amps

Powerful with frugal running costs

Fantastic grip for even difficult loads


Nothing at all at this price 

Build Quality:

Good with well laid out internals

Sound Quality:

Can sound a little clinical in some systems but the op-amps will help

Wonderful even-handed presentation in the right system

Value For Money:

An astonishing price of £1409 this power amplifier represents a true bargain buy

Price: £1409

Lionel Payne 

HiFi Pig Review, Highly Recomended

June 27, 2016

Nord One UP 500 DM ST Dual Mono Stereo Amplifier Review  


And you think you’re so clever and classless and free…Speaking as a peasant. I don’t like Class D amplifiers.


Well, I have kept a weathered eye on the world of Class D amplifiers. And I have seen it move from being only suitable for bass speakers to something a little better, but not that much better. Following all the glowing reviews on the web I bought a pair of Nuforce power amps. We went through Version V1, V2 and V3 together and although they improved I still found the good came with bad. The good was the neutrality in the frequency response and the ability to go really loud. They could push out nearly 200w without getting hot and weighed less than Boris Johnson’s book of tact. The bad was the dynamics and the high frequencies. The dynamics were flat and not really involving.


The high frequencies were really odd despite reading on the net that the high frequencies were exceptional. Yea, exceptionally bad. Real they were not. So I just went back to keeping a cynical eye on developments. Oh and wondering what some guys were drinking and where I could buy some.

All went quiet and then along comes a guy called Bruno Putzeys with a brand new breed of Class D. Last year I had a chance to hear the latest creation from Bruno Putzeys, who by that time was the new wunderkid on the Class D block. He had updated his UCD Class D amplifiers to the newer cleaner, super nCores. They are sold through Hypex amplifiers. They have bucket loads of negative feedback and a switch mode power supply, of all things. I heard the nCore NC1200 in the Merrill Veritas and the UCD 400 in the Merrill Thors. Kevin Fiske wrote up his thoughts about them on the Wam. For me, despite all the good they still had that flat and undynamic sound that did not involve me. So having tried two bites of the Class D cherry I concluded they were not for me. Hey ho….. back to the drawing board and just keeping an eye on things.
Next, guess what……a new net buzz. This time it was about the newest guy in town, Nord Amplifiers, with the recently developed nCore NC500 amplifiers. The Nord amplifiers are made in Cheltenham. Was this a case of the same old, same old??


They had brought some new USPs (unique selling points). Nord had changed the voltage regulators used in the amps from chips to discrete components, which has certainly helped Naim amplifiers, although these two amps are poles apart. Nord also introduced the ability change the Op amps from the stock LM4562 to the more expensive and better(?) Sparkos opamps or the even better Sonic Imagery 994 chips. Nord also offer Burson op amps as well if you prefer their sound. The amplifier has a socket on the main board that will take any of these opamps and all you do is plug/unplug to change the sound of your amp for the cost of an op-amp. Good idea if it works.
So I got the stereo power amplifier with the Sonic Imagery 994 op-amps. This amp produces 400w per channel at 8 ohms, 700 w at 4 ohms and about 550w at 2 ohms. A real powerhouse. As with most Class D amps it is small and light. I plugged it in and let it warm up. I use an Auralic Aries digital front end. This feeds my Audionote DAC 2.1x, a Nuforce P9 pre-amplifier and the sound comes out of my Audionote E HE Signatures. Now these speakers do not need 500w/channel (6 ohm speaker impedance) but there is no way they are going to run out of power. Oddly enough the power amps actually get warm to the touch. They only generate 40w of heat, which is channelled through to the case, so the cases do get warm. Not hot. They are still as efficient as other Class D amps.

As with most NC500 amplifiers they only accept XLR inputs (Nord can sell you a RCA/XLR cable which does the job). The connectors used are of a good quality, Switchraft XLRs and CHK for the speakers. The case is made in Italy and whilst better than the case on my Audionote preamps it is, fortunately, not expensive audio jewellery.

So the big they have all the positives of Class D and finally get rid of what for me was the big negative of a flat and undynamic sound. YES.

OK giving you some more information than that. I use a wide range of music to try out new components and a lot of it is not audiophile music which I find in most cases boring and bland.

This amplifier sounds sublime. It is very neutral, has a tremendous amount of real detail that is nicely presented and integrated into the music. The bass is deep and powerful and has great tonality where you can tell what strings are being used on a bass guitar as opposed to a boom, boom, thud, thud. It is very clear without the mid-range boost used by other amps attempting to give you detail, DETAIL, detail.

As I said I have pretty wide tastes in music and I play a lot of classical music including piano music and opera (when the wife is out as she hates it). Classical piano music is very difficult to reproduce correctly. I find the Nords are very truthful and will show when the recording is done naturally or has been messed about with mics on the lid or using ‘fill-in’ microphones.

Classical piano is not only a stringed instrument but a percussion instrument with a large wooden sounding board that can echo well in a hall. The Nords play well recorded pianos really well and maybe only miss out on a little of the weight of the piano. Although with some burn-in that improves. So for me that makes it one of the better SS amps. It can really highlight how much other SS amps mess up something simple like the frequency response or make instruments sound fuzzy and indistinct.

Pop pianos have a wide range of tones with very dry being favoured to add impact but there are very few really natural recordings. I find with a lot of SS amps that it can be difficult to tell whether the piano is real or electronic. That was less of an issue with the Nord.

I have recently really enjoyed recordings of Maria Callas and a lot of SS amps can make her powerful voice sound edgy, especially when she really lets go. The Nord rarely if ever do that. Her voice is very, very clear. It really lets you know that although she may not have been the most technically brilliant singer the emotion in her voice can on occasions be off the scale good.

When I was around at the manufacturer’s place he played Eilen Jewel’s live album. I was transported back to Texas where I was sat in a bar, having a few beers, eating peanuts and tossing the shells over the bench and really enjoying the music. What a great time. At home I had that same experience again. The music sounds very alive and the detail was easy to hear without harshness.

‘London Lights’ on Songs of Separation has the singers and the band in my room. When the backing singers came in it was easy to hear how many people were singing, with their different tonal qualities and trying to guess who had the most powerful voice. Although the bass sounds light when you first hear it, if you listen carefully the bass is there, it is very clean and very, very deep.

With live Roger Waters at an incredible volume level (empty house) the naturalness of the amp stopped the sound from becoming unbearable or shouty. The amplifiers are more truthful and some of the on-stage dynamics were outstanding. Passenger’s ‘Let Her Go’ was poignant and really sad and the amplifiers show how he changes the way he sings to emphasise what the words are saying. Some SS amps can make his voice mono- emotional. It ain’t.

Overall the problems with the previous Class D amps has mainly gone and the use of better voltage regulators and higher quality op amps has really improved the dynamics without losing the good things from the nCore amps.

If you prefer a different type of sound you can always change the op amps. I had the Sonic Imagery 994 op amp. I tried the Sparkos and they gave me a more weighty sound with a small emphasis on bass impact and a slight softening of the dynamics. Comparing the two, I would say it is down to your own personal preferences. Do you prefer Rioja or Beaujolais….?? I preferred a Beuajolais (Sonic Imagery 994) as a lighter more dynamic wine as the Rioja (Sparkos) is a little too full bodied. Although having said that, I do like a nice Chateauneuf du Pape (Audionote). The opamps were not fully burned in so their sounds may change a bit. Whichever you prefer remember it does not cost a lot to experiment. And speaking of cost this stereo amplifier cost me £1350, which gives you an awful lot of amplifier for the cost.

I bought it at full price, £1350. Yes, Mr Dudley there was no accommodations or price reductions for good reviews here. Just a normal punter paying full price. But in the world of nCore Class D that is a cracking price.
I did pitch it against my Naim Supernait2 and whilst the Naim is meaty, beaty big and bouncy it sounds somewhat artificial compared to the neutrality of the Nord. Heresy about Salisbury but that it is what I heard.
If you get a chance, try to hear it at the Cranage North West Show if not give Colin a quick e-mail or call at Iqspeakers.

It has now become my summer amplifier as the Audionotes put out too much heat in the summer. Oh and the Krell 600 monoblocks have gone.



If you want to be a hero well just follo

By George Sallit from HiFi WigWam

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