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Review and Measurements of Hypex NC400 DIY Amp

maty

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You are right about the reactive load. It is another of the problems of the current electrical grid, especially if you live near supermarkets or industrial centers a few kilometers.

Well, the HF noise injected what interest us is usually inside the LF (< 300 kHz) and MF (< 3 Mhz) bands that surround us, then we say the same. It is the noise/interference that must be filtered in class A and AB.

In class D, the > 1 Mhz must also be taken into account. That interference many people have not taken into account when building amplifiers in class D, accustomed to the problems of class A and AB technologies.
 
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Roen

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Multiple ganged pots like this:

View attachment 20450

Or these days, mostly done in silicon with VCAs or digital attenuation at 24/32 bit.

Lots of ways to skin a cat.
The reason why I ask is that in the headphone world, it's generally best practice to maximise digital volume and use analog volume control to arrive at desired volume levels, at least to the best of my understanding.

I wonder why it is tough to achieve this in the Home Theatre world?
 

svart-hvitt

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These aren't the droids you are looking for.

Coming from a company that refuses to release schematics, service manuals or even sell spare parts directly to their own customers? How many people in far flung countries are effectively forced to landfill their gear due to those practices? Sustainable, I don't think so.

@restorer-john , you raise some interesting points on sustainability that I wanted to elaborate on :)

Many companies insist on servicing their own products, for a myriad of reasons. Some reasons are profit oriented, others are customer focused.

Genelec have about €30 million in annual sales, of which 15 percent go back into R&D. So margins are high, on an EBITDA level. I imagine the size (small, but big in a niche) makes Genelec vulnerable to copy-cats. High resolution schematics and spare parts scattered all over the world would make it easier for the most competent copy cats to copy the company’s accumulated R&D intangibles. Remember, Chinese copy even spare parts for highly specialized goods like aircrafts.

In some cases, Genelec have worked with the same distribution partners for over 30 years. Having a skilled distribution network is of great value; needless to say isn’t it?

So sharing high resolution schemetics and distributing spare parts to a jungle of autodidacts, industrial spies, hobby solderers and the like; how intelligent is that? @March Audio has had his time explaining this from a startup point of view.

Your remark on landfilling is important though. Consumerism and global trade of cheapo products; are they compatible with sustainability?

As you know, Genelec speakers are strikingly expensive. And hardly something you discard after a malfunction.

Here’s what @Thomas Lund wrote just around the days our retailers celebrated their sales campaigns of the fall of 2018 and just in time for Christmas:

«Slow buying
  • Published on November 22, 2018
Do yourself a favour. Do Earth a favour. Don't buy a new smartphone, a new sofa, a new lamp, a new loudspeaker, a new whatever. Use what you have a little longer».
Source: https://www.linkedin.com/pulse/slow-buying-thomas-lund/

Audiophiles I talk to always ask when I will discard my speakers for something new. This is the mentality that deserves shaming, wouldn’t you agree?
 
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restorer-john

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Many companies insist on servicing their own products, for a myriad of reasons. Some reasons are profit oriented, others are customer focused.

Obtaining schematics/service manuals back in the day (70s/80s/90s) was controlled to a certain extent due to the fact they were large format foldout schematics, often multi-colour and had to be ordered directly from an 'authorised' parts reseller or directly from the distributors/manufacturers. There was a defacto weeding out of unqualified hobbyists.

Digital scanning, laser colour printing and internet distribution of high res PDFs didn't exist, so there was little chance of your IP getting into the wrong hands. The low-cost Chinese manufacturers were merely making fireworks, chopsticks and Tai-Chi balls, not HiFi.

Technical manuals were always obtainable however, but they were expensive. A typical Sony, Yamaha or Pioneer service manual was AU$30-$50 from an authorized reseller. For dealers with factory supported, warranty service departments, every single available manual was free and supplied (at least two copies). Often new model service manuals would arrive in our service department before the new products themselves.

Then the world went through a very bad time where parts and information got hard to get. Fortunately, the penny has dropped and the 'right to repair' movement is forcing EU changes that are being enshrined into law. There is pressure worldwide for manufacturers to do a better job, once again. Genelec (and others) will be forced to provide schematics and parts to enable repairs to be performed or face massive fines.

Go look at a 70s, 80s, early 90s service manual for a random brand's HiFi component. Go to the parts listings. Every single part was available. Easily. Cheaply and quickly from Japan or locally.

parts.jpeg
 

Ron Texas

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@restorer-john

«Slow buying
  • Published on November 22, 2018
Do yourself a favour. Do Earth a favour. Don't buy a new smartphone, a new sofa, a new lamp, a new loudspeaker, a new whatever. Use what you have a little longer».
Source: https://www.linkedin.com/pulse/slow-buying-thomas-lund/

Audiophiles I talk to always ask when I will discard my speakers for something new. This is the mentality that deserves shaming, wouldn’t you agree?

There are a lot of things which will do the earth a favor, but you will not notice it. However, this will improve your financial situation and you will notice it. Use it up, wear it out, make it do, do without.
 
OP
amirm

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Technical manuals were always obtainable however, but they were expensive.
When I was repairing audio gear in 1970s, most of the time we did not have schematics so had to reverse engineer everything. The only ones we had schematics were for the lines we were authorized warranty service center. And oh, that business sucked because they would be a fraction of what a retail customer would pay for the same repair.
 

Theo

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High resolution schematics and spare parts scattered all over the world would make it easier for the most competent copy cats to copy the company’s accumulated R&D intangibles.
As Amir said above, when you really want to service or... copycat:mad: an equipment, reverse engineering is the way to go. Certainly cheaper than doing the R&D work yourself:p. So, if someone wants to copy Genelec or major brands technology, I'm not sure they would need parts or schematics...
 

sergeauckland

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Back in the 70s when I was designing Pro audio equipment, mostly for broadcast, all our 'user' manuals were in effects service manuals as they contained full circuit diagrams and setup information. Our customers demanded such information as part of the Conditions of Purchase. We also had to supply spares kits for typically 5 years operation, and guarantee spares availability for 10 years, containing all the components that one couldn't just go to a Radio Shack or equivalent in Africa or South America and buy.

For a studio installation or Outside Broadcast vehicle, the manuals filled a good size crate. However, in those days we didn't have to worry about copies of our kit turning up in the market. One broadcast company I was speaking to recently who no longer supply circuit or detailed software information told me of going to a trade show in Asia and finding copies of one of their products being shown openly. They knew it was a copy as they bought one and took it apart and found that even some of code had the same bugs in it that they had in one of their earlier versions!

S
 

Toku

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Obtaining schematics/service manuals back in the day (70s/80s/90s) was controlled to a certain extent due to the fact they were large format foldout schematics, often multi-colour and had to be ordered directly from an 'authorised' parts reseller or directly from the distributors/manufacturers. There was a defacto weeding out of unqualified hobbyists.

Digital scanning, laser colour printing and internet distribution of high res PDFs didn't exist, so there was little chance of your IP getting into the wrong hands. The low-cost Chinese manufacturers were merely making fireworks, chopsticks and Tai-Chi balls, not HiFi.

Technical manuals were always obtainable however, but they were expensive. A typical Sony, Yamaha or Pioneer service manual was AU$30-$50 from an authorized reseller. For dealers with factory supported, warranty service departments, every single available manual was free and supplied (at least two copies). Often new model service manuals would arrive in our service department before the new products themselves.

Then the world went through a very bad time where parts and information got hard to get. Fortunately, the penny has dropped and the 'right to repair' movement is forcing EU changes that are being enshrined into law. There is pressure worldwide for manufacturers to do a better job, once again. Genelec (and others) will be forced to provide schematics and parts to enable repairs to be performed or face massive fines.

Go look at a 70s, 80s, early 90s service manual for a random brand's HiFi component. Go to the parts listings. Every single part was available. Easily. Cheaply and quickly from Japan or locally.

View attachment 20473
Previously, I have ordered SONY repaired parts at the request of a friend of USA. Procedures were troublesome for the export model, but it was possible to obtain repair parts. But now it is no longer possible.
 

snip3r77

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Since this amp's sinad is slightly more than a hundred
hence, ANY DAC that can do more than 1xx should be sufficient I guess
 

Jaimo

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Just spent the evening reading through this thread - I feel like I need to buy a few folks an appreciation beer sometime soon - Restorer John, 6 Speed and of course Amir to name a few
 

GioF71

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Hello, I would like to thank Amirm for this review. It has been the confirmation I needed to pull the trigger on a similar amp, a North Acoustics NC 502MP SE. I set it up yesterday with a Aune S6 as dac/preamp, driving a pair of Kef LS50. I am really satisfied with the change (I was using a PopPulse T150).

I wonder if a dedicated preamp (maybe passive) might be advisable. Must not be too expensive though :)

Thanks again!
 

filo97s

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i've built months ago an amp around an Anaview AMS 1000 module... I would be very interested in how this compare to the hypex.
I've done some researches and found that is a module commercially used also in the Marten M-AMP and in Amphion pro amps, i really like the sound but i do not have the equipment to test it.
Comparing specs from datasheets i see an SNR of 93dB (measured at 1W) vs hypex' 124dB, and a noise of 60 vs 23uV, but the anaview is interesting because it costs way less than the NC400, around 360 dollars for the bigger version and 150$ for the smaller AMS0100.
Recently i've added also some chinese VU meters driven by an instrumentation amplifier since they're adding quite a lot of noise when idling using only the board provided. Don't know why this problem is only when no signal is fed, maybe something related to balanced drive.

For those interested: http://www.anaview.com/sites/default/files/PDS AMS1000-2600-C.pdf
 

Bjorn

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i've built months ago an amp around an Anaview AMS 1000 module... I would be very interested in how this compare to the hypex.
I've done some researches and found that is a module commercially used also in the Marten M-AMP and in Amphion pro amps, i really like the sound but i do not have the equipment to test it.
Comparing specs from datasheets i see an SNR of 93dB (measured at 1W) vs hypex' 124dB, and a noise of 60 vs 23uV, but the anaview is interesting because it costs way less than the NC400, around 360 dollars for the bigger version and 150$ for the smaller AMS0100.
Recently i've added also some chinese VU meters driven by an instrumentation amplifier since they're adding quite a lot of noise when idling using only the board provided. Don't know why this problem is only when no signal is fed, maybe something related to balanced drive.

For those interested: http://www.anaview.com/sites/default/files/PDS AMS1000-2600-C.pdf
I have compared AMS1000 to Hypex NC400. AB testing back and forth with some level matching but not withing 0.1 dB. I found the NC400 a tad more open and transparent sounding in the highs (or could be midrange too). The slightly less "resolution" from AMS1000 made them however less revealing, which I'm sure some may prefer. They are both great.

The smaller AMS0100 has lower distortion on paper compared to AMS1000, so it may be on pair or closer to the NC400 in transparency. I haven't tested it yet though.
 

filo97s

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I have compared AMS1000 to Hypex NC400. AB testing back and forth with some level matching but not withing 0.1 dB. I found the NC400 a tad more open and transparent sounding in the highs (or could be midrange too). The slightly less "resolution" from AMS1000 made them however less revealing, which I'm sure some may prefer. They are both great.

The smaller AMS0100 has lower distortion on paper compared to AMS1000, so it may be on pair or closer to the NC400 in transparency. I haven't tested it yet though.
yes i've read that the 0100 is slightly better but at the time it was out of stock for over 2 months in Europe, so i decided to go with the 1000.
It's a nice diy kit for the price, better than the equivalent icepower for me.

Sometimes i wonder how much i have to pay in order to find the same performance on a standard amplifier... Can the hypex or anaview be comparable to, say, a Roksan blak or a Luxman LX-550AXII?
 

Bjorn

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Sometimes i wonder how much i have to pay in order to find the same performance on a standard amplifier... Can the hypex or anaview be comparable to, say, a Roksan blak or a Luxman LX-550AXII?
They are likely to be far better then such exotic amps, which normally have a good amount of audible distortion. But if you want distortion and think that sounds better, the answer is different. The best class D amps don't really add audible distortion.
 

filo97s

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They are likely to be far better then such exotic amps, which normally have a good amount of audible distortion. But if you want distortion and think that sounds better, the answer is different. The best class D amps don't really add audible distortion.
so from the point of view of distortion, precision, accuracy, driving capability and resistance to phase shifts/low impedance loads, a class D performs way better than exotic amps? Really interesting.
Is there an off-the-shelf amplifier that can perform similarly or hypex can be judged as a "last man standing" ultra high end amp?
 

Bjorn

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so from the point of view of distortion, precision, accuracy, driving capability and resistance to phase shifts/low impedance loads, a class D performs way better than exotic amps? Really interesting.
Is there an off-the-shelf amplifier that can perform similarly or hypex can be judged as a "last man standing" ultra high end amp?
Or as good it gets as long you the load doesn't drop much below 2 ohm and you have sufficient watts for the usage. There are a few amps of other classes with good amount of watts that more or less rival Hypex, i.e. the Halcro and ASR Emitter II. But they cost much more and I don't see them being any better.
https://halcro.com/product/eclipse-mono/
https://www.stereophile.com/content/asr-emitter-ii-exclusive-integrated-amplifier-measurements
 

filo97s

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Or as good it gets as long you the load doesn't drop much below 2 ohm and you have sufficient watts for the usage. There are a few amps of other classes with good amount of watts that more or less rival Hypex, i.e. the Halcro and ASR Emitter II. But they cost much more and I don't see them being any better.
https://halcro.com/product/eclipse-mono/
https://www.stereophile.com/content/asr-emitter-ii-exclusive-integrated-amplifier-measurements
holy... 125k $... i've always read and believed that class D are a great bargain for the price but don't expected that much. Interesting to see that apart from fancy caseworks, even mcintosh and similar other high priced amps, have a THD that is at least ten times more than the hypex.
 
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