Review and Measurements of Hypex NC400 DIY Amp

[Matias]

Bruno designed the highest performance class D technologies for over a decade, and now also the best measuring DAC in ASR. Results speak for themselves.

 

[Koeitje]

Bruno designed the highest performance class D technologies for over a decade, and now also the best measuring DAC in ASR. Results speak for themselves.

Same for his DACs and loudspeakers systems. Absolute state of the art.

 

[Julf]

Bruno designed the highest performance class D technologies for over a decade, and now also the best measuring DAC in ASR. Results speak for themselves.

But... But... You know, it's just that people like this... you know... they get all they want so they really don't understand, you know... about a life like Frank's. I mean, when you've loved and lost the way Frank has, then you, uh, you know what life's about.

 

[HammerSandwich]

Are you saying that class D is just a fad?

 

[Julf]

Are you saying that class D is just a fad?

Well, I don't really think that the end can be assessed as of itself as being the end because what does the end feel like? It's like saying when you try to extrapolate the end of the universe, you say, if the universe is indeed infinite, then how - what does that mean? How far is all the way, and then if it stops, what's stopping it, and what's behind what's stopping it? So, what's the end, you know, is my question to you.

 

[Voxy]

Are you saying that class D is just a fad?

it has permeated into our lives and won’t go away... TV, cars, PA systems, compact hifi, sound bar, BT speakers.... it will replace 90% of the market for most applications.

I had also a convert due to many reasons.... space, kids safety, heat dissipation etc. that’s the way to go like CD is slowly dying.

 

[Julf]

it has permeated into our lives and won’t go away... TV, cars, PA systems, compact hifi, sound bar, BT speakers.... it will replace 90% of the market for most applications.

I had also a convert due to many reasons.... space, kids safety, heat dissipation etc. that’s the way to go like CD is slowly dying.

I think HammerSandwich was responding to my Spinal Tap quote with another one.

 

[landco]

Bruno is one of the best audio engineers in the world.

In his kit-set HYPEX no radiator, at 400 watts per channel it will burn.

For comparison: Denon class D, 65 watts per channel, there are 3 radiator

And HYPEX NC400, kit-set by the manufacturer, together with the body, a complete solution: 400 watts per channel, the number of radiators - 0

 

[Julf]

In his kit-set HYPEX no radiator, at 400 watts per channel it will burn.

No, it won't.

For comparison: Denon class D, 65 watts per channel, there are 3 radiator

And HYPEX NC400, kit-set by the manufacturer, together with the body, a complete solution: 400 watts per channel, the number of radiators - 0

Has it occurred to you that the hypex design might just be much more efficient?

 

[Willem]

Thus far the fire brigade did not need to be called.

 

[landco]

Has it occurred to you that the hypex design might just be much more efficient?

All the amplifiers of class D the same efficiency of 90-95%

 

[Koeitje]

All the amplifiers of class D the same efficiency of 90-95%

So 40 watts through the chassis at full power....which is nothing.

 

[JimB]

In his kit-set HYPEX no radiator, at 400 watts per channel it will burn.
... HYPEX NC400, kit-set by the manufacturer, together with the body, a complete solution: 400 watts per channel, the number of radiators - 0
View attachment 45611

400W. One channel. But, for music, you cannot use this at 400W, continuously - MAYBE 130ish at the absolute max to avoid constant, gross clipping distortion on music peaks. Using the NC400, estimated dissipation then is about 13W and that of an SMPSN600A400 is about 10W, so 23W total in that case. As for 0 radiators, NC400 heatsinking is through it's cast aluminum 'puck' to the case. The SMPS600 waste heat dissipates to air via its aluminum plates. That case provides adequate heatsinking for the application at normal ambient temperatures and unobstructed air flow. And for most people, most of the time, it is much better than this, so the system will not have a reduced life due to operating at elevated temperatures. No problem here. This is all discussed in the NC400 datasheet:

 

[Julf]

All the amplifiers of class D the same efficiency of 90-95%

Any evidence for that claim?

 

[landco]

400W. One channel. But, for music, you cannot use this at 400W, continuously - MAYBE 130ish at the absolute max to avoid constant, gross clipping distortion on music peaks. Using the NC400, estimated dissipation then is about 13W and that of an SMPSN600A400 is about 10W, so 23W total in that case. As for 0 radiators, NC400 heatsinking is through it's cast aluminum 'puck' to the case. The SMPS600 waste heat dissipates to air via its aluminum plates. That case provides adequate heatsinking for the application at normal ambient temperatures and unobstructed air flow. And for most people, most of the time, it is much better than this, so the system will not have a reduced life due to operating at elevated temperatures. No problem here. This is all discussed in the NC400 datasheet:

I see that the Denon to the much less powerful amplifier added 3 full radiator and HYPEX, a much more powerful amplifier - radiators are not added. It looks suspicious.

 

[boXem]

In his kit-set HYPEX no radiator, at 400 watts per channel it will burn.

For comparison: Denon class D, 65 watts per channel, there are 3 radiator

View attachment 45610

And HYPEX NC400, kit-set by the manufacturer, together with the body, a complete solution: 400 watts per channel, the number of radiators - 0

View attachment 45611

Hypex stuff dissipates via the chassis, which represents about 38000 cm2 in contact with outside air. Even if Denon dissipators would be the same surface, they are enclosed in a steel chassis, which is not known for a good thermal conductivity.
If I were you, I wouldn't bet on the Denon for the coolest amp, even with lower power...
Last but not least, the heat generated by class D amplifiers is mainly due to idling losses, and here they differ a lot.

Nothing is perfect and there are defects in Hypex stuff. But to find them, you should raise the level a bit, for the moment it looks more like trolling.

 

[landco]

Hypex stuff dissipates via the chassis, which represents about 38000 cm2 in contact with outside air

there is no heat sink to the body, where do you see?

 

[boXem]

there is no heat sink to the body, where do you see?

The body IS the heat sink.

 

[landco]

The body IS the heat sink.

Show me where you can see the power supply thermal contact with the outer casing?

 

[boXem]

Show me where you can see the power supply thermal contact with the outer casing?

Fair enough. It's an old design that I hadn't in mind. But it has two heatsinks