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Review and Measurements of Hypex NC400 DIY Amp

6speed

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#21
@amirm do you have the ability to do THD vs frequency at a several constant power output levels? I would hope to see nearly straight lines that would be on the Z axis in your THD vs power graph above. Here is a Bryston 4B3 for reference:
 

rajapruk

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#22
A nc400 module is designed to have it's own smps600. Would that improve these measurements even more, you think?
Or is it sufficient to use only one smps600 per dual nc400 like this?

I am also concerned about the SMPS longevity of these components due to heat. Solutions to that would be welcome.

I am planning to build nc400 amps again, soon. I had 3pc of bridged dual nc400 monoblocks, each with single SMPS1200A400, some years ago.
 

rajapruk

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#25
I built this as a stereo unit to save money and maintain a compact footprint. As an alternative power supply, Hypex also has the SMPS1200A400, which has far better heatsinking, higher output power, and also fits the same case. I have used that to power UCD modules.
The wiring for 1 smps600 for dual nc400, did you do it yourself?
 

rajapruk

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#26
One reason for me selling my previous nc400 builds was because I did not have the confidence they would last forever. Next time, I will make heat a higher priority in the design.
 

LarsS

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#28
Built these nCore NC400 monoblocks five years ago. Notice the heatsinks, really good chassies from a German firm, name escapes me now.

1545954445563.png


They never made it for me, could it be the jagged waveform, sold them after a year or so.

Would be interesting to see how much they can deliver continously (FTC way), seems as they only publish Peak power for the NC400.

1545954894612.png
 
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amirm

amirm

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Thread Starter #29
I had also noted how cool the chassis stays even after listening to loud music, but had not popped the top to touch the SMPS heatsinks.
Just a caution: I did not check to see if the heatsink is isolated from the transistors. If it is not, it may be running at rectified mains voltage that could be lethal. So please be careful :). A remote/IR thermometer may be a better idea.

Thanks a lot for loaning the unit to me by the way. :)
 
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amirm

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Thread Starter #31
@amirm do you have the ability to do THD vs frequency at a several constant power output levels? I would hope to see nearly straight lines that would be on the Z axis in your THD vs power graph above. Here is a Bryston 4B3 for reference:
Sure. What power levels do you like to see?
 

levimax

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#33
Sure. What power levels do you like to see?
Great review. I didn't ask the original question but I would be interested to see 250 mW ..... not only is this where amps are commonly operated but many amp's performance falls apart at low levels. Thank you.
 

LarsS

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#34
Hypex do specify cont power for the OEM nCores eg NC500. Comparing the NC500 figures with the NC400 makes me think the NC400 actually is a ~80W cont power amp ... or?

1545957275905.png
 

restorer-john

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#35
OK, so let's clarify the power output here.

We get [email protected] 4ohms, both channels driven (on a single PSU) just prior to clipping. The unit is marketed with a headline number of 400W at 4ohms and only when you look hard at the specs do we see it may not be the case.

What does it do at the industry standard of 8 ohms, with just a single channel driven? Let's see what one module, in isolation, with one correct correct PSU can do. I want to see that 400W number- if it exists.
 

6speed

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#38
Just a caution: I did not check to see if the heatsink is isolated from the transistors. If it is not, it may be running at rectified mains voltage that could be lethal.
Good point :) If I ever get around to it, I'll take a reading with a meter first.
 

RayDunzl

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#39
Last edited:

6speed

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#40
Sure. What power levels do you like to see?
Enough to establish a trend or see where it diverges. I would say 1W, 10W, 100W, full power.
 
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