Review and Measurements of Hypex NC400 DIY Amp

[restorer-john]

Just buy another one and you have the choice. There's nothing worse down the track trying to find a matching power amp for that purpose when they have been discontinued.

(John's rule: If in doubt, buy two- one for a 'spare')

 

[veeceem]

OK, the Salon 2s are definitely less sensitive, but I am still not sure bridging is a sensible idea. How close have you been to using full power with the Tannoys?

I don't know how to calculate, but I set the gain on NAD M22 v2 to low (19dB) and the Anthem STR preamp to -22db position (with ARC on). That's the volume I perceive as "loud". But I guess it's in the 20-40 watt range

 

[Julf]

I don't know how to calculate, but I set the gain on NAD M22 v2 to low (19dB) and the Anthem STR preamp to -22db position (with ARC on). That's the volume I perceive as "loud". But I guess it's in the 20-40 watt range

Then you should be fine even with the Revels even with a single amp. I would suggest starting with that, and seeing if you run out of power.

 

[JimB]

Have anyone tried to bridge a pair of Hypex Ncore modules? I wonder how much performance will drop in measurements :/

Not sure what you would gain. The Salon 2 are rated at 3.7 ohms at 90 Hz. So your maximum power is more at the current limit than the voltage limit (of the NC400, for example). Bridging will give more voltage swing, but not more current. So no real benefit. The NC400 is already twice the power of the AHB2 (nominally). Of course this might depend on the specific NCore module you had in mind.

 

[batfunk]

Hi! Just received the nc400 stereo amp from Audiophonics a few days ago and it's a great amp! Big, sturdy built, heavy( nearly 5kg of aluminium), big thermic dissipators(no heat) , no buzz or hum(like mentioned by some French owners about nc122mp or nc252mp based one).
Well, for me and it's not scientifically measured, it's totally transparent(much more than my "old" Teac Ai-501). My loudspeakers proved to be punchier, nearly brutal, like if an army of tanks is on the verge to debarking in my apartment.
Most of all, knowing that I can push my loudspeakers to 105 db, without a hint of distortion is very rewarding, even if it will Never happen...
Well, I think I can close my ASR account now...

 

[rajapruk]

Was there any ”32-tone test resembling music” done for this amp (nc400)?

 

[Julf]

Was there any ”32-tone test resembling music” done for this amp (nc400)?

What would that show?

 

[Dion_Sinewave]

That’s what I’ve done! 8 channels of NC400

Just buy another one and you have the choice. There's nothing worse down the track trying to find a matching power amp for that purpose when they have been discontinued.

(John's rule: If in doubt, buy two- one for a 'spare')

 

[rajapruk]

What would that show?

Intermodulation distortion for more ”complex signal” and distortion per frequency, all in one nice condensed graph. I like to look at those graphs.

 

[Julf]

Intermodulation distortion for more ”complex signal” and distortion per frequency, all in one nice condensed graph. I like to look at those graphs.

A two-tone test is just as good for showing IMD.

 

[Filio45]

The only major concern I have is not regarding the assembly but the design of the switchmode power supply by Hypex. A number of power transistors are mounted to the bottom clear aluminum heatsink which is nothing but bent piece of metal. It gets quite warm and is sitting within a millimeter or two of the large electrolytic capacitors below it. The two caps were getting quite warm even in limited use and will surely result in them drying out prematurely and failing. This case is plenty large so personally I would attempt to straighten the bent aluminum so that it is more vertical.

You may have a point but the SMPS600 has been on the market for quite a while and it seems strange that Hypex would still be selling if it was prone to a short shelf life.

 

[6speed]

You could always jumper those tiny heatsinks to the case. As often as I waste time doing things just because it make sense in theory, or I like things overbuilt or just reliable, this was not one of them.

As for the caps, they are counting on the overhead in the ratings for the voltage and temperature to extend the lifetime to something acceptable. The rated lifetime is going to be low, but you double it for every 10deg under, and the lower operating voltage has a similar multiplicative effect.

 

[pos]

You may have a point but the SMPS600 has been on the market for quite a while and it seems strange that Hypex would still be selling if it was prone to a short shelf life.

They did update it: the newer smps600 have a smaller heatsink surface there, probably to let the caps “breath”
anyway, it is not too difficult to connect this heatsink to the encoluse using a piece of aluminium and some thermal pads

 

[CRKebschull]

They did update it: the newer smps600 have a smaller heatsink surface there, probably to let the caps “breath”
anyway, it is not too difficult to connect this heatsink to the encoluse using a piece of aluminium and some thermal pads

I contacted Hypex about the new SMPS600 a few months ago. I said I have the old version, and I see there is a new one, and if I should buy the new ones because they are intrinsically better. They told me that no, the old model works just fine, it doesn't perform worse than the new model, and seeing as I don't have defective power supplies (in use the last 3.5 years) there's no reason to upgrade the SMPS.

 

[veeceem]

Not sure what you would gain. The Salon 2 are rated at 3.7 ohms at 90 Hz. So your maximum power is more at the current limit than the voltage limit (of the NC400, for example). Bridging will give more voltage swing, but not more current. So no real benefit. The NC400 is already twice the power of the AHB2 (nominally). Of course this might depend on the specific NCore module you had in mind.

Hi, can you or anyone make a brief explaination of this "current" and "voltage" thing? And why no benefit? Or at least gives some keywords/articles to understand. English is not my mother language, struggle reading something too techie/long >.<
Thanks

 

[Julf]

Hi, can you or anyone make a brief explaination of this "current" and "voltage" thing? And why no benefit? Or at least gives some keywords/articles to understand. English is not my mother language, struggle reading something too techie/long >.<
Thanks

Pretty hard to explain the basics of electricity without getting too technical, but basically power is the product of two things - voltage and current. If the amplifier was ideal, and the load purely resistive, the current would we directly proportional to voltage (both would increase in the same proportion as you increase power), but at some point the amp starts becoming the limitation. It depends on the amp and the load which limit you hit first, current or voltage.

 

[JimB]

Hi, can you or anyone make a brief explaination of this "current" and "voltage" thing? And why no benefit? Or at least gives some keywords/articles to understand. English is not my mother language, struggle reading something too techie/long >.<
Thanks

A classic analogy for basic understanding is with water, where voltage is like pressure and current is like flow. And resistance is like flow restriction (small hose, small nozzle). These amps have well defined maximum output voltages and currents - limits. Accept that, for a given amp, a bridged configuration provides double the output voltage swing, but no greater output current capability. That is, you can get greater maximum pressure, but no greater maximum flow.

When your speakers have high resistance, it takes more pressure (voltage) to get a particular power into them. Once you have enough voltage (pressure) for your speakers to reach the current (flow) limit of an amp, it cannot provide any more current or voltage or power. With higher impedance (resistance) speakers, you might benefit from bridged outputs, but with lower impedance speakers, you might hit the current limit before you can take advantage of the potential for higher output voltage. How to tell when bridging can give more power? When the amp does not reach its current limit for your speakers in direct, unbridged operation. Then it could deliver more current (and power) if it had more output voltage range, which bridged outputs can provide.

For the Salon 2, at 3.7 ohms, you are pretty close to the maximum power output capability of the 1ET400A, but not exactly. So you could get a little more power into them from a bridged setup, but not enough to make much difference in perceived maximum sound volume. Others might care to offer a more precise estimate for you, but how much is that extra dB worth?

 

[veeceem]

@JimB @Julf thanks, it's clear now! This is why I really like asr, not only I can read science-based review but also learn from ppl on this forum! For someone who knows zero of these technical stuffs, explaination like these are miracle, I'm learning more and more thanks again!

 

[Karu]

I currently run the following chain: Roon->Eero->Digione Sig->Coax->Mytek 192 DSD->Wyred4sound mAmp x2 via balanced-> KEF LS50 + Rhytmik sub from the Mytek unbalanced. I have not found any measurements of the W4S monoblocks, would changing to the DIY NC400 bring an audible improvement?

I have a similar question about the DAC I will ask in the RME thread.

 

[veeceem]

@Karu switching to Nc400 will ensure that your speakers have no sound. I keep wondering everyday why music played so effortlessly thru my NAD M22 v2 (Hypex Nc400 based) tested with Tannoy Kensington GR, Monitor Audio Bronze 2. Soon will test Revel M16 and Salon2