Review and Measurements of Hypex NC400 DIY Amp

[amirm]

More physical material mass doesn't mean it's more expensive.

Of course it does. Shipping alone will cost a lot as will tooling and making the speakers. Think of them as furniture and very high-end one at times.

 

[Thomas savage]

can we keep things to Class D amp testing and Hypex modules pls. A bit of relevant drift is fine but let’s not go off on a totally diffrent tangent pls.

Iv moved the ‘ how much power for my speakers ‘ posts to https://www.audiosciencereview.com/forum/index.php?threads/how-much-power-for-my-speakers.5979/

A intresting question deserving of its own thread.

Cheers

 

[MZKM]

wow, that's very expensive!

For Hi-Fi setups, that’s actually on the cheaper side for it’s performance, there are power amps that are $15,000 to $100,000 and up, and they do sell, and they aren’t much better than this Hypex, showing how awesome it is.

 

[rebbiputzmaker]

Sorry, I find this entire conversation rather amusing, more like a dog chasing his tale, getting nowhere. The amp in question was build for music not testing, in it current state needs to pass zero tests.

Build one, sink it properly and then test to your hearts content. One proves nothing by frying one's amp.

Maybe more telling for the real world would be to run them into overload/clipping with music and observe the quality of the waveform. See how the amp recovers, reacts etc.

 

[ofrappier]

Hi ,

i've found this :

https://www.audiophonics.fr/fr/modu...BNZw5A0pd4eET6OV0Oh-TINrsgviNxqF_Euy0LwHTG1eM

It's could be a good upgrade for my active speaker and there is a free crossover/FIR software for PC.

It use the same NCORE quality ? inside ?

https://www.hypex.nl/plate-amplifiers/

https://www.hypex.nl/product/fusionamp-fa252/156

https://www.hypex.nl/product/fusionamp-fa253/157


Regards,

Olivier

 

[Sancus]

Sorry, I find this entire conversation rather amusing, more like a dog chasing his tale, getting nowhere. The amp in question was build for music not testing, in it current state needs to pass zero tests.

That doesn't mean testing isn't useful. I'm no expert and I've learned a lot from this thread, when @restorer-john first complained about the low continuous power rating of the NC400 I thought that was unreasonable, because to me it doesn't make sense to test an amplifier's maximum power for hours and hours. As someone who cares about weight, size, power consumption and heat output of the things I'm buying, I don't want manufacturers including heatsink capacity for my amplifier to run at maximum 24/7, because it's a silly waste of my money and my space. I'm not a person who is ever going to want to buy those insane 100lb+ amplifiers

However, after reading more and realizing that the FTC test is only 5 minutes, which Hypex themselves even have a defined rating for(!), I changed my mind. 5 minutes seems like a pretty reasonable standard for any piece of electronics to run flat out. Some kind of continuous testing is definitely relevant to real world usage, because it is entirely possible to overheat an amplifier with music. I've overheated my Denon X4000 running 4 ohm Magnepan 1.7s many times(with rock, unsurprisingly ). The receiver doesn't have a 4 ohm rating, so I knew that this was a risk and that it didn't have enough heatsink capacity for that usage. I dealt with it for a few years before eventually adding a more powerful amplifier(SDS-470C). If there was no standard for continuous testing, then Denon could simply say 'oh sure its fine into 4 ohms at max power....' without mentioning that that's for 30 seconds... or even less.

If @amirm and other experts consider 5 minutes to be an unreasonable standard, that's totally fair... but then some standard should be set for reviews to be consistent. Whether it be 30 seconds or 1 minute or 3 minutes, I don't know, but if you don't test output for more than a second or two, I don't think that's actually sufficient.

 

[Matias]

These plate amplifiers look very nice for a DIY speaker project.

 

[DDF]

I thought I'd join the conversation after reading in guest mode for so long. I first want to thank everyone for such a great forum and community.

I built a Hypex 2xNC400 + SMPS1200A400 amp for daily use and have a few thoughts that might help the conversation.

The benefits of SMPS600 include a slightly higher rail voltage (65 vs 63 V nominally) but the difference in maximum output at the speaker should be imperceptible from a practical perspective. The SMPS600 also has separate diodes in the bridge rectifier and automatic mains voltage switching. Neither seemed to offer any functional benefit but I've yet to see any EMI or noise comparisons for the SMPS1200 vs SMPS600. My amp is dead quiet so that bodes well.

The SMPS600 provides a 16V Vdr which allows the NC400 internal driver regulator to remain off, dissipating 5W less per NC400 than when using the SMPS1200 (Vdr = 15.6V). My amp modules don't seem to generate much heat so this doesn't seem to be a cause for concern in practice. They were cool enough to the touch at idle or when driven hard that I haven't felt any need to monitor the amp modules' heat sink temperatures. They're mounted directly to the base plate of an all aluminum chassis with very thin thermal paste. I chose aluminum as it is much more thermally conductivity than carbon steel.

I occasionally listen to compressed music at high levels including hip hop with drawn out bass, or classical with long extended bass lines. Most speakers will have an impedance minimum an octave or so above woofer resonance so the long duty cycle bass lines and this speaker load can make for a tough combination for an amp and its power supply. The added headroom of the 1200W supply seemed to provide welcome insurance and this amp does play very loud and clean. The much lower cost of the 1200W supply vs 2 600W supplies sealed the deal.

The power supply heat and reliability is something to consider. After a year or so of use I had one channel start to drop out when played near clipping with sustained bass lines. Hypex performed a quasi RCA from afar and looked at hi res pictures of the internals. They replaced the SMPS1200 under warranty, sending a unit that I noticed uses caps from different manufacturers than the original supply. So far, all is working as expected. Hypex's customer support has been fantastic.

The case around the power supply does get modestly warm to the touch when it's idle, so I connect it to a switched power bar and shut it down when not in use, boosting the odds of a long life.

It has allot of power. To me it's not clinical, bright or glary at all and I don't detect it adding or subtracting anything. I can't say that about most other amps I've heard (rightly or wrongly). I think it's a wonderful amp. If it proves reliable, it'll probably be my last amp for a very long time.

 

[Milt]

You guys who built your own NCore amp, how are you getting the SMPS1200 PS?
I thought they were sold to OEM only?

 

[restorer-john]

I thought I'd join the conversation after reading in guest mode for so long. I first want to thank everyone for such a great forum and community.

I built a Hypex 2xNC400 + SMPS1200A400 amp for daily use and have a few thoughts that might help the conversation.

Welcome and thanks for the contribution to this thread.

Considering you were using their "1200W" supply with two NC400s and had an issue with normal musical signals after a mere 12 months is not a good sign for long term reliability of those SMPSs.

Just out of interest, if you still have the high res shots of the old SMPS1200, post them here?

 

[rajapruk]

It would be very interesting to know if "2 nc400 + 1 SMPS1200A400" also gives higher distortion than "2 nc400 + 2 SMPS600" (like "2 nc400 + 1 SMPS600" did).
I.e if sharing a SMPS induces some extra distortion vs dual SMPS, in general, or if it is something specific to sharing SMPS600.

 

[Killingbeans]

You guys who built your own NCore amp, how are you getting the SMPS1200 PS?
I thought they were sold to OEM only?

Nope, Hypex sells them for DIY:

https://www.diyclassd.com/product/smps1200a400/10

 

[rebbiputzmaker]

Considering you were using their "1200W" supply with two NC400s and had an issue with normal musical signals after a mere 12 months is not a good sign for long term reliability of those SMPSs.

This is only one out of how many. Does not reflect on all, or the design.

 

[DDF]

Welcome and thanks for the contribution to this thread.

Considering you were using their "1200W" supply with two NC400s and had an issue with normal musical signals after a mere 12 months is not a good sign for long term reliability of those SMPSs.

Just out of interest, if you still have the high res shots of the old SMPS1200, post them here?

Thanks John.

I don't think my unit failure is indicative of an issue with Hypex's design and I hope that I didn't infer that. I'm an electrical engineer and used to work in audio so I'm sensitive to capacitor life derating with temperature. I don't think these units run abnormally hot at all, but the SMPS1200 and NC400 combination will draw more power than a standard design using the SMPS600.

Here's a picture of the internals of my build.

 

[jmmaher]

I mentioned my experience in a previous comment. I have owned one of these units almost identical to yours. Stereo unit with two NC400 units and a SMPS1200. While I really do like the amp I have had two power supplies fail since it was built in July 2014. Until the last failure I kept it powered up 24 hrs a day. I believe this is reasonably standard since the original design did not call for a power switch. I had James Romeyn (who originally built this for me) install a standby switch in mine and I now try to use that at least occasionally. Both power supplies were repaired by Hypex. It would seem that better heat sinks or a fan might make sense.

 

[6speed]

@amirm You can test one channel for 5 minutes...do you have a way of reading the temp of the SMPS heatsink at the end?

 

[amirm]

@amirm You can test one channel for 5 minutes...do you have a way of reading the temp of the SMPS heatsink at the end?

Thanks and of course I do.

 

[restorer-john]

and used to work in audio so I'm sensitive to capacitor life derating with temperature. I don't think these units run abnormally hot at all,

Based on the huge number of SMPS supplies I have repaired (or written off) over the years, it's less about the radiated heat produced by the switching mosfets/switcher ICs/rectifiers and more about the internal rise in electrolyte temperature in the secondary filter capacitors on the high current rails that causes a short life, rise in ESR and eventual failure/venting.

Take PC computer power supplies for instance, the entire power supplies are fan cooled and the heatsinked silicon stays very cool, but the crowded together secondary filter caps on the 5V rails have no ability to get rid of the internal heat. They're even covered with a nice little plastic sleeve that keeps the heat in. They fail, short and take out power supplies all the time.

As the ESR goes up, the ripple increases and a lot of uP based consumer gear behaves intermittently or refuses to operate altogether.

 

[6speed]

Here's a picture of the internals of my build.

Are those the original caps that failed or the new ones? I also have two SMPS1200 in other builds, but with UCD modules.

 

[Sylafari]

Somehow it feels like the air has gone thick with tension all of a sudden.

*Fingers crossed* (I'm seriously considering picking up a Hypex amplifier!)

I saw that the DIY Kit is solderless? Also some 3rd party makes cases with no soldering required? Maybe I'll build one myself...