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Hypex NCx500 Class D Amplifier Review

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  • 1. Poor (headless panther)

    Votes: 3 0.7%
  • 2. Not terrible (postman panther)

    Votes: 6 1.3%
  • 3. Fine (happy panther)

    Votes: 55 11.9%
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    Votes: 397 86.1%

  • Total voters
    461

Matias

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Using three NCx500 modules with one 3K smps is not recommended by Hypex therefore I don't think the Apollon 3 or 5 channel NCx500 is a good choice due to the supply pumping that will result. I would stay away from the 3 or 5 channel Apollon.

My inquiry to Hypex:
Subject:power supply for 3 channel NCX500
Department:Technical support
Details:Hello-

Can you tell me if it is possible to use your 3K smps with a three channel NCx500 module amp? I understand there are issues with using the 3K supply with half bridge (NCx500) amps below 100Hz due to supply pumping but have read that one simply puts one module out of phase to solve the issue. Would using 3 modules, one wired out of phase, work or would it create an imbalance and not be advised? Thank you.

Hypex answer:
That would only work when two amps used for frequencies below 100Hz are getting more or less the same signal and the third amp is used for frequencies above 100Hz.
I don't know, but Tibor has plenty of experience building top amplifiers for years now and has an APx555 in house for testing at will. @Apollon Audio would you clarify this for us please?
 

Meridius

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So you’re telling me this power amp is no good for the Yamaha . Not to sure what’s going on ? lol
 

goryu

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So you’re telling me this power amp is no good for the Yamaha . Not to sure what’s going on ? lol

I'm saying the Apollon 3 and 5 channel NCx500 amp using a Hypex 3K SMPS power supply is susceptible according to Hypex to power supply pumping issues and not a recommended Hypex configuration. I would say therefore it is not good for any speaker below 100Hz.
 

Meridius

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I'm saying the Apollon 3 and 5 channel NCx500 amp using a Hypex 3K SMPS power supply is susceptible according to Hypex to power supply pumping issues and not a recommended Hypex configuration. I would say therefore it is not good for any speaker below 100Hz.
So what would u recomend ?
 

goryu

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So what would u recomend ?

Perhaps a 4 channel Hypex amp with a single channel monoblock, or a 6 channel amp based on the NC502MP modules with built in power supplies like that offered by Buckeye.
 

Meridius

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Could you explain why the other post for the Apollon was no good is it because it had one psu what would happen if I went with that how would that unit work in other amps if it has this problem. just trying to learn as I go. Thanks
 

goryu

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Could you explain why the other post for the Apollon was no good is it because it had one psu what would happen if I went with that how would that unit work in other amps if it has this problem. just trying to learn as I go. Thanks
The issue is the design of the 3K power supply and how it would interact with half bridge amp modules.

The 3K power supply, according to Hypex:

"The SMPS3K is intended to power our range of high power amplifier modules, such as UcD2K and NC2K. As a
result, this SMPS product does not feature the 2-quadrant operation as most of our other SMPS products do.
Therefore, they are unable to handle large reverse currents generated by half-bridge amplifiers operated at
low frequencies. For this reason, it is not advisable to use this SMPS to power half bridge amplifiers
like our UcD700 and UcD400 modules when used in the frequency range below 100Hz. A workaround for this could be
using the UcD700/UcD400 in bridge mode, or reversing phase for half of the modules."

The UcD400/UcD700/NC500/NC1200, NCx500 are half bridge amplifiers. If the number of amp channels is even, one can simply invert the output of one amp model to get around the supply pumping. You can not do this with an odd number of amp channels since there would be an imbalance.
 

Meridius

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Something like this u mean

Or
Or


So basically what your saying my amp need a power amp that has its own psu for each channel instead of a power amp with multi Channels and one psu.

So what are the single psu multi channels used on what type of avrs or are they used mainly on processors only
 

Meridius

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Still confused. lol would it be better to get one power amp that is based on full bridge.

As Half bridge amp deal with supply pumping > bigger SMPS
Full bridge amp no supply pumping > simpler SMPS

So why do you build half bridge systems ? Are they easier to build or cheaper than full bridge amps Or more suited for mono locks. Do they have advantages or disadvantages.

So anything with the power built onto the two channels boards will power each two channel ant not a system that shares the power to 5 channels. Like


Or if going for single Chanel’s and say wanted to drive 3. You could go with three of these.

Or am I still looking at this the wrong way



 

boXem

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There are power supplies designed to deal with half bridge designs. Not a lot. They are can deal with energy flowing from the amplifier to the supply. The Hypex SMPS1200 is one of them. It can support whatever number of channels reproducing whatever frequency range.
When a power supply cannot deal with negative energy flow, like the SMPS3k and a lot of others, some precautions need to be taken so that negative energy flows are absorbed by the other channels.
Easiest solution is to have pairs of channels reproducing the same frequency range and wired in opposition of phase. Obviously, such a solution doesn't work with odd channel numbers but gives good results with even numbers.
 

Apollon Audio

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The issue is the design of the 3K power supply and how it would interact with half bridge amp modules.

The 3K power supply, according to Hypex:

"The SMPS3K is intended to power our range of high power amplifier modules, such as UcD2K and NC2K. As a
result, this SMPS product does not feature the 2-quadrant operation as most of our other SMPS products do.
Therefore, they are unable to handle large reverse currents generated by half-bridge amplifiers operated at
low frequencies. For this reason, it is not advisable to use this SMPS to power half bridge amplifiers
like our UcD700 and UcD400 modules when used in the frequency range below 100Hz. A workaround for this could be
using the UcD700/UcD400 in bridge mode, or reversing phase for half of the modules."

The UcD400/UcD700/NC500/NC1200, NCx500 are half bridge amplifiers. If the number of amp channels is even, one can simply invert the output of one amp model to get around the supply pumping. You can not do this with an odd number of amp channels since there would be an imbalance.
My opinion is that you have misread the datasheet of the SMPS 3K.

"A workaround for this could be
using the UcD700/UcD400 in bridge mode, or reversing phase for half of the modules"

Please note that we have sold more than thousand of multichannel amps with this configuration with not one single issue or problem reported. If you use the SMPS3K power supply the correct way, it performs excellent. We have done a lot of testing before we started selling these amplifiers.
 
Last edited:

goryu

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My opinion is that you have misread the datasheet of the SMPS 3K.

"A workaround for this could be
using the UcD700/UcD400 in bridge mode, or reversing phase for half of the modules"

Please note that we have sold thousands of multichannel amps with this configuration with not one single issue or problem reported. If you use the SMPS3K power supply the correct way, it performs excellent. We have done a lot of testing before we started selling these amplifiers.

No, I believe you have misread the data sheet. Please tell me how to reverse phase for 1.5 modules, or 2.5 modules.

Perhaps you missed the part where I copied Hypex's reply to this very questions. I won't repeat it here, you can scroll up. The bottom line is they do not recommend it.

Whether or not you have had issues is rather irrelevant. It is not a recommended practice and puts unnecessary stress on the components.
 

Apollon Audio

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No, I believe you have misread the data sheet. Please tell me how to reverse phase for 1.5 modules, or 2.5 modules.

Perhaps you missed the part where I copied Hypex's reply to this very questions. I won't repeat it here, you can scroll up. The bottom line is they do not recommend it.

Whether or not you have had issues is rather irrelevant. It is not a recommended practice and puts unnecessary stress on the components.
In utilizing our 3-channel NCx500 amplifier within a LCR surround sound setup, it adeptly powers the left main, right main, and center speakers for instance. Channels 1 and 2 are respectively dedicated to the left and right speakers, while the center speaker should be connected to the 3. channel. Our amplifier distinctively features phase inversion at input and output for the second channel, effectively neutralising any potential 'pumping' effects arising from full range utilisation. Furthermore, the center speaker, typically subject to a high-pass filter in most surround configurations connected to the third channel for instance represents no strain on the components and no power supply pumping. This robust configuration has been thoroughly tested, even in three-way monitor setups, demonstrating no detectable 'pumping' phenomena. Should you be interested, I am available to provide detailed measurements of our multichannel amplifier. I am confident that its performance, mirroring that of our dual mono or mono configurations, will significantly impress you.
 

Meridius

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@Apollon., Amazing that I asked for help but nothing from you on the subject that I wanted help with as I was considering your equipment.
 

AudioJester

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@Apollon., Amazing that I asked for help but nothing from you on the subject that I wanted help with as I was considering your equipment.

Some Audio companies do post/participate on here regularly, others only sporadically.
Your better off contacting them directly, rather than through a forum they may not monitor closely.
 

goryu

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In utilizing our 3-channel NCx500 amplifier within a LCR surround sound setup, it adeptly powers the left main, right main, and center speakers for instance. Channels 1 and 2 are respectively dedicated to the left and right speakers, while the center speaker should be connected to the 3. channel. Our amplifier distinctively features phase inversion at input and output for the second channel, effectively neutralising any potential 'pumping' effects arising from full range utilisation. Furthermore, the center speaker, typically subject to a high-pass filter in most surround configurations connected to the third channel for instance represents no strain on the components and no power supply pumping. This robust configuration has been thoroughly tested, even in three-way monitor setups, demonstrating no detectable 'pumping' phenomena. Should you be interested, I am available to provide detailed measurements of our multichannel amplifier. I am confident that its performance, mirroring that of our dual mono or mono configurations, will significantly impress you.

Not everyone obviously is going to use this amp in a LCR configuration nor obviously are all consumers aware of the supply pumping issue. Again, I would listed to Hypex who recommend against using this supply in odd module full range configurations.
 
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