Hypex NCx500 Class D Amplifier Review

[pras1011]

Any companies using these yet?

 

[ozlegend]

The usual concern about high-frequency intermodulation effects is because the tweeters (in the speaker systems) generate IMD when presented with such high signals, modulating "electromechanically" to create distortion that falls into the audible frequency range. An electrical test at the output of the amp will not show that.

I have NC502MP and NCx500 amps plus various speaker measuring equipment and a range of different tweeters (from soft dome to beryllium) so can try to measure something at the TWEETER output - but I am not clear what that measurement would be?? If it involves say a 10 kHz test tone interacting with say a 500 kHz amp-generated signal the intermodulation products would be at? I am also not sure what 'modulating electromechanically' means and how it could be tested?

 

[Julf]

I have NC502MP and NCx500 amps plus various speaker measuring equipment and a range of different tweeters (from soft dome to beryllium) so can try to measure something at the TWEETER output - but I am not clear what that measurement would be?? If it involves say a 10 kHz test tone interacting with say a 500 kHz amp-generated signal the intermodulation products would be at? I am also not sure what 'modulating electromechanically' means and how it could be tested?

'Modulating electromechanically' means intermodulation through the actual movement of the voice coil and membrane, so you would only be able to measure it with a mic, not from the electrical output of the amp.

 

[ozlegend]

So this electromechanical modulation would cause vibration/movement of the tweeter voice coil and membrane at around 500 kHz (or whatever the sampling frequency of the class D amp is)? What effect would this have on say a 10 kHz test tone if I tried to measure it?

 

[Julf]

So this electromechanical modulation would cause vibration/movement of the tweeter voice coil and membrane at around 500 kHz (or whatever the sampling frequency of the class D amp is)? What effect would this have on say a 10 kHz test tone if I tried to measure it?

In theory at least you might get intermodulation products, possibly in the audible frequencies, but I doubt the tweeter will really react much to frequencies as high as the switching frequency of the amp.

 

[Chrisloop]

Does anyone have a list of Class D manufactures using toroidal power supply's ? The only one I can find are ATI's build. They are nice but super pricey.

 

[Julf]

Does anyone have a list of Class D manufactures using toroidal power supply's ? The only one I can find are ATI's build. They are nice but super pricey.

It is like asking a list of car manufacturers still using solid axles instead of independent suspension.

 

[Dj7675]

Does anyone have a list of Class D manufactures using toroidal power supply's ? The only one I can find are ATI's build. They are nice but super pricey.

Yes. ATI does.

Class D Amplifiers - Amplifier Technologies Inc.

ati-amp.com

 

[Chrisloop]

Yes. ATI does.

Class D Amplifiers - Amplifier Technologies Inc.

ati-amp.com

Any others?

 

[Sokel]

It is like asking a list of car manufacturers still using solid axles instead of independent suspension.

They can come handy if you want to load them a 30 ton cargo

 

[Julf]

They can come handy if you want to load them a 30 ton cargo

They are fine on a truck. Most of us are not truck drivers.

 

[boggit10]

For anybody interested in how they sound I have not been able to stop listening to our pre production amp using the evaluation modules for the last 2-3 months.

 

[Redwine]

For anybody interested in how they sound I have not been able to stop listening to our pre production amp using the evaluation modules for the last 2-3 months.

I think this statement calls for some kind of elaboration?

 

[multisport4me]

I think this statement calls for some kind of elaboration?

Nord sells amps. Not much to elaborate here. The only thing missing from that post was a pre-order link. lol

 

[Vacceo]

For anybody interested in how they sound I have not been able to stop listening to our pre production amp using the evaluation modules for the last 2-3 months.

I asked Rick about efficiency and heat, so chances are you have more data and experience than him in that particular area.

Have you been able to track any improvement in that area over the previous NC modules?

 

[Burning Sounds]

Picking up on the turn/off pops on Hypex amps would it possible for amirm to also do this measurement when turning off the amp after it has reached a "normal" operating temperature (say 30deg C+) as the results could potentially be quite different. Mine seem to be as dependant on temperature as much as time.

For example, my four NC502MP modules behave quite differently depending on time and temperature. On power up (already on standby and using Octo Research DAC8 PRO as the preceeding equipment) there is no power up noise at all. If I power down to standby after about 7 minutes (from cold) there is a quite loud pop from the left channels, but nothing from the right channels. Conversely, after reaching 30deg C and then powering down there is no noise from the left channels at all and a quieter pop from the right channels.

As these modules are in one case I guess it is possible that there is some interaction between them at turn off. Each pair of modules have their own power cords and standby switches.

 

[boggit10]

This is why as a small time manufacture we feel reluctant to post things. As a OEM manufacture I can sell Purifi, ICE Power or Hypex so posting my personnel experience of a new module from any given company is not biased towards a particular manufacture as I can sell amps from other manufactures it makes no difference to us. The only driver is to supply the customer with the best solution. And yes posting on here raises our profile that's why we do it. As long as the information is helping or useful everybody is a winner its what makes the world go round I think most readers can figure out I am a manufacture and would be sensible enough to collate opinions from multiple sources. Bearing in mind only Hypex and OEM's have heard the amp and we are also in the best position to compare to other products.
Its also why I did not post all my thoughts on sound I was seeing if there was any interest.

Hi Redwine
NCx500 My personnel opinion is I like the a lot.
You can listen louder without it being uncomfortable and the speakers protesting.
More bass
Better soundstage
More engaging and musical, I had to stay all afternoon in my listening room I have never done that with other products
Hope that helps.

 

[boggit10]

Picking up on the turn/off pops on Hypex amps would it possible for amirm to also do this measurement when turning off the amp after it has reached a "normal" operating temperature (say 30deg C+) as the results could potentially be quite different. Mine seem to be as dependant on temperature as much as time.

For example, my four NC502MP modules behave quite differently depending on time and temperature. On power up (already on standby and using Octo Research DAC8 PRO as the preceeding equipment) there is no power up noise at all. If I power down to standby after about 7 minutes (from cold) there is a quite loud pop from the left channels, but nothing from the right channels. Conversely, after reaching 30deg C and then powering down there is no noise from the left channels at all and a quieter pop from the right channels.

As these modules are in one case I guess it is possible that there is some interaction between them at turn off. Each pair of modules have their own power cords and standby switches.

This has now been resolved for a few months now. None of the recent NC502MP pop.

 

[boggit10]

I asked Rick about efficiency and heat, so chances are you have more data and experience than him in that particular area.

Have you been able to track any improvement in that area over the previous NC modules?

Hi Yes they defiantly run cooler along with the SMPS. I could not find a figure on NCx datsheet for Idle losses to give you.

 

[multisport4me]

This is why as a small time manufacture we feel reluctant to post things. As a OEM manufacture I can sell Purifi, ICE Power or Hypex so posting my personnel experience of a new module from any given company is not biased towards a particular manufacture as I can sell amps from other manufactures it makes no difference to us. The only driver is to supply the customer with the best solution. And yes posting on here raises our profile that's why we do it. As long as the information is helping or useful everybody is a winner its what makes the world go round I think most readers can figure out I am a manufacture and would be sensible enough to collate opinions from multiple sources. Bearing in mind only Hypex and OEM's have heard the amp and we are also in the best position to compare to other products.
Its also why I did not post all my thoughts on sound I was seeing if there was any interest.

Hi Redwine
NCx500 My personnel opinion is I like the a lot.
You can listen louder without it being uncomfortable and the speakers protesting.
More bass
Better soundstage
More engaging and musical, I had to stay all afternoon in my listening room I have never done that with other products
Hope that helps.

Relax. You support your customers up here more than market your stuff so I have no issue with you posting at all. It was a tongue-in-cheek reply - nothing more, nothing less. I'm sure there are many who prefer manufacturers to be proactive on sites like these vs. just showing up when they have some inventory to sell (e.g. Monolith).