This is a review and detailed measurements of the Buckeye Hypex NC502MP 8-channel class D amplifier. It was sent to me by the company and costs US $2,295.
There is not a whole lot to look at here. Sheet metal is rather thin and fitment not that great. So put it in a cabinet and forget about it. The backside shows the expected including trigger control to sequence powering up multiple units with one stroke:
I was surprised by the weight of the amplifier. Mind you, it is far lighter than a class AB amplifier but it is still not light. The reason for that is that each amplifier module has a large vertical heatsink with quite stout mounting bracket tying it to the chassis.
If you are not familiar with Hypex NC502MP, it is an all-in-one high power stereo amplifier with on-board switching power supply and input buffer. Supply the connectors and you have a complete amplifier. In this case, four such modules are included to get to 8 channel. Due to large amount of power these amplifiers can produce in tandem, dual AC inputs are provided. The amplifiers are split between the two AC inputs. If you don't need continuous power, you can connect both inputs to the same power strip which is how I tested it.
Buckeye Hypex NC502MP Amplifier Measurements
Let's start with our usual dashboard by measuring one amplifier module's dual outputs:
Performance is very good as we expect from Hypex modules. A minor issue was the power supply spikes in one channel (blue). I tested all the amplifier modules and they all do the same thing. So likely is due to leakage from the onboard power supply bleeding into the more adjacent channel on NC502MP. Using the "good" channel on each board removes that bit of bleeding:
Using the former SINAD for ranking, the amplifier nicely lands in our "excellent" bucket:
Here is all of them in that category:
Frequency response is essentially flat in audible band and changing the load has no impact on output:
Multitone shows the superb performance, albeit somewhat worsened by the less good channel:
Noise performance is extremely good:
My target is 96 dB at 5 watts which the Buckeye nicely exceeds. And provides full transparency up to reference level of 120 dBSPL.
Crosstalk naturally is beyond approach if you use two separate modules but even in the same module, it is excellent:
Let's measure power into 4 ohm using channels in the same module or two separate ones:
As you see, there is no difference. You are only limited by how much AC power you have as power supplies are not shared.
Max and peak power is impressive:
We are talking nearly 1.3 Kilowatts in stereo! Needless to say, if you are going to have all 8 channels whaling, you better have good amount of current on dual AC lines. And make an appointment at your ear, nose and throat doctor because hearing damage is most likely!
Measuring response at 8 ohm gave me a really hard time:
Reason being that online specs from Hypex does not show that hump from 10 to 100 watts at all. I tried everything from testing my instrumentation to measuring every amplifier module and still got the same results. I shared the graph with Buckeye only to be told there is updated measurements from Hypex showing the same hump.
While performance is superb up to about 8 watts, I wish that the hump wasn't so pronounced.
I was most impressed by the ability of these modules to drive down to 2 ohms with both capacitive and inductive loads:
It produces the same 53 volts no matter what! At 1 ohm though, it instantly went into protection but recovered very quickly.
This is one powerful and robust amplifier!
Finally, you don't really need to warm it up:
FYI, I left the unit on overnight and in the morning, the top was warm especially in the center. All the amps combined, do generate some amount of heat so best to not leave it on if you don't need it and provide good ventilation.
Conclusions
The Buckeye NC502MP is a perfect amplifier for home theater duty. It provides incredible amount of power from each module to drive even the most inefficient speakers to ear piercing levels. It does so with extremely low noise and excellent distortion at modest levels. At higher powers, distortion does climb. While I wish this was lower, I don't think there is an issue at all for home theater applications. Even with music, I think you will be fine but the purist may want to have better. Then again, if you are going to lose power to get there, this amplifier may be a better choice.
I am going to put the Buckeye NC502MP 8-channel amplifier on my recommended list.
EDIT: teardown now posted: https://www.audiosciencereview.com/forum/index.php?reviews/
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
There is not a whole lot to look at here. Sheet metal is rather thin and fitment not that great. So put it in a cabinet and forget about it. The backside shows the expected including trigger control to sequence powering up multiple units with one stroke:
I was surprised by the weight of the amplifier. Mind you, it is far lighter than a class AB amplifier but it is still not light. The reason for that is that each amplifier module has a large vertical heatsink with quite stout mounting bracket tying it to the chassis.
If you are not familiar with Hypex NC502MP, it is an all-in-one high power stereo amplifier with on-board switching power supply and input buffer. Supply the connectors and you have a complete amplifier. In this case, four such modules are included to get to 8 channel. Due to large amount of power these amplifiers can produce in tandem, dual AC inputs are provided. The amplifiers are split between the two AC inputs. If you don't need continuous power, you can connect both inputs to the same power strip which is how I tested it.
Buckeye Hypex NC502MP Amplifier Measurements
Let's start with our usual dashboard by measuring one amplifier module's dual outputs:
Performance is very good as we expect from Hypex modules. A minor issue was the power supply spikes in one channel (blue). I tested all the amplifier modules and they all do the same thing. So likely is due to leakage from the onboard power supply bleeding into the more adjacent channel on NC502MP. Using the "good" channel on each board removes that bit of bleeding:
Using the former SINAD for ranking, the amplifier nicely lands in our "excellent" bucket:
Here is all of them in that category:
Frequency response is essentially flat in audible band and changing the load has no impact on output:
Multitone shows the superb performance, albeit somewhat worsened by the less good channel:
Noise performance is extremely good:
My target is 96 dB at 5 watts which the Buckeye nicely exceeds. And provides full transparency up to reference level of 120 dBSPL.
Crosstalk naturally is beyond approach if you use two separate modules but even in the same module, it is excellent:
Let's measure power into 4 ohm using channels in the same module or two separate ones:
As you see, there is no difference. You are only limited by how much AC power you have as power supplies are not shared.
Max and peak power is impressive:
We are talking nearly 1.3 Kilowatts in stereo! Needless to say, if you are going to have all 8 channels whaling, you better have good amount of current on dual AC lines. And make an appointment at your ear, nose and throat doctor because hearing damage is most likely!
Measuring response at 8 ohm gave me a really hard time:
Reason being that online specs from Hypex does not show that hump from 10 to 100 watts at all. I tried everything from testing my instrumentation to measuring every amplifier module and still got the same results. I shared the graph with Buckeye only to be told there is updated measurements from Hypex showing the same hump.
While performance is superb up to about 8 watts, I wish that the hump wasn't so pronounced.I was most impressed by the ability of these modules to drive down to 2 ohms with both capacitive and inductive loads:
It produces the same 53 volts no matter what! At 1 ohm though, it instantly went into protection but recovered very quickly.
This is one powerful and robust amplifier!
Finally, you don't really need to warm it up:
FYI, I left the unit on overnight and in the morning, the top was warm especially in the center. All the amps combined, do generate some amount of heat so best to not leave it on if you don't need it and provide good ventilation.
Conclusions
The Buckeye NC502MP is a perfect amplifier for home theater duty. It provides incredible amount of power from each module to drive even the most inefficient speakers to ear piercing levels. It does so with extremely low noise and excellent distortion at modest levels. At higher powers, distortion does climb. While I wish this was lower, I don't think there is an issue at all for home theater applications. Even with music, I think you will be fine but the purist may want to have better. Then again, if you are going to lose power to get there, this amplifier may be a better choice.
I am going to put the Buckeye NC502MP 8-channel amplifier on my recommended list.
EDIT: teardown now posted: https://www.audiosciencereview.com/forum/index.php?reviews/
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Last edited:
