Buckeye NC502MP 8-Channel Amp Review

[SharinganUser]

No fan. Beauty of class D and switching power supply. Efficiency is as high as 90% so while some heat will be generated, it should be OK as is given the large heatsinks Buckeye has put in there.

I'd really like to know why these need heatsinks, but the 6 channel doesn't. They are the same amps right?

 

[Buckeye Amps]

I'd really like to know why these need heatsinks, but the 6 channel doesn't. They are the same amps right?

Because they are mounted vertically and do not have the same amount of surface area for heat dissipation as the horizontal configurations.

 

[SharinganUser]

That Makes sense. So where does the heat on the 4 and 6 channels go when they are laying flat? Is their some other form of cooling or does it just get that much warmer with the extra amp in the 8 ch?

 

[Buckeye Amps]

That Makes sense. So where does the heat on the 4 and 6 channels go when they are laying flat? Is their some other form of cooling or does it just get that much warmer with the extra amp in the 8 ch?

Dissipated throughout the entire bottom section of the case aluminum.
The heatsinks were not necessary for proper operation in the 8ch NC502 but an added bonus due to the module orientation.

 

[SharinganUser]

Fair enough! Thanks for the clarification! That's some crazy response time man. I see why everyone loves you and this company so much.

 

[Doodski]

@Buckeye Amps. Vertical heatsinks for all the right reasons and ... It looks darn HoT/GooD!

 

[ryanmh1]

I hate to come back to an old review, since they cannot be rechecked, but there's an issue with the PowerCube measurement here that I can't understand. I was curious how these low-cost stereo Hypex modules would do into two ohms. I read the datasheet, but ... you know, curiosity killed the cat. The PowerCube measurement here raises a lot of questions, showing a perfect voltage source capable of supplying 53V flat out down to 2 ohms. How can that be even remotely possible? The burst testing shows the amplifier hitting 1% THD into 4 ohms around 600W. The PowerCube claims it will do 702W. It then claims that the thing will put out a ridiculous 1400W into 2 ohms. That seems wildly implausible. Hypex says it won't, and their measurements tend to be relatively accurate--particularly for an all-in-one module that does not depend on externalities such as the power supply or buffer. Granted, this is burst 1kHz testing which is of questionable utility since the burst is too short to represent actual music, but still, something doesn't wash.

How to explain this seemingly inexplicable result? One explanation is measurement error. But the test is fully automated, so that seems unlikely unless something went way off the rails. Another explanation could be measurement standard differences. PowerCube uses the EIA RS-490 standard of a 20mS toneburst followed by -20dB for 480ms. Audio Precisions says their CEA 490A stimulus is exactly the same burst. So that's not it. So what's going on here? Teething issues with proper use of the PowerCube perhaps? I'm stumped. Whatever did happen, it seems clear the test result here is unlikely. The module's performance is impressive for what they cost--very impressive--but I don't think it can do what is shown.

EDIT: There are some PowerCubes for other Purifi/Hypex modules that show imperfect cubes, as expected. I think that answers the question. Something went wrong with the measurement or the display settings for the measurement, and the results are invalid. There's no magic here, and the amp fails to increase power to any meaningful degree into 2 ohms, which is what the datasheet suggests.

 

[375HP2482]

Granted, this is burst 1kHz testing which is of questionable utility since the burst is too short to represent actual music, but still, something doesn't wash.

Burst testing represents actual music.

 

[ryanmh1]

Burst testing does represent actual music.

It can, but the 20ms tone burst specified by the test standards is far too short to be representative of much music. There are good AES papers about this and multiple articles. It should have been increased to 200ms decades ago. Not the point, though. The point is that both devices claim to use the same test protocol, but report disparate results. Something is wrong, and its almost certainly the "perfect" Powercube results down to 2 ohms. I suspect something was (is?) going on that was causing the Powercube to report false results. Not sure what.