Buckeye NC502MP 8-Channel Amp Review

[Doodski]

Thanks @amirm and @Buckeye Amps
I just got this exact same model few days ago.
Here is a non professional taken photo for your reference.

@Buckeye Amps it appears that you have near perfected the assembly of this amp. It looks fantastic. A very sensible assembly, layout and the workmanship appears exemplary.

 

[Trell]

The backside shows the expected including trigger control to sequence powering up multiple units with one stroke:

That tiny trigger input that is black on black could for sure have been marked better. Perhaps a white circle?

 

[xaxxon]

It's super expensive and overpowered though.
I rather eye the successor of the Topping PA5 for that and use a stronger amp for the bass.

You would never say that if you owned a pa5.

 

[xaxxon]

I was looking at one of these, but then saw that 2x 4-channel amps was the same price and I went that direction instead. More flexibility and ability to sell just one of the two in the future if needed is great.

 

[Mkaram]

There are pictures on Buckeye site. I can also take them but I think it would be redundant.

This is actually my unit I had ordered from buckeye a long time ago. I asked Dylan to ship it to you before shipping back to me the two units I bought.

If you can spare the time I'd love to see you do a teardown. The reason is because you did a buckeye teardown a few years ago and you had some feedback at that time about grounding, burring off the anodizing in places, and wire placement.

Buckeye Hypex NC252MP Amplifier Teardown

I just reviewed the 6-channel Buckeye Hypex class D amplifier. This is a follow up teardown to that review. The amplifier is an assembly affair as all active electronics are contained in the Hypex NC252MP stereo class D amplifiers with integrated switching power supplies: So the main job is...

www.audiosciencereview.com

I think it would be great for you to evaluate whether your concerns have been addressed in the construction.
That would give the community here insight into whether buckeye has addressed previous comments and also maybe give Dylan new targets for improving next gen.

Afaik it would be the very first time that an audio community would get to reevaluate manufacturing changes made based on their feedback, and provide iterative feedback.

 

[Hellboy.]

@amirm Thanks for the review. But i thinks you should make the review with the worse channels, because people that buy 8 channels amp probably are going to use the 8 channels. And is better to know how the worse channels behave.

 

[Sal1950]

This is actually my unit I had ordered from buckeye a long time ago. I asked Dylan to ship it to you before shipping back to me the two units I bought.

Congrats, a very super amp on beer budget money, just my speed..
The price of electric is going thru the roof and breaking the house budget this year
It's to the point I'm thinking of trading my 5 Classic A/B Adcoms for one of these.
And certain folks here want me to replace my ICE pickup truck for a battery powered toy?
Never Happen My Friends.

 

[Doodski]

Congrats, a very super amp on beer budget money, just my speed..
The price of electric is going thru the roof and breaking the house budget this year
It's to the point I'm thinking of trading my 5 Classic A/B Adcoms for one of these.
And certain folks here want me to replace my ICE pickup truck for a battery powered toy?
Never Happen My Friends.

Lol... My buddy bought a new RAM 1500 and he took me for a ride and progressed to do ~85mph down a city road with potholes and dips in the road and that truck managed those bumps and holes like a champ. It was a hoot. If you get a power meter you can calculate the expense for operating your Adcom amps. Then you know if they are the culprit on the increased electricity expense.

 

[Sal1950]

The you know if they are the culprit on the increased electricity expense.

Oh I know, I can see the change month to month depending on my late night listening habits.
Not only that but with summer already here in FL, I can hear the AC also coming on during those
late nighters, that's another extra cost..
But I really do have a soft spot for these seniors.

 

[Ein]

Using NC502MP with its 600W peak power for surrounds is insane imo. I chose and use a smaller NC252MP for surrounds and only the NC502MP for front LCR speakers.

Great review though. A monster of a home theater amp!

For private cinema hall tip top nice and good.

 

[amirm]

So looking at the amp from the rear which of the outputs of the channel pairings is the "good" channel, left or right? Would seem to make sense to connect my LCR to them.

From what I recall, with the AC outlet to the right, channel 1 (good) would be next to AC outlet and Channel 2 would be one to the left of that.

 

[amirm]

@amirm Thanks for the review. But i thinks you should make the review with the worse channels, because people that buy 8 channels amp probably are going to use the 8 channels. And is better to know how the worse channels behave.

I showed the worse channel and used that for SINAD average in the rankings. And all the tests that say "same module" are using the less good channel as well.

 

[Doodski]

Oh I know, I can see the change month to month depending on my late night listening habits.
Not only that but with summer already here in FL, I can hear the AC also coming on during those
late nighters, that's another extra cost..
But I really do have a soft spot for these seniors.

Mmmmmm AC drooL... I've been considering getting a AC unit before summer hits while the selection of available units is still good. Last summer in June we had a reallly hot month. I was out all night on the first day of summer and it was about 76F all night long that night. That's very good for where I live. How much do you think those Adcom amps are expensing you per month? It would be interesting to see the cost delta between the class D and your Adcoms.

 

[Prince Valiant]

A nice option for anyone wanting a lot of power for a lot of channels.

May I ask where you got it? I'm currently searching for one and apart from the "standard" IKEA, there isn't much I could find.

You might consider looking into local custom options if your budget is high enough.

 

[AdamG]

Let’s all try and stay on topic please. This is a Review Thread and we ask our readers/members to keep the content directly related to the technical details of the product tested.

Please and thank you for your understanding and support.

 

[jimk1963]

This amp does have the brass (non-steel/non ferrous metal) tabs, so the hump you see is exactly the same hump Hypex publishes in the datasheet.

If you want to see the difference the tabs make for the Hypex amps, look at the 8ohm graph from the 6ch NC502MP review Amir did back in 2021 and compare to the 8ohm graph from this review with the brass tabs. The rise in distortion is still there for both (expected due to the Hypex 502 behavior), but in the older review (with steel tabs) there isn't that tiny drop before the knee (so there isn't so much a hump as just an increase). But the difference is very subtle and no, it would not make an audible difference.

Is it understood why steel (ferrous) vs. brass (non-ferrous) binding posts affect SNR at all? The difference is small, as Dylan pointed out (6-ch steel vs 8-ch brass), but what's the deal here...? The ferrous metal does what - pick up a tiny bit of nearby EMI?

After being schooled on how lining up the amp's input and output cables right on top of each other is actually a good thing at audio frequencies (something we'd never, ever do at RF frequencies), the pendulum swings completely the other way here, with some measurable effect due to the tiniest of differences in binding posts that I would have never imagined could matter in the slightest. More schooling required!

 

[Blumlein 88]

Wow look at that Power Cube measurement. The most perfect one I've seen. All you folks with "difficult to drive" speakers need this. I wonder if connected to my Soundlab ESLs if the near/sub 1 ohm impedance with very high phase angle near 20 khz would cause it to shut down?

 

[squared80]

Awesome. Can't wait to see the re-review of the 3-channel Purifi.

 

[Dundas]

From what I recall, with the AC outlet to the right, channel 1 (good) would be next to AC outlet and Channel 2 would be one to the left of that.

Thanks, so the odd numbered channels are the "good" ones. Not that I would be able to hear the difference but nice to know. Dylan can you please confirm?
Already had my LCRs connected to channels 1,3 and 5.

 

[jimk1963]

The 4-ch and 6-ch NC502 amp modules lie flat, while the 8-ch modules lie sideways w/ massive heat sinks. Does this mean there is "less" heat sinking on the 4-ch / 6-ch models? Wondering if Buckeye has measured actual thermal rise on the hottest element(s) for the two mounting styles.

I realize that by mounting sideways, a heat sink is mandatory, otherwise the modules have nothing to dissipate into. But what I'm not sure about is with the lower-channel models, is the chassis base as effective at dissipating the heat?