Buckeye NC502MP 8-Channel Amp Review

[tktran303]

Thank you @amirm

Just a little over a decade ago I had to build my own Hypex nCore monoblocks. 6 in total for my 3 way active speakers.

I also remember having to build my own PC in the late 20th century from a parts list; smorgasbord style! Now I can order an almost state of the art consumer machine, placed online, & deliver to my home, from the likes of Microsoft, Apple, Lenovo etc.

The modern world just keeps getting better and better.

Thank you @Buckeye Amps
PS.
Looking forward to the day you have Airplay2/WISA/Bluetooth/DSP/ARC enabled tri or quad amplified solution with selectable 1000/250/100HF amp modules. I’ll be the first to buy it.

@amirm
How’s the distortion into 2ohms? Is it almost as good as 4 ohms?

 

[amirm]

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?

If I recall correctly, it shut down immediately with 1 ohm before I drove it with a signal. Then again that is the DC load it saw so may be OK with 20 kHz being that way.

 

[amirm]

@amirm
How’s the distortion into 2ohms? Is it almost as good as 4 ohms?

I don't know unfortunately. I have not had time to test if the PowerCube load at any impedance presents a low distortion load or not.

 

[EJ3]

Someone that has a home cinema or multi room setup that is relevant to go for that much power, and that can dedicate two circuits for amplification power is very likely to have a dedicated electrical closet with a rack. Are there rack mounting option? Nobody need such an ugly beast in plain view and it doesn't belong in typical living room credenzas, It's not made for a living room.

I do not know why (house built in 1968 and is [at 1100 sq. ft.] the smallest house in the neighborhood) but my house has 20 amp outlets through out the house and the ones in the living room are on 2 separate circuits. Serendipity strikes here with my homes outlet and circuits being what they are (this is actually the first Class D that really has my attention as the power side of my system. I run a pair of main speakers and a pair of subs. With my pair of APT/Holman preamps I can have QUAD with QUAD subs with the Buckeye Hypex NC502MP 8-channel class D amplifier:

Quadraphonic Synthesis

With two Holman Preamplifiers, you can synthesis and control four output channels from just two input channels.

Apply all your inputs to the first Holman Preamplifier. Use it for all your tone controls, filters and source and tape selections. Leave its Stereo Mode in Stereo.

Connect the first Holman Preamplifier's MAIN 1 output to one power amplifier and your two front speakers.

Connect the first Holman Preamplifier's MAIN 2 output to any line-level input of the second Holman Preamplifier.

Connect the second Holman Preamplifier's MAIN 1 output to the power amplifier for your two rear speakers.

Rotate the second Holman Preamplifier's stereo mode control to L-R, and start by setting it to about unity gain or a bit less, and keep its tone controls flat. The tone and filter settings of the first Holman Preamplifier are fed automatically to the second Holman Preamplifier.

Set balance on the first preamp. Set front-rear balance on the Volume control of the second preamp.

Leave the power switch of the second preamp ON, and plug its power cord into a switched outlet of the first Holman Preamplifier. Now the power is controlled by the first Holman Preamplifier, too.

Not to mention what you can put into the processor loops using using ADC DAC EQ's, etc.

Finally a Class D to seriously consider for my application (and reduce boxes). I can actually formulate a plan for next year now (I already spent this years budgeted audio $'s)

and This one off one

 

[enricoclaudio]

Thanks @amirm for another great review and also thanks to @Buckeye Amps for making another fine piece of equipment. I would love to see a Buckeye Amp with a transparent top so I can enjoy watching the internals

 

[JohnBooty]

Is it possible to use this as a monoblock by bridging all eight channels into one? I'm interested in seeing if I can destroy a mountain with sound.

 

[jimk1963]

Is it possible to use this as a monoblock by bridging all eight channels into one? I'm interested in seeing if I can destroy a mountain with sound.

… hooked up to a 96” sub with jumper cables? I like it.

 

[EJ3]

Is it possible to use this as a monoblock by bridging all eight channels into one? I'm interested in seeing if I can destroy a mountain with sound.

Sounds like fun to me!

 

[anphex]

You would never say that if you owned a pa5.

I own a PA5.

 

[TNT]

I don't know unfortunately. I have not had time to test if the PowerCube load at any impedance presents a low distortion load or not.

This would be as natural as checking the power - I mean now that you made the trouble to get a proper load you should try to take time to really utilise it - most logical would be to run almost all test in low reactances. I do understand it takes time but perhaps some automation could help - or do you feel it is necessary to overlook these kind of torture test in person perhaps due to risk of fire etc?

//

 

[amirm]

This would be as natural as checking the power - I mean now that you made the trouble to get a proper load you should try to take time to really utilise it - most logical would be to run almost all test in low reactances. I do understand it takes time but perhaps some automation could help - or do you feel it is necessary to overlook these kind of torture test in person perhaps due to risk of fire etc?

//

The load box is not designed for this purpose. It limits you to max and peak power measurements in Audio Precision. I can bypass that and test it for distortion but that is "off label" use for the box. My own dummy loads are used for precision measurements of distortion. I can parallel the loads to get to 2 ohm but only one channel.

I don't understand the rest of your comments. I measured with 2 ohm with +-60 degree phase angle. What else do you want to see there? The loadbox goes to 1 ohm but as I reported, the amp instantly shuts down. The performance that I measured is already superb as hardly any speaker goes down to 2 ohm with that kind of difficult phase angle.

 

[tktran303]

Before we all get excited and blow a load.

200W is only 3dB more than 100W.
Like 2W is 3dB louder than 1W.

What is 3dB? Like having 2 speakers instead of one.

Try for yourself:

Peak SPL Calculator

Btw I was just asking for curiosity.
The data sheets show it all anyway.
Continuously stable into 2ohms is excellent.

Most people have high power amplifiers to avoid amplifier clipping ie. hitting 1% distortion.

What’s the point of having your 96+ dB SINAD DAC when your amp regularly clipping (1% distortion is SINAD 40)

 

[amirm]

I think it would be great for you to evaluate whether your concerns have been addressed in the construction.

They have indeed been addressed. See the teardown: https://www.audiosciencereview.com/forum/index.php?reviews/

 

[Oldasdrt]

Because when you’re spending thousands on speakers, TV/projector, furniture, etc, you simply want the best possible components to handle anything you throw at it.

An extra $2k for the piece of mind of never having to think about upgrading your amplifier (or running out of power) is less than 10% in the overall cost.

I agree with your point, but even with high eff speakers, you wont ever get near max power, even my 90' Pioneer with 6 Ineffiencent Bose speakers, 901s,601s 301s and a Polk sub sat system probably never even reached half power, but I definitely see your point

 

[Oldasdrt]

Before we all get excited and blow a load.

200W is only 3dB more than 100W.
Like 2W is 3dB louder than 1W.

What is 3dB? Like having 2 speakers instead of one.

Try for yourself.

Btw I was just asking for curiosity.
The data sheets show it all anyway.

Continuously stable into 2ohms is excellent.

Peak SPL Calculator

Most people have high power amplifiers to avoid amplifier clipping ie. hitting 1% distortion.

What’s the point of having your 96+ dB SINAD DAC when your amp regularly clipping (1% distortion is SINAD 40)

Yep, with my old Pioneer into all my inefficient speakers, if I had ever even got close to clipping, I would be more deaf than I am now
VSX D1S 2 90'
901s,601s Spec edition 301s and Polk sub sat

 

[Oldasdrt]

Even high end AVR's cannot come close to what this can do. Try running 11-13 channels of hard to drive 4ohm speakers at reference level. Not everyone will need this but those that do, or want something like this to never have to worry about having enough power, it is a great option. Also, not everyone uses an AVR and use processors instead.

Yep. I wish I still had my old inefficient system and was still SINGLE,

 

[geekosa]

This buckeye amp is hard to find in europe.

But this audiophonics amp is :

AUDIOPHONICS HPA-Q250NC Amplificateur de Puissance Class D 4 Canaux NCore NC252MP 4x250W 4 Ohm - Audiophonics

Le Audiophonics HPA-Q250NC est un amplificateur quatre voies basé sur deux module d'amplification Hypex Ncore NC252MP.

www.audiophonics.fr

It's a 4 chennels amp made with 2 Hypex Ncore NC252MP

Should it perform the same way than this buckeye ?

 

[Matias]

This buckeye amp is hard to find in europe.

But this audiophonics amp is :

AUDIOPHONICS HPA-Q250NC Amplificateur de Puissance Class D 4 Canaux NCore NC252MP 4x250W 4 Ohm - Audiophonics

Le Audiophonics HPA-Q250NC est un amplificateur quatre voies basé sur deux module d'amplification Hypex Ncore NC252MP.

www.audiophonics.fr

It's a 4 chennels amp made with 2 Hypex Ncore NC252MP

Should it perform the same way than this buckeye ?

Buckeye also sends to Europe. But if you want an European manufacturer you also have Audiophonics, Nord, Apollon, KJF Audio, etc. Several options for you to research and choose from.

 

[IAtaman]

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?

You have the brilliancy control turned to max?

 

[TNT]

The load box is not designed for this purpose. It limits you to max and peak power measurements in Audio Precision. I can bypass that and test it for distortion but that is "off label" use for the box. My own dummy loads are used for precision measurements of distortion. I can parallel the loads to get to 2 ohm but only one channel.

I don't understand the rest of your comments. I measured with 2 ohm with +-60 degree phase angle. What else do you want to see there? The loadbox goes to 1 ohm but as I reported, the amp instantly shuts down. The performance that I measured is already superb as hardly any speaker goes down to 2 ohm with that kind of difficult phase angle.

The rest where: could we see distortion also in complex loads - not just output power. The "only" thing we see now is how the DUT keeps up the voltage in tricky reactance situation. Maybe it starts to distort like crazy in 3 ohm - 30 deg Cap even if it manages to keep the voltage/power. Btw - isn't it also interesting to see how it behaves in inductive reactances? Now it seems to be only cap.

And while at it... I'd really like to see a 18+19kHz test for power amps so that the meas. filter don't come into play suppressing creation of sum/diffs occurring in the passband or the multi-tone without the measurements filter at 25k so that we can see how the amp would behave with our amps/speakers - this would be more helpful in choosing power amps from specs I believe.

Tnxs!

//