Buckeye 3 Channel Purifi Amplifier Review (2nd)

[Too Many Notes]

I was sort of on the fence with Alan although now he seems to have some sort of character defect. He has what is apparently a operating business in his own corner of the world and yet he comes here to cast his web. That's just stupid.

Dylan is probably eating his lunch, along with some of the other big players' meals. Congrats indeed Buckeye, you must be doing something right to have their attention.

 

[xaxxon]

Dylan is probably eating his lunch, along with some of the other big players' meals. Congrats indeed Buckeye, you must be doing something right to have their attention.

Let's be honest, what Buckeye is "doing right" is essentially running a non-profit amp maker. It's not surprising people trying to make traditional audio margins don't like it.

I'm not putting down what they do - I just bought 8 channels of 502mp from them. And I did so because of the price.

 

[Doodski]

Let's be honest, what he's "doing right" is essentially running a non-profit amp maker.

We don't know the numbers or do we? I don't think we do.

It's not surprising people trying to make traditional audio margins don't like it.

It's capitalism at it's finest. What other way could they compete for dollars?

 

[dkinric]

My troll-dar was definitely going off. That's really pathetic

 

[Mike-48]

Others may choose to jump in but all I will say this one last time so it is on record for those who may read these threads and not know any better:
You cannot compare amps (or speakers, DACS, etc. for that matter) using YouTube. It is not accurate. At all. Period.

Agreed.

I'll go further -- anyone who posts such a video has immediately marked themselves (in my mind, anyway) as irrelevant, and possibly deluded, in the audio world. One can struggle to hear differences among components when listening in person. The idea that sound comparisons can be picked up by microphones, run through ADC, compressed by YouTube with an unknown algorithm, and still make sense is . . . well . . . crazy.

 

[thecheapseats]

people 'pretending' on the internet?... I'm shocked... shocked...

 

[AdamG]

people 'pretending' on the internet?... I'm shocked... shocked...

Right? It gets me every time. Shocked

 

[jimk1963]

Technically it would be Medium gain if someone has a 4v source.

Question re: amp gain. Am running a Marantz Cinema 40, which I believe has internal amp gains of 29 dB. If I mated it with this 25.6 dB gain Purifi amp, is this correct:

Marantz is rated for 125W/ch into 8 ohms (2 channels driven) --> 31.6 V (RMS)

At 29 dB Gain (internal amp), input signal level is 31.6 / [10^(29/20)] = 1.12V RMS (takes a little over 1V RMS to drive internal amp to max power)

If I substitute Purifi amp @ 25.6 dB, need 3.4 dB more input voltage to reach same 125W --> 1.12V x {10^(3.4/20)} = 1.66V RMS

Input signal needed to reach Purifi amp's measured 8 ohm max power (172 W, from Amir) --> 1.66V x sqrt(172/125) = 1.95V RMS

Buckeye website lists max power as 225W (8 ohms) --> 2.23V RMS

Do these modern AVR's handle up to 2.3V RMS on their unbalanced outputs, with no issue? (Cinema 40 doesn't have balanced pre-outs)

Does SINAD/THD/etc suffer on these AVR pre-outs when voltage is cranked up? The difference between 25.6 dB and 29 dB is about 1.5x (50% higher voltage needed).

Not that I'd ever listen to anything at these ear-splitting levels... Just really asking, are there any signal quality "penalties" by substituting a lower gain amp in the chain vs. higher-gain internal amps, assuming the same output SPL to the listener.

 

[Extreme_Boky]

I did a bit of research and liked an unorthodox approach - an attempt to further improve things and not just slap an amp and SMPS-of-the-self products in a metal box.

March Audio seems to have an outside-of-the-box approach with their amplifiers... they use high-quality OPAmps and the best linear Vcc/Vee regulation currently available, which I also like and use extensively. Their SMPS are custom-built as well, and judging by an effort to use low-noise DC rails for the low-signal stage (the LT3045/3094 regs), I am pretty sure that the high voltage rails (i.e. that custom-built SMPS) would also receive the same approach, i.e. focus on low noise, with an addition of the high capacitor banks to combat digital pumping. Their cases seem to be milled from a solid block of aluminium and look really good. The only thing missing is the lack of internal photos, to see how everything is connected together.

But this Buckeye amp is such a value for money - unbelievable. Very nice option for multichannel setups, especially if the amp can be hidden away.

Shame that it had to come to such a drastic step and remove the March Audio guy from forums... but I do get why it happened.

 

[Extreme_Boky]

Question re: amp gain. Am running a Marantz Cinema 40, which I believe has internal amp gains of 29 dB. If I mated it with this 25.6 dB gain Purifi amp, is this correct:

Marantz is rated for 125W/ch into 8 ohms (2 channels driven) --> 31.6 V (RMS)

At 29 dB Gain (internal amp), input signal level is 31.6 / [10^(29/20)] = 1.12V RMS (takes a little over 1V RMS to drive internal amp to max power)

If I substitute Purifi amp @ 25.6 dB, need 3.4 dB more input voltage to reach same 125W --> 1.12V x {10^(3.4/20)} = 1.66V RMS

Input signal needed to reach Purifi amp's measured 8 ohm max power (172 W, from Amir) --> 1.66V x sqrt(172/125) = 1.95V RMS

Buckeye website lists max power as 225W (8 ohms) --> 2.23V RMS

Do these modern AVR's handle up to 2.3V RMS on their unbalanced outputs, with no issue? (Cinema 40 doesn't have balanced pre-outs)

Does SINAD/THD/etc suffer on these AVR pre-outs when voltage is cranked up? The difference between 25.6 dB and 29 dB is about 1.5x (50% higher voltage needed).

Not that I'd ever listen to anything at these ear-splitting levels... Just really asking, are there any signal quality "penalties" by substituting a lower gain amp in the chain vs. higher-gain internal amps, assuming the same output SPL to the listener.

I always prefer a lower gain to a waste of gain... I'd rather crank the volume pot higher and utilise the (close to) full dynamic range I have at my disposal (and these class D amps are superb in that respect), than hover at a low-volume setting. Plus, with a lower (just enough) gain setting, the amplifier noise performance would be (much?) better.

 

[phoenixdogfan]

Great review as always, Amir, thank you. I continue to be amazed at the power cube measurements for the NCore and Purifi designs. Anyone who ever looked at Peter Aczel's Audio Critic reviews of some very expensive (at the time) amps would immediately see just how stellar the performance of the Hypex and Purifi designs truly are in this area.

Now, if it were possible to have a tear down of this one. I'd like to see which SMPS they're using on this one.

 

[Buckeye Amps]

Great review as always, Amir, thank you. I continue to be amazed at the power cube measurements for the NCore and Purifi designs. Anyone who ever looked at Peter Aczel's Audio Critic reviews of some very expensive (at the time) amps would immediately see just how stellar the performance of the Hypex and Purifi designs truly are in this area.

Now, if it were possible to have a tear down of this one. I'd like to see which SMPS they're using on this one.

Hypex SMPS1200A400

And there are internal photos on our website.

 

[xaxxon]

We don't know the numbers or do we? I don't think we do.

It's capitalism at it's finest. What other way could they compete for dollars?

Yeah, the margin has been commented on in other threads. Not precise numbers but mentions that it's quite small. A guy who resells the amps as well as the guy that runs the company have both commented.

And yeah, that's fine to do, obviously. I'm just stating why people may frustrated by it. It's tough to compete with people who are essentially giving away their time - at least compared to traditional hifi design/sales.

That's not saying that it shouldn't be commodity. Just saying that it may be hard for people to adjust.

 

[pseudoid]

Thanks @amirm for the added/enhanced graphs with reactive loads, although they must increase your workload! [happy/sad]
Such information should be revealing in future tests of good design and performance.

I am a bit confused about 3 channel amplifiers:: is there such a thing as a '3 channel' audio?
If not, where did the other two channels (and their content as rear L/R) go... or where is the 3rd one coming from?

 

[xaxxon]

Thanks @amirm for the added/enhanced graphs with reactive loads, although they must increase your workload! [happy/sad]
Such information should be revealing in future tests of good design and performance.

I am a bit confused about 3 channel amplifiers:: is there such a thing as a '3 channel' audio?
If not, where did the other two channels (and their content as rear L/R) go... or where is the 3rd one coming from?

3+2 = 5 Source

Great for home theater.

You can also buy a 2-channel version of this - but you're paying for an over-built power supply then.

 

[pseudoid]

3+2 = 5

Oh!

 

[amirm]

If not, where did the other two channels (and their content as rear L/R) go... or where is the 3rd one coming from?

Center channel for home theater where this is aimed.

 

[Kimbrough Xu]

I really don't quite understand how o connect the 3 channel amplifier, I mean, my output is stereo, but the amp has 3 channel inputs. Why not just 2 channel inputs and output to 3 channels?

By the way, what amplifier chip does it use?

 

[xaxxon]

I really don't quite understand how o connect the 3 channel amplifier, I mean, my output is stereo, but the amp has 3 channel inputs. Why not just 2 channel inputs and output to 3 channels?

By the way, what amplifier chip does it use?

It's for left/center/right for home theater. Your AV processor has a bunch of pre outs and you hook up three of them.

It's not for a 2 channel setup, but they do sell a 2 channel version - but the price is higher per channel because of the overhead for the case and power supply which don't get cheaper.

Here's the link:

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

 

[goryu]

In my case I will be actively amping my 3 way speakers so I need 3 channels per side. One three channel amp per speaker plus another 2 channel amp for the 4 subs...