Buckeye 3 Channel Purifi Amplifier Review (2nd)

[Matias]

It would be the best idea not to show that chart at all, for several reasons, one very important of them you have just mentioned. That chart only leads to oversimplified conclusions of those who have not gained enough knowledge to be able to separate apples from pears.

And how would those "who have not gained enough knowledge to be able to separate apples from pears" decide between amps without the chart? Bad with it, worst without it. At least it's a pretty good predictor/proxy of an overall good measuring amplifier.

Anyway, back to the Buckeye amp re-review.

 

[enricoclaudio]

As always, thanks @amirm for another great review and thanks to @Buckeye Amps for sending a second unit for retest. These are the amps I’m currently recommending my customers to purchase. Pure performance at an affordable price.

 

[Buckeye Amps]

The chart should show the gain setting used by 90% of the customers. 90% of customers are going to have a source with 4v output. Therefor 90% of customers will use the high gain mode. Then when you factor in the fact that many amps only have a high gain option, it makes the decision a no brainer.

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

 

[Jochen]

That moment, when your are looking at the THD+Noise charts and don't realize if these measurements are for a DAC or an amp as they are so clean...

 

[Too Many Notes]

And how would those "who have not gained enough knowledge to be able to separate apples from pears" decide between amps without the chart? Bad with it, worst without it. At least is a pretty good predictor/proxy of an overall good measuring amplifier.

Anyway, back to the Buckeye amp re-review.

Agreed that having the chart is better than not having it. At the same time, it seems a valid critique that comparisons are made without all things being equal. Perhaps adding an icon to each score indicating the gain setting would be useful? Ideally, Amir employs his time machine to remeasure each amp at an identical gain.

 

[Sokel]

Same gain for all would be nice but in some amps you can't select,some have fixed very high and some fixed very low.
It wouldn't work.

 

[Sokel]

The industry standard has been around 27dB for decades. If the amp is fixed to a single setting then obviously that would be the setting you would need to use. But when you have the option, it should be set to the closest to industry standard.

It has been already stated here many times that obviously an amp with lower gain has an unfair advantage against one with high (recent example the 30 plus gain of the Mcintosh of the recent thread).
So one more time and lets hope people take that as a consideration.
Chart is only a visual clue,no serious buying decision should be made after it.

 

[michaelahess]

Still too expensive, certainly not the fault of Buckeye though! Chinese companies have really shown how overpriced this field is, and some are starting to even do the same...

 

[Sokel]

Still too expensive, certainly not the fault of Buckeye though! Chinese companies have really shown how overpriced this field is, and some are starting to even do the same...

I'm sure that if these companies had half the decent after sale service and support these amps here have price would be much-much higher.
Without considering any other condition,which are many.

 

[michaelahess]

I'm sure that if these companies had half the decent after sale service and support these amps here have price would be much-much higher.
Without considering any other condition,which are many.

If the product is good quality, neither of those matter. I can count the times I've needed support for my AV gear on one hand, over 30+ years.

 

[Too Many Notes]

On sale for $1,395. Outstanding. Can be customized with speakons, etc.

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

Holy cow, $1400 is a huge price drop. Can't say I'm thrilled at having paid $300 more, but such is the free market. How is this expensive considering what you get? This amp and others like it perform leaps and bounds better than amps costing much more.

 

[amirm]

The chart should show the gain setting used by 90% of the customers. 90% of customers are going to have a source with 4v output. Therefor 90% of customers will use the high gain mode.

Those 90% should riot in streets and demand standardization in amplifier gain. I didn't create that problem. Industry did. I am just trying to live with it. There are amplifiers with no gain above 15 dB. Are you asking that they don't get put in the chart regardless of their performance?

As to Purifi reference, there was no low gain in it. You could bypass the buffer but that is not the same as low gain and hence the reason it is not listed that way in the graph.

Also, since I have put amps with max gain of 15 dB in the chart, then it follows that I use low gain for other amps.

Finally, everyone better get onboard 4 volt output requirement since vast majority of proper DACs I test have that level of output. We need to move the industry in that direction, not fight against it.

Really, just live with an imperfect situation. Remember that the power of SINAD is not necessarily in the value itself but the predictive power it has to indicate excellence in engineering which is what we are after.

 

[thegeton]

...the distortion is 8dB higher than the Purifi reference. 8dB is a bit more than “slightly more” in my books.

It might be more meaningful if the 8dB were in the audible range, but since it's not, its kind of a moot point.

 

[Feyire]

I remain astonished at how significant the impact of the binding post's material was on the original unit. This is such a valid demonstration of the value of objective measurement. Well done @amirm and @Buckeye Amps

Not sure why @amirm is vague in regards to the cause of the issue in the review, simply stating "..had an issue with its binding posts increasing distortion."

Let's be more specific, because the issue and its resulting distortion was caused by hysteresis due to ferromagnetic material in the amplifier's binding posts.

 

[thegeton]

So when you’re listening at 100W output it isn’t audible? That measurement is with a 1Khz test tone. Is 1khz not audible?

Read the left axis of the graph again. The 8dB in question occurs between (approximately) -102dB and -112dB, well below the audible threshold for most people even at 100W output.

 

[Too Many Notes]

Really, just live with an imperfect situation. Remember that the power of SINAD is not necessarily in the value itself but the predictive power it has to indicate excellence in engineering which is what we are after.

This makes sense to me. At at certain point, can we admit to ourselves we're not comparing audible differences but rather engineering ones, whether something performs to spec, and that other attributes/features may be more important when considering an amp? Still, I've come to appreciate the singular emphasis of this site on measurements. No one else is doing it and I think it extremely valuable, when kept in perspective. Thanks for the followup review, Amir.

 

[dkinric]

So when you’re listening at 100W output it isn’t audible? That measurement is with a 1Khz test tone. Is 1khz not audible?

@Hifidelity welcome to ASR! Really hitting the ground running on your first day.

 

[thecheapseats]

Been here about a month and posted 250+ messages already. I can't tell trolls from willfull ignorance anymore.

hmmm... am I posting to much?...

 

[ryanosaur]

If that argument is valid, why even bother with Purifi at all? Just get something cheaper because distortion and noise isn’t audible anyways. But for me, if I’m buying a Purifi amp, I want it to perform at least as well as the reference design. Otherwise If quality isn’t important to me, I’ll purchase something cheaper. Like the Hypex NC502 based amps.

If you bought a Lamborghini that was rated at 700hp, and it only had 550, would you be cool with it anyways because the interstate speed limit is only 70mph?

This has come up in conversation. A big part is persnoal values. Some people just have to have the Purifi, because "what if?," or bragging rights, or whatever. I know I consider it as a possibly superior design though I won't hear an audible difference. When I upgrade, maybe I choose that or a new Hypex. And it will more likely depend on how good a month I'm having when I upgrade! I'll know either way I have one of the best products available. For many... it isn't a rational decision. For some, pragmatics matter; for some of those, pragmatics will trump fancy.

 

[thegeton]

...the reference design...

A reference design is a complete circuit design provided by a component manufacturer to help design and manufacturing engineers understand and best use the components they sell. It's not actually intended for commercial use. It may lack some of the higher order functionality of a design released for commercial use. Sure, many reference designs measure well, that's the point - to show off their fancy device. However, the Purifi reference deisgn does not have a soft start/off, an opamp input stage, power autosense, etc.

Feel free to buy whatever you think is right for you. For me personally, I would shy away from operating a reference design as my go-to amp.