Buckeye 3 Channel Purifi Amplifier Review (2nd)

[anphex]

Awesome value and performance.
The case though ... It's like it's trying to win a boringness contest.
But I must admit my Audiphonics look pretty bland too and it's not a bad thing. You're putting it into a shelf once and let it stay they and let the sound speak instead of the design.

Still, I little cool silver "BUCKEYE" sticker or something would be nice

 

[pma]

As long as the claim is backed up by evidence. Otherwise we are back to power cables making a difference bullshit

Output relay distortions


And, I wonder the surprise that steel pads introduced nonlinear distortion. It is only a question of current level and measurement sensitivity, as the material is electrically nonlinear. BTW, do you always support your statements by proofs, immediately?

 

[thegeton]

...that decimates the pristine performance...

It disturbs me greatly to appreciate this phrase so much.

 

[Descartes]

Oh yes, I have my own setup now. And all new designs/revisions go through separate testing by other parties as well.

Pictures please and more details

 

[Mr. Widget]

Awesome value and performance.
The case though ... It's like it's trying to win a boringness contest.
But I must admit my Audiphonics look pretty bland too and it's not a bad thing. You're putting it into a shelf once and let it stay they and let the sound speak instead of the design.

Still, I little cool silver "BUCKEYE" sticker or something would be nice

I like the understated aesthetic.
I would much rather have a simple Buckeye enclosure with the rack mount option instead of the ridiculously over baked D'Agostino look.

 

[thegeton]

I like he understated aesthetic.
I would much rather have a simple Buckeye enclosure with the rack mount option instead of the ridiculously over baked D'Agostino look.

View attachment 279443View attachment 279445

As an avowed minimalist, I am Buckeye all the way when it comes to aesthetics.

 

[ryanosaur]

As an avowed minimalist,

Whew... I thought I was the only one.


Oh, and I am totally fine with Buckeye's Chassis!

 

[pseudoid]

I prefer the graphical representation as @amirm depicted.

Reactive Load Amplifier Power Testing
Let's use our fancy Powercube loadbox to simulate both capacitive and inductive loads ranging from 8 down to 2 ohms (amplifier goes into protection with 1 ohm):

(ignore the color differences.) Response is perfect. Regardless of load impedance down to 2 ohm reactive, the amplifier maintains the same output voltage. Can't ask for more.

Although, some math calisthenics becomes required to derive the ultimate delivered power from his graph. [P = V*2 ÷ R]

I am afraid that the impact of reactive load is generally not well understood. Their impact is to peak power dissipation of output transistors, their safe operating area. Not that much on distortion, and paradoxically, at much reduced distortion you get high peak power stress. Let's open a new thread for this. Some thumbnails attached. Peak power is high at the area where impedance magnitude seems to be high enough. EPDR and phase are telling the story. EPDR plot should be a part of every speaker impedance measurement, as it defines amplifier stress.

View attachment 279384 View attachment 279385 View attachment 279386 View attachment 279387

I'd be willing to get skool'd, if you are willing to start such a thread!
I had thought that what an amp sees as the 'Load' became more capacitive at higher frequencies but your graphs indicate otherwise.

 

[pma]

I'd be willing to get skool'd, if you are willing to start such a thread!

I will try to prepare something meaningful. Need to summarize some collected data.

 

[jaymarnz]

I greatly appreciate that Buckeye = excellent performance + awesome customer support + reasonable pricing. A winning formula and especially important for small companies with many larger well-known competitors.

But with regards to price comparisons, keep in mind that companies usually don't just do bottom-up BOM+ pricing. Besides margins they must consider whether low price is justified by volume (eg. commodities) or where higher price places them in market perception (eg. premium product). In the end, it's very hard to grow a business in a small/niche market with low margins but super satisfying to both owners and customers. Thanks Buckeye

 

[amirm]

EPDR and phase are telling the story. EPDR plot should be a part of every speaker impedance measurement, as it defines amplifier stress.

EPDR doesn't apply to class D amplifiers. And even if it did, no one drives the speakers with flat amplitude across the entire audible band. Just get more power than you need and your golden without stressing over the speaker load.

 

[xaxxon]

Oh, and I am totally fine with Buckeye's Chassis!

I wish they had better tolerances. They don't actually mount flush (the center bows up) if you screw in the screws to the point where they won't fall out. Maybe some rubber o-rings would help with getting the screw under tension but not squeezing the sides in?

I knew what I was getting, but the case is lacking even for a plain case.

(I have 2 and they both have this issue and it's been mentioned in other reviews here, too)

 

[SuicideSquid]

I wish they had better tolerances. They don't actually mount flush (the center bows up) if you screw in the screws to the point where they won't fall out. Maybe some rubber o-rings would help with getting the screw under tension but not squeezing the sides in?

I knew what I was getting, but the case is lacking even for a plain case.

(I have 2 and they both have this issue and it's been mentioned in other reviews here, too)

I actually asked Dylan when I ordered last year if he's sell me the amplifier without a chassis at all, but he can't do that because of his OEM deals with Hypex and Purifi. I'm making a new faceplate for the Buckeye to give it a bit classier/high-end look. Will post some photos in the DIY forum when complete.

 

[Rottmannash]

I wish they had better tolerances. They don't actually mount flush (the center bows up) if you screw in the screws to the point where they won't fall out. Maybe some rubber o-rings would help with getting the screw under tension but not squeezing the sides in?

I knew what I was getting, but the case is lacking even for a plain case.

(I have 2 and they both have this issue and it's been mentioned in other reviews here, too)

Here's a photo of mine. It is slightly bowed but I can't see it unless at the right angle.

 

[xaxxon]

Here's a photo of mine. It is slightly bowed but I can't see it unless at the right angle.

Yep, about the same as mine. There is nothing for it to mount/attach/hook in to in the center so it bows up like that. It's not awful by any stretch but I'd have paid a bit more for a better built case if it were an option.

I'd also have paid for better XLR females. I didn't even know there existed non-locking XLR plugs. Was disappointed by that but I should have looked harder before buying. It wasn't mis-advertised.

 

[restorer-john]

It's not awful by any stretch but I'd have paid a bit more for a better built case if it were an option.

Someone needs to step up and offer a Scandi-style brushed aluminium, silver front panel and a light ash timber outer sleeve cover as a 'lifestyle upgrade'.

 

[theREALdotnet]

Someone needs to step up and offer a Scandi-style brushed aluminium, silver front panel and a light ash timber outer sleeve cover as a 'lifestyle upgrade'.

How about wooden cheeks, like vintage Japanese HiFi?

 

[Mr. Widget]

How about wooden cheeks, like vintage Japanese HiFi?

Kind of like this?
I built a pair of these passive crossovers for a vintage JBL dealer in Japan.

 

[freedomgli]

I'd also have paid for better XLR females. I didn't even know there existed non-locking XLR plugs. Was disappointed by that but I should have looked harder before buying. It wasn't mis-advertised.

I didn’t know that, either. Thanks for the awareness. This might be a deal breaker for me. I wanted secure connections on the back of all my power amps. If they’re not locking XLR then I might have to look elsewhere. Seems odd to offer the security of speakON yet cheap out on non-locking XLRs. If I wanted weak friction fit connections I’d still be using RCAs. But I don’t and I’m not.

 

[RichB]

Someone needs to step up and offer a Scandi-style brushed aluminium, silver front panel and a light ash timber outer sleeve cover as a 'lifestyle upgrade'.

Black works better for me, but I do think premium case options would be wonderful.

- Rich