Buckeye 3 Channel Purifi Amp Review

[Buckeye Amps]

@Buckeye Amps
Is it correct to assume you replicated Amir’s initial measurements so the increase in SINAD at higher power is not related to this?

Post in thread 'Hypex NCx500 Class D Amplifier Review'
https://audiosciencereview.com/foru...0-class-d-amplifier-review.41007/post-1451614

Thanks in advance for clarifying.

Correct

 

[boXem]

Correct

Congrats for not taking the opportunity to close the subject.

 

[musicforcities]

The case doesn’t look very well manufactured. There’s large gaps all along where the top and bottom meet.

The gap is uneven (wider towards the center). However I think it is more likely a variation of material tolerances (corrected, not stamped) : schiit manages it only by having tiny boxes. it also might be an issue isolated to this unit.

And rather than try to bend it back as someone suggested here (hard to do actually and not cause other distortion), in such cases it usually better to epoxy an l or c channel or two to the inside, clamping it in place until dry. That will flatten the curve without risking deformation.

Or enjoy the wonders of industrial Velcro tape. Problem solved.

And can I just say, regardless, the manufacturer’s responses here indicate great service would be forthcoming. Amazing

 

[Buckeye Amps]

And uneven (wider towards the center. However It is hard to get stamped sheet metal of that thickness so flat: schiit manages it only by having small boxes and using aluminum. a bolt in the middle would help

Just for clarity, not stamped sheet metal. The cases are aluminum

 

[musicforcities]

Just for clarity, not stamped sheet metal. The cases are aluminu

Just for clarity, not stamped sheet metal. The cases are aluminum

I stand corrected and edited my post accordingly. By stamped I meant bent by deformation (not cnc’d, etc).

And again kudos to you for your engagement here. I would have zero qualms about the case issue. I actually was trying to say that it’s not a case (sorry about the pun) of poor manufacturing but likely a fluke and an inherent limitation in tolerances of the metal and forming process itself. Which is even harder to manage at what I guess are small runs.

And using less material for lids is good: lighter unit, better heat transfer likely and better for the environment all around. Money spent where it counts. As is part reduction. So I applaud that.

Though I would pay a couple hundred more for nice giant VU meters like my old luxman m2000. I know pointless.

FYI: I inherited a ayre cd player that has machined aluminum 20mm sides, 15mm front and a top/bottom plates 3.5mm thick. weighs a ton. Looks amazing. And is most wasteful and stupid case design I ever encountered. I’m sure they would claim some bs about vibration. Or resonance or magic string theory. Whatever, it still measures worse than a $100 disc man from the same era. Better off streaming medium bit rate on Spotify. Or using it as the most obscenely absurd transport with the digital out to a cheap topping DAC. Even my cheap AVR DAC is better.

 

[Chrispy]

I stand corrected and edited my post accordingly. By stamped I meant bent by deformation (not cnc’d, etc).

And again kudos to you for your engagement here. I would have zero qualms about the case issue. I actually was trying to say that it’s not a case (sorry about the pun) of poor manufacturing but likely a fluke and an inherent limitation in tolerances of the metal and forming process itself. Which is even harder to manage at what I guess are small runs.

And using less material for lids is good: lighter unit, better heat transfer likely and better for the environment all around. Money spent where it counts. As is part reduction. So I applaud that.

Though I would pay a couple hundred more for nice giant VU meters like my old luxman m2000. I know pointless.

FYI: I inherited a ayre cd player that has machined aluminum 20mm sides, 15mm front and a top/bottom plates 3.5mm thick. weighs a ton. Looks amazing. And is most wasteful and stupid case design I ever encountered. I’m sure they would claim some bs about vibration. Or resonance or magic string theory. Whatever, it still measures worse than a $100 disc man from the same era. Better off streaming medium bit rate on Spotify. Or using it as the most obscenely absurd transport with the digital out to an AVR.

That one of the Ayres that simply had a fancier case around an Oppo player?

 

[musicforcities]

That one of the Ayres that simply had a fancier case around an Oppo player? It

Not to hijack thread:but no it was before that model. It’s well built inside at least with balanced outs. It plays sacd, dvd-a, anything really. which is why I keep it. You just have to use the digital out or at least keep a dip switch set to “measure” (a sharp filter I think)rather than “listen” which rolls off the highs like it’s a bad tube preamp and creates high order distortion I can’t hear.

Anyway…I’ve been perusing the shopping pages at Buckeye …
I think they should offer a version of the same models but housed in a solid block of aluminum and charge 15x -30x the price for only $200 extra material costs and put a dip switch on the back that allows you to “listen” to the special inaudible distortion artifacts discovered here, or “measure” with the fix. and big warm VU meters

 

[Doodski]

and big warm VU meters

There appears to be several or more peeps looking for a class D amp with big VU meters. A common request although finding suitable big VU meters is apparently not so easy.

 

[musicforcities]

There appears to be several or more peeps looking for a class D amp with big VU meters. A common request although finding suitable big VU meters is apparently not so easy.

It’s like piping motor sounds through the stereo of electric cards …comfort eye candy. But yeah, they need to be nice ones which are rare. The old luxman ones were gorgeous. No blue leds allowed either.

 

[Audiomn]

View attachment 260240

Cool stuff guys, but please start a new thread.

 

[Buckeye Amps]

Enough people have actually made this comment over the last year that they would be interested in VU meters that I feel I should give an official answer: I myself do not plan on offering them as an add on option.

However, I do work very closely with @Rick Sykora who does custom work/builds. If anyone was seriously considering one of my amps but is holding out for VU meter integration (or another such visual modification along those lines), there is no harm sending him a message to get his thoughts, etc.

 

[Sokel]

There appears to be several or more peeps looking for a class D amp with big VU meters. A common request although finding suitable big VU meters is apparently not so easy.

I have try HARD to find the source of the Audio Research meters but no success
(no more OT,I promise!)

 

[RickS]

Enough people have actually made this comment over the last year that they would be interested in VU meters that I feel I should give an official answer: I myself do not plan on offering them as an add on option.

However, I do work very closely with @Rick Sykora who does custom work/builds. If anyone was seriously considering one of my amps but is holding out for VU meter integration (or another such visual modification along those lines), there is no harm sending him a message to get his thoughts, etc.

While somewhat OT, good VU analog meters are simply hard to find. The last ones I used were plastic and needed a custom glass bezel to protect them. I looked again today and no real change. With supply chain issues, they are seemingly not a priority. Many legacy products that have VU meters are often too expensive to consider retrofitting with new amplification.

As for more on topic news, as @Buckeye Amps reported, the distortion rise is reproducible by those closest to the situation. The challenge has been validating potential remediation as the designer has had test equipment issues. As many know, supply chain issues have hampered test equipment availability too. The designer has had to consider alternative test equipment and, along with personal priorities, progress has been slower than expected. He is pursuing multiple potential solutions and expects to have resolved very soon. Stay tuned and will update as soon as we can!

 

[AdamG]

While somewhat OT, good VU analog meters are simply hard to find. The last ones I used were plastic and needed a custom glass bezel to protect them. I looked again today and no real change. With supply chain issues, they are seemingly not a priority. Many legacy products that have VU meters are often too expensive to consider retrofitting with new amplification.

As for more on topic news, as @Buckeye Amps reported, the distortion rise is reproducible by those closest to the situation. The challenge has been validating potential remediation as the designer has had test equipment issues. As many know, supply chain issues have hampered test equipment availability too. The designer has had to consider alternative test equipment and, along with personal priorities, progress has been slower than expected. He is pursuing multiple potential solutions and expects to have resolved very soon. Stay tuned and will update as soon as we can!

And with that, let’s get back on topic. This is an Official Review Thread and we try to keep the conversation on topic. Please start a new thread to further discuss VU meters. Please and thank you for your understanding and support.

 

[Fuzzy]

I bought the 2 channel version of this Purifi amp from Dylan at Buckeye last year and received it in September. So I have been following this thread with interest and doing my best to understand the issue. I am using the Buckeye amp with a direct XLR feed from a RME ADI-2 dac. The dac is connected by usb from a Intel NUC running JRiver. Speakers are Ohm Walsh 3 with replacement drivers. The Buckeye amp took the place of a venerable Adcom amp. I have been using the low gain setting on the Buckeye Purifi amp. With my old ears I am very pleased with the music I am hearing. I believe this amp is distinctly better than any amplifier I have ever had in this system. I use a Benchmark amp and pre-amp in my upstairs system. I haven't been able to hear anything that seems like it could be the distortion that was found in the testing. It is just clear and quick and the lower frequencies sound particularly good. I am pretty sure my ears are the weak link in the chain at this point. I really do appreciate the perspectives that everyone is bringing to this.

I found Dylan to be a great and responsive guy when I was ordering the amp and have been impressed with how he is handling this situation. I would buy his work again.

Thanks!

 

[RickS]

Looks as though Buckeye's buffer designer also had a dummy load issue. I talked to him today and found he was using some PE dummy loads. I had bought the same ones and returned them. I found they could not be used for measuring low distortion situations. Might have found this sooner but we had limited interaction as it seemed desirable for my testing to be blacker box than his.

Since nobody else complained about the PE dummy loads, I was not sure it was a common problem. In hindsight, seems likely they exhibit the VcR characteristic that Amir discusses here: https://www.audiosciencereview.com/forum/index.php?threads/asr-dummy-load-configuration.8026/page-5

So, the good news is the designer should not have to resort to a pricey AP rental as he was able to get a clean measurement once the PE dummy loads were replaced. More importantly, should also mean he should be able to determine potential remediations fairly soon.

 

[Walter]

@Rick Sykora and @Buckeye Amps I have to really applaud how you are keeping everyone updated on this.

 

[Too Many Notes]

Look as though Buckeye's buffer designer also had a dummy load issue. I talked to him today and found he was using some PE dummy loads. I had bought the same ones and returned them. I found they could not be used for measuring low distortion situations. Might have found this sooner but we had limited interaction as it seemed desirable for my testing to be blacker box than his.

Since nobody else complained about the PE dummy loads, I was not sure it was a common problem. In hindsight, seems likely they exhibit the VcR characteristic that Amir discusses here: https://www.audiosciencereview.com/forum/index.php?threads/asr-dummy-load-configuration.8026/page-5

So, the good news is the designer should not have to resort to a pricey AP rental as he was able to get a clean measurement once the PE dummy loads were replaced. More importantly, should also mean he should be able to determine potential remediations fairly soon.

Been following along and appreciate the update. Sounds like good news. Just placed an order for a 3-channel Purifi and super excited! I have faith the cause of this (minor) distortion issue will be determined and resolved. It's clear that Dylan stands behind his products and his zero-BS approach is very confidence inspiring.

 

[Buckeye Amps]

So, not ready to call the distortion issue officially fixed, but we are very comfortable that we have found the culprit. We have a few more variables/variations to test to be 100% sure, along with a 3rd party measuring/testing as well, but we can reproduce distortion-free measurements by replacing the culprit in every different variation we have tried so far.

The great news: if the results hold up, it will be a super simple fix. Won't say more yet. But for those who have been patient and waiting, I think there is finally light.

 

[Audiomn]

So, not ready to call the distortion issue officially fixed, but we are very comfortable that we have found the culprit. We have a few more variables/variations to test to be 100% sure, along with a 3rd party measuring/testing as well, but we can reproduce distortion-free measurements by replacing the culprit in every different variation we have tried so far.

The great news: if the results hold up, it will be a super simple fix. Won't say more yet. But for those who have been patient and waiting, I think there is finally light.

This is awesome news! <Fingers crossed>