Comparing the NAD C298 and 1ET6525SA Purifi-based Buckeye build

[-Matt-]

Has Amir reviewed any Buckeye amps using the Purify 1ET6525SA modules?
I searched but could not find.

Not sure if a Buckeye one has been reviewed but there are these...

Apollon 1ET6525SA ST Amplifier Review

This is a review and detailed measurements of the Apollon 1ET6525SA ST Purifi based class D stereo power amplifier. It was kindly loaned to me by a member and costs 1,190.00€ (USD $1,348). Apollon designs are unique a step up from some of its competitors. Even the power switch feels nice and...

www.audiosciencereview.com

boXem A 4216/E2 Stereo Amplifier Review

This is a review and detailed measurements of the boXem A 4216/E2 stereo balanced amplifier based on Purifi 1ET6525SA class D module. It was sent to me by the company and costs €1,160 (USD $1,350). While not built out of billet of aluminum and such, the 4216/E2 still manages to look unique and...

www.audiosciencereview.com

 

[rjp]

Yes, I read the Apollon review. I guess eventually he will review a Buckeye implementation.

 

[-Matt-]

Yes, I read the Apollon review. I guess eventually he will review a Buckeye implementation.

Don't hold your breath!

I expect @amirm would decline to test another implementation of the same module; or, at least to prioritise as-yet untested modules.

This would be valid on the grounds that performance is likely to be very similar (and we also tend to see good agreement with Purifi datasheets).

 

[Michael Zenkl]

Is it known if the NAD M23 v2 has any performance/sound quality differences compared to the Buckeye?

I might be able to give my five cents to this question soon: I have been fine-tuning some old JBL 4350 with a NAD M66, two NAD M23 V2 and two other amps, and have now progressed to a point where I want to simplify and am asking Buckeye to build me an 8 channel amp with 4 channels NC502MP and 4 NCx252MP (The tweeters need much less power!). I will be able to report my subjective experience after I get the Buckeye.

For now, let me presume my driver matching and L/R comparison: This is a REW measurement (1/6 smoothing) of the 4350B with no PEQ's at all, different gain settings according to the performance of these old drivers, no Dirac (The hump at 114 Hz is 2nd, 4th and 6th order harmonics of a 6 x 9 room which is 3 meters high). I only use Dirac from 17 to 180 Hz (not shown in the graph) and it smoothes out this room mode, but keeps the visceral impact of these beasts intact. I am very happy with the result and am very curious if using one amp (although an 8 channel one) instead of four will work...

BTW: Ref my profile pic: The 2360 birad horn on top of the 4350B is inactive, I got that for an outdoors speaker project, but it is a nice storage space. I put a 3/4" steel plate weighing 92 kg on each 4350B, so not much vibration....

 

[rjp]

I might be able to give my five cents to this question soon: I have been fine-tuning some old JBL 4350 with a NAD M66, two NAD M23 V2 and two other amps, and have now progressed to a point where I want to simplify and am asking Buckeye to build me an 8 channel amp with 4 channels NC502MP and 4 NCx252MP (The tweeters need much less power!). I will be able to report my subjective experience after I get the Buckeye.

Thanks Michael. I look forward to hearing your subjective review regarding sound quality when completed.
I doubt there will be any difference that you can measure.

I have been comparing my Buckeye 2ch purifi gen2 ET with my Audiolab 9000p for a few weeks now and although I do hear a subtle difference I cannot say one sounds better than the other. They are both just different flavors of excellent. Hard to describe, impossible to measure.

 

[Morinor]

Thanks Michael. I look forward to hearing your subjective review regarding sound quality when completed.
I doubt there will be any difference that you can measure.

I have been comparing my Buckeye 2ch purifi gen2 ET with my Audiolab 9000p for a few weeks now and although I do hear a subtle difference I cannot say one sounds better than the other. They are both just different flavors of excellent. Hard to describe, impossible to measure.

Though I find the two amps two be close on character, I wouldn't say the difference is subtle and not obvious on favor of Purifi. Room accoustic are important on accentuate the differences. Out of curiosity what are your speakers that you are using?

 

[rjp]

Though I find the two amps two be close on character, I wouldn't say the difference is subtle and not obvious on favor of Purifi. Room accoustic are important on accentuate the differences. Out of curiosity what are your speakers that you are using?

Have you tried the same two amps side by side? If so I would love to hear more of your comparisons. I can't really tell from your post which your liked better.

I had my son over today for an blind A/B session and he seemed to very slightly prefer the Purifi, though he also found the differences subtle.
Although his musical tastes differ a bit from mine, he has the benefit of youthful perfect hearing, so I'll take his word for it.

My main speakers are Dynaudio Special 40.

 

[Morinor]

Have you tried the same two amps side by side? If so I would love to hear more of your comparisons. I can't really tell from your post which your liked better.

I had my son over today for an blind A/B session and he seemed to very slightly prefer the Purifi, though he also found the differences subtle.
Although his musical tastes differ a bit from mine, he has the benefit of youthful perfect hearing, so I'll take his word for it.

My main speakers are Dynaudio Special 40.

Ι had tried both on a two different systems at different times. On my Quad Revela 2 in a small room closer to the speakers, but in a good triangle position of speakers and listening position. On a pair of QLN Prestige 3 in a much larger room with more distance, but the speakers are more closely to each other having less perfect triangle position. The difference was quite obvious. On Audiolab 9000P, treble and midrange was good on each case. Bass was controlled and tight. Much better results than an Arcam A25. Something seemed not so perfect on bass though on the larger room and due to the speaker placement, the soundstage was obvious tighter. I didn't like it so much also with poorer metal recordings, especially using my Aune S17 Pro as preamplifier. Those things made me considered the switch. On the same systems, Purify correct all of them. Soundstage opened up on bigger room with the QLN. Also treble was further improved and in correlation with the bass improvements, I can hear pleasantly the poorer metal songs now through my Aune. I think that it has faster and clearer treble.
Audiolab 9000P is one last choice only for those still in fear of class D. I cannot find any reason to pay more on an AB amplifier. And I strongly suggest selecting any of those class D implementation over any AB amplifier above 1000€.

 

[rjp]

Ι had tried both on a two different systems at different times. On my Quad Revela 2 in a small room closer to the speakers, but in a good triangle position of speakers and listening position. On a pair of QLN Prestige 3 in a much larger room with more distance, but the speakers are more closely to each other having less perfect triangle position. The difference was quite obvious. On Audiolab 9000P, treble and midrange was good on each case. Bass was controlled and tight. Much better results than an Arcam A25. Something seemed not so perfect on bass though on the larger room and due to the speaker placement, the soundstage was obvious tighter. I didn't like it so much also with poorer metal recordings, especially using my Aune S17 Pro as preamplifier. Those things made me considered the switch. On the same systems, Purify correct all of them. Soundstage opened up on bigger room with the QLN. Also treble was further improved and in correlation with the bass improvements, I can hear pleasantly the poorer metal songs now through my Aune. I think that it has faster and clearer treble.
Audiolab 9000P is one last choice only for those still in fear of class D. I cannot find any reason to pay more on an AB amplifier. And I strongly suggest selecting any of those class D implementation over any AB amplifier above 1000€.

That is encouraging to hear how switching to the Purifi corrected all the problems. If I understand correctly, you are saying if one is determined to stick with class AB then the Audiolab 9000P is one of the best. Is this what you mean by "one last choice only for those still in fear of class D"?

This was exactly my position. I feared class D would not sound good enough ( I had previously tried a cheaper class D amp and it did not) . So I did some research and bought the Buckeye 6525SA Purifi 2ch to see what "really good" class D can do, and to compare with the Audiolab 9000P in my own home on my speakers. I figured it was the only way I was ever going to know for sure. Otherwise, all I had was measurements.

I have not experienced the clear difference you noted, but this could certainly be due to speakers and room. However, I no longer fear class D. This Purifi build sounds as good to me as the Audiolab, sometimes even better. I will likely sell one of them in the near future, but for now I am enjoying the opportunity to compare them side by side.

 

[mike70]

That is encouraging to hear how switching to the Purifi corrected all the problems. If I understand correctly, you are saying if one is determined to stick with class AB then the Audiolab 9000P is one of the best. Is this what you mean by "one last choice only for those still in fear of class D"?

This was exactly my position. I feared class D would not sound good enough ( I had previously tried a cheaper class D amp and it did not) . So I bought both the Audiolab 9000P and the Buckeye 6525SA Purifi 2ch to compare. I figured it was the only way I was ever going to know for sure. Otherwise all I had was measurements.

I have not experienced the clear difference you noted, but this could certainly be due to speakers and room. However, I no longer fear class D. This Purifi build sounds as good to me as the Audiolab, sometimes even better. I am enjoying the chance to compare them side by side.

Well, measurements are all you need to compare transistor amplifiers ... even more ... if they doesn't have big flaws, surely they're indistinguishable.
To compare "side by side" as you said, you need at least to level the volume and better yet to do a blind listening.

Try to do it that way with a multimeter and check the differences, you can be surprised, i bet on it
Is what happened to me and everyone that tried.

 

[rjp]

Yes, volume is carefully matched with attenuation, and switching is done by a single remote toggle so with eyes closed I have no idea which amp is playing. The switch is immediate with no interruption at all in the music. It's so smooth and balanced that often times I cannot even tell if it changed. I am very excited by this outcome, because it has convinced me of just how good class D has become.

 

[mike70]

amplifiers are commodities in 21th century, you need to search for price per watt, looks, warranty, whatever ... but SQ isn't a goal anymore.

 

[rjp]

amplifiers are commodities in 21th century, you need to search for price per watt, looks, warranty, whatever ... but SQ isn't a goal anymore.

I am beginning to think this is the case. In one sense this is exciting because it means we can buy the best and stop fussing. But in another way it's a little sad because this means there is no more pursuit of greatness, it's just done. If we think of it this way, we can just buy the amp based on price per watt, or appearance/build quality, but there is no need to even consider sound quality. This seems very similar to what has happened with DACs recently. For not too much money, we can now buy essentially a "perfect" DAC and a "perfect" power amp. Do you guys agree it has come to this?

 

[mike70]

Absolutely, and I'm glad about it.
No more elitism , more people can have SOTA quality