Purifi. Purifi vs Aegir. Purifi vs ...

I've listened Aegir OG for 8 years and Purifi class D for some time. As I don't have golden ears for me they sound identical, I mean identically great. The only difference is that Aegir is heating like mad and clipping, all those years I had to run it with active cooling computer fan, which is adding high pitched noise, and unfortunately cannot use it with passive cooling at all.
I only created this thread because Purifi deserves it, I want it to live here. That's it, that's the thread.

 

And a question. Purifi usually comes with some Opamp pre stage, and a gain switch. I have 4 steps, low gain Opamp is off, then 3 steps of gain. The naked mode sounded too dry for me, perhaps I would love it eventually but I only gave it few hours of listening. Lowest Opamp gain sounds very fun and exciting, paired with Bifrost.
My question is, have you played with Opamp swapping game, do you recommend Sparkos or prefer something over Sparkos?

 

However, Opamps are nothing more than coloration. Recently I've decided to run with Windows Equalizer APO because my DIY speakers roll the lows too fast. It was a major improvement and it's a keeper. I wonder if I abandon the Opamp rolling game completely, switch the Purifi gain stage off and just use the EQ to get the coloration I want - will this be a superior approach?

Update: I will never claim that the latest Purifi sounds great and can compete with a good AB not even saying A. It sounds great compared with a _clipping_ and overheating Aegir OG with a noisy fan on top of it. My speakers are low efficiency and require 100W. I was afraid to go dual Aegir OG because I think it would clip as well. Selling it and going full upgrade round would be 3x of my budget. I have what I can afford and I'm happy with it.

 

https://x.com/i/grok/share/LNFLtcHsRJfe22YHDyJj2kbjb
I've asked Grok to compare Burson V7 Vivid vs Sparkos. As Purifi is by far too analytical sound than what the average music source is mixed for, it seems that Sparkos coloration by enhancing harmonics without changing the frequency response might be better.
Also in my particular case I've built 2 Ohm speakers capable of taking advantage of the very high current, and apparently Sparkos are optimized on delivering more current in the bass region. I'll take time, no rush to roll, the stock ops are still pretty good.

 

Maybe you should get your aegir looked at ? I've had 2 for a couple years and they don't over heat and they don't clip. If you have low efficiency and hard to drive speakers you're using the wrong amp anyway. My ageirs will drive a 4ohm load without overheating or clipping at high enough volume....

 

Honestly in my opinion, dual aegir for some speakers (highish efficiency around 90db) is like a completely different amp altogether. I always recommend that folks should try dual aegir if it's feasible for their setup, before saying it's not for them.

For OP, it sure sounds like purifi is the amp for them particularly given the costs. Happy discrete opamp experiences await!

 

seriously?

 

Strangely, the battle between Burson V7 Vivid and Sparkos Pro is very inconclusive online. Apparently, they are so close that the difference is more influenced by where they are plugged to. Both are class A btw. While it's obvious either is a significant upgrade and are pretty much mandatory for Purifi, deciding between them remains very inconclusive even after many reviews. What's nice with Grok, it sounds with such an authority on what you get in either case that it will save me from buying remorse. It won't happen soon but I will put a review. I agree that it cannot compete with dual Aegirs, however for me the superiority of my speakers by far outweighs any possible differences between amps in this price category, in short my speakers with Purifi are superior to any budget speakers with dual Aegirs.

 

Despite being released in 2020, there are only few reviews of Purify OG. A notable one would this , where it's put directly against Aegir. It came very close to Aegir stereo, but fell quite behind monoblocks - the reviewer puts Purify OG at about 70% performance of Schiit monoblocks.. It also easily beats the Rega Elicit R in almost any metric. With all that, Purify OG is 5 years old and is not really supposed to be the state of the art.

Despite being released in late 2024, I found only a single sound impression review of the Purify NextGen: https://www.stereophile.com/content/buckeye-purifi-eigentakt-1et9040ba-monoblock-power-amplifier . Here the reviewer was A-B swapping Purify with Benchmark AHB2 amp and could not spot any difference. However, here the reviewer was running the Buckeye amp with stock input board that comes with OPA 1656 opamps. From the picture, I could not tell if the Buckeye board comes with a swappable DIP8 socket. By my experience sprinkling the input stage with Sparkos Pros offers a notable improvement in soundstage, dynamics and soundstage. Some complex tracks that I found congested and unclear with 1656 are perfectly split into separate instruments with Sparkos. I would only guess that with proper opamps it should easily outclass the Benchmark AHB2.

In the comments, one user said that he upgraded his $9,400 Pass Labs int-60 to DIY Purify monoblocks and is quite happy with the improvement, will never go back.

I also found a multitone measurement https://audioxpress.com/article/fre...i-1et9040ba-balanced-class-d-amplifier-module . I think a swipe or a single sine is not the proper way to stress an amp, here a 31 frequency multitone was fed and passed with -120 Db noise.

Let me also note that the Purify input board serves as a preamp, and offers swappable opamps to tune it into the desired sound signature. It doesn't need a separate preamp, runs happily with RCA cables and can be adjusted with a simple volume control or with a DAC having an integrated volume control. It can be paired with a DAC that has only RCA outputs, which could be a killer feature. I would not run Aegir monoblocks with anything less than Kara preamp, so we are talking about >2X price difference, that could be deployed into better speakers.

 

I think Yota's post was more inspired by how LLMs (including Gemini, Grok, MeowGPT, all of them) are prone to making things up and ought never be taken at face value.

It did seem like not a lot of folks offered insight into your original post over several days, but if the Purifi (not a brand I've heard of before, I think) ends up working out for you then hell yeah! We need competition to make things FUN and INTERESTING! I have a Schiit ton of... well yes Schiit, but that's just because I happen to like how their gear sounds I think-- lots of other folks DON'T care for the sound of gear I've liked, and that's fair and valid; you've got to account for the fact that not everyone prioritises the same things in sound reproduction.

There's no guarantee that, even if you went with dual-mono Aegirs, it will suddenly suit your preferences more.

No clue about that YouTube channel or how trustworthy their impressions are but maybe this COULD be something other folks on here might be interested in trying, who knows.

 

It's Bruno Putzeys' successor to the nCore class D amp. I've heard it, not a fan but a lot of people like it.

 

But now I want to shift the focus from comparing the amps while driving the speakers they all have synergy with towards the problem that not every amp is capable of driving any speaker.

Some background: first, the baffle step. At high frequencies, the sound radiates from the speaker baffle and the energy required to drive it corresponds to half space. Once the wavelength becomes longer, the exact formula is 115 / baffle width in meters, the sound radiates into full space, which requires 4X power if you compare to "infinite" baffle.

Besides that, the power required to drive at lower frequencies is 4X compared with the same sound pressure at 2X frequency. Example: the power required at 40 Hz is 4X the power at 80 Hz.

Example comparing both: suppose your baffle step is 500 Hz (pretty typical). Then the power required to drive the speakers at 400 Hz is 8X of the power at 800 Hz for the same volume. This is why it's pretty typical to see home theater subwoofer that go below 30 Hz to be rated at 1,000 W, far beyond any reasonable class A amplifier can provide.

Now let me show the frequency response of my speakers, measured at 80 Db from 2.5 ft. I can easily go to 90 Db still almost flat, and that would be the maximum volume my ears would tolerate. Those are DIY speakers that took me 5 months to design and build, a hobby project, link in my signature. As you see they go flat to 45 Db, and still have significant volume at 40 Hz. The speakers are sealed, low efficiency (on purpose, that was my goal, I'll explain later).



With all said above, I expect that those speakers require an amp rated at least at 100W and maybe even 150W. The requirement is not only to go low, but to build well controlled low distortion speakers. This is the harmonic distortion chart from the same REW measurement:



You can scan DIY boards to find this distortion to be well below average. To achieve that, I've used a very large 2 mH inductor in series with the foofer. The driver is an electro-mechanical device with its inertia dampened by huge inductance and by the sealed box. It sounds very clean and resolving. I can't really compare, but I don't think it's easy to find a commercial speaker under $5,000 that sounds and measures this good. If you are interested, a measuring microphone will cost you only $25, and perhaps it's a useful tool in any experiment anyway.

The next question is, if you have an amp rated under 100W, can it drive your speakers this low with low distortion? First of all, would be nice to measure how low the speakers can go, if you mind spending $25. If the speakers cut off at 60 Hz or above, the question is probably yes, but it still depends on efficiency. The 2nd octave of grand piano starts with 65 Hz, so with many speakers the 1st octave is not audible.

Now the listening test, which is very simple. If the speakers are measured to go quite below 50 Hz, make them to play the track Sarabande https://tidal.com/browse/track/209060146?u by MMMD. You can also play other tracks from the same album. The ultra low sound you will hear is the specially made electric cello. While standard cello goes to 65 Hz, this one goes below 40 Hz, lower than my speakers can go. Still being a cello, it sounds like a cello. You should hear exactly the same peculiarities of a wooden string instrument that any cello makes - only much lower. You should hear the textured complex sound with many harmonics, it has the distinct sound of a string vibrating under a bow moving back and forth. The sound must be beautiful and pleasant, this track actually sounds very nice and on the proper system, you will have the desire to listen the whole album, and listen it again in the future. If the amp is not capable of driving the speakers this low, it will probably clip. In this case you will hear some kind of a rumble, I don't know exactly because for me it sounds great. At any case, there won't be a desire to listen this again.

 

I was slightly mistaken, Purifi is the company not the product. Eigentakt is the product name, I think NAD uses it, among others. They also make some interesting speaker drivers under the Eigentakt name.

 

One more fresh review of Purify NewGen, praised but without direct compare with anything: https://www.stereophile.com/content...040ba-monoblock-power-amplifier-new-auditions

Detailed review of OG, so it might be slightly dated: https://forum.psaudio.com/t/benchma...son-333-listening-impression-conclusion/27195
There Purify OG was outclassed by Benchmark AHB2 and Mark Levinson 333, however the reviewer noted that without direct A/B test it would be very good.

 

Fresh review:

Purifi was outclassed by 4X priced jeff rowland 535, however the reviewer said the difference was 10% or so.

 

I finally see a really high end amp based on Purifi, however with in-house modification:



it was compared vs NAD, Technics and Hagel, and only Hagel was more or less at the same level. I don't know if what they call the Purifi-Marantz co-developed board is actually better than vanilla NewGen Purifi because there is no review for it at all except the one from Stereophile linked above. So for now we only know that potentially Purifi can punch very high but we have no clue how good the NewGen is, vs OldGen.

 

Next time I research some component for pre-selection from diyaudio.com forums, I give it a try. I've spent days wasting time to filter all the noise from the good content.

Using AI I get reminded of a cool bad guy from Witcher 3. Gaunter'o'Dimm. He'd grant your wish, but not what you want.

 

Purifi fans especially are making it feel a bit like a Head-Fi boomer cult right now. It really doesn't seem like there's much useful information to be had generally around the whole area of more legit class D, such as it is. It's necessary to approach with caution due to all the hand-waving blather, and that's annoying.

I know that Marv and similar people with good ears/experience and access to lots of kit still aren't whelmed on the whole, but I hope that they keep checking in. It could get quite expensive for the unwary meantime.

 

My boss just picked one up for demo unit. Not sure the purifi tie in, but I'm sure it's fine sounding. But for me that price tag is way into diminishing returns!
Edit: ya, joint effort with purifi. Huh.