Purifi Amps - Top Choice or No?

[Buckeye Amps]

When looking at speaker performance, what is the threshold impedance that suggests a speaker does indeed need higher current? For example would it be a minimum impedance below 8 or 4, or does it depend on frequency vs impedance, etc.

Frequency vs. impedance.

But I usually don’t recommend the need for higher current from something like the NCx or 7040SA Purifi unless impedance is under 4ohms nominal OR there is a drop down/under 2ohm that is known to cause issues (ie a customers current amplifier enters clipping or protection).

 

[lc6]

At the High End Show in Munich next week, Purifi says it will exhibit

That's < 0.0001% THD. I wonder what the real-life (with a suitable power SMPS) SINAD will be?

 

[tmtomh]

Frequency vs. impedance.

But I usually don’t recommend the need for higher current from something like the NCx or 7040SA Purifi unless impedance is under 4ohms nominal OR there is a drop down/under 2ohm that is known to cause issues (ie a customers current amplifier enters clipping or protection).

That seems very reasonable. For what it's worth, I have an original Purifi 400-based amp running Infinity Kappa 9s, which present a ridiculous load at certain frequencies, and to my pleasant surprise the amp is driving them just fine. Based on SPL measurements I've taken, I've been able to run them at the equivalent of 100dB at 1 meter and the amp hasn't complained or done anything unusual. I had the amp for three years before I got the Kappas. If I'd had the Kappas first and were looking for an amp know, I'd have chosen a Purifi 7040SA or NCx solution. But as you say, those aren't necessary unless one's current amp is having difficulty driving the load.

 

[radeon]

Hey guys, quick question:

I bought 8x 1et400a's and 8x SMPS 1200w power supplies to build 8 monoblock amps in a single chassis for a multichannel system.

I also bought the Hypex Evaluation Board input buffers to use on the purifi modules, but I just found out that these input buffers dont have any EMI/RFI filtering on the input stage, nor does it have any GBW limiting.

Is this a huge problem and should I get new input buffers? I'm using fairly sensitive horn speakers.

 

[arn]

Here is my story… two years ago, i wanted to step up from my hifi. I bought a klh5, i was really impressed, next to that i used the rme adi2. At those time i had an old nait xs amp, i wanted to upgrade this too.

Temporary i bought an a800 pa/studio amp - previously i used a crown xls, it showed me the naim hifi weaknesses - yeah, it was not a sophisticated sound, but give some concert feeling, what is completely missing from the smooth “hifi” amp. From another aspect, sometimes felt too much for a living room, so i stayed at the naim. I expected simiar - and i got it, but the scale of somewhere between the two. After a couple of months i realized, i never enjoyed the music so much, than with the el cheapo a800.

So i wanted to stay on the same studio/pro side, but in a higher level, i bought an ahb2. It was exceptionally clean, and boring again… i played a lot with the input/ output levels the adi2 is a really good partner in that, but nothing happened, no cheerful sound. After a month i give up, and bought a c298.

I still have this amp - since 1.5 years, from many aspect it is better than the a800, but sometimes i felt something is not ok, and i put back the a800. I did it many times, last time i promised myself, ok… i hear the a800 issues if i connect after the c298, but do i have any issues, if i left there for weeks? None. It has dirtier sound, but more cheerful, and more concert feeling. Sometimes i felt the my biggest issue with the a800, it is so cheap, a more expensive amp must be better.

So here i started to give up to force to love more expensive amps, if i enjoyed the listening with then far the cheapest amp, what ive ever had. I can imagine somewhere else, or in a different setup, the a800 is the worst, but i learned the lession, finally is the most important, which is the most enjoyable for me.

 

[Count Dacula]

I went thru just a few popular AB amps in my lifetime, but I bit the bullet and ordered a Nord Hypex NC252-MP. It's power slightly edges out the previous amps I've owned, so it should present a true comparison to my AB amps....for me.

I used my own formula for comparison sake, I call it the "6 ohm spec". Since output doesn't always double at 4 ohms, I feel like the 4 ohm number gets exaggerated and should have less weight for quick comparison sake, so splitting the difference between the 8 and 4 ohm specs gives me a usable number. I went thru 125w, 150w, 162w amps and the Hypex is 150/250 watts, giving me a usable "6 ohm" spec of 200w. So a nice progression from my vintage 1989 ADCOM poweramp. I love that thing, but it very much time to retire. My Parasound is terrible, and my Vidar is pretty good, but I still ordered the Nord.

NORD VALUE-LINE Archives

nordacoustics.co.uk

If money wasn't an issue, I'd get the NAD. I had my eye on this IA, but got the Nord instead to keep the powerup and the price down.

Was very close to pulling the trigger on it, but my various SMSL DACs make full size/price preamps obsolete.

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[pawsman]

Dylan,
When will the Purifi 7040sa Stereo amplifier be available? I realize it needs a redesigned Micro Audio PS

pawsman

 

[UNICRON-WMD]

Why is no one talking about the Audiophonics HPA-S400ET? I have one in art room and love it.

I am thinking of getting the 3 channel version for my theater. I was also thinking of getting a Buckeye, but I hate the look.

 

[TheWalkman]

Why is no one talking about the Audiophonics HPA-S400ET? I have one in art room and love it.

I am thinking of getting the 3 channel version for my theater. I was also thinking of getting a Buckeye, but I hate the look.

Unicron,

I’m with you.

I live in the states and have had the Audiophonics-S400 for a year and love it. I really dont want or mean to take anything away from Buckeye and what Dylan is doing, but the AP case design/ heat sinks, etc. and Amir’s great review were the deciding factors for me.

I was really nervous about ordering an amp from France but it was easy, cheap and quick. Zero problems.

Driven by a Pi Zero2W streamer and an Sangean HD receiver via a Topping DAC, this Audiophonics is an endgame amp for this happy listener.

 

[tmtomh]

Why is no one talking about the Audiophonics HPA-S400ET? I have one in art room and love it.

I am thinking of getting the 3 channel version for my theater. I was also thinking of getting a Buckeye, but I hate the look.

Yes, a fantastic amp. I own one too.

 

[Jim Creek]

I’ve had my VTV Eigentakt for about 6 months. I just love it. Kicks ass.

 

[guyboisvert]

Are the current Purifi based stereo amps and monoblocks considered the best in terms of measurements, power, heat, weight, sound and cost/value vs class A and AB models like Bryston and the like?

For example, 2 x Bryston 7b3 monoblocks are about $16k, weigh a ton and generate a lot more heat, with larger footprint.

Purifi amps like those from Apollon, BoXem, NAD, March and others cost just a fraction of that, even for monoblocks. They have the power, current and damping factor to drive and control even demanding speakers, run a lot cooler, have a smaller footprint, are lighter, etc.

So, I am wondering the following:
1. Is class D basically now good enough to make good, pricier, class A and AB stuff less relevant in 2023?

2. If Purifi is still popular and considered the way to go, which maker is currently considered the best right now from a build quality, reliability, parts and power supply quality, and engineering perspective?

About Class D from Hypex and Purifi, it's not "good enough", it's better than the traditional class A/AB competition! Numbers speak by themselves. Bought a Hypex Nilai 500 Steron DIY + Hypex Preamp DIY, using my Topping D70 Pro (could have bought a less expensive one like an SMSL D6-s, but i wanted 12V Trigger!) and Ryan R610, it sounds superb!

As for makers, it's more or less all the same. It all depends what you mean by "build quality", assembling modules is very easy. But sure, there are nice looking cases, good binding posts and nice input plugs (but i'd never pay a premium for this!). Sure, some try to differenciate themselves by swapping the default gain stage (which is already very good). It doesn't bring much to the table, maybe coloration like the ones using the crappy tubes. As always, people should look at their speakers and room before spending money on a gain stage... we all know that this is the place where the distortion is much higher!

 

[guyboisvert]

Answer to #1, most of us here would say, yes. Purifi, and at a lower cost, Hypex. If starting out today and needing higher power levels, I think definitely the way to go.

As to #2 - it kinda varies depending on where you are geographically located. There are higher priced-builds and value-forward builds. I don't own, but definitely have my eye on, a Buckeye amp build in the future, no-frills, but well built and great customer service. They are here in the U.S. Different good choices in Europe.

And yeah, if you have the $$ to spend, Benchmark. Out of my price range, but wonderful.

The Benchmark is surely a great amp but i don't think it brings much to the table compared to Hypex and Purifi. Passed a certain level of fidelity, your ears are not able to distinguish. Get better / more linear speakers and take care of your room, this is the place where the distortion is easily the highest!

 

[pogo]

The Benchmark is surely a great amp but i don't think it brings much to the table compared to Hypex and Purifi. Passed a certain level of fidelity, your ears are not able to distinguish.

Even between these amplifiers, differences can still be perceived on real loads (speakers).

 

[Rhamnetin]

Even between these amplifiers, differences can still be perceived on real loads (speakers).

Is this something that should be evident on the reactive load tests? Comparing the reviews here of the AHB2 and NCx500, I see no way to justify the AHB2 anymore at its price point.

 

[Redwine]

Even between these amplifiers, differences can still be perceived on real loads (speakers).

And for what reason did you then end up with a Nad M33, streaming or?

 

[pogo]

And for what reason did you then end up with a Nad M33, streaming or?

Because it is a very good overall package and has absolute control over my passive sub. This also means that my room modes are less stimulated.

 

[pogo]

Is this something that should be evident on the reactive load tests?

I don't think so. This is more likely to have something to do with the output impedance: Link

 

[radeon]

Hey guys, quick question:

I bought 8x 1et400a's and 8x SMPS 1200w power supplies to build 8 monoblock amps in a single chassis for a multichannel system.

I also bought the Hypex Evaluation Board input buffers to use on the purifi modules, but I just found out that these input buffers dont have any EMI/RFI filtering on the input stage, nor does it have any GBW limiting.

Is this a huge problem and should I get new input buffers? I'm using fairly sensitive horn speakers.

bump on this if anyone has an answer. my built amp seems to have a fairly high noise floor, not sure if getting new input buffers that have EMI/RFI filtering will fix this

 

[Killingbeans]

I would probably look critically at the layout of the modules and wiring first.