Buckeye Amps: 2nd Generation Purifi EIGENTAKT 1ET9040BA Amplifier

[Julf]

It's not that bad. When I was first getting started in 2020/early 2021, the USD to EUR was lower than it is now.

Really?

 

[Julf]

See my above post. It's not anywhere near how bad it has been before. So it's not even on my radar for worry/consideration yet. As of right now it is just tariffs I have to consider and adjust for.

So what you are saying is that you have a high enough profit margin?

 

[Buckeye Amps]

So what you are saying is that you have a high enough profit margin?

I wouldn't say the profit margin is high, especially when compared to most other brands.

But being the sole employee, I can absorb swings in things like the dollar value or shipping costs or incremental price increases by vendors without it making/breaking the business.

I drew a line at the tariffs, however.

 

[Buckeye Amps]

Really? View attachment 445804

Your chart indicates the point I made very clearly in 2021...so yes, really.

 

[David_M]

Yes.

Sure, as long as the US amp builders don't use any foreign components. Too bad pretty much all PCBs are made in China, assembled from semiconductors are made in China, Malaysia and Taiwan, using photo-lithography equipment from The Netherlands. Oh, and even the enclosures are made from steel from Canada or India.

As for our favorite class D amps, the Purifi modules will be tariffed from Denmark @10%, and AC/DC switching power supplies from some foreign country @10%, (as long as it's not China @145 or 245% !!!). PC boards, ICs, and passives can be locally sourced easily. Chassis can also be made locally. Ditto for power cords, etc. So, our exposure is not that great, I believe. Do I have this right?

 

[Buckeye Amps]

As for our favorite class D amps, the Purifi modules will be tariffed from Denmark @10%, and AC/DC switching power supplies from some foreign country @10%, (as long as it's not China @145 or 245% !!!). PC boards, ICs, and passives can be locally sourced easily. Chassis can also be made locally. Ditto for power cords, etc. So, our exposure is not that great, I believe. Do I have this right?

You would have to ask each brand/manufacturer for a breakdown. For instance, the price difference between having PC boards manufactured in the US vs. China is still such a drastic price difference that even a 500% tariff would be cheaper than turning to US manufactured PC boards.

 

[Full Zhou]

"Ha, how much is a square meter of two-layer FR4 made in the USA? Currently, the price for double-sided PCB in China is 210 RMB/square meter."

 

[David_M]

Since 1$ = 7.3 rmb (approx) ==> China price of 210 rmb/meter = $28.77/square meter or per 1550 square inches. That's quite a big panel capable of tens (or more) of pre-amp pcbs for the Purifi modules.

 

[Buckeye Amps]

Just wanted to put a PSA out there so no one reads into the current extended lead times for something they are not (such as thinking it is due to issues procuring parts, cost barriers, etc). It is merely because we are finally taking an official vacation for the first time in over four years:

For the first time in over four years, we are taking a short vacation here at Buckeye Amps. We will be gone for 10 days at the end of May/beginning of June. Once we return from vacation, we will work diligently to bring the build times back down to previous levels. Thank you everyone!

 

[muslhead]

Just wanted to put a PSA out there so no one reads into the current extended lead times for something they are not (such as thinking it is due to issues procuring parts, cost barriers, etc). It is merely because we are finally taking an official vacation for the first time in over four years:

For the first time in over four years, we are taking a short vacation here at Buckeye Amps. We will be gone for 10 days at the end of May/beginning of June. Any new orders starting today (5/8) will have an extended build time of 4-5wks. Once we return from vacation, we will work diligently to bring the build times back down to previous levels. Thank you everyone!

Enjoy your time off

 

[JRT]

FYI... The follow-up article, which Dylan had mentioned that he was expecting in the June issue of Stereophile, did make it into the June issue, on page 109 of the printed version, which arrived in my USPS mailbox yesterday (Saturday, 10 May 2025). Not sure, but that issue may also be out on the news stands by now. Not sure if or when the online version may be updated with the follow-up.

 

[JRT]

FYI... The follow-up article, which Dylan had mentioned that he was expecting in the June issue of Stereophile, did make it into the June issue, on page 109 of the printed version, which arrived in my USPS mailbox yesterday (Saturday, 10 May 2025). Not sure, but that issue may also be out on the news stands by now. Not sure if or when the online version may be updated with the follow-up.

The follow-up content has been appended to the online version of the article.

Here is a link to John Atkinson's new set of measurements of the newer version of the pair of monoblock amplifiers with proper functioning modules representative of current regular production.

Here is a link to Kalman Rubinson's report on his follow-up auditions of that new pair.

These had not yet been added at the time of when I posted yesterday.

 

[Carlton80@0]

Nice amplifier that can be sourced here for USA buyers. Nice set of features and options that other assemblies don’t offer without a much higher price of entry. Unfortunately due to space constraints of my current setup and the width they will not fit side by side in my allotted space.

 

[kyuu]

Pretty telling how little (read: no) difference technical faults of that magnitude, due to a faulty module, made in practice. Perhaps people shouldn't obsess so much about their amps (or electronics in general)...

 

[Julf]

Pretty telling how little (read: no) difference technical faults of that magnitude, due to a faulty module, made in practice. Perhaps people shouldn't obsess so much about their amps (or electronics in general)...

This! Lots of worrying about amps, DACs and even cables and connectors, when it is the speakers, room and source material that make the difference.

 

[Impossible]

I am in need of some new amps, this purifi is on my shortlist. I have limited knowledge of amps but trying to learn the in's and outs so I can make an informed decision.

I am looking for an amp to run my low freq driver on my 2 way speaker. This is the driver https://www.eighteensound.it/en/products/lf-driver/15-0/8/15NTLW3500.
Mainly I care about 1000hz and lower.

I dont think I need 8ohm 900w as its for home use, 300w should be more then enough, please correct me if i am wrong.
but i do want to understand these parameters better, not just what they are but to put them into context, as in how much of a difference they will make.

I am considering Parasound - HALO A21+ and Purifi 1ET9040BA

Here is some info i have gathered.

Amplifier	8ohm	Peak Voltage Swing (Vpk)	Damping Factor	Slew Rate
Purifi 1ET9040BA​	375w	±90 V (180 Vpp)​	>2,000​	26 V / µs​
Parasound A21+​	300w	±78 V (156 Vpp)​	>1,100 @ 20 Hz​	> 130 V / µs​

If these are both overkill and I would be actually better off with something like a bridged hypex nc502 then please let me know and also explain why as id love to learn more about it.

 

[rdenney]

The voltage swing, damping factor, and slew rate are distractions. Voltage swing doesn't matter without the ability to feed the current required for that voltage into an actual speaker, and that's where you need power. Power = voltage X current, to use common terms. But even the power ratings for these amps are at 1% distortion, which is on the very steep part of the power vs. distortion curve.

That driver is rated to produce 98 dB SPL at one meter driven by 2.83 volts into 8 ohms in free air. If you want 120 dB SPL from that speaker at 1 meter, you'll need 22 dB gain, or 35.6 volts into 8 ohms. You'll need 158 watts. If you want 120 dB SPL at a listening position, say, 4 meters from the speaker, you'll need an additional 6 dB of power, or 632 watts, assuming the speaker is linear at those levels (which their power rating, if real, suggests can be assumed).

An NC502MP that is bridged is still showing a SINAD in the range of 100 dB at that power output into 8 ohms. That's twice the output of the Purifi module you listed into 8 ohms, though the Purifi will maintain lower distortion while doing so. This is unimportant--the Hypex is already inaudibly low in distortion.

But all my assumptions are worst-case. In a real room (rather than free air) you'll get room gain because the lateral sound waves will be in part reflected back to you (as they would not be in free air). And 4 meters is over 13 feet--that's a fairly large room though it might be realistic. But mostly you may not need 120 dB SPL which is extremely loud and beyond the requirement or tolerability of most residential situations. It would not take much moderation of those requirements to bring that Purifi amp into line with your needs. I would probably use the NC502MP because it's less expensive and more powerful when bridged for single-channel output. Just don't use the bridge 502 for really difficult speakers. (This is not a difficult speaker with a minimum impedance of 6 ohms.)

The driver you listed seems to be made for line-array applications for PA systems--they aren't claiming performance in the subwoofer range (20-40 Hz) but rather very high efficiency in the woofer range. If built into a sub cabinet, an 18" cube (outside dimensions) would provide their recommended interior volume.

Rick "party speakers?" Denney

 

[Impossible]

The voltage swing, damping factor, and slew rate are distractions. Voltage swing doesn't matter without the ability to feed the current required for that voltage into an actual speaker, and that's where you need power. Power = voltage X current, to use common terms. But even the power ratings for these amps are at 1% distortion, which is on the very steep part of the power vs. distortion curve.

That driver is rated to produce 98 dB SPL at one meter driven by 2.83 volts into 8 ohms in free air. If you want 120 dB SPL from that speaker at 1 meter, you'll need 22 dB gain, or 35.6 volts into 8 ohms. You'll need 158 watts. If you want 120 dB SPL at a listening position, say, 4 meters from the speaker, you'll need an additional 6 dB of power, or 632 watts, assuming the speaker is linear at those levels (which their power rating, if real, suggests can be assumed).

An NC502MP that is bridged is still showing a SINAD in the range of 100 dB at that power output into 8 ohms. That's twice the output of the Purifi module you listed into 8 ohms, though the Purifi will maintain lower distortion while doing so. This is unimportant--the Hypex is already inaudibly low in distortion.

But all my assumptions are worst-case. In a real room (rather than free air) you'll get room gain because the lateral sound waves will be in part reflected back to you (as they would not be in free air). And 4 meters is over 13 feet--that's a fairly large room though it might be realistic. But mostly you may not need 120 dB SPL which is extremely loud and beyond the requirement or tolerability of most residential situations. It would not take much moderation of those requirements to bring that Purifi amp into line with your needs. I would probably use the NC502MP because it's less expensive and more powerful when bridged for single-channel output. Just don't use the bridge 502 for really difficult speakers. (This is not a difficult speaker with a minimum impedance of 6 ohms.)

The driver you listed seems to be made for line-array applications for PA systems--they aren't claiming performance in the subwoofer range (20-40 Hz) but rather very high efficiency in the woofer range. If built into a sub cabinet, an 18" cube (outside dimensions) would provide their recommended interior volume.

Rick "party speakers?" Denney

thank you this is very helpful.

sometimes amirm does a transfer function graph showing different frequencies. I see class d struggles here after 1khz compared to class AB e.g. topping b200.
Where does this fit into the picture?

 

[rdenney]

thank you this is very helpful.

sometimes amirm does a transfer function graph showing different frequencies. I see class d struggles here after 1khz compared to class AB e.g. topping b200.
Where does this fit into the picture?

It doesn't. The issue Amir saw was well up in the top octave. This speaker has no response in that region, and will be filtering out those frequencies anyway.

The Hypex modules do have a distortion floor of about -100 dB, but that will also have no effect on your plans.

Rick "don't see any struggles related to Class D" Denney

 

[Impossible]

It doesn't. The issue Amir saw was well up in the top octave. This speaker has no response in that region, and will be filtering out those frequencies anyway.

The Hypex modules do have a distortion floor of about -100 dB, but that will also have no effect on your plans.

View attachment 460660

Rick "don't see any struggles related to Class D" Denney

OK thanks. Can you confirm if I do later decide to use the amp for full range speakers, if then it would be of concern?