• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Review and Measurements of Purifi 1ET400A Amplifier

mocenigo

Major Contributor
Joined
Dec 8, 2018
Messages
1,274
Likes
1,034
Oh boy. As much as I like the progress, the old modules just came out? I'd like some investment security.

I do not think the old modules would be no longer produced. The new one has more current, much more power into 2Ω, slightly more noise and distortion, and therefore has a different usage profile. It is not an upgrade.
 

mk1classic

Member
Joined
Aug 20, 2019
Messages
75
Likes
95
It's more powerful and looks to be a nice contender for use on heavier load speakers, or a bass amplifier in a multichannel setup, or as a high power bridged unit with a suitable controller / buffer stage.
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,802
Location
São Paulo, Brazil
Finally! Exactly what I was waiting for!

Purifi 1ET7040SA
Output Power: 950W(2Ω), 500W(4Ω), 250(8WΩ)
Output Current: ~40A
THD+N: <0.00035% @ 200W, 4Ω, 1kHz
Dynamic Range: ~129 dB(A)
Output Noise: ~14µV(A)
Gain: 13dB
Output Impedance: <13µΩ @ 1kHz
Efficiency: 94% @ 500W, 4Ω, 1kHz
Idle losses (outpt stage): 2.8 W

purifi 1et7040sa graphics_edited.jpg
 
Last edited:

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,802
Location
São Paulo, Brazil
I do not think the old modules would be no longer produced. The new one has more current, much more power into 2Ω, slightly more noise and distortion, and therefore has a different usage profile. It is not an upgrade.
Agreed. This is targeted to other customers, where high power in low impedances is necessary. Good news is that the distortion and noise is very close to the 1ET400A, but obviously it will be more expensive too, so users that don't need all this power (majority btw) should keep their current 1ET400A or buy it if it is a new user.

Now the question is if the 1ET7040SA is compatible with SMPS1200A700 and with the same pins of NC500 for an easy swap of modules for all current NC500 users. That would be perfect.
 
Last edited:

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,802
Location
São Paulo, Brazil
The answers are in the leaked data and picture. :)
I saw the picture of the module itself:
1ET7040SA.jpg


But if it is pin compatible with NC500 and if it accepts the 85V of the SMPS1200A700 I cannot know. Could you confirm it if you know it? Or NDA?
 

tmtomh

Major Contributor
Forum Donor
Joined
Aug 14, 2018
Messages
2,636
Likes
7,495
Oh boy. As much as I like the progress, the old modules just came out? I'd like some investment security.

I hear you, but in addition to being for a different use case as others have noted - I guess this is more or less Purifi's version of the Hypex1200, yes? - keep in mind that this module is also rated officially at 500wpc into 4 ohms - the 960wpc rating is for 2 ohms.

And remember that the original Purifi module is rated at 400wpc into 4 ohms.

In the real world, it appears from Amir's measurements that the 400wpc Purifi (and Hypex) modules actually produce something closer to 250wpc into 4 ohms, if we're talking the full 20Hz-20kHz at very low levels of distortion.

Using that metric, this new module would likely provide just over 300 wpc into 4 ohms compared to about 250 wpc into 4 ohms for the current module. That extra 50 wpc is not likely to mean much of anything in 99+% of home listening use cases, when you consider that you have to double or quadruple the wattage of an amp to get much louder playback capability.

Finally, this new module has virtually the same gain as the old one: 13dB on the new one vs 12.7dB on the old one (IIRC). So again, you're not really going to hear any volume difference with the new one vs the old one. So unless you have speakers that present a 2 ohm load to an amp, or unless the current Purifi module does not provide enough power (or gain, even when put in an amp with buffer stages) for your needs - in other words unless the current Purifi module won't work at all for you in your situation - then I don't see any benefit to this module over the current one. As others have said, this is not a sonic upgrade or a meaningful power upgrade if you've already got a Purifi-based amp and it's meeting your needs.
 

JohnYang1997

Master Contributor
Technical Expert
Audio Company
Joined
Dec 28, 2018
Messages
7,175
Likes
18,292
Location
China
Comparing the two, they are not that different are they? Power is only up a small percentage for each load.
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,802
Location
São Paulo, Brazil
Comparing the two, they are not that different are they? Power is only up a small percentage for each load.
History repeats itself as Hypex NCore NC500 x NC1200 are both 700W in 4 ohms, but 550W x 1200W in 2 ohms.

Now Purifi Eigentakt 1ET400A x 1ET7040SA are similar 425W x 500W in 4 ohms, but 450W x 950W in 2 ohms.

So the Purifi Eigentakt line trades some power for ultimate low distortion compared to Hypex NCore.
 
Last edited:

EdW

Senior Member
Joined
Jul 5, 2020
Messages
329
Likes
413
Location
Cambridge, UK
I hear you, but in addition to being for a different use case as others have noted - I guess this is more or less Purifi's version of the Hypex1200, yes? - keep in mind that this module is also rated officially at 500wpc into 4 ohms - the 960wpc rating is for 2 ohms.

And remember that the original Purifi module is rated at 400wpc into 4 ohms.

In the real world, it appears from Amir's measurements that the 400wpc Purifi (and Hypex) modules actually produce something closer to 250wpc into 4 ohms, if we're talking the full 20Hz-20kHz at very low levels of distortion.

Using that metric, this new module would likely provide just over 300 wpc into 4 ohms compared to about 250 wpc into 4 ohms for the current module. That extra 50 wpc is not likely to mean much of anything in 99+% of home listening use cases, when you consider that you have to double or quadruple the wattage of an amp to get much louder playback capability.

Finally, this new module has virtually the same gain as the old one: 13dB on the new one vs 12.7dB on the old one (IIRC). So again, you're not really going to hear any volume difference with the new one vs the old one. So unless you have speakers that present a 2 ohm load to an amp, or unless the current Purifi module does not provide enough power (or gain, even when put in an amp with buffer stages) for your needs - in other words unless the current Purifi module won't work at all for you in your situation - then I don't see any benefit to this module over the current one. As others have said, this is not a sonic upgrade or a meaningful power upgrade if you've already got a Purifi-based amp and it's meeting your needs.
One obvious way to get the increased power delivery into 2 Ohms in the IET7040 vs the IET400 would be to double up on the O/P stages. This would allow the same PSU to be used but just in a mono application. Such an amp might be expected to marginally improve the delivery into 4 ohms as a well. However the increased loading might require that the driver stages need re-optimisation and maybe this is where a small increase in THD comes from.
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,802
Location
São Paulo, Brazil
Last edited:

JohnYang1997

Master Contributor
Technical Expert
Audio Company
Joined
Dec 28, 2018
Messages
7,175
Likes
18,292
Location
China
History repeats itself as Hypex NCore NC500 x NC1200 are both 700W in 4 ohms, but 550W x 1200W in 2 ohms.

Now Purifi Eigentakt 1ET400A x 1ET7040A are similar 425W x 500W in 4 ohms, but 450W x 950W in 2 ohms.

Ultimately the Purifi Eigentakt line trades some power for ultimate low distortion compared to Hypex NCore.
So bridging the 1ET7040As should give lots of power for 4Ohm.
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,802
Location
São Paulo, Brazil

EdW

Senior Member
Joined
Jul 5, 2020
Messages
329
Likes
413
Location
Cambridge, UK
So bridging the 1ET7040As should give lots of power for 4Ohm.
So a bridged IET7040 might drive speakers like the Salon 2, KEF Blade or similar rather well. Pair that with a Topping D90SE and PRE90 and you’d have a pretty fine setup until of course the Topping power amps are available :)
 

boXem

Major Contributor
Audio Company
Joined
Jun 19, 2019
Messages
2,014
Likes
4,852
Location
Europe
Purifi agreed that I comment on the leaked info. So:
- @Matias, the answer to your question about compatibility with NC500 is no, mainly due to power supply, but also because more pins are needed to carry all this current. You are right the spirit 1ET400A -> 1ET7040SA is the same as NC500 -> NC1200
- @JohnYang1997 the slight power increase in 4/8 Ohm is with higher supply rails but lower distortion. So comparison is difficult on paper.

As a general comment, because I see it coming, the 4/8 Ohm numbers given cannot be reached with an SMPS1200A400.
 

jdhiro

Member
Joined
Mar 18, 2021
Messages
23
Likes
14
This is interesting, but I was hoping for something more similar to the NC2K for driving my mains.
 

nerdoldnerdith

Senior Member
Joined
Sep 10, 2020
Messages
495
Likes
690
Location
Chicago
This is interesting, but I was hoping for something more similar to the NC2K for driving my mains.
I'm hoping for something like this as well. I already have the NC2K and it sounds fantastic, but there's something to be said for being able to hit reference levels with zero theoretical audible distortion and noise. I guess designing a perfect amplifier with unlimited headroom isn't that easy. :)
 

jdhiro

Member
Joined
Mar 18, 2021
Messages
23
Likes
14
I'm hoping for something like this as well. I already have the NC2K and it sounds fantastic, but there's something to be said for being able to hit reference levels with zero theoretical audible distortion and noise. I guess designing a perfect amplifier with unlimited headroom isn't that easy. :)

I am curious, did you ever compare your NC2K side by side with lesser Hypex, and if so, did you notice a headroom difference?
 

nerdoldnerdith

Senior Member
Joined
Sep 10, 2020
Messages
495
Likes
690
Location
Chicago
I am curious, did you ever compare your NC2K side by side with lesser Hypex, and if so, did you notice a headroom difference?
I am driving Revel Salon2's. Before I was driving them with Purifi 1ET400A's, which were clipping at 3dB below reference. Now I am driving them with the NC2K's, and the headroom difference is very noticeable when you are listening loud enough. However, that level is indeed quite loud (100+dB). I am not using the full capability of the amp, which I think would probably fry the speakers.

Ideally I would like an amp that does 1500W into 4 ohms and hits 106dB SINAD at full power. The NC2K is only perfectly transparent up up 70W, and the 1ET400A is perfectly transparent up to about 250W. Most of the low distortion is wasted with my speakers.
 
Top Bottom