Nord Three SE 1ET400A Dual Mono Stereo Amp Review

[gsp1971]

Because a voltage is the difference of potential between 2 points. Ground and tip for RCA, hot and cold for XLR.
The gain of an amplifier is the factor applied to the input voltage to obtain the output voltage. Not to the potentials.
If you need different voltages depending of the type of the input to obtain the same power at the output, then different gains are applied depending of the type of the input.

So if gain RCA = gain XLR = 26dB (or so), which means I need 1.5V-2V or so output voltage from my source, then in theory the 4.1Vout RMS from the Oppo 105 XLR outputs is more than enough to drive a Hypex power amp, with the volume knob on the Oppo not needing to be more than half-way full, right? (wouldn't it be easier if manufacturers produced a Hypex-based integrated amp? )

 

[gsp1971]

Thank you boxem and JimB. Your calculation is correct, it is the one I used as well, I just read somewhere that the result of the formula (i.e. the 1.55V) is the RMS input V, whereas if you want the peak V you do 1.55 V * SQRT(2) = 2.2V. May be that last part is not needed.

In any case, let's use the 1.55V. Even if I use the increased power rating at 1% distortion, say 250W @ 8Ω, it still gives me 2.0V Vin, which is the standard RCA output of most digital devices. So the question remains, can I use my Oppo 105 to drive them, skipping the preamp? Or would I be safer with an active preamp? (and I am not talking unbuffered Purifi modules, I am talking 25-27 dB gain, either Hypex, or buffered Purifi).

PS. @Boxem, just for my understanding / learning, why is the XLR Vin the same as the RCA? Isn't the XLR gain lower by 6 dB?

Thanks guys - the more I learn / understand, the more I love this game.

Edit: I saw the calculation about Vpeak vs. Vrms on the Hypex specs, page 7
https://www.hypex.nl/documenten/download/908

 

[boXem | audio]

So if gain RCA = gain XLR = 26dB (or so), which means I need 1.5V-2V or so output voltage from my source, then in theory the 4.1Vout RMS from the Oppo 105 XLR outputs is more than enough to drive a Hypex power amp, with the volume knob on the Oppo not needing to be more than half-way full, right? (wouldn't it be easier if manufacturers produced a Hypex-based integrated amp? )

Right. Included the Hypex integrated idea.

 

[Labjr]

Yep, a Hypex integrated amp with choice of a quality volume pot or stepped attenuator.

 

[hapnermw]

What "amp" were you driving? Was it an unbuffered Purifi module, or an assemble amp from someone with an input buffer with ~26 dB gain?

It was exactly this amp.

 

[JimB]

It was exactly this amp.

The NORD Three SE 1ET400A Dual Mono stereo amp, with Sonic Imagery 990Enh? I'm surprised. The D90 easily swings 4.0VRMS out on its XLR outputs, per the ASR review. Was your input buffer set to low gain? I don't see details about that on their website now. Actually, I can't find any Purifi based amps there now.

 

[gsp1971]

The NORD Three SE 1ET400A Dual Mono stereo amp, with Sonic Imagery 990Enh? I'm surprised. The D90 easily swings 4.0VRMS out on its XLR outputs, per the ASR review. Was your input buffer set to low gain? I don't see details about that on their website now. Actually, I can't find any Purifi based amps there now.

https://www.nordacoustics.co.uk/purifi1et400aamplifiers

 

[JimB]

https://www.nordacoustics.co.uk/purifi1et400aamplifiers

Thanks. They do not appear on the "MAIN PRODUCT PAGE" itself, but I now see that they are listed in the drop-down, if you pull it, from the top.
https://www.nordacoustics.co.uk/products

That page lists the input specs as ~27 dB, with full rated power at ~2.5V input.

 

[board]

I know this question will be very difficult to answer, since it requires some speculation, but I'm perfectly okay with an educated guess:

Besides the amp being tested in this review, Nord also makes an integrated version called Three SE INT-C Purifi 1ET400A Integrated Amplifier, which can be seen here:
https://www.nordacoustics.co.uk/product-page/nord-three-se-int-c-purifi-1et400a-integrated-amplifier

The dual-mono stereo amp being tested here in Amir's review can be seen here:

https://www.nordacoustics.co.uk/product-page/nord-three-se-1et400a-dual-mono-stereo-amp

From what I can tell the components in the integrated amp are exactly the same as in the power amp, and the integrated one is also dual-mono, so it really just seems like exactly the same amp with a pre-amp built in. Please correct me if I'm wrong.

So my question is: Do you think the integrated would offer the same or close to the same performance as the power amp (SINAD, distortion, power, noise, etc.)?
If it's a few dBs off that's perfectly okay .

And then I have an additional question: Have any of you tried either the integrated or the power amp in question or any other amps from Nord?
Did you like them subjectively? Did you have any problems with them (breakdowns, etc.)?

 

[Matias]

I know this question will be very difficult to answer, since it requires some speculation, but I'm perfectly okay with an educated guess:

Besides the amp being tested in this review, Nord also makes an integrated version called Three SE INT-C Purifi 1ET400A Integrated Amplifier, which can be seen here:
https://www.nordacoustics.co.uk/product-page/nord-three-se-int-c-purifi-1et400a-integrated-amplifier

The dual-mono stereo amp being tested here in Amir's review can be seen here:

https://www.nordacoustics.co.uk/product-page/nord-three-se-1et400a-dual-mono-stereo-amp

From what I can tell the components in the integrated amp are exactly the same as in the power amp, and the integrated one is also dual-mono, so it really just seems like exactly the same amp with a pre-amp built in. Please correct me if I'm wrong.

So my question is: Do you think the integrated would offer the same or close to the same performance as the power amp (SINAD, distortion, power, noise, etc.)?
If it's a few dBs off that's perfectly okay .

And then I have an additional question: Have any of you tried either the integrated or the power amp in question or any other amps from Nord?
Did you like them subjectively? Did you have any problems with them (breakdowns, etc.)?

I would get the RME ADI-2 DAC and use with the Nord Three SE, note that Nord sells both (I bought my ADI-2 from them). Unless you really need additional analog inputs, then consider and ADI-2 Pro or a Schiit Freya S preamp now that they are back being produced.

 

[board]

I would get the RME ADI-2 DAC and use with the Nord Three SE, note that Nord sells both (I bought my ADI-2 from them). Unless you really need additional analog inputs, then consider and ADI-2 Pro or a Schiit Freya S preamp now that they are back being produced.

What I should buy instead wasn't really the question. And yes, I do need several analogue inputs.

 

[MediumRare]

I know this question will be very difficult to answer, since it requires some speculation, but I'm perfectly okay with an educated guess:

Besides the amp being tested in this review, Nord also makes an integrated version called Three SE INT-C Purifi 1ET400A Integrated Amplifier, which can be seen here:
https://www.nordacoustics.co.uk/product-page/nord-three-se-int-c-purifi-1et400a-integrated-amplifier

The dual-mono stereo amp being tested here in Amir's review can be seen here:

https://www.nordacoustics.co.uk/product-page/nord-three-se-1et400a-dual-mono-stereo-amp

From what I can tell the components in the integrated amp are exactly the same as in the power amp, and the integrated one is also dual-mono, so it really just seems like exactly the same amp with a pre-amp built in. Please correct me if I'm wrong.

So my question is: Do you think the integrated would offer the same or close to the same performance as the power amp (SINAD, distortion, power, noise, etc.)?
If it's a few dBs off that's perfectly okay .

What I should buy instead wasn't really the question. And yes, I do need several analogue inputs.

It looks to me like a very solid choice. Two questions I’d have for Nord:
1. How to choose the best buffer options.
2. Amir’s power results seem 1/2 of what the spec says, so how much power should you expect? 200 is a fair bit better than 100.

 

[board]

It looks to me like a very solid choice. Two questions I’d have for Nord:
1. How to choose the best buffer options.
2. Amir’s power results seem 1/2 of what the spec says, so how much power should you expect? 200 is a fair bit better than 100.

Maybe amirm can chime in?