The commonly adopted standard is 1% THD. Can't remember if there is an AES standard for that.
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Review and Measurements of Hypex NC400 DIY Amp
- Thread starter amirm
- Start date
The commonly adopted standard is 1% THD. Can't remember if there is an AES standard for that.
maty
Major Contributor
To finish, I listen to very good modern digital recordings with high DR too.
Maybe, the Spanish blinds are the cause that I do appreciate differences -at night- between MP 320 kbps vs FLAC 16/44 and...
Years ago, when I had so many problems, I had a motto: in the audio world all kinds of noise is our enemy. What good is a good SNR-A measured in a laboratory with very clean power supply and without atmospheric RF / EMI.
Maybe, the Spanish blinds are the cause that I do appreciate differences -at night- between MP 320 kbps vs FLAC 16/44 and...
Years ago, when I had so many problems, I had a motto: in the audio world all kinds of noise is our enemy. What good is a good SNR-A measured in a laboratory with very clean power supply and without atmospheric RF / EMI.
So what is the best dynamic range (in numbers) you have come across?
Maybe, the Spanish blinds are the cause that I do appreciate differences -at night- between MP 320 kbps vs FLAC 16/44 and...
Or maybe just lack of proper double-blind testing?
Which is why it is good to make measurements in your own environment too.
maty
Major Contributor
Silent Study Room: 20 dBA.
Good vinyl recording: 65 dBA
=> I need 20 dBA + 65 dBA = 85 dBA.
What you described is an error from @Audiophonics specs. The SNR of the NC500MP is now 124db (it has been corrected in the revised datasheet).
https://www.hypex.nl/documenten/download/1245
At last, NC250MP still has the lowest THD+N, though.
No, not really. You need marginally more than 65 dB. What is the maximum volume you need to achieve?
maty
Major Contributor
Julf, too much off topic here.
Usually, about 60-65 dBSPL continuous. KEF Q100 working in near-field. When I get excited, I get up and go around the room, conducting the orchestra and sometimes simulating playback.
KEF Q100 loves watts. And LS50 (83 dB/W/m) need more!
Usually, about 60-65 dBSPL continuous. KEF Q100 working in near-field. When I get excited, I get up and go around the room, conducting the orchestra and sometimes simulating playback.
KEF Q100 loves watts. And LS50 (83 dB/W/m) need more!
maty
Major Contributor
65 + 15 (peaks) = 80 dB. 1 watt, 2 m, near field -> 85 dB.
Then I need about 0.3 watt when I am not excited.
That is why Nelson Pass insists so much on the importance of the quality of the first watt.
Then I need about 0.3 watt when I am not excited.
That is why Nelson Pass insists so much on the importance of the quality of the first watt.
Right. But your noise floor in your (very quiet) room is 20 dBSPL, so you need 80 - 20 = 60 dB of SNR.
maty
Major Contributor
But when the music is very good I must have about 85-90 dB (night is problematic, you know). Then I need more watts.
My modded AVR Marantz SR4500 has 100 watts at 8 Ohms, 0.1% and 128 watts at 4 Ohms, 0.1%
https://www.soundandvision.com/content/marantz-sr4500-av-receiver-ht-labs-measures
Volume begins at -70 dB. Step by0.5 1 dB. Sometimes, with recordings with very high DR and I got excited it marks less of -20 dB, sometimes near -15 dB.
KEF Q100: true 85 dB/W/m and minimum 3.9 Ohms.
It would be a mistake to buy an amplifier that had no reserve power in case one day I changed speakers or room (and longer listening distance), I think.
In short, the amplifier that interests me is the new Purifi 1ET400A, if the modules are for sale at a reasonable price. And others are those who take the risk with the purchase to be the first, I am not in a hurry because I enjoy music a lot in my second system. And I still have an improvement in the speakers, starting first with the big ones.
I leave, I plan to watch chapters seven and eight of the City on a Hill series in the main system.
https://en.wikipedia.org/wiki/City_on_a_Hill_(TV_series)
My modded AVR Marantz SR4500 has 100 watts at 8 Ohms, 0.1% and 128 watts at 4 Ohms, 0.1%
https://www.soundandvision.com/content/marantz-sr4500-av-receiver-ht-labs-measures
Volume begins at -70 dB. Step by
KEF Q100: true 85 dB/W/m and minimum 3.9 Ohms.
It would be a mistake to buy an amplifier that had no reserve power in case one day I changed speakers or room (and longer listening distance), I think.
In short, the amplifier that interests me is the new Purifi 1ET400A, if the modules are for sale at a reasonable price. And others are those who take the risk with the purchase to be the first, I am not in a hurry because I enjoy music a lot in my second system. And I still have an improvement in the speakers, starting first with the big ones.
I leave, I plan to watch chapters seven and eight of the City on a Hill series in the main system.
https://en.wikipedia.org/wiki/City_on_a_Hill_(TV_series)
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maty
Major Contributor
SPL, like you know.
Usually I listen to music from PC (ODAC USB) at near field between -25 dB and -35 dB. From FM radio, about -35 dB.
https://www.diyaudio.com/forums/music/6958-playing-listening-post5898813.html
- The End -
Usually I listen to music from PC (ODAC USB) at near field between -25 dB and -35 dB. From FM radio, about -35 dB.
https://www.diyaudio.com/forums/music/6958-playing-listening-post5898813.html
- The End -
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No, I don't always know what you mean.
If it is SPL, then 75 dB SNR is sufficient for you. That still puts the noise well below the room noise floor.
-25 dB from what?
maty
Major Contributor
OK, -25dBFS. KEF Q100 is officially 8 Ohms but is more like 6 Ohms or a little less. For calculations it is always better to be conservative and put yourself in the worst situation., then 4 Ohms.
With SS, the apropiate max power measurement is at 0.1% THD. Then, the max power to the small coaxial is almost 128 watts, aka 0 dBFS (105 watts at 8 Ohms, THD 0.1%).
With SS, the apropiate max power measurement is at 0.1% THD. Then, the max power to the small coaxial is almost 128 watts, aka 0 dBFS (105 watts at 8 Ohms, THD 0.1%).
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So at -25 dBFS you are using 0.4 W. Fair enough.
As I pointed out, 75 dB SNR is sufficient for you.
maty
Major Contributor
But only when the music acts as accompaniment and I do not leave everything to focus on enjoyment. That is why the calculations have to take into account when I need more power.
Imagine if the speakers had a minimum impedance of only 3 Ohms or less, as happens too many times, especially in three-way systems or Magnepan or...
Imagine if the speakers had a minimum impedance of only 3 Ohms or less, as happens too many times, especially in three-way systems or Magnepan or...
maty
Major Contributor
If you want to continue the off-topic, open a specific thread and I will participate in it.
My last answer in this thread to you.
* The logical thing is that when I enjoy music at high volume at home (with nearby walls) the amplifier is not squeezed, that is, it works at 50% capacity (power with THD graph), say a number.
https://www.soundandvision.com/content/marantz-sr4500-av-receiver-ht-labs-measures
* It is relationed to the power. If at hundreds of Hz the impedance has a minimum of 3 Ohms, the amplifier must deliver more power in that range, and not all amplifiers can keep it for a while. If the minimum is 1.7 Ohms then you need a very well designed amplifier.
Class D amplifiers usually have serious problems with such low impedances. And the modern AVR too.
Conclusion: with the quantity of amplifiers, speakers, DAC and other hards, it is better to focus on those in which there are independent measurements (with graphs). It is not a guarantee of a sound that pleases us a lot but avoids having unpleasant surprises.
BTW: in the image we can view how the signal processing inside of the AVR degrades the response. I supose the same with SNR and others parameters like THD. To music, better with Pure Direct mode. If you want processing better by software from a computer, if it is the source.
My last answer in this thread to you.
* The logical thing is that when I enjoy music at high volume at home (with nearby walls) the amplifier is not squeezed, that is, it works at 50% capacity (power with THD graph), say a number.
https://www.soundandvision.com/content/marantz-sr4500-av-receiver-ht-labs-measures
* It is relationed to the power. If at hundreds of Hz the impedance has a minimum of 3 Ohms, the amplifier must deliver more power in that range, and not all amplifiers can keep it for a while. If the minimum is 1.7 Ohms then you need a very well designed amplifier.
Class D amplifiers usually have serious problems with such low impedances. And the modern AVR too.
Conclusion: with the quantity of amplifiers, speakers, DAC and other hards, it is better to focus on those in which there are independent measurements (with graphs). It is not a guarantee of a sound that pleases us a lot but avoids having unpleasant surprises.
BTW: in the image we can view how the signal processing inside of the AVR degrades the response. I supose the same with SNR and others parameters like THD. To music, better with Pure Direct mode. If you want processing better by software from a computer, if it is the source.
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I am not the one who started the SNR discussion...
The 50% is an arbitrary value that happens to apply to that specific amp.
Still don't see how that is related to SNR.
That is a really ironic comment in a thread about the Hypex nC400 that is happy to drive loads down to 1 Ω
I totally agree, I just have no idea of how that conclusion relates to any of the earlier discussion
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