WOW ,i guess for at least now things stay as they are untill my knowledge is of a level of requirement(that may be never
) cheers for that though, i find it all very interesting, even if i only understand part of it all.
The PCB is actually a collection of capacitors, inductors and low value resistors. Adjacent tracks behave like transformers albeit with very low mutual inductances. In radio frequency applications, tracks also behave like resonators and transmission lines.
The charge on electrons and protons makes electronic currents extremely richly behaved.
So called better quality parts make little to no difference tbh. Design changes and tweaks can subtly alter things but it is really the basic circuit topology that sets how it is going to sound.
It certainly was done is LTspice
You can even play a music file into a simulation and record the output.
So called better quality parts make little to no difference tbh. Design changes and tweaks can subtly alter things but it is really the basic circuit topology that sets how it is going to sound.
It certainly was done is LTspice
realy how do you do that?
could you run music off your own amp and analize it?
What is a more important figure of merit? IMD? Noise measurements related to the forest of products produced?
I ask and wonder because of the attached spectrum from a piano note. There is very high harmonic content already from the bare instrument. (Is the same is true of many (most?) instruments?) How could one hear a tiny addition to the already present much higher amplitude harmonics? (2nd harmonic in that image is only 30 dB down?)
Is the problem more from products which are not found in the musical scale and/or normal spectra of the instrument? Is that what sounds bad? Along with noise?
Attachments
Good 'innit
Although the files are long gone you might like looking at this:
Welcome to the (virtual) listening room.
This attached file is the one I used today and it records 10 seconds of audio (because the sim runs for 10 seconds).
Look at the spice directive:
It has to be exactly as written but you can alter the file path. Working Files is just a folder in my Documents. Output.wav is what you want to call the file. It must use the .wav extension. It must be 16 44.1k (16 bit 44.1kHz) and V(Vout) is the name of the point on the simulation you want to capture the audio from. it is the voltage at point Vout on the sim.
Although the files are long gone you might like looking at this:
Welcome to the (virtual) listening room.
This attached file is the one I used today and it records 10 seconds of audio (because the sim runs for 10 seconds).
Look at the spice directive:
Code:
.wave "C:\users\Karl\Documents\Working Files\Output.wav" 16 44.1k V(Vout)It has to be exactly as written but you can alter the file path. Working Files is just a folder in my Documents. Output.wav is what you want to call the file. It must use the .wav extension. It must be 16 44.1k (16 bit 44.1kHz) and V(Vout) is the name of the point on the simulation you want to capture the audio from. it is the voltage at point Vout on the sim.
So when I run that sim which I did a couple of minutes ago it produce this.
Getting it to work with a music file requires you to have a .wav file of the music on your PC and you have to alter the input voltage source of the sim to use that file.
Doing a stereo set up is a bit more involved because you have to duplicate the amplifier (easy in LT) and also split the .wav file into stereo and that is where Audacity comes into its own.
These were valid notes I made at the time.
Getting it to work with a music file requires you to have a .wav file of the music on your PC and you have to alter the input voltage source of the sim to use that file.
Code:
Settings for importing and exporting .wav files into LTspice.
1/Set the voltage input source by holding down CTRL and right clicking the source.
2/In the 'Value' field enter:
wavefile=nameoffile.wavDoing a stereo set up is a bit more involved because you have to duplicate the amplifier (easy in LT) and also split the .wav file into stereo and that is where Audacity comes into its own.
These were valid notes I made at the time.
Code:
NOTE...
In creating stereo files (split to mono) in Audacity something odd happens. The right channel .wav file, while perfect in media player, will not function in LTspice. The final output from the circuit under test is just silence.
To correct this, first split the tracks and export the left file as normal. Now undo (use edit>undo) and now reverse the tracks. Again export the left channel (which is now the right of course). That seemed to work.Attachments
Good 'innit
Although the files are long gone you might like looking at this:
Welcome to the (virtual) listening room.
This attached file is the one I used today and it records 10 seconds of audio (because the sim runs for 10 seconds).
Look at the spice directive:
It has to be exactly as written but you can alter the file path. Working Files is just a folder in my Documents. Output.wav is what you want to call the file. It must use the .wav extension. It must be 16 44.1k (16 bit 44.1kHz) and V(Vout) is the name of the point on the simulation you want to capture the audio from. it is the voltage at point Vout on the sim.Code:.wave "C:\users\Karl\Documents\Working Files\Output.wav" 16 44.1k V(Vout)
ill give it a go
whos karl?
Very good questions. Yes, it is a natural line of thinking as to the audibility of harmonic distortion when musical instruments create a substantial "forest" of harmonics to begin with, as you say.
This is, I believe, the reason why it takes so much low-order HD to be audible, while higher-order HD is more audible as they seem to be naturally generated in smaller amplitude, typically.
Noise is not a good thing either, but if you can't hear the noise from your listening position (easy to test), then it's nothing to worry about. So I think that leaves the following to ponder:
- higher-order HD products (4/5/6/7/xxx) - although very high orders may be outside the limits of hearing anyway, e.g. a 5th order HD on a 5 kHz tone is 25 kHz
- IMD
- forms of linear distortion - resonances / ringing - more on the speaker side though