Modeler Time Domain Response Analysis

[Orvillain]

@James Freeman You can use Python+PyWavelets if you want to do some wavelet analysis of a signal. You should also grab the Librosa library if you're going that way, as you can use that to do FFT's and retrieve all sorts of features from the audio signal.

Grabbing features from your input and features from your output, and doing a diff between them can sometimes reveal interesting things.

 

[PLX]

Sure thing, here you go;

Great tone !

Nice playing too !

 

[Lele]

I am very curious to measure other modelers and have a look at how they behave

I don't have the competence that is necessary, but now I'd be curious to see an analysis of the Line6 custom amps (Litigator, Voltage, etc.) because by building "ideal" amps Line6 could have domesticated the weird(er) behaviour of the real amps.

 

[ballhawk]

It also occurred to me that the amp model is a complex polynomial equation that the DSP solves on the fly, so the Gibbs phenomenon and sinusoidal nature of the Fourier transform is what we see on the output.

All this time I thought it was a fibonacci sequence based on claily's law of rebounding springs

Now I find out that tone is in the pre-sag (which suspiciously sounds like some sort of erectile dysfunction)

 

[DrewJD82]

 

[Antipodes]

Watch yourselves or I will be bustin out the lectric viledin and makin all your ears bleed.

 

[fretworn]

Watch yourselves or I will be bustin out the lectric viledin and makin all your ears bleed.

Jean Luc? Is that you?

 

[aerial7]

[Suddenly feeling very unqualified to hang around TGF. Everyone seems to be a multi-PhD guitar god with looks, hair, youth, and a great sense of humor. I have none of those things....]

 

[Bob Zaod]

 

[holoholo]

[Suddenly feeling very unqualified to hang around TGF. Everyone seems to be a multi-PhD guitar god with looks, hair, youth, and a great sense of humor. I have none of those things....]

Everyone’s welcome here my brotha

 

[laxu]

[Suddenly feeling very unqualified to hang around TGF. Everyone seems to be a multi-PhD guitar god with looks, hair, youth, and a great sense of humor. I have none of those things....]

Looks? Maybe if I lost 10 kgs...
Hair? Based on my father, it's going to silver fox season in 10-20 years
Youth? They better get off my lawn!
Great Sense of humor?
Multi-PhD? if this "PhD" means "Perpetually hungry Dude".
Guitar God? I'm more of a Guitar Follower. They have more fun!

 

[murphy brown]

Cliffs comment on the Fractal forum on how he cannot share super secret information about time domain measurements got me interested in time domain measurements and what they can tell us about the modeler.

Helix Brit 2203;
In this example I have a few cycles of 82Hz sine at -10dB, the output is quite interesting.
First of all, the output was correctly (unless I'm wrong) phase flipped because the JCM800 has 3 inverting gain stages, but I have reversed it in this image below so we can see better what's going on.
What I notice immediately is some "pre-sag" before the amp starts to reproduce the tone, also, there is "post-ringing", both of these tell me that there are some elements (components?) that cause this sag and ringing, in a real amp it will be the power supply inductance and filtering capacitance.

I am very curious to measure other modelers and have a look at how they behave, I think time domain response has a lot to do with how the model feels to play.


View attachment 14233

82Hz & 400Hz.
View attachment 14234

Yes, it's another James Freeman thread, go ahead post your shitty memes and destroy beautiful science you banjo twanging luddites.

It's fascinating how Cliffs' insights into time domain measurements have sparked your interest, especially in analyzing the Helix Brit 2203 model. The visualization of the 82Hz sine wave and the observations on "pre-sag" and "post-ringing" provide a unique perspective into the behavior of the modeler, hinting at the influence of power supply characteristics.