Interesting Distortion Discussion By Nelson Pass....

[laatsch55]

https://www.passdiy.com/project/articles/audio-distortion-and-feedback

 

[Bradrock]

I had to look up Sackbutt.

 

[laatsch55]

Me too....

 

[marcok]

My opinion is that THD can be negligible for the human brain .
The most important thing is the phase .
Remember always that the human ear is not an audio analyzer ,
but it's another thing .
Make a comparison between a CD player and a cart . 0.01 vs 1-2 %
Ciao
Marco

 

[BlazeES]

I enjoy reading through these distortion 'white papers'. There's always good takeaways from the individual perspective and good theories to ponder.

The problem is, I see very little presented in terms of human trials (blind tests) and/or controlled microphone tests to substantiate the qualitative value of what is heard or perceivable vs. what is easily measured at the internal electrical level - in most if not all white papers on the subject. In a somewhat related theme, I am certain I hear a warmth and positive change in cassette recordings that are sourced from CD that - without a doubt - others perceive as a negative change to the character of the intended sound, a muddiness -
a shift - or a distortion.

So in other words, these types of discussions paired with electrical theory are super interesting but at the end of the day ... mean what exactly ?

The external variables:

The sound producing actuator
The acoustical environment
The human ear
Mood
RH

This is why owning an AP ATS-1 is so intriguing.

 

[laatsch55]

Exactly Tony.
My Spec 2 after running a battery of tests on the AP looks MUCH better on paper than a WOPL. But after 5 minutes of listening to a WOPL the Spec's are retired. It's that simple, and the Spec I bought brand new in 1975 and LOVED IT!!

WE are trying to compare objective measurements with subjective hearing........leaving lots of room for robust debates....

 

[marcok]

Don't forget the noise !
The human brain needs a little noise ( approx. 80dB below )
See the Carver DTL manual.
http://thecarversite.com/manuals/mandir/Carver DTL owner manual.pdf
Moreover see Meridian CD player , that has a special function ( called absolute phase )
that modify the phase .
Ciao
Marco
PS: For Pass only class A amp is a good amp .
Correct from theoretical point of view ,
but for me a class A amp is a " barbecue that sounds ".

 

[laatsch55]

My latest pre-amp has a phase inverter function. I was not aware that some components, recordings, etc may not be in the same phase as .....say.....the crossovers....

 

[BlazeES]

That's pretty cool Lee. But I guess not much of surprise considering the stature & the lineage of the pre-amp, and that it's probably commonly used married to tube amps.

 

[laatsch55]

No doubt there Tony. In Stephens system his Wadia CD player also has a phase inverter function, and at times it makes a helluva a difference, like lifting a veil.....

 

[laatsch55]

I enjoy reading through these distortion 'white papers'. There's always good takeaways from the individual perspective and good theories to ponder.

The problem is, I see very little presented in terms of human trials (blind tests) and/or controlled microphone tests to substantiate the qualitative value of what is heard or perceivable vs. what is easily measured at the internal electrical level - in most if not all white papers on the subject. In a somewhat related theme, I am certain I hear a warmth and positive change in cassette recordings that are sourced from CD that - without a doubt - others perceive as a negative change to the character of the intended sound, a muddiness -
a shift - or a distortion.

So in other words, these types of discussions paired with electrical theory are super interesting but at the end of the day ... mean what exactly ?

The external variables:

The sound producing actuator
The acoustical environment
The human ear
Mood
RH

This is why owning an AP ATS-1 is so intriguing.

RH???????

 

[BlazeES]

RH???????

Relative Humidity. Believe it or not, it can effect microphone diaphragms and the workings of the human ear.

 

[laatsch55]

Hookay, just didn't get the abbreviation...