Do you truly like 2nd harmonic or third harmonic distortion?
Not me.
Why do I prefer zero GNFB feedback then?
I find the sound colouration of global NFB to be worse.
Aren't you just hearing more low-harmonic distortion?
Given otherwise identical zero-GNFB amps, I prefer the lower distortion amp.
I strive to reduce distortions with other means than GNFB because I really don't want the distortion.
How about you?.
Not me.
Why do I prefer zero GNFB feedback then?
I find the sound colouration of global NFB to be worse.
Aren't you just hearing more low-harmonic distortion?
Given otherwise identical zero-GNFB amps, I prefer the lower distortion amp.
I strive to reduce distortions with other means than GNFB because I really don't want the distortion.
How about you?.
Weighting of ear sensibility to an order of harmonics (audibility) is an unexceptionable fact. You will never hear -90dB 2nd. You can make your own tests, if you have equipment.
people still work on quantifying distortion perception.
See this thesis for example:
http://projekter.aau.dk/projekter/fbspretrieve/9852082/07gr1061_Thesis.pdf
regards
See this thesis for example:
http://projekter.aau.dk/projekter/fbspretrieve/9852082/07gr1061_Thesis.pdf
regards
myhrrhleine said:
I prefer the warm sound of valves/tubes.
I use a valve mixer/pre amp for my disco but also play guitar through it. The guitar sounds much better through the valve pre amp.
Re: Re: GNFB and distortion
Given otherwise identical zero-GNFB amps, I prefer the lower distortion amp.
I strive to reduce distortions with other means than GNFB because I really don't want the distortion.
How about you?.
nigelwright7557 said:
Given otherwise identical zero-GNFB amps, I prefer the lower distortion amp.
I strive to reduce distortions with other means than GNFB because I really don't want the distortion.
How about you?.
Global NFB is fine so long as you take steps to isolate the speaker from the feedback loop. A 2uH inductor goes a long way to doing this.
I think people sometimes hear things in their imagination.
I thought my first home design sounded good until I looked on the scope and there was severe cross over distortion. I hadnt set the bias properly.
I think people sometimes hear things in their imagination.
I thought my first home design sounded good until I looked on the scope and there was severe cross over distortion. I hadnt set the bias properly.
myhrrhleine said:
Usually such level of 2'nd harmonic signifies high enough intermodulation distortions.
myhrrhleine said:
No, actually, no 🙂
For Pavel Macura maybe 😀
But not for one listener.
I explain:
- Tube amplifiers are know to distotion producers.
- Loudspeakers are REALLY distortion producers. Does not matter what power amplifier you use.
Valve power or Solid State power or MOSFET power.
No big difference for our loudspeaker part.
It will produce considerably more distortion than any modern amplifier.
von Schweikert are expensive High End audiophile speakers
no doubt about this 🙂
Still von Schweikert has a level of 0.5% THD at 1-2 Watt RMS.
1 meter away from speaker on axis.
PMA talks about the -90 dB level. He is in his dreams 😉
Because when listen with loudspeaker
and consider the Listening Room effects
( floor and ceiling and walls indirect sounds )
we are close to 1 % THD at 1 Watt.
===============================
1% = -40dB
0.0032 % = -90dB
What will dominate what we hear?
the Op-Amp THD or the Speaker THD.
===============================
I do not know what you think is correct answer.
But fortunately still I have some intact logics in my brains.
===============================
I attach the THD test curve of von Schweikert very expensive speakers.
They are NOT low or ordinary quality as of yours and mine speaker systems.
And they try to avoid Room influencis when measure
by putting Test Microphone 1 meter on Axis in front of speakers baffle.
Attachments
The distortion mechanisms of speakers and amps are quite different.
And they are perceived different. So the higher speaker THD is still less objectionable than the amp's nonlinear distortion.
Earl Gedds has a nice paper on that.
Regards
Charles
And they are perceived different. So the higher speaker THD is still less objectionable than the amp's nonlinear distortion.
Earl Gedds has a nice paper on that.
Regards
Charles
phase_accurate said:
Does somebody need any paper to understand that we are surrounded by so called "mechanical distortions" the whole our life; we sing, cry, communicate using them, we play music using mechanical oscillating system that generate such "distortions", but we don't perceive them as distortions. We perceive them as sounds and when level of such "distortions" change we perceive as changed loudness
I boldly claim that it isn't the origin as such (i.e. mechanical or electrical) that causes the differences in perception.
It is how the nonlinearities behave. If a "mechanical distortion" is made to behave like amplifier crossover distortion for instance it will be perceived the same way I claim.
Regards
Charles
It is how the nonlinearities behave. If a "mechanical distortion" is made to behave like amplifier crossover distortion for instance it will be perceived the same way I claim.
Regards
Charles
Re: Re: Re: GNFB and distortion
Me too. Any distortion is undesirable in principle. But it depends on the type of distortion. Our brains are very choosy about the specific mix not just the total. It is a bit like judging the impact of noise pollution based on total amplitude rather than specific noises. For this reason, amongst others, THD+N is not an effective parameter to compare sound quality between amps or speakers.
Also, when two amps have the same total distortion, any two people might have different preferences of the mix. When modest distortion is present there may be disagreement about which amp plays music better. Only when all audible distortion is eliminated will there be a good chance of agreement.
myhrrhleine said:
Me too. Any distortion is undesirable in principle. But it depends on the type of distortion. Our brains are very choosy about the specific mix not just the total. It is a bit like judging the impact of noise pollution based on total amplitude rather than specific noises. For this reason, amongst others, THD+N is not an effective parameter to compare sound quality between amps or speakers.
Also, when two amps have the same total distortion, any two people might have different preferences of the mix. When modest distortion is present there may be disagreement about which amp plays music better. Only when all audible distortion is eliminated will there be a good chance of agreement.
Not at the moment but maybe I will stumble upon one.
The difference in perception is not coming from the fact that one is natural and the other isn't IMO.
HOW they influence a signal is what matters IMO. Just imagine that a nonlinearity around the zero crossing will influence almost any signal and the weakest even the most.
Whereas 2nd and 2rd order distortion from a speaker is almost absent for really weak signals and is rising with level. It is influencing signals of high amplitude (where the ear is also far from linear) but leaves weak signals (and fine details) almost untouched.
Regards
Charles
myhrrhleine said:
I like New York in June.
How about you?
I like a Gershwin tune.
How about you?
I like a fireside when a storm is due.
How about you?
I like potato chips, moonlight, and motor trips.
How about you?
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