The Sound of Distortion

[WGTP]

I haven't tried the test yet, but I have been experimenting with over a dozen different op amps lately, and finally decided that most of the difference was due to more or less gain, distortion, highs and/or lows.  These are all things that can be addressed with different caps or different gain settings.  The ones I thought had sweeter smoother highs, turned out to have less gain and/or bass, which smoothed out the highs and could be accomplished by using smaller input caps.

Each time I thought I heard something different, I would later be unable to duplicate the finding.

It's difficult to hear differences between 2 seemingly different designs of op amps like a 4558 and 2272 cmos, I'm not sure I could hear a difference between to op amps of the same basic design or not.

The diodes in the circuit such as GE's, SI's and LED's make a much more noticable difference than the op amps.

It's all pretty subjective, but I developed a couple of simple tests, that I will post when completed.

It's fun searching though.   My double picking and jazz scales are much better than before I started.  

[smoguzbenjamin]

I definately didn't hear anything? But I'm curious though when the distortion starts/ends you get it. Jack could you PM me with  the info?

[Elektrojänis]

I could not even make myself to believe I could hear a difference even after I loaded it in a wave editor and checked the change in the spectral view. I was not in a totally quiet enviroment though.

I think my headphones (Cheapish Sennheiser model, not too bad but not too good either) might have that 1% of distortion. Usually headphones and speakers distort much more than amplifiers etc.

Even though intermodulation products are a lot easier to detect, the capacitors are really not distorting  enough that I would be worried to use them in some distortion pedal.

BTW. Probably most of the distortion/fuzz/overdrive pedals have quite large amounts of intermodulation distortion. It is very hard to make a circuit that gives only harmonic distortion and no intermodulation.

[Jason Stout]

I hear something at ~the 3sec mark

[Jason Stout]

I'd like to hear a popular effect using electrolytics wherever possible and the same box with all film caps.

film caps are expensive!

[Nasse]

The more the sound system was crap that I heard it trough, the easier I heard it. Well, maybe not but I tried it trough one pc´s bult in small speaker and it perhaps had some weird resonance just at that harmonic.

Before there were amplifiers some musicians have told me about some old magig accordion. Those had such a tone, that it they were heard over dance audience without amplifiers. Maybe some harmonics that cut trough. Maybe squarewave.

[Paul Perry (Frostwave)]

It is very hard to make a circuit that gives only harmonic distortion and no intermodulation.

I would go so far as to say "impossible", excluding digital signal processing. Running a pure sine wave into both input of a multiplier will give a sine of twice the original frequency, but that is about it!

[Ansil]

Seems you unknowingly sabotaged your own inquiry by insinuating the two clips could possibly be of different lengths in time, and subliminally tricking people to try and listen for something that's not there.  Knowing they're both continual throughout.   :?

Maybe next you could put two farts in the same jar and ask people to identify which one smells worse.   :lol:

I'll pass. :twisted:

ok dude just because you can't hear it doesnt' mean it isn't there, and putting it into a scope will show where it is .. where some of us already heard it.

open mouth insert foot

[Steve C]

ok dude just because you can't hear it doesnt' mean it isn't there, and putting it into a scope will show where it is .. where some of us already heard it.

open mouth insert foot

First thing I did was look at it with a sound editor, the sample is the same all the way through.

Besides Jack's a big boy I'm sure he can take a little facetious sarcasm.

[Ansil]

i know jack can take care of himself.  but i hate to break it to you, even if he was just busting our balls here and there wasn't nothing there,  i have three different programs to show that there is.  i have used creative media.  winamp and soundrecorder  all showing the blip.  not to mention nero and windows media player.

[Steve C]

but i hate to break it to you, even if he was just busting our balls here and there wasn't nothing there,  i have three different programs to show that there is.  i have used creative media.  winamp and soundrecorder  all showing the blip.  not to mention nero and windows media player.

Okay third time, hopefully you get it this time.  I said both sound samples were for the full duration of the clip. . . pause. . . Understand?

[Ansil]

i know jack can take care of himself.  but i hate to break it to you, even if he was just busting our balls here and there wasn't nothing there,  i have three different programs to show that there is.  i have used creative media.  winamp and soundrecorder  all showing the blip.  not to mention nero and windows media player.

Okay third time, hopefully you get it this time.  I didn't say there was nothing there. . . pause. . . I said both sound samples were for the full duration of the clip. . . pause. . . Understand?

ok,,  i can see  your point there.  pause.  but i could also show you in your own post how you coud misinterperet what  you were trying to say,  pause,  but i have better things to do so i will drop it.

[mstoppini]

mmh, my 2 cent.
electrolytic capicitors tends to change the characteristic with frequency, I'm quite sure about it, so I don't believe a pure sine wave is a good simulation. The harmonic context a guitar signal is much more complex and involves consideration on dynamics.
Same consideration for transistor and opamp, as far as I know, considering frequency, different opamps 'follow' the signal with different 'speed', and that's something we got to take care of.
I'm not a 'big ear' but I'm quite sure that some differecies between component are more evident just under the fingers when you're playing, I tend to believe a listener can't hear the differences a performer hear, but this doesn't mean they don't exist.
bye,
M.

[mstoppini]

I posted the last msg without clicking preview, sorry, my english is not that good and I had to careful read before posting.
However, I hope the contents were clear, sorry again.
M.

[amz-fx]

Last time...  it's not a trick.  The harmonic is clearly visible on an FFT display in the proper part of the wav.  Remember it is -40db so your display must cover that much range. Also if you are looking at a wide bandwidth the second harmonic can be buried under the fundamental because the display is scrunched up.

This isn't audiophile testing...  it is an example. An eye-opener to some.... blasphemy to others... indifferent to many :!:  Whether you agree or not is immaterial, it's only important to get those brain cells churning!

regards, Jack

[Dai H.]

there's a G#(?) (comparing from my gtr. which is probly bit out of tune), then a subtle bit of  A coming in after a bit(?). There is a change almost halfway(?) or somewhere around there.

[Mike Burgundy]

Whoa - considering second harmonic is an octave, the G#-A change is quite a stunt!
Sure this doesn't have something to do with small computer speakers/overloading soundcards etc?

In the old days, some technicians reputedly stated preamp ditortion under 10% (!!!) would be unaudible. Preamp distortion with tubes is, you guessed it, mostly 2nd harmonic.
It's actually a little trick you can use to "fatten up" a sound - makes it just a little fuller, warmer.
That said, kudos to those who heard it without tinkering. I needed a little low end roll-off to get a *hint* of a change between 3-3.5s. I'm not even really positive it's there - and I had comments on the quality of my hearing, heh. Now I don't even hear it anymore. I need to get some sleep anyway
Nice test Jack! I'm curious what this would do with a more "complex" signal like a sawtooth or something.

[brett]

I'm a bit confused.  Jack said above that the harmonic was at -40dB.  To me, dB means 10^(dB/10), where ^ means exponent, so -40dB is 10^-4, 0.0001, or 0.01% (of the reference at 0dB = 10^0 = 1).  

If there's 1% distortion in there, shouldn't it show up at -20dB (10^-2 = 1%)?

Jack? Anyone?

[Dai H.]

Whoa - considering second harmonic is an octave, the G#-A change is quite a stunt!
Sure this doesn't have something to do with small computer speakers/overloading soundcards etc?

In the old days, some technicians reputedly stated preamp ditortion under 10% (!!!) would be unaudible. Preamp distortion with tubes is, you guessed it, mostly 2nd harmonic.
It's actually a little trick you can use to "fatten up" a sound - makes it just a little fuller, warmer.
That said, kudos to those who heard it without tinkering. I needed a little low end roll-off to get a *hint* of a change between 3-3.5s. I'm not even really positive it's there - and I had comments on the quality of my hearing, heh. Now I don't even hear it anymore. I need to get some sleep anyway
Nice test Jack! I'm curious what this would do with a more "complex" signal like a sawtooth or something.

Ooh sorry! I meant to say B. To be specific, the first tone is the 1st fret after the nut on the G string, then I heard this overtone which was the same note as a couple of frets higher--four frets higher, so not an A, sorry! My gtr. is most probably not well tuned, so as I mentioned, it's probably off, but that's what it sounded like to me, FWIW.

[Dai H.]

Sooo, what am I hearing (or not hearing)?