What causes grain?

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warnerwh

What causes grain?
« on: 1 Oct 2003, 11:28 pm »
Trying to understand why electronic components can add a grainy texture to music.  Two high quality pieces of electronics both measure the same but one will have more grain than the other. I'd appreciate the answer in layman terms. thanks

jqp

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What causes grain?
« Reply #1 on: 1 Oct 2003, 11:34 pm »
This might be a good one for the Starting Block

definition of grain, and also what can cause it...

Mad DOg

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What causes grain?
« Reply #2 on: 2 Oct 2003, 12:10 am »
Quote from: jqp
This might be a good one for the Starting Block

definition of grain, and also what can cause it...


from http://www.stereophile.com/showarchives.cgi?50:4

grainy A moderate texturing of reproduced sound. The sonic equivalent of grain in a photograph. Coarser than dry but finer than gritty.

gritty A harsh, coarse-grained texturing of reproduced sound. The continuum of energy seems to be composed of discrete, sharp-edged particles.

eico1

What causes grain?
« Reply #3 on: 2 Oct 2003, 03:56 am »
There is a strong chance if one amp seems more gainy than another they do not measure the same, but anyway I could think noise modulation sounding grainy.

steve

_scotty_

What causes grain?
« Reply #4 on: 2 Oct 2003, 04:47 am »
Quote from: eico1
There is a strong chance if one amp seems more gainy than another they do not measure the same, but anyway I could think noise modulation sounding grainy.

steve

 I have heard grain that I think could be caused by power supply caps not being broken in yet,{ie,the dielectric was in the process of forming as a result of voltage being applied to the electrolytic cap for the first time}.This of course doesn't explain grain in equipement that is broken in.
Ultimately "grain"or anything else that bothers you when reproducing
music other than sheer volume,is distortion, whether we can measure it or not. Real life does not have any distortion. I am referring to live unamplified acoustic instruments or voice
in the above statement. Your individual tolerance for distortion may differ
dramatically from the next persons. But as soon as you hear some piece
of gear with lower distortion there is no going back to the old standard.
Grain once identified is easy spot a second time. The kind of distortion
I hate is like fingernails on a blackboard somehow above the normal  range of hearing. You don't exactly know where it is coming from
but you know that this sound will sterilize frogs at 500yds. I have no idea
what causes this distortion and I don't own and won't listen to systems
that have it. Life is too short.

randytsuch

What causes grain?
« Reply #5 on: 2 Oct 2003, 06:24 pm »
I had an old quad 306 amp (not retired to storage, need to sell one of these days).  When it was about 15 years old, I decided to change the main electrolytic caps in it, as lytics age, and really should be changed after 10-15 years.

So, after changing the caps, I heard a reduction in grain in my system.  I really had not noticed the grain before, but could tell it was gone after I changed the caps.  I also bypassed the caps when I changed them, and that could also have helped kill the grain.

I am sure there are many ways for grain to enter your system, but it was in the power supply in my amp where it entered mine.

Randy

warnerwh

What causes grain?
« Reply #6 on: 3 Oct 2003, 12:52 am »
I'd like to know why caps cause grain, and exactly what it is about the component(cap) that makes a sound grainy.  We're going to need some engineering people on this I believe.

_scotty_

What causes grain?
« Reply #7 on: 3 Oct 2003, 03:49 am »
Quote from: warnerwh
I'd like to know why caps cause grain, and exactly what it is about the component(cap) that makes a sound grainy.  We're going to need some engineering people on this I believe.


We can't generalize like this and categorically say that caps cause grain.
Grain is a subjective term used to describe what we hear from a system.
It can and probably does have more than one cause. On the subject of electrolytic capacitors, in my earlier post I mentioned that when voltage is first applied to an electrolytic capacitor the dielectric forms as a consequence.The dielectric is the insulator between the conductors in the capacitor. Until it forms completely the capacitor isn't very good at doing its job of filtering and storing energy for the circuit to operate on. The circuit may sound grainy as a result of this less than operational state on the part of the capacitor,or it may sound harmonically thin,slow,undetailed
have poor PTRB,and the potential list goes on.

avahifi

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Grain, my thoughts.
« Reply #8 on: 3 Oct 2003, 10:50 am »
I would suggest that "grain" is  caused by underdamped oscillations in the electronic circuits.  These can occur at any frequency, many way out in the megahertz range, far beyond the reach of direct hearing or test equipment.  Some of the oscillations can however be observed by careful mathematical modeling of the circuit design.  Things that can cause the oscillations are wire lengths and routing, the stray behavior of electronic parts (both resistors and capacitors have stray inductive and reactive elements for example), PC card layout, underdamped power supply and ground feeds, all kinds of things very difficult to identify.  The oscillations are not audible in and of themselves, and many are at very low levels, but its kind of like throwing rocks in a calm pond, after a few splashes, the surface is a scramble of chop, no longer reflective, and with waves and ripples all over the place.  Changing part brands, wire brands, connection cable brands, and so on will likely change the shape and frequency of the oscillations, but not eliminate them, one reason there is so much subjective discussion about "good sounding parts and cables."  The way the cables and parts interact with your system is essentially random and you may or may not like the effect.

As designers, we feel our goal is to identify and eliminate as many possible causes of internal underdamped oscillations as possible (one reason for the completely damped power supply, audio, and ground feeds on our power amplifiers).  One difficulty with dealing with the vendors of "good sounding parts and cables" is that they rarely provide any useful engineering data that can aid us in figuring them into the mathematical models necessary to identify stray oscillations.  "This is just wonderful cause it was dipped in virgin's blood at midnight" is not useful engineering information.

Making changes without any understanding of what the changes are really doing makes listening and liking the changes essentially a random experience.  Not useful in a serious attempt to design audio equipment that screws up the source material less than before.

The grain is there, it does not show up in IHF specifications, but it can be eliminated if the engineering design gets it all right all at once.  Of course that has not happened yet, but we are working on it.

Frank Van Alstine

audiojerry

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What causes grain?
« Reply #9 on: 3 Oct 2003, 03:16 pm »
That was a great explanation by Frank!

warnerwh

What causes grain?
« Reply #10 on: 3 Oct 2003, 10:04 pm »
Frank: Greatly appreciate your input and an excellent explanation. Thanks

witchdoctor

What causes grain?
« Reply #11 on: 6 Oct 2003, 12:49 am »
The Absolute Sounds review of Franks grainless DAC:

In my system, the OmegaStar eliminated digital tension, and turned CD playback from paint-peeling to musically lustrous. Gone is that vague feeling that I am listening to connect-the-dots reconstituted music.

Digital grain is all but gone,  :D

the noise floor plummets, and CD sound emerges as unstrained, un-gritty, and tonally articulate. At $1,399 [now $999], this "purist" component has to find justification in exceptional performance: The OmegaStar DAC ramped my system up more than a couple of notches on the CD side. If you think your stand-alone CD player can't be improved upon, the OmegaStar will challenge that notion...” – Anna Logg

Now that's what I'm talking about!

Ronm1

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What causes grain?
« Reply #12 on: 26 Mar 2005, 02:10 pm »
Frank

   Superb reply...My hats off to you!

GHM

What causes grain?
« Reply #13 on: 26 Mar 2005, 02:39 pm »
I found the grain in my system was caused by several things. Crossovers..especially garbage crossovers. Cd players can cause grain..the ones with crappy rectifiers,op amps and power supplies and cheap OEM clocks.
Cds themselves are sometimes grainy. Using audio equipment to cover this up also covers up the great recordings as well.

So I only buy well recorded music now..it is a part of the system like any other component.

BeeBop

What causes grain?
« Reply #14 on: 27 Mar 2005, 10:31 am »
lousy cables also cause grain. The grain in my system disappeared when I upgraded my cables.

witchdoctor

What causes grain?
« Reply #15 on: 27 Mar 2005, 05:45 pm »
Bee Bop,
What did you upgrade from and to?