[Jukebox-list] Audio question

[Jay Hennigan]

David Breneman wrote:
> --- Ray Finch <babylon at swcp.com> wrote:
> 
> 
>> There was some mention before of digitally reproduced sound not
>> being as 
>> good because it is sampled and that the tube amps have a "warm"
>> sound to 
>> them.  I have heard these arguments before...
> 
>> The "warm" sound of a tube amp is not anything that I have ever
>> been able to notice. 
> 
> 
> The so called "warm" or (gag!) "phat" sound of tube amps
> primarily  expresses itself in distortion.  When overdriven,
> tube amps tend to distort br producing harmonics.  Transistor
> amps tend to distort by clipping.  If you never drive your
> amp to distortion there is very little difference in the
> sound.  As far as sampling goes, the notion that analogue
> media have "limitless" frequency response is pur snake oil.
> CDs top out at 20 kHz, which most people over 20 can't
> hear.  My hearing tops out at about 18+ kHz, and 15 kHz
> isn't uncommon.  Most LP albums contain nothing above
> about 17-18 kHz.

Two different discussions here.  Tube vs. solid-state analog amplifiers 
and analog vs. digital recording and reproduction.

Clipping is a form of distortion as well.  Clipping tends to result in 
odd-order harmonics.  Push-pull tube amps and some transformer-coupled 
solid state amps exhibit even-order harmonics when overdriven, which are 
generally less harsh-sounding than odd-order harmonics.

Uncompressed digital sound reproduction, given a high enough sampling 
rate and sufficient bits per sample, is going to be as good as analog 
reproduction.  CDs approach this very well.  Most studio recording and 
mixing is now digital, even if the end medium is a vinyl record.

Typical MP3 files give up a lot of the music as a tradeoff for file 
size, and will be degraded.  Someone listening to an IPod through $2 
earbuds while jogging on a busy street isn't going to notice it, but 
critical listening to a decent system will show it.  Sibilants in 
vocals, cymbals, etc. are noisier and you can hear an aliasing or 
flanging on some notes.

A Sheffield Lab direct disk pressing on a good system in a decent 
listening room will literally give you chills.  Occasionally but rarely 
a good CD will do the same.

--
Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
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