Thermal noise study...

[dkemppai]

Ok,

I've heard discussions on silver in audio, and solder in audio, but what about resistors in audio... ....or wires, or semiconductors, or tubes....

Seems to me that thermal noise would be of more concern than Seebeck, or Peltier, or that stuff. Since thermail noise is porportional to temperature...

And, man... ...imagine a tube, where amplification happens because of thermal noise bouncing electrons off the filament. I mean, think about all you tube freaks, you like auido made by a one way movement of noise!!! Hi-Fi, my butt! Maybe tubes "sound better" because the Noise Floor in tubes masks most subtle tones! Me, I'll take a good clean mosfet amp any day. At least in a mosfet you're using an E Field to displace stable electrons, and not counting on a plate to hold back audio, er, I mean noise!

-Dan

[fdegrove]

Hi,

At least in a mosfet you're using an E Field to displace stable electrons, and not counting on a plate to hold back audio, er, I mean noise!

And I thought thermal noise was more an issue in semiconductors than in tubes?

What happens inside tubes is shot noise,not thermal noise IMO.
Tubes works in a vacuum,semi-conductors do not.

Cheers,

[halojoy]

Tubes have a beautiful warm glowing light.
MOSFETs are deadly boring in comparision.

[fdegrove]

Hello,

Tubes have a beautiful warm glowing light.

Halojoy,

I like your style but what would happen to me were I to live in Skandinavia?
Polar light, would that generate thermal noise or shotnoise?

All,

If you want to read something more boring than watching FETS glow under infra-red light:

SHOT NOISE

Cheers,

[fdegrove]

Hi,

And, man... ...imagine a tube, where amplification happens because of thermal noise bouncing electrons off the filament.

Explain to me please how filaments in a tube are going to emit electrons?

Maybe tubes "sound better" because the Noise Floor in tubes masks most subtle tones!

No,that is NOT the reason.
The noise generated by tubes (shot noise,NOT thermal noise) is that it is not bundle in a range of bands as in a semi-conductor but spread over the entire audible range.
So subjectively it is less obtrusive to the human ear.

and not counting on a plate to hold back audio, er, I mean noise!

By this statement you prove no understanding of the flow of electrons in the vacuum tube,AKA thermionic device.

Sorry Dan,

[tmc]

well,
AS a guitarist, AND owning both tude amps and SS amps AND hybrid amps , i must saythat the tube amp offers a smoother transition of amplitude. for clean signals right on over to flat out overdrive and distortion
( which does not intrest most of ya'll. I know, I know.)
the other preferable feature of the tube amp is the ability to "tweak the damn thing without replacing have of your circut to do so.....( i'm not talking about overall circuit mods, just biasing in general....) and different tubes have a much greater effect on signal as opposed to SS.
A good example on the Audiophile side of this would be An old Phase linear Power amp i had the pleasure of using for a year or two in a studio i was camped out in....that thing DID NOT liked to be moved and was by far the cleanest sounding amp in the house....and the engineer was constantly tweaking it....
so
preferences aside....i dig tubes
But !!!
i like horns and lenses too

[fdegrove]

Hi,

Happy for you you enjoyed them.

While I worked in the "Studio World" I remember a more than desperate engineer looking for alufoil since these PLs popped a fuse again.

Three months later all the Phase stuff was gone and tube amps were installed.
I saw a happy grin on the engineers' face.

Cheers,

[tmc]

hey F
so
You are'nt in the studio world anymore?
Reason?

And that phase linear was not having tinfoil put in it.

Btw - in case you did not notice, I was agreeing with you

[fdegrove]

Hi,

At the time it was a contractual consultancy+maintenance job.

And that phase linear was not having tinfoil put in it.

But of course they did,alu or tin whatever they found.Doesn't everyone?
These amps had those typical U.S fuses driving half of Europe mad when they popped at Murphys' best times.
No surprise,the tinfoil was well protected but the outputbanks went up in smoke.

Btw - in case you did not notice, I was agreeing with you

Sure I did,don't worry I'm Mr.Tube himself.
I wasn't addressing you as a person but all this thermal noise shot my nerves.

Ciao,

[dkemppai]

Originally posted by halojoy
Tubes have a beautiful warm glowing light.
MOSFETs are deadly boring in comparision.

Good point! Maybe that's where all the 'warmth' comes from

Actually, tubes are pleasing to watch. Kind of like a fireplace/cold winter day effect. (I live above the 45th)