Sorry, it must have been late when I posted. Being at an AES show tends
to create a bit of overload and nonlinearity. I was thinking of the noise
from the power supply itself which is common mode, the rejection of which
by the preamp is determined by the match of phantom power resistors and
the CMRR of the whole system (including the preamp, cable, symmetry of the
microphone output stage etc.) Of course, noise generated in the phantom
power resistors themselves (both Johnson or thermal noise, and "excess
noise" created by current through the resistors, is uncorrelated,
differential mode and amplified by the preamp.

--
David Josephson

"David Josephson"

Sorry, it must have been late when I posted. Being at an AES show tends
to create a bit of overload and nonlinearity. I was thinking of the noise
from the power supply itself which is common mode, the rejection of which
by the preamp is determined by the match of phantom power resistors and
the CMRR of the whole system (including the preamp, cable, symmetry of the
microphone output stage etc.) Of course, noise generated in the phantom
power resistors themselves (both Johnson or thermal noise, and "excess
noise" created by current through the resistors, is uncorrelated,
differential mode and amplified by the preamp.



** There is no need for phantom power feed resistors add ANY discernable
noise to the audio signal from a condenser mic and likely no cases exist
where it does.

The few microvolts of excess noise from a *metal film resistor* used for
phantom power is negligible in practice since the mic's output impedance
attenuates it by a factor of 100 or more - reducing it to the nanovolt
level and oblivion.

The use of wirewound resistors would eliminate the issue entirely since wire
has no excess noise whatever.



.......... Phil

David Josephson wrote:

Sorry, it must have been late when I posted. Being at an AES show tends
to create a bit of overload and nonlinearity. I was thinking of the noise
from the power supply itself which is common mode, the rejection of which
by the preamp is determined by the match of phantom power resistors and
the CMRR of the whole system (including the preamp, cable, symmetry of the
microphone output stage etc.) Of course, noise generated in the phantom
power resistors themselves (both Johnson or thermal noise, and "excess
noise" created by current through the resistors, is uncorrelated,
differential mode and amplified by the preamp.

--
David Josephson

Thanks, david.

--
ha

"hank alrich"
David Josephson wrote:

Sorry, it must have been late when I posted. Being at an AES show tends
to create a bit of overload and nonlinearity. I was thinking of the noise
from the power supply itself which is common mode, the rejection of which
by the preamp is determined by the match of phantom power resistors and
the CMRR of the whole system (including the preamp, cable, symmetry of
the
microphone output stage etc.) Of course, noise generated in the phantom
power resistors themselves (both Johnson or thermal noise, and "excess
noise" created by current through the resistors, is uncorrelated,
differential mode and amplified by the preamp.

--
David Josephson

Thanks, david.


** Lick, lick, lick ....



............. Phil

"Chel van Gennip"

Phil Allison wrote:

The use of wirewound resistors would eliminate the issue entirely since
wire has no excess noise whatever.


I hope you are not saying that current in a wirewound resistor is free of
noise. It is not.


** Yes it is - you ranting bloody nut case.


It may be neglectable in most situations, except in
cases of design flaws. The basic problem is that the 10mA phantom power
current is 7 orders of magnitude greater than the lowest detectable noise
current of about 1nA. 1nA at 1KOhm will give 1uV, 1uV is about 90dB below
a normal microphone signal of 30mV at 100dBA. The design problem is that
any differential noise in the phantom power current will show up as signal
noise.


** What a pack of utterly ridiculous lies.

Chel van Bunyip is not merely a misguided ****ing idiot.

The prick is a lunatic and a criminal liar.




............ Phil

Chel van Gennip wrote:

On Sat, 08 Oct 2005 06:53:01 +0200, Phil Allison wrote:
The use of wirewound resistors would eliminate the issue entirely since
wire has no excess noise whatever.

I hope you are not saying that current in a wirewound resistor is free of
noise.

He said it was free of *excess noise*. Aren't you familiar with the specs fror
resistors ? Excess noise is additional to thermal noise. It's typically quoted
as uV( noise)/V of applied DC.

Graham

Phil Allison wrote:
"hank alrich"

Thanks, david.



** Lick, lick, lick ....

Respect, respect, respect...

Is there anyone you respect, Phil?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

"Bob Cain"
Phil Allison wrote:
"hank alrich"

Thanks, david.


** Lick, lick, lick ....

Respect, respect, respect...


** Seems all you Septic Tank morons see no distinction.


Is there anyone you respect, Phil?


** Plenty do - but not one arse licker.



............ Phil

Bob Cain wrote:

Phil Allison wrote:
"hank alrich"

Thanks, david.



** Lick, lick, lick ....

Respect, respect, respect...

Is there anyone you respect, Phil?

Himself ?

Graham

Phil Allison wrote:
"Bob Cain"

Is there anyone you respect, Phil?

** Plenty do

Try again. You answered the question you saw, not the one I
asked.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

"Bob Cain"
Phil Allison wrote:

Is there anyone you respect, Phil?

** Plenty do

Try again. You answered the question you saw, not the one I asked.


** Try defining your question properly.

Instead of falsely equating respect with public arse licking.



............ Phil

"This post may contain material some find objectionable. Reader
discretion is advised."

On Sun, 09 Oct 2005 01:48:19 +0100, Pooh Bear
wrote:



Bob Cain wrote:

Phil Allison wrote:
"hank alrich"

Thanks, david.



** Lick, lick, lick ....

Respect, respect, respect...

Is there anyone you respect, Phil?

Himself ?

ARGH! Bad visual. This could have used some kind of warning,
perhaps like what I have above - definitely not a C&C warning.

Graham

Bob Cain wrote:

Phil Allison wrote:
"hank alrich"

Thanks, david.

** Lick, lick, lick ....

Respect, respect, respect...

Is there anyone you respect, Phil?

Yes, Filly's technical credentials are so much greater than those of Mr.
Josephson that we can only wonder at the power of Assilon's so-called
mind.

One day I shall have my own Josephson mics, and yes, I intend to feed
'em a few good licks.

--
ha

--
"Phil Allison" wrote in message
...

"Bob Cain"
Phil Allison wrote:

Is there anyone you respect, Phil?

** Plenty do

Try again. You answered the question you saw, not the one I asked.


** Try defining your question properly.

Instead of falsely equating respect with public arse licking.



........... Phil

If you've never had your ass properly licked I can understand why you think
it's a bad thing . . . . .


John L Rice