Resistor Excess Noise is caused by DC current flow. It is dependent on the type of resistor and has a 1/f, pink spectrum.
http://linearaudio.net/userfiles/file/letters/Volume_1_LTE_FB.pdf
Frank Blohbaum reply to David Kimber re “A New, Low-Noise Circuit Approach for Pentodes” in Vol 0
says Excess Noise is dependent only on the voltage across the resistor and independent of its value.
He quotes a value of 0.06uV/V/decade for metal film resistors.
http://books.google.com.au/books?id=PvKPEFu2PVkC&pg=PA46&lpg=PA46&dq=resistor+excess+noise&source=bl&ots=YiN4vyZH-C&sig=IN81Jku14oWRHAFOV4F50XRi0qg&hl=en&sa=X&ei=Z0swT-rOMPGYiAfAmJDxDg&ved=0CGIQ6AEwBg#v=onepage&q=resistor%20excess%20noise&f=false
Douglas Self in "SMALL SIGNAL Audio Design" p46 says
“.. low ohmic resistor has lower excess noise .. rises approximately with the square root of resistance”. Fig 2.4
I have 3 questions
1 Is Frank correct about Excess Noise being independent of resistor value?
2 What is the source resistance of this "voltage noise source"? Is it the value of the resistor?
3 Is Self's uV/V the same as Frank’s uV/V/decade?
[edit] Thanks to Sam, the answers are
1 Frank is wrong. Self is correct
2 Source resistance is the value of the resistor
3 Yes.
See Sam's post for more detail & good references.
http://linearaudio.net/userfiles/file/letters/Volume_1_LTE_FB.pdf
Frank Blohbaum reply to David Kimber re “A New, Low-Noise Circuit Approach for Pentodes” in Vol 0
says Excess Noise is dependent only on the voltage across the resistor and independent of its value.
He quotes a value of 0.06uV/V/decade for metal film resistors.
http://books.google.com.au/books?id=PvKPEFu2PVkC&pg=PA46&lpg=PA46&dq=resistor+excess+noise&source=bl&ots=YiN4vyZH-C&sig=IN81Jku14oWRHAFOV4F50XRi0qg&hl=en&sa=X&ei=Z0swT-rOMPGYiAfAmJDxDg&ved=0CGIQ6AEwBg#v=onepage&q=resistor%20excess%20noise&f=false
Douglas Self in "SMALL SIGNAL Audio Design" p46 says
“.. low ohmic resistor has lower excess noise .. rises approximately with the square root of resistance”. Fig 2.4
I have 3 questions
1 Is Frank correct about Excess Noise being independent of resistor value?
2 What is the source resistance of this "voltage noise source"? Is it the value of the resistor?
3 Is Self's uV/V the same as Frank’s uV/V/decade?
[edit] Thanks to Sam, the answers are
1 Frank is wrong. Self is correct
2 Source resistance is the value of the resistor
3 Yes.
See Sam's post for more detail & good references.