And of course not 6c33c-b
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BTW , I never experienced any electret capsule electrical fail incorporated in this simple design , but only few with mechanical fails , mostly caused from surrounding moisture .
And of course not 6c33c-b
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BTW , I never experienced any electret capsule electrical fail incorporated in this simple design , but only few with mechanical fails , mostly caused from surrounding moisture .
Of course, you guys are goofing on improbables, but I've seen pictures of a real phono equalizer built with Eimac type 450TL final stage tubes. Maybe falls into the category of an art project (in Japan, where it's allowed). Sorry for using the forbidden "a" word in serious company.
All good fortune,
Chris
Northern and southern. But Europe, Japan, Austalia and New Zeland don't span more than one actual hemisphere. In other words, it's just half the world.
se
But Europe and Asia don't span the whole damned world. Just one half of it. Need another half to get a whole.
se
If memory serves, South America did not take part in the whole WW2 mess, so that leaves out a significant part of the Western hemisphere, reducing it geographically to just North America.
That's only if you work in percentages of territory engaged in WW2. If so, then only South America sat on the bench, and workig by continents, 5 of 6 were in it. Quite enough for a decent Wordl War, I think.
That's only if you work in percentages of territory engaged in WW2. If so, then only South America sat on the bench, and workig by continents, 5 of 6 were in it. Quite enough for a decent Wordl War, I think.
Still having total mental block with this one..........
Say capsule bias is fed from a noise-free voltage source via a resistor. This resistor has unavoidable associated JN noise which increases with sqrt of its resistance. Then bigger resistor is more noisy, and 5G resistor itself generates about -60dBu of audioband noise........!?!
kT/C
For a parallel R-C at equilibrium, the rms voltage is independent of R, namely (kT/C)^(1/2). As bkdog says, the corner frequency gets lower with larger R and thus more of the noise is infrasonic.
The T dependence is real, but cooling is not of much help unless the microphone is bathed in dry gas to prevent condensation, and then only proportional to T^(1/2)
Preamp gate leakage is important. If it shows full shot noise, an equal contribution to resistor noise occurs with a leakage current of about 10.3pA for a 5G resistor at 300 K. This means choosing a JFET for low voltage noise alone may not be optimal (this is discussed by Scott W.). Since JFET leakage increases with temperature, roughly doubling for every 10 degrees K, cooling would help a lot were it not again for condensation (and power consumption).
For a parallel R-C at equilibrium, the rms voltage is independent of R, namely (kT/C)^(1/2). As bkdog says, the corner frequency gets lower with larger R and thus more of the noise is infrasonic.
The T dependence is real, but cooling is not of much help unless the microphone is bathed in dry gas to prevent condensation, and then only proportional to T^(1/2)
Preamp gate leakage is important. If it shows full shot noise, an equal contribution to resistor noise occurs with a leakage current of about 10.3pA for a 5G resistor at 300 K. This means choosing a JFET for low voltage noise alone may not be optimal (this is discussed by Scott W.). Since JFET leakage increases with temperature, roughly doubling for every 10 degrees K, cooling would help a lot were it not again for condensation (and power consumption).
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Since WWII started in 1939, you're both wrong!
They were in the 1939 catalog according to an AES paper.
Still having total mental block with this one..........
Say capsule bias is fed from a noise-free voltage source via a resistor. This resistor has unavoidable associated JN noise which increases with sqrt of its resistance. Then bigger resistor is more noisy, and 5G resistor itself generates about -60dBu of audioband noise........!?!
It also falls out of the classical KT/C noise derivation (R goes to infinity). I know you love this stuff.
http://www.coe.montana.edu/ee/andyo/ee503/ieee_abbott1996_thermalnoise.pdf
Or simply plot the noise spectral density of a parallel R and fixed C as R gets larger as others have said. The pole goes as R and the noise as sqrt(R).
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You left out the WBA and WWF.
(the US was always good for a giggle now and then, alas no more. At least the aliens still land in central park, to start the destruction of earth in America, but they may be still bound by contract)
Yes a good rule of thumb is when the current makes 2Vt on the R diminishing returns set in. Unfortunately the JFET datasheets don't help, the Ig spec is invariably sandbagged, for instance, SK170 typically measure only 2-3pA on an electrometer at low Vgd.
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