John Curl's Blowtorch preamplifier part III
I'd say Minelabs future is secure, given there are estimated 80 million UXOS in Laos alone,
Any company naming itself "Longwood" has an elevated opinion of themselves...
Howie
Well, Max you don’t believe Einstein formulated General Relativity and you can hear the difference in the chemical composition of a 75 Ohm resistor in parallel with a complex impedance for the most part 10x lower in magnitude.
Just think about how that looks for a minute.
Just think about how that looks for a minute.
Any company naming itself "Longwood" has an elevated opinion of themselves...
Howie
The sound of speaker cable terminating resistors - now we are cooking!
This a topic to the thread
If I get the chance I will show the measured difference in results depending on the type of resistor used in the impedance correction network!
Very dramatic results and if you think about it you should be able to figure out why!
If I get the chance I will show the measured difference in results depending on the type of resistor used in the impedance correction network!
Very dramatic results and if you think about it you should be able to figure out why!
I like your jokes, Ed. Yes, 75 ohm resistor in parallel to speaker impedance both driven by almost ideal voltage source, through uH of cable inductance. Yes, the -130dBr non-linearity of the 75 ohm resistor must be clearly audible! (for those with slower perception, this is a joke)
A small suggestion to the listeners what they should hear is also not too bad.
Obviously you never read the article or have a clue what it is about. Microdiodes were from Scott Wurcer's comments. I have already mentioned in one of these threads what actual measurements of oxidized copper compared to clean for distortion and directivity effects.
And where Pavel understood the emoticons and message you clearly didn't.
Scott do read the words carefully!
No problem Ed, I no longer have any interest in discussing this stuff with you. BTW the micro-diodes came from at least three or four snake oil cable vendors why you dwell on this is clearly only known to you. Last night I saw a short documentary on where the term snake oil came from.
After all this time you still have not presented your theory of how things all breakdown at low current with any testable hypotheses.
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I did (well, at least honestly tried to). Good resistors are linear and not directive. Ohm's law holds at all current levels. -140dB effects can be safely ignored, with enough safety margin. Copper oxide rectification or other pathological effects (carbon volume resistors, temperature and voltage coefficients, etc...) are not new and not a problem for any half competent designer.
Conclusion: if one puts a 0.5W carbon volume resistor in the feedback loop, then he gets what he deserves.
Scott maybe Pavel would explain humor to you. As I recall you brought up the micro diode theory as an example of what you thought was nonsense. I did what I thought was a simple test to see if there could be any measurable effect. Comparing a deliberately oxidized copper wire before and after at levels apptoaching -160 dB from the reference signal showed no difference. Now the humor is you brought up the theory, not that you believe it and we both agree that it is most likely not a real issue.
As to how contaminating films cause low level circuit disruptions, this is well evidenced in practical sound system use. Lots of folks have experienced signals not passing through circuits until a surge occurs. The best example is a microphone not working until someone taps on it. The typical example is a Shure SM58 dynamic microphone. In normal use the incircuit unit voltage may range from 500 picovolts to 5 millivolts into a 150 to 10,000 ohm load. Tapping on it may increase the voltage to perhaps 100 millivolts. A frequently observed phenomena. You keep insisting this can't happen. I even posted a nice single shot of this "break over" effect.
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Pashen's Law, the mechanical action on the connection is required there is no open circuit that can be completed with a change of 100mV alone. As usual you don't remove all confounders from your experiments. What is profound about mechanically working a dirty connection to fix it?
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Scott,
In the microphone example mechanical motion may exist if the fault is at the microphone connector, but there are many other cases where it just signal doing it. Having repaired some of these bad connectors it frequently is the one in the floor box not at the microphone end.
Last time I encountered the problem it was a sound system where raising the fader level would get the system to work. Changing a connector solved the problem. Full amplifier power required .775 volts. The system popped in well below that voltage.
Yes many possible explanations. That is why I did the single pass test. If I find another bad connector I will run it again and then send you the connector.
In the microphone example mechanical motion may exist if the fault is at the microphone connector, but there are many other cases where it just signal doing it. Having repaired some of these bad connectors it frequently is the one in the floor box not at the microphone end.
Last time I encountered the problem it was a sound system where raising the fader level would get the system to work. Changing a connector solved the problem. Full amplifier power required .775 volts. The system popped in well below that voltage.
Yes many possible explanations. That is why I did the single pass test. If I find another bad connector I will run it again and then send you the connector.
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