Hi Farhan,
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? Thanks for your look at the circuit fragments. I see how a simple buffer (just a 3904 and emitter resistor) can be DC coupled.
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? ?I'm back in the water, and back to trying to wrap my mind around the mic amp.? Unfortunately, the above analysis and the basic common emitter design info in internetlandia and The Art of Electronics don't seem to match.
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Gain...? If gain is estimated by R sub C over R sub E, and if R63 and R64 in series is the DC portion of R sub E, the gain would be 0.68.? Removing R63 suggests a gain of 1. It seems for a gain of 2 to 3, R sub E should be between 333 and 500 Ohms.
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If the above is incorrect, what else is happening to "adjust" the gain of that stage (and to make the common emitter amp rules of thumb not work)?
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Would you please confirm which parts in the emitter circuit you suggested removing? I figured at least C62. Did you intend that one of the Rs (63 or 64) go as well?
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I'll be traveling back to my storage place in September and will be returning with my scope and 2-tone generator. ?One way or another I want to figure this out.
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Thanks and 73
Andy
Happily back MM
