[Harp-L] Question on impedance and Z matching

[Jonathan McAnulty <mcanultj@xxxxxxxxxxxxxxxxxxx>]

> Hi, I've been lurking here for over a year just absorbing info, for which 
> I am quite appreciative having learned a lot. I have been playing amplifed 
> at home through my home theater system using a mixing board to get 
> everything I want to go smoothly through that system. However, now I have 
> acquired some tube amps and have a selection of mics and need a little 
> info if possible. Since I'm just getting into the variations on amplified 
> playing, could anyone set me straight on the ins and outs of impedance 
> matching, what are considered Hi and low Z ranges, etc. Specifically, I 
> have a tube amp that does not say what the input impedance is. The 
> schematic shows a 63K resistor between the input jack and the amplifier 
> circuits. Would this be the input impedance rating? If not, how do you 
> determine this value? There is also a 1M resistor between the input jack 
> and a ground. Next question is, if I have a high impedance mic, say 1 M 
> ohm, what kind of impedance is needed at the amp to properly match to 
> that? If someone can give me some advice on what is good-better-best in 
> terms of Z matching or what is inadvisable with respect to Z matching I 
> would be grateful. If you could also tune me in to the Z matching devices 
> and how they should be set up that would also be helpful. I don't really 
> understand the pros and cons of it so any info would be of benefit.

Cheers.
Jon

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