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Impedance Question?

OK so I know there's a lot of threads about matching impedance with pre/amp.  It would be really nice if someone could help out here! The whole impedance thing confuses me (doesn't take much).

So if I have an amp that has 10k impedance what range for output impedance would work for a preamp?

Any help would be great!
sqitis
toddverrone's avatar
toddverrone
838 posts
 
@georgehifi oh man, sorry. I didn't mean to repeat myself. I've the schematics for my pre somewhere, I'll see if I can figure out what value the coupling cap is. 
What formulae are you using to calculate low frequency roll off?
georgehifi's avatar
georgehifi
4,966 posts
 
(2 pie x 10kohm x 5uf)

6.28 x 10000 x 5 to the minus 6, = then 1/x (reciprocal) the answer
which equals -3db @ 3.18hz

Cheers George


georgehifi's avatar
georgehifi
4,966 posts
 
Before anyone corrects me on pie, I’m an Aussie we love our beer, meat pie’s/ with blood.

Cheers George
toddverrone's avatar
toddverrone
838 posts
 
Wait, the answer is a number (I've yet to calculate). Is that the gain or the frequency? How do you find the other?
georgehifi's avatar
georgehifi
4,966 posts
 
You say your amp this 10kohm, this is the 10000 in the formula, and the 5 is the 5uf cap I said should be the minimum for -3db at 3.18hz bass rolloff.

Cheers George 
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