Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Paramount => Topic started by: kip.duff on March 07, 2017, 10:28:30 PM
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what is input impedance of my Paramount 1.1s? I was not able to find this info in the manual.
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It's the value of the first resistor on the RCA input to ground which should be 249k
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johnsonad:
Thanks. But forgive my lack of knowledge here- does this satisfy the definition of "input impedance" statistic as used for audio gear? Example: the DC resistance measured across the terminals of a speaker measured with a DVOM is not the same as its impedance when being played.
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Thanks. But forgive my lack of knowledge here- does this satisfy the definition of "input impedance" statistic as used for audio gear? Example: the DC resistance measured across the terminals of a speaker measured with a DVOM is not the same as its impedance when being played.
In this case, the resistor is the dominant factor in determining the input impedance of the Paramounts. Do note that if a 12AX7 was present instead of a 12AT7 or 5670 (depending on Paramount version) we would have to alter the input impedance to account for the difficulty in driving the Miller capacitance of the 12AX7.
The DC resistance across the terminals of a speaker is just that: the impedance of the speaker at DC. The impedance of a speaker generally wanders all over the place, and the actual number given is simply an average or sometimes just representative of the drivers used. (EG a 2-way speaker with an 8 Ohm woofer and an 8 Ohm tweeter may be more than 8 Ohms at most frequencies, but it may still be listed as an 8 Ohm speaker)
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Thanks :)