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Old 2nd August 2014, 01:27 PM   #1
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Default tube outputs

I know this is probably an obvious question. If tubes works way above almost all speaker impedance and a speaker varies from a dead short to 20 ohms (8 ohm speaker) when it moves causing distortion, why can't you just have a huge resistor inline? I was just figuring a 800 ohm tube 792 ohm resistor with 8ohm speaker varies around 792 to 812 thats around 2.5% of variation which would cause that a nearly fixed sound response from the tube right and, tuning to a fixed response could mean the perfect amp? I was just thinking.
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sometimes a 49 general electric am radio is just down right cooler than the 100+ watts of sound around

Last edited by namesmeanlittle; 2nd August 2014 at 01:29 PM.
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Old 2nd August 2014, 01:34 PM   #2
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The resistor and the speaker would have the same current, and since power is the current squared times the resistance, the 8 ohm speaker would only get 1% of the output power. The other 99% would be dissipated as heat in the resistor.
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Old 2nd August 2014, 01:39 PM   #3
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The impedance of an 8 ohm speaker usually varies from about 5 ohms up to somewhere in the region of 100 ohms.
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Old 2nd August 2014, 02:05 PM   #4
Merlinb is offline Merlinb  United Kingdom
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This would give you something approximating to a current-driven speaker, rather than voltage driven. In general, SPL is roughly proportional to voltage drive rather than current drive, so you would get some unpleasant frequency response errors with that resistor in place. Not to mentions the astonishing waste of power in the resistor!
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Old 2nd August 2014, 09:10 PM   #5
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Ok I was just wandering. Sounds like something luxury audio would build and sell for millions.
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Last edited by namesmeanlittle; 2nd August 2014 at 09:13 PM.
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