in fine tuning my amp, i find that biasing the second triod warmer with cathode resistance of say 800-1k seems to open up the sound in my amp. with a 1.5k resistor, things seem comparably tight and abrupt. are my ears deceiving me? i realize that there's a little more gain in lowering the resistor but r8 & r9 are in the circuit to attenuate the already too-much gain, not to mention my experiments w/ bypass caps.....so i know what higher gain sounds like and it's not the same as lowering rk. i could be wrong though as i've been working this poor circuit board to death and my brain is cluttered with all the changes. it's a good learning experience though.
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warmer triod bias?
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"with a 1.5k resistor, things seem comparably tight and abrupt"
These are typical Fender pairs (1.5K and 100K), and tight and abrupt might be a good description of fender amps.
Other pairs include 820 and 47K.
Different resistor pairs cause different characteristic curves which sound different.-Bryan
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And to nit pick, R8,9 do not reduce gain, they reduce signal level into the following stage. That signal level is the result of gain in previous stages. There is a difference between gain (amount of amplification in a stage) and signal level. SO adjusting the gain of a stage and adjusting the amount of signal fed to it are dofferent animals.Education is what you're left with after you have forgotten what you have learned.
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