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This is the Official Unofficial Mesa Forum. Nothing is too silly.
OK, experts... Please tell me what gain is. I've been playing for almost 50 years and have no clue...
- Thread starter bukowski
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0XI0
Roadie
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food for thought, all the knobs on the mesa are potentiometers, which are variable resistors. so turning up a gain knob is reducing attentuator of that gain stage. there's a cool thing you can do with potentiometers is use a capacitor across the output in a certain way and it makes a variable resistor capacitor network (RC network), since the value of the pot resistance changes as you turn it. basically the capacitor acts with the pot to a little EQ circuit, and dump low frequency to ground, they call it a "high pass". or in a guitar pot a "treble bleed". in a guitar amp they call it a "bright cap". when the knob is maxed out the circuit is deactivated, no resistance. as you turn the knob down the resistance increases (variable resistor), and the bigger the resistance value, the stronger the capacitor works to dump signal at the set frequency. it's pretty cool, caveman tech.
the textbook definition of "gain" applies to all of the above, signal amplification or (most always) reduced attenuation of gain. any knob on an amp is gonna be a potentiometer, and that pot is gonna be an attentuator for a gain stage, where that gain stage is set to do what it does with the pot maxed out (no resistance), and the pot just attenuates down from max.
confusion is from missing the context or awareness of context, context being the gain "structure" and gain "staging". meaning there's way more than one gain stage, and depending on gain structure, gain adjustment at a given stage will have a different sonic affect. hence the half dozen descriptors.
volume and level are most used for how loud you want it.
gain and drive are most used for how distorted (and compressed) you want it.
but there's also a missing context of "is this thing even designed for distortion" or not. cause like on little tweed, volume is the distortion. they didn't have a clean channel and a dirty channel then lol. hence some current label confusion... on studio preamp, the primary gain control is still labeled volume. cause on the clean channel that's all it does. but the lead channel adds gain stages, clean channel becomes distortion channel, now that volume knob controls how distorted the sound is, where another knob controls how loud the sound is, by attenuation down at the end, after the distortion, usually called level now.
