What do vacuum tubes (valves) do?

this so what do vacuum tubes or valves do well they're comprised of a few different parts inside the first one is the heater and heaters job is just to throw off a bunch of electrons now it does this in a vacuum in the same reason that you have a vacuum inside your incandescent bulb is if there was any oxygen inside that that tiny filament would just burn up so within a vacuum there's no oxygen in there and that allows the stuff not to burn up so the heat of throws off electrons on the other side of that we have a plate whose job is to collect those electrons but in between we have a grid and a grids job is to vary the electron flow and kind of modulate the blockage between the heater and the plate to vary that that those flow of electrons now this is what it looks like on a circuit diagram you might have seen a circuit diagram like this in this case we have three valves in the circuit diagram and if we were to zero in on that a symbol of a vacuum tube we have our heater we have our plate and we have our grid in the middle so let's zero in on that with those three parts there the heater grid and the plate and as I said before the heaters job is just to throw off and electro throw off lots of electrons and if there were no grid there then all of them would just flow straight to the plate but there is a grid then a grids job is to vary that flow between the heater and the plate so that's kind of in in the middle the nut will resist some of those that electron flow that that current so if we'll look at that grid what could we send into that grid to modulate and open and close that well we can send it a week AC signal what do you know that produces a really weak a signal AC signal back and forth waveform what do you know absolutely a pick up the pick up a new guitar if it's connected to a grid will allow you to vary the amount of those electrons that move from the heater to the plate so your pickup is basically open closing that variable resistance between the here and the plate and what do we get out of that well we get a stronger AC signal that's coming off of the plate now here's something that very worthwhile kind of understanding this stronger AC signal is not an amplified week AC signal in fact the week AC signal is just simply modulating the amount of electrons that are flowing from the heater through to the plate so you kind of get that idea that stronger AC signal is just an analogy of that week AC signal now here's an analogy that might be able to make a little bit more sense imagine i'm using this faucet and i'm moving this lever back and forth i'm not generating any water pressure i'm just modulating that water pressure you could think of this area down the bottom here is the heater here's our plate and the lever adjusting the water flow is the grid

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Views: 81,165

Keywords: vacuum tubes, Guitar Tone, Guitar, Guitar Controls, Guitar Types, Guitar String, Distortion, Modulation, guitar tone knobs explained, guitar tutorial, guitar tone tutorial, guitar lessons for beginners, guitar tone knob

Id: kRSiTog2-No

Length: 3min 16sec (196 seconds)

Published: Mon Oct 24 2016