Deep circuit diving with the Marshall Bluesbreaker

around 1991 marshall released a couple of different pedals in black boxes one of those being the marshall blues breaker now the pedals apparently didn't sell too awful well because they discontinued them a little while after and about 2006 john mayer started using this marshall blues breaker and the pedal got wildly popular again now it should be noted that about 10 years after they initially created the marshall blues breaker pedal that uh they came out with i think it's called the blues breaker two it's in a silver box not quite the same circuit didn't sound the same so let's go to about 2003 or so analog man creates the king of tone now the king of tone was based around the topology of the blues breaker but was radically changed to sound completely different and have more gain and some other things and he put two of these circuits together of course that was incredibly popular as well later on he created the prince of tone i think was just single one of those for shirts but but today i thought let's take a look at what makes the blues breaker so great so here on this breadboard here i have the blues breaker circuit as you well you may not be able to see but that's really what it is here so we have the initial gain stage it's just non-inverting gain stage into a uh inverting gain stage into basically simple tone control and then out so let's take a little bit of a look at it and look at some frequencies and really kind of you know do some of the fun nerdy stuff with this particular circuit first of all my clean tone going through the bravado now on this particular breadboard here i have over here is the gain control this is going to be the tone control and this is the volume control so you know what i'm turning that's what's going on here now with the way this is set up this gain control is going to change not only the gain in the first section the non-inverting amp stage but also going to change the gain in the second section the inverting op amp stage so it's kind of doing both so let's start with it all the way down it's going to be really really clean not a whole lot going on there uh some people like to modify these in different ways to give it a little bit more added gain as well in fact this one thing is the king of tone deadest but a little more bit more added gain whenever it's down all the way [Music] let's turn the gain up [Music] so [Music] of course one of the things that people love to use this particular circuit for is kind of like a kind of like a warmer slightly dirty boost let's start with the gain around noon or so give or take turn up the volume just a little bit [Applause] [Music] and add a little sparkle to it i actually made a little bit more now the fun part what happens with each part of the circuit let's start changing some parts out and just kind of see what it's doing here all right the input capacitor normally this is a 0.01 microfarad let's see what happens we make the cap a lot bigger you know sometimes this does a lot depending on the circuit sometimes it doesn't do a whole lot let's see first of all we're going to start off in the stack setting then i'll turn this little switch on here and uh that will basically put the larger capacitor in the signal path [Music] [Applause] not a whole lot of difference there let's go on to the next part we have several different things we can do here first of all we have the potentiometer as i explained it it's going to change the gain so if we make that larger it's going to have a lot more gain now there's also the feedback part of the circuit which has some capacitors resistors all you know in series and parallel here and changing that can have some effect too that can change the uh basically the frequencies and how much gain it's going to have and some other things like that first of all let's start with a different potentiometer and see what happens now keep in mind i have the gain all the way up right now just to really exaggerate any sort of setting that's going to happen in this circuit okay i have a 1 mega ohm potentiometer here instead of the 100k so this is a much bigger potentiometer it's going to give it a lot more gain in one way but also a lot less gain in the other way let's start with it all the way down [Music] let's turn it on first so due to the way it's set up with this second op-amp because it is controlling gain in the second op-amp it's really taken away a lot of signal with all of that resistance there let's turn it up a bit so even half it's still not not much so once we get up almost all the way and this is a linear pot here so we can do some things with taper to make it work a little bit better but we really have to turn the pot all the way up or almost all the way up to really get to that point where we have a lot more gain let's go ahead and turn it all the way up [Music] so so i'll explain more in a little bit but you're hearing a lot of clean signal in there and it's really just due to the way the diodes are set up in this particular type of gain stage it's allowing some clean signal to come through almost i know some people hear the same sort of sound on a tube screamer it's not a tube screamer but you're still kind of getting that clean signal on this particular type of circuit with the way it's set up sort of like you would on the gain section of a tube screamer even though they're completely two different types of op-amps now one thing that analog man did on this is because you could give it a lot more gain you can clip it differently so you can add diodes in different places and make it clip much more kind of like a distortion in a way uh it's another thing we did on the pantheon whenever we came out to pantheon we allowed you to have more gain and also clip it several different ways flip the signal several different ways so you get the soft clipping you could also get a much harder more distorted tone so from this particular potentiometer let's go to the resistor and capacitor network that's going to kind of help shape the frequencies and and you know so the amount of gain that's in the circuit i'm going to switch back to the original potentiometer and uh let's see what we have okay so what this little area is here is the resistors and capacitors that sort of form how much gain is going to this first stage is going to have and what frequency is going to be affected so what we can do is just kind of give it a few we if we sort of simplify a little bit kind of do the frequency range that the tube screamer is going to do but just give it a lot more gain you can see what we can do just by changing this area so first of all let's go to stock and then i'll flip it over to the modification i have it i have it on a switch right now just temporarily so stock [Music] now we're gonna add a lot of gain to it so that's just one section that we can change give it uh giving it a lot more gain just a handful of resistors and capacitors so let's go to the next section this is part of the inverting op amp stage there's a couple of resistors that's going to limit how much gain it's going to have and i think it might be fun to kind of maybe swap in a potentiometer potentiometer is going to allow us to change that resistance quite dramatically just on the pot because that's kind of what potentiometers do and so we can see what those resistors are controlling in the in the circuit itself first of all let's start at um i'm going to start actually in the op amp in in the in between the input pins of the op-amp itself because we already know whenever we change the resistance before it what happens you get a lot less gain that's why the larger potentiometer dropped all kinds of volume because you lost a lot of gain it was cutting some signal there so let's go inside this op amp and actually increase the resistance and we'll decrease it as well stock is a 220k okay here we go i'm going to start out with the resistance down fairly low gain is up on the circuit it's up all the way or the what would normally be the gain potentiometer [Music] [Music] okay now there's a resistor that's going from the diodes because we have we have soft clipping diodes in here and this 6.8 k resistor that's kind of connecting the diodes to the other uh input pin this resistor is what's kind of giving us that clean signal it's not giving it to us but it's allowing some of that clean signal to come through so what we could do with this type of stage is just kind of pinch that bridge off just get rid of that resistor and jumper it sort of so to speak or we can make it bigger and get even more of a uh you know more clean signal so let's experiment with that i'm going to go back to my 220k in the in the uh in the gain section here just so we can experiment with the diodes here's the potentiometer i'm using i'm putting it in place of that 6.8 k so instead of 6.8 000 ohms we can go from zero ohms well theoretically all the way to about 100 000 ohms so let's start with it all the way down this is going to be the least amount of clean signal that we can get into it again gain is all the way up [Music] now let's turn this up all the way see what happens [Music] let's go ahead and start all the way [Music] down [Music] so so you can hear it got more compressed it did clip more but you also got more compression in there just by making that one resistor smaller so i have other videos that talk about changing diodes i'll let you check those out rather than go through all the different types of diodes we can use here we we should probably know by now that if you change the diodes you're going to also change the clipping structure as well understanding that let's change some other things there's a 1k when we're exiting this op-amp there's a 1k there we can then take diodes from there to uh we'll have to take it to half voltage can't go to ground here so we need to go to a voltage reference which is 4.5 volts with the way this particular circuit is set up and then we can clip the circuit the circuit there again this is another trick like the king of tone does the pantheon does it this way as well when you the switches will kind of add in these diodes there okay so i have a yet same switch that i'm going to use here that's just uh it's just taking these diodes from 1k to this voltage reference so i still have the soft clipping diodes in there and i'm just adding these diodes in after that to kind of hard clip it a little bit more so again let's start with it off i'll flip the switch and it'll have both sets off [Music] turn it on [Applause] [Music] ah [Music] so as we can see more compression more clipping but still yet more compression so these diodes are going to kind of contribute to more of a type of compression now please don't misunderstand i don't mean this is like putting a compressor pedal with the pet with this circuit it is still compression but it's a different kind of compression so to speak it's it's not like having a compressor pedal on but it is technically still compressing the circuit all right so that's that let me pull out this 6.8 k so you can see when there is no soft clipping what happens whenever you just have the hard clipping [Music] [Applause] [Music] so an interesting thing thing to think about right here is with it set up this way now we kind of have kind of roughly the first two stages of what would be like the governor uh a million other pedals have been based on this from our plextortions to riot i think what's in my audio crunch box i think even like the shredmaster i mean these they're all kind of using these little uh these little lego pieces so to speak of the circuit in order to create um you know a tone now there's other things coming after this to make it a different circuit in the other petals i just mentioned but still like these are two building blocks that are used in this way to kind of do what they do so let me put that 6.8k back in and we'll fiddle around with the tone controls almost done here okay we're now back to the stock circuit here let's mess with the tone control again let's go with the highs all the way down [Music] so what happens if we put a different potentiometer in here well we change the tone circuit completely so let's take a look at it all right here's our new tone pot i went from a 25k to a 100k so let's see what that does [Music] [Applause] so as you can see there is a lot more uh highs being removed we could actually do something sort of similar if we keep the same pot but just make the capacitor bigger there so let's check that out all right we're going from a .01 microfarad to a much larger capacitor one microfarad i'm going to turn the tone pod around 11 o'clock or so just to really make sure there's a lot of resistance there if i turn it all the way up you're not going to hear a whole lot here's stock modified let's throw the bigger cap in it's rolled all the way down go back to stock [Music] and let's fill the big cap in there with the tonkatra all the way down so again this is a much larger capacitor um we can change this capacitor to really get a little bit more of what we want but it is yet another change that we can do here from here um the pantheon has this uh and also the king of tone rather than a fixed resistor in a capacitor we're actually using a fixed resistor a capacitor and a variable resistor to kind of create a present control so and it's basically kind of like two of these potentiometers one right after the other not exactly but that's kind of what's going on is two different types of of high filtering controls one right after the other now i have a 100k pot in place of this 6.8 k resistor so this is not only going to change the highs this is also going to change well a lot of stuff from impedance on the output to how much signal you're going to be able to uh really send the output because we're changing all this stuff resistance and everything else before it gets to the volume pot and so they kind of all kind of interact together i've i've got this presence control up quite a bit i still have the tone control up just just a bit past noon so here's what we have here [Music] so let me roll this presence control down [Applause] [Music] so this 6.8 k resistor again making it larger removes more highs there now we're back to stock so what happens if we make the 0.01 microfarad capacitor that's going to ground after that you know from that 6.8 k what happens if we make that bigger again less highs let's try it let's put this big one microfarad capacitor right in its place [Music] gets rid of pretty much almost everything except some very low end all right and then finally we have the output capacitor it's a 1 microfarad i believe uh 0.1 microfarad sorry all right here is the stock.1 microfarad on the very output let's add a 1 microfarad to it not a whole lot of difference here not to the year anyways so what happens if we make it a lot smaller let's see i'm going from a .0022 microfarad to a one microfarad so here we are stuck so it's going to take away base whenever the capacitor is smaller at a certain point now there is a point like like we could see with from point one to one not much of a difference but we get too low then we start taking away base so there you go that's basically what you have whenever you're changing all the different parts of the circuit that's what happens whenever you're fiddling around with them hopefully that gives you some ideas of things to change i'll include a schematic in the description in case you just want to see a schematic of the blues breaker or you're welcome to google for one yourself uh they're all over the place and uh you can kind of see what we're doing here and uh hope you like the video love to hear your comments if you like more of these a little bit more techy not super like no one's gonna be an engineer after watching this but i hope you kind of like this video and let me know if you do thanks for watching we'll see you next time

Channel: Wampler Pedals

Views: 52,837

Keywords: wampler, pedals, guitar, effects, pedalboard, wampler pedals, guitar effects, guitar pedal, guitar pedals, Marshall, bluesbreaker, pantheon, king of tone, morning glory, electronics

Id: fVdgttr5RhQ

Length: 22min 41sec (1361 seconds)

Published: Fri Jun 11 2021