BuddytheReow
Breadboard Baker
Just got your breadboard or protoboard in the mail and don't know where to begin? The Test Kitchen's got your back! Let's start with a classic and simple circuit: the LPB-1. This is a simple booster and a basic building block for many circuits out there. Here is a schematic taken from Coda Effects.
If you'd like to read their write up about this circuit check this out!
Coda Effects also does a good step by step of this circuit too on a breadboard here.
Let's set up our basics first: guitar input (I used an orange jumper wire), power (+ is red jumper and - is black jumper), the input capacitor C1, and a 2n5088 NPN transistor. Notice the transistor's flat side is facing left in the picture. The pinout for this as read from top to bottom is Emitter (E), Base (B), Collector (C). If you don't have a 2n5088 lying around try another NPN transistor such as a 2n3904 or similar. Just check to make sure the pinouts go this way and if not, simply rotate the transistor 180 degrees.
Next we need to add R1 and R2 and then connect that to the Base pin of our transistor. The schematic calls for 430k ohm and 43k ohm transistors, but I chose to use 1m and 100k for 2 reasons. First, I had these values lying around on my workstation and decided to be lazy
. Secondly, the relationship between R1 and R2 matters more than anything else: R1 is 10 times the value of R2 so you can use nearly any values (just keep r1 pretty high) as long as the relationship stays.
R1 goes from power to the same row as the capacitor and R2 goes from that same row to ground. The result? This is a voltage divider and the "new" voltage created is approx 1/10 of the input. In this case about 0.9v. Yours may differ slightly due to the tolerances of each resistor, but it should be pretty close.
From the row with the 2 resistors and capacitor we jumper this to the base pin. Why do we need to add power to the base? It is called "biasing" a transistor. The transistor needs DC power in order to operate and your guitar signal is AC. So, we add both at the same time to "trick" the transistor into working.
OK. 3 more components and we are done with the basic circuit. Let's add R3, R4, and C2.
R3 (390ohms) goes into the row with the emitter (remember, that's the top pin mentioned above) and out to ground. This resistor controls the amount of gain in the circuit. 390 ohms tends to be the sweet spot here, but you can alter it to you liking. Anything above 1k doesn't really work but you can give it a go.
R4 (10k) goes into the row with the collector (bottom pin) and the other end to power (red strip). The body of the resistor is kinda blocking the picture below but trust me on this one.
C2 goes into the same row as the collector and down a few rows. From here you can add your "Boost" potentiometer (it's just a volume pot going to ground) or you can test your circuit by merely adding an output jumper wire. I chose a white one. Be careful: since it's a boost circuit it will get loud!!
If you're looking at the potentiometer with the knob sticking up, the pinout is 1-2-3. 1 goes to ground, 2 goes to your output jack or plug, and 3 goes to the end of C2, right where my white jumper cable is.
I don't have a picture of the Boost pot wired up since I will talk about mods below and you'll see why I skipped this step.
And that's it. The LPB-1!!
Let's talk MODS for a bit. You can alter the value of C1: lowering it allows less bass frequencies into the circuit. Going higher than 100n won't have as much of an effect since most guitar signal goes through with 100n, but of course try it and find out!
The write up from Coda Effects (link above) does a pretty good job explaining what each piece does and how you can alter it.
This can easily be turned into a fuzz/distortion pedal!! Let's see how!
If you want to turn this into a fuzz pedal, simply add a diode (I chose a 1n4148) from the collector to the base. The cathode side (it has the black end on it or if you're using an LED it is the shorter end) goes into the row with the base pin of our transistor.
When I tried this out I noticed that the fuzz effect doesn't last as long as I like when I hold notes for a period of time. That's simply because of the way diodes work: it needs a certain amount of input or voltage in order to transmit signal.
Want to make this a distortion pedal?
We can add a 1k resistor out of C2 and down a row or two and then add 2 hard clipping diodes: they go in opposite directions and 1 end of each goes to ground. The 1k resistor is merely to protect the diodes.
OK. Now were cooking in the test kitchen! I feel like something's missing. Hmm.....let's add a tone control to alter the amount of treble!
A tone control like I will show here is pretty simple. It is merely a low pass filter and you will need a 10k pot and a 22n capacitor. Pin 2 of the pot goes into the same row as our diodes and C2. Pin 3 goes into a different row and this row only has our 22n capacitor (I will call it C3) going to ground. Your output jumper can go here if you'd like to test out your new tone control! You can alter the value of C3 here to suit your tastes: increasing the value will reduce the highs that much quicker. Pin 1 won't be used here.
Now, you run over to your amp, hook up your breadboard and your guitar, and fire off a sweet power chord!
Wait a minute? I thought this was supposed to be a boost/dirt pedal. Why is it kinda quiet?
I'll tell you!
Tone controls and hard clipping diodes like this tend to suck out a decent amount of volume. That's just the way these work. So, how can we make this louder? How about we add a booster after it!! Add another LPB-1 circuit block directly after your tone control, keeping the input and output capacitors as well. After the output capacitor here you should wire up your official "Boost" potentiometer like in the schematic: Pin3 to the output cap (100n), Pin 2 to your output jack, and Pin 1 to ground. My output jumper is yellow here. For some reason I kept my white one still on the board.
Behold! I present to you an "original" circuit that I'd like to call the L-PB&J Sandwich!! Why a sandwich? Well, because there are LPB-1's in the beginning and end of the circuit and thinking about sandwiches makes me hungry! Once I'm done eating my sandwich I will whip up a schematic for this and post below.
Thanks for making it all the way to the end of this!
BuddyTheReow
If you'd like to read their write up about this circuit check this out!
Coda Effects also does a good step by step of this circuit too on a breadboard here.
Let's set up our basics first: guitar input (I used an orange jumper wire), power (+ is red jumper and - is black jumper), the input capacitor C1, and a 2n5088 NPN transistor. Notice the transistor's flat side is facing left in the picture. The pinout for this as read from top to bottom is Emitter (E), Base (B), Collector (C). If you don't have a 2n5088 lying around try another NPN transistor such as a 2n3904 or similar. Just check to make sure the pinouts go this way and if not, simply rotate the transistor 180 degrees.
Next we need to add R1 and R2 and then connect that to the Base pin of our transistor. The schematic calls for 430k ohm and 43k ohm transistors, but I chose to use 1m and 100k for 2 reasons. First, I had these values lying around on my workstation and decided to be lazy
. Secondly, the relationship between R1 and R2 matters more than anything else: R1 is 10 times the value of R2 so you can use nearly any values (just keep r1 pretty high) as long as the relationship stays.R1 goes from power to the same row as the capacitor and R2 goes from that same row to ground. The result? This is a voltage divider and the "new" voltage created is approx 1/10 of the input. In this case about 0.9v. Yours may differ slightly due to the tolerances of each resistor, but it should be pretty close.
From the row with the 2 resistors and capacitor we jumper this to the base pin. Why do we need to add power to the base? It is called "biasing" a transistor. The transistor needs DC power in order to operate and your guitar signal is AC. So, we add both at the same time to "trick" the transistor into working.
OK. 3 more components and we are done with the basic circuit. Let's add R3, R4, and C2.
R3 (390ohms) goes into the row with the emitter (remember, that's the top pin mentioned above) and out to ground. This resistor controls the amount of gain in the circuit. 390 ohms tends to be the sweet spot here, but you can alter it to you liking. Anything above 1k doesn't really work but you can give it a go.
R4 (10k) goes into the row with the collector (bottom pin) and the other end to power (red strip). The body of the resistor is kinda blocking the picture below but trust me on this one.
C2 goes into the same row as the collector and down a few rows. From here you can add your "Boost" potentiometer (it's just a volume pot going to ground) or you can test your circuit by merely adding an output jumper wire. I chose a white one. Be careful: since it's a boost circuit it will get loud!!
If you're looking at the potentiometer with the knob sticking up, the pinout is 1-2-3. 1 goes to ground, 2 goes to your output jack or plug, and 3 goes to the end of C2, right where my white jumper cable is.
I don't have a picture of the Boost pot wired up since I will talk about mods below and you'll see why I skipped this step.
And that's it. The LPB-1!!
Let's talk MODS for a bit. You can alter the value of C1: lowering it allows less bass frequencies into the circuit. Going higher than 100n won't have as much of an effect since most guitar signal goes through with 100n, but of course try it and find out!
The write up from Coda Effects (link above) does a pretty good job explaining what each piece does and how you can alter it.
This can easily be turned into a fuzz/distortion pedal!! Let's see how!
If you want to turn this into a fuzz pedal, simply add a diode (I chose a 1n4148) from the collector to the base. The cathode side (it has the black end on it or if you're using an LED it is the shorter end) goes into the row with the base pin of our transistor.
When I tried this out I noticed that the fuzz effect doesn't last as long as I like when I hold notes for a period of time. That's simply because of the way diodes work: it needs a certain amount of input or voltage in order to transmit signal.
Want to make this a distortion pedal?
We can add a 1k resistor out of C2 and down a row or two and then add 2 hard clipping diodes: they go in opposite directions and 1 end of each goes to ground. The 1k resistor is merely to protect the diodes.
OK. Now were cooking in the test kitchen! I feel like something's missing. Hmm.....let's add a tone control to alter the amount of treble!
A tone control like I will show here is pretty simple. It is merely a low pass filter and you will need a 10k pot and a 22n capacitor. Pin 2 of the pot goes into the same row as our diodes and C2. Pin 3 goes into a different row and this row only has our 22n capacitor (I will call it C3) going to ground. Your output jumper can go here if you'd like to test out your new tone control! You can alter the value of C3 here to suit your tastes: increasing the value will reduce the highs that much quicker. Pin 1 won't be used here.
Now, you run over to your amp, hook up your breadboard and your guitar, and fire off a sweet power chord!
Wait a minute? I thought this was supposed to be a boost/dirt pedal. Why is it kinda quiet?
I'll tell you!
Tone controls and hard clipping diodes like this tend to suck out a decent amount of volume. That's just the way these work. So, how can we make this louder? How about we add a booster after it!! Add another LPB-1 circuit block directly after your tone control, keeping the input and output capacitors as well. After the output capacitor here you should wire up your official "Boost" potentiometer like in the schematic: Pin3 to the output cap (100n), Pin 2 to your output jack, and Pin 1 to ground. My output jumper is yellow here. For some reason I kept my white one still on the board.
Behold! I present to you an "original" circuit that I'd like to call the L-PB&J Sandwich!! Why a sandwich? Well, because there are LPB-1's in the beginning and end of the circuit and thinking about sandwiches makes me hungry! Once I'm done eating my sandwich I will whip up a schematic for this and post below.
Thanks for making it all the way to the end of this!
BuddyTheReow
