BuddytheReow
Breadboard Baker
You've got your breadboard, jumper wires, offboard components, and breadboard components in hand and are ready to go. You download a build doc from PedalPCB website, skip the pretty picture of the PCB, skip the components listing since your order came in the mail 3 and a half minutes ago, get to the schematic and all the anxiety in the world is telling you to run away and return everything you just bought because you see THIS...
Don't worry! We are here to help you!
For purposes of this thread I would rather talk about what the components are rather than the why/how they work. The why/how is more theory based and can/will be a separate thread once the basics are covered here.
Schematics in general are read from left to right with input on the left and output on the right. Schematics on PedalPCB generally break down a schematic into either 1 or 2 sections, the second section being the power section. You can see in the schematic above that there are 2 circuit blocks. The smaller section on the bottom is the power section. Your guitar/bass do not go into this section, but this section is needed in order to properly power the main circuit.
OK. Read it left to right. Power section is sometimes separated. Got it. But what are all those symbols?
Here is a basic list of the symbols needed to understand, IMO, 2/3 to 3/4 of the circuits on PedalPCB. Some of the more complex digital circuits have a basic block with all the pins numbered showing what connects to where. There are definitely other things to talk about here, such as the pinouts for transistors (what line does what), electrolytic capacitor polarity (the minus sign on the actual component corresponds to negative end and should go where the curved line in the symbol is connected to), diode polarity, potentiometer lug numbering, etc. But those are separate threads for another day. You should learn the basic circuit itself before you whip out your breadboard.
Squiggly line is resistor, triangle with a line on the tip is a diode, triangle with + and - is an IC or opamp. Got it. What about all those dots?
Dots you say? Oh you mean these?
Those dots represent a connection point between components. Looking at the top right hand corner, the schematic is telling me that the signal is coming out of pin one of an IC chip and into a resistor, labelled R6. Before it reaches the resistor a separate connection must also be made to a capacitor, a potentiometer, and a resistor before being fed into pin 2 of the IC chip. This is called a negative feedback loop in an opamp circuit and more will be talked about in (potentially) a separate post by someone who wants to share their circuit knowledge with the universe or anyone who cares to listen.
What about the Vcc and Vref I see in nearly every schematic?
VCC actually stands for Voltage Common Collector. Think of it as the main power input to the circuit after any preliminary tampering has been done via a couple of components. Since we're all building pedals here it will most likely be 9v (most common), 12v, or 18v depending on the power supply you have available.
Vref refers to a voltage reference. Think of this as after more tampering has been done to the supply voltage. From here, check the rest of the schematic to see where in the circuit this point connects to. Here, there are two points.
I get the power points after the "tampering" like you said, but where do I plug in my power source into?
Right here.
What about those ground points. Where do I connect those?
You mean like this resistor here?
You can do 1 of 2 things: either connect the lead of that resistor directly to the blue column on your breadboard OR you can put that lead in an unused or commonly used row with other components that should go to ground and THEN add a jumper wire to the blue column on your breadboard.
I think I understand now. Let me brainwash myself and learn these symbols even while I sleep.
Such a good little pedal builder...pretty soon you'll be starting your own company. They grow up so fast!
Don't worry! We are here to help you!
For purposes of this thread I would rather talk about what the components are rather than the why/how they work. The why/how is more theory based and can/will be a separate thread once the basics are covered here.
Schematics in general are read from left to right with input on the left and output on the right. Schematics on PedalPCB generally break down a schematic into either 1 or 2 sections, the second section being the power section. You can see in the schematic above that there are 2 circuit blocks. The smaller section on the bottom is the power section. Your guitar/bass do not go into this section, but this section is needed in order to properly power the main circuit.
OK. Read it left to right. Power section is sometimes separated. Got it. But what are all those symbols?
Here is a basic list of the symbols needed to understand, IMO, 2/3 to 3/4 of the circuits on PedalPCB. Some of the more complex digital circuits have a basic block with all the pins numbered showing what connects to where. There are definitely other things to talk about here, such as the pinouts for transistors (what line does what), electrolytic capacitor polarity (the minus sign on the actual component corresponds to negative end and should go where the curved line in the symbol is connected to), diode polarity, potentiometer lug numbering, etc. But those are separate threads for another day. You should learn the basic circuit itself before you whip out your breadboard.
Squiggly line is resistor, triangle with a line on the tip is a diode, triangle with + and - is an IC or opamp. Got it. What about all those dots?
Dots you say? Oh you mean these?
Those dots represent a connection point between components. Looking at the top right hand corner, the schematic is telling me that the signal is coming out of pin one of an IC chip and into a resistor, labelled R6. Before it reaches the resistor a separate connection must also be made to a capacitor, a potentiometer, and a resistor before being fed into pin 2 of the IC chip. This is called a negative feedback loop in an opamp circuit and more will be talked about in (potentially) a separate post by someone who wants to share their circuit knowledge with the universe or anyone who cares to listen.
What about the Vcc and Vref I see in nearly every schematic?
VCC actually stands for Voltage Common Collector. Think of it as the main power input to the circuit after any preliminary tampering has been done via a couple of components. Since we're all building pedals here it will most likely be 9v (most common), 12v, or 18v depending on the power supply you have available.
Vref refers to a voltage reference. Think of this as after more tampering has been done to the supply voltage. From here, check the rest of the schematic to see where in the circuit this point connects to. Here, there are two points.
I get the power points after the "tampering" like you said, but where do I plug in my power source into?
Right here.
What about those ground points. Where do I connect those?
You mean like this resistor here?
You can do 1 of 2 things: either connect the lead of that resistor directly to the blue column on your breadboard OR you can put that lead in an unused or commonly used row with other components that should go to ground and THEN add a jumper wire to the blue column on your breadboard.
I think I understand now. Let me brainwash myself and learn these symbols even while I sleep.
Such a good little pedal builder...pretty soon you'll be starting your own company. They grow up so fast!
