Couple of Protoboard Questions

[Fizz]

I am breadboarding my Odd One Out pedal before I solder the PCB and realized I am not sure how to wire lugs 2 & 3 on the B1M Drive Pot. Do both 2 & 3 go to the same connection or do I just connect one and leave the other disconnected?

Also, since this board already has its power conditioned do you all just make a voltage divider on your breadboard to bring 9 volts down to 4.5 VR? Or do you build out the power supply as on the schematic?

One last one. Since the board is powered on when you turn it on, how to you breadboard your LED so it only comes on when you switch from Bypass to Effect? I guess it is not necessary to do this but I thought it would be cool to understand it.

It took me two tries but I got it to work and sounds great. No noise at all as I thought there would be because of all the wires everywhere.

 

[spi]

you can connect to either lug 2 or 3, and put a jumper between lugs 2 and 3.

 

[jwin615]

If doing off board wiring, strip a little more insulation off and loop both lugs at once, then solder.
Often in pedals we use pots as variable resistors. When doing so. It's advisable to wire them so.
From FSB

 

[Fizz]

So if I'm wiring these up with my Protoboard that has Terminal blocks that I screw the Pots into, Do I just connect 3 to ground and 2 to pin 1 of my IC with my jumpers? I actually got it working.. or so I think by leaving 3 disconnected and bringing 2 down to pin 1 of the IC.

 

[Fama]

I think the best thing here is to understand how potentiometers work. So there is a resistive track inside the pot. For a 1M pot, it's 1M ohms from lug 1 to 3. Lug 2 moves along that track as you rotate the potentiometer, so for example measuring from lug 1 to lug 2, the resistivity changes from 0 to 1M ohm as you rotate the pot.

In this case you can see both lugs 2 and 3 are connected to each other. But whether you actually connect pin 3 or not doesn't really matter that much.

For example, if the pot is set halfway, so 500k ohms, the electricity travels from lug 1 to lug 2 through the track (that's 500k ohms), then it can either move directly onwards (~0 ohms) or go through lug 3 (500k more ohms). So connecting lug 3 doesn't really change the functionality very much (if there's a choice between no resistance or lots of resistance, the path of no resistance will be chosen).

AFAIK it's still advisable to connect it (rather than leave it hanging) because that might affect how the circuit behaves if the pot fails for some reason, but in a protoboard situation which is going to be temporary for that circuit, it doesn't really matter much.

So if I'm wiring these up with my Protoboard that has Terminal blocks that I screw the Pots into, Do I just connect 3 to ground and 2 to pin 1 of my IC with my jumpers? I actually got it working.. or so I think by leaving 3 disconnected and bringing 2 down to pin 1 of the IC.

Don't connect 3 to ground, just leave it hanging or connect it to 2. If you connect it to ground, it will behave very differently.

 

[Fizz]

I think the best thing here is to understand how potentiometers work. So there is a resistive track inside the pot. For a 1M pot, it's 1M ohms from lug 1 to 3. Lug 2 moves along that track as you rotate the potentiometer, so for example measuring from lug 1 to lug 2, the resistivity changes from 0 to 1M ohm as you rotate the pot.

In this case you can see both lugs 2 and 3 are connected to each other. But whether you actually connect pin 3 or not doesn't really matter that much.

For example, if the pot is set halfway, so 500k ohms, the electricity travels from lug 1 to lug 2 through the track (that's 500k ohms), then it can either move directly onwards (~0 ohms) or go through lug 3 (500k more ohms). So connecting lug 3 doesn't really change the functionality very much (if there's a choice between no resistance or lots of resistance, the path of no resistance will be chosen).

AFAIK it's still advisable to connect it (rather than leave it hanging) because that might affect how the circuit behaves if the pot fails for some reason, but in a protoboard situation which is going to be temporary for that circuit, it doesn't really matter much.


Don't connect 3 to ground, just leave it hanging or connect it to 2. If you connect it to ground, it will behave very differently.

Thanks.. I don't have 3 connected to anything and it sounds like it is working normally. I'm glad the PCB will take care of this when I build it out but I was confused about how to breadboard it. Thanks to everyone for the tips! Now I am going to play with some of the options and then build it out.