General questions on component orientation

[carlsoncoder]

Hi all -

I just ordered some parts for the "Cross Contaminator" build. I have all the components and just waiting on the PCB's in the mail.

I'm familiar with soldering but not so much with reading PCB layouts. I figured most of it out with some searches and the WIKI, but have a few quick questions I was hoping someone might be able to answer. I'm referring to this build guide:

https://docs.pedalpcb.com/project/CrossContaminator.pdf

Questions:

1. Some of the capacitor connections on the PCB show a +/- (C2, C3, C7, C100, C5), while others don’t (C1, C4, C6, C8, C9). Does this mean the polarity orientation just doesn't matter for those ones?
2. 2N1711 transistors - these are NPN and I know which pin on the transistor is the Base/Emitter/Collector - but I’m not sure which pin goes to where on the PCB?
3. 1/4” TS jacks - Sleeve goes to ground (on PCB) and tip goes to the footswitch, right?

Thanks for any help you can provide!

 

[Nostradoomus]

1) Yes, generally the polarized capacitors are electrolytic (which have the negative leg marked with a band on the side or designated by a shorter leg) and everything nonpolarized is film/ceramic.

2) On the top silkscreen of the board there should be a flat side and a rounded side just like the transistor itself. Be careful if you use a substitute that the pin out matches, check the data sheet as you may need to flip it around.

3) Yes

 

[carlsoncoder]

Awesome, thanks a ton for the quick and helpful reply!!

 

[carlsoncoder]

On the top silkscreen of the board there should be a flat side and a rounded side just like the transistor itself. Be careful if you use a substitute that the pin out matches, check the data sheet as you may need to flip it around.

So, I just checked my transistors. They are 2N1711 transistors from Central Semiconductor:

I found the datasheet (https://my.centralsemi.com/datasheets/2N1711.PDF), so I'm able to tell which pin is the Emitter/Base/Collector. However, the full transistor is circular all around, and does not have a flat-side.

I followed the circuit diagram on the cross contaminator build docs, and I think that the arrow points in the direction of the current of the transistor, so I'd assume that would be the emitter right? If that's right and I read the rest of the circuit right, I think it would go like this:

• Q1
  • (Left most pin on board for Q1) - Pin labeled as “1” with an arrow pointing towards R3
    • Emitter goes here
  • (Middle pin on board for Q1) - Pin labeled as “2”, no arrow, trace goes to R4
    • Base goes here
  • (Right most pin on board for Q1) - Pin labeled as “3”, no arrow, trace goes to R6
    • Collector goes here
• Q2
  • (Left most pin on board for Q2) - Pin labeled as “1” with an arrow pointing towards R5/C5
    • Emitter goes here
  • (Middle pin on board for Q2) - Pin labeled as “2”, no arrow, trace goes to C6/Q1/R6
    • Base goes here
  • (Right most pin on board for Q2) - Pin labeled as "3", no arrow, trace goes to C7
    • Collector goes here

Does that sound right or did I miss something? Just want to make sure it's right before I solder.

Thanks!

 

[Nostradoomus]

That’s correct. Usually if the transistor is a metal can the silkscreen on the PCB would reflect that and have a tab for where the emitter lines up...not this time though haha