Basic question – “omitting“ components

[mkstewartesq]

I’m currently building the Lectric-FX Old Chap, which has options for building different versions of the pedal depending on which components you include or “omit“.

My basic question since I’m still not expert at interpreting schematics – when the instructions say to “omit“ certain components, does that mean just to leave them off, or do you still need to jumper the empty solder pads so that the circuit continues to be completed even though there are no values in those spots?

I’m building rev C, for which the instructions state to “omit” R23 and C17. Schematic attached with those components circled.

Any advice appreciated.

Thanks,

Mike

EDITED to add an image with the proper components circled because I’m kind of a numbnuts.

 

[Bricksnbeatles]

Just omit. If it says to “omit” or “leave out” or “DNP”, it always means to leave those pads empty. If something is meant to have a jumper it will explicitly state it.

In this case, if you put jumpers in the c23 and r35 slots, you’d be shorting the output of your vreg to ground, which would not be good.

 

[mkstewartesq]

Just omit. If it says to “omit” or “leave out” or “DNP”, it always means to leave those pads empty. If something is meant to have a jumper it will explicitly state it.

In this case, if you put jumpers in the c23 and r35 slots, you’d be shorting the output of your vreg to ground, which would not be good.

Thank you, @Bricksnbeatles !

Mike

 

[szukalski]

First things first. You circled C23 and R35. That's needed for VC.

Look at R23 and C17...

 

[fig]

First things first. You circled C23 and R35. That's needed for VC.

Look at R23 and C17...

Beat me to it.

 

[mkstewartesq]

First things first. You circled C23 and R35. That's needed for VC.

Look at R23 and C17...

Doh! That’s what I get for doing this without my reading glasses. Image corrected and post edited. Thanks for catching.

 

[fig]

Doh! That’s what I get for doing this without my reading glasses. Image corrected and post edited. Thanks for catching.

Without my glasses, I'd have posted the wrong schematic on the wrong web site, using my mixing console instead of a laptop.

 

[mkstewartesq]

Just omit. If it says to “omit” or “leave out” or “DNP”, it always means to leave those pads empty. If something is meant to have a jumper it will explicitly state it.

Actually, unfortunately it turns out this is not a hard and fast rule. I posted a troubleshooting thread because my pedal was working in every respect except that, in one mode, one of the knobs was having no effect even though it worked in all of the other modes. I posted basically the same question over at the Lectric FX subforum over on the MBP site and Haberdasher from Lectric asked if I remembered to jumper R23 (which his instructions said to merely “omit“). Once I jumpered it everything worked fine.

This is not to knock @Bricksnbeatles’ advice. When he was responding to my question I had posted a schematic where I had marked the wrong components in question and I’m sure he was 100% correct that putting a jumper in the positions I marked would be a very very bad idea. Just following up this thread for future reference by others as it appears that some builders say “omit” but they may also mean “omit and jumper”.

Mike

 

[szukalski]

You need to look at the schematic. Removing the component without a jumper will take a part out of the circuit. Is that the Intent? But yeah. Bottom line. Different makers, different expectations of what the builders will understand.

I would say most of the Lectric FX is aimed at experienced builders.

 

[mkstewartesq]

You need to look at the schematic. Removing the component without a jumper will take a part out of the circuit. Is that the Intent? But yeah. Bottom line. Different makers, different expectations of what the builders will understand.

I would say most of the Lectric FX is aimed at experienced builders.

Yeah, every maker has their own idiosyncrasies. For example, when I was building this pedal, I was used to the convention that, for an LED, the square pad denoted the cathode (Lectric doesn’t put the helpful A and K notations or other markings to be safe). Neither of my LEDs worked. Once I flipped them around where the anode was on the square pad, both worked.

M

 

[szukalski]

Yeah, every maker has their own idiosyncrasies. For example, when I was building this pedal, I was used to the convention that, for an LED, the square pad denoted the cathode (Lectric doesn’t put the helpful A and K notations or other markings to be safe). Neither of my LEDs worked. Once I flipped them around where the anode was on the square pad, both worked.

M

Don’t PANIC! (Positive Anode, Negative Is Cathode).