LED polarity

PedalPCB

Administrator
Staff member
The LED symbol printed onto PedalPCB circuit boards is being updated, please read!


Proper installation of LEDs in PedalPCB circuit boards


Traditionally the Cathode of a diode is installed into the Square pad of a PCB.

Symbol #1 and Symbol #2 conform to this standard. Symbol #3 is technically incorrect by this standard and will be phased out of all future PedalPCB circuit boards. This transition will be progressive as new stock is ordered, so care must be taken to ensure that the correct pinout is identified during this period.

Whenever possible identifiers (A for Anode, K for Cathode) will be printed beside the LED symbol on the PCB for clarification.

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damonp

New member
Im building the duo-phase right now and Im a little concerned as there are 2 different identifiers on the board, the implication of this article is I should wire them opposite of each other...
665
 

evitative

New member
Just to make sure I understand: for polarized caps the square pad indicates the anode and the circular pad indicates the cathode, but for LEDs it's the opposite?
 

PedalPCB

Administrator
Staff member
I've never really referred to the positive side of an electrolytic as the anode, although that is proper terminology...

But yes, the positive lead of polarized caps go into the square pad. The silkscreen is marked with a + so there shouldn't be any confusion there.
 

Diatrive

Member
Are clipping diodes different?
I am building the Parentheses Fuzz and what looks to be the status LED's are like symbol 1 but there is one that has the square pad under the A.
What do I do with those?

Thanks!
 

PedalPCB

Administrator
Staff member
Haha, well that's confusing, ain't it?

This same thing applies to clipping diodes, but the silkscreen is backwards on that one..... o_O

Install the anode into the Round pad.


Thanks for pointing that out, I'll get it corrected ASAP.
 

JetFixxxer

Active member
Haha, well that's confusing, ain't it?

This same thing applies to clipping diodes, but the silkscreen is backwards on that one..... o_O

Install the anode into the Round pad.


Thanks for pointing that out, I'll get it corrected ASAP.
So is that my issue with my Parentheses Fuzz?
 

K Pedals

Active member
Im building the duo-phase right now and Im a little concerned as there are 2 different identifiers on the board, the implication of this article is I should wire them opposite of each other...
View attachment 665
I wish I would have seen this post before I built mine because I assumed if the square pad was the positive on the led it was the positive for the ldr led... and I had to desolder both ldr leds
 

PedalPCB

Administrator
Staff member
So is that my issue with my Parentheses Fuzz?
It might be why you don't hear a difference between the two switch positions, but I doubt it has anything to do with the octave / blend issues.

If it's easier for you, you can reverse the polarity of D4 and D5 (two diodes left of the DPDT) rather than having to fool with the LED.
 

ody

New member
Hello,

on the Parentheses Fuzz I do not understand the use of the switche, what is it supposed to do? D4 and D5 is the same pair as D7 and D8. Someone to tell me the role of the three positions?

the switche has been replaced by an SPST, for reasons of rationality or is there a major change? Was there a bug with the previous DPDT?
 

PedalPCB

Administrator
Staff member
D4 has D6 (3mm LED) in series, so it's asymmetrical clipping on that side.

Center position has no clipping.

The other position is D7 / D8 (symmetrical clipping).


The DPDT was overcomplicated, the same job could be done with an ON/OFF/ON SPDT (which are much easier to find) so the board was updated.
 
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Kelmark1

New member
D4 has D6 (3mm LED) in series, so it's asymmetrical clipping on that side.

Center position has no clipping.

The other position is D7 / D8 (symmetrical clipping).


The DPDT was overcomplicated, the same job could be done with an ON/OFF/ON SPDT (which are much easier to find) so the board was updated.

I have one of the boards that has a DPDT to be put on it, the new boards have a SPDT switch there , what switch should I put on it?, one of those odd DPTP switches from bitches love my switches?
 
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