LED polarity

[PedalPCB]

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.

 

[Willybomb]

Just want to say thanks for updating this. I was as confused as hell.

 

[damonp]

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...

 

[Robert]

That's correct.

 

[damonp]

That's correct.

So, top is Anode square, bottom is cathode square?

 

[Robert]

So, top is Anode square, bottom is cathode square?

Yep.

 

[evitative]

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?

 

[Robert]

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]

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!

 

[Robert]

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

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

Install the anode into the Round pad.


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

 

[JetFixxxer]

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

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

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]

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

 

[Robert]

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]

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?

 

[Robert]

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.

 

[the_grumpy_gnome]

Fyi: If you're still unsure, LEDs are a pretty easy thing to test and flip if necessary.

 

[Mourguitars]

Thermionic Distortion the LEDS on the circuit its self is long leg round hole correct?

 

[Robert]

Thermionic Distortion the LEDS on the circuit its self is long leg round hole correct?

It depends on which revision of the board you have, refer to the symbols in the first post.

 

[Mourguitars]

Trying to up load a photo but files to large....I put long leg in ( A )

 

[Kelmark1]

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?