Relay Bypass and (bi-color) LED Always On

Jovi Bon Kenobi

Well-known member
I just finished building the Circulator and first off I want to just say WOW, it's such a perfect phaser. My question is, did I do something wrong? The bi-color LED is always indicating the LFO in red whether the pedal is bypassed or not. It never switches to green. The footswitch turns it off and on like it should but the LED is just always on, pulsating the LFO, not indicating if it's on or off. Other than that the pedal works perfectly and sounds AMAZING.
IMG_20190928_101339.jpg
 
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Jovi Bon Kenobi

Well-known member
I also used a DC splitter. Running the +/- from the relay to one set of it's pads and the +/- from the Circulator to another set of pads. Not sure if that's the right way to do it or if there is another way without using the splitter.
 
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Jovi Bon Kenobi

Well-known member
Another question...why does it require a Common Anode bi-color LED? The original used a standard one I thought. The LED pads in the Circulator board stated "R · G" so I oriented it so the red was on the R side and the green on the G side.
 

Nimm

New member
Hi Jovi
I was wondering if you were able to sort this out? I just built it and just as you everything works and sounds great but the led is always red. I just spent a while trying to troubleshoot but glad I found someone else with the same issue.
I used this led:
 

PedalPCB

Administrator
Staff member
The problem here is likely because the LFO isn't supplying enough current to light both sides of the LED. Try lowering the value of R100 and see if that helps. Originally R100 (and R33) were spec'd at 4K7, then were lowered to 1K because of this.

I used an RGB LED with one of the leads clipped off. It worked fine, but wasn't quite as bright as I would have liked.

The most recent revision has done away with the dual LED (and LFO speed indication) altogether.
 

Jovi Bon Kenobi

Well-known member
I was wondering if you were able to sort this out?
Nope, but it sound so good I'm tempted to just leave it as is...not knowing if it's on or off😂

The problem here is likely because the LFO isn't supplying enough current to light both sides of the LED. Try lowering the value of R100 and see if that helps. Originally R100 (and R33) were spec'd at 4K7, then were lowered to 1K because of this.
R100 may be too well buried under the relay bypass. I'll try give it a shot though. Would changing the bi-color LED to a regular one be possible?

Also, I have RGB LEDs. Which lead did you snip?
 

Nimm

New member
Thank you!
Putting the 1k in R100 mostly worked for me. Still a bit red but fits the more psychedelic theme I’m going with so going to keep as is.

I can open another thread if necessary but to be sure would phase be switch left and vibe switch right? Thanks again
 

Jovi Bon Kenobi

Well-known member
Thank you!
Putting the 1k in R100 mostly worked for me. Still a bit red but fits the more psychedelic theme I’m going with so going to keep as is.

I can open another thread if necessary but to be sure would phase be switch left and vibe switch right? Thanks again
Cool! Just to be clear, it turns off for you now? Or was your issue that it never switched to green?
 

Nostradoomus

Well-known member
Thank you!
Putting the 1k in R100 mostly worked for me. Still a bit red but fits the more psychedelic theme I’m going with so going to keep as is.

I can open another thread if necessary but to be sure would phase be switch left and vibe switch right? Thanks again
Should be left for phase right for vibe yeah
 

PedalPCB

Administrator
Staff member
One side of the LED (Red) never turns off, this is by design so you could see the rate of the LFO even in Bypass.
The other side (Green) is switched by the SW line.

When the pedal is in Bypass the LED should pulse Red. When the pedal is Active the LED should pulse Yellow-ish. (Red + Green)
If the Green side isn't working the LED will just pulse Red all the time, regardless of Bypass.
 

Nimm

New member
Cool! Just to be clear, it turns off for you now? Or was your issue that it never switched to green?
My issue was not switching to green when pedal is on, which it is now with a bit of redness still mixed in. Goes to all red in bypass, which is nice so you can adjust the rate before clicking on.
I see we picked the same bright green for pedal color. I think that’s the only option for this one.
I had gotten a MXR M290 not long ago and on quick comparison so far the Circulator seems to keep the signal intact more as the m290 seems to darken it a bit. Also much more control on Circulator.
Should be left for phase right for vibe yeah
Thank you!
 

Jovi Bon Kenobi

Well-known member
Well, I was going to try and swap out the CLR so I removed both the C9 and R100 because I couldn't reach the R100. Problem is, the build doc says 4.7k, so that's what I assumed I originally installed, but upon removing the R100, the PCB is silk-screened with 1k, which is what I installed. I was going to replace it with a 1k! Haha. Anyway, while I'm here is there anything else I can try to resolve this issue?

This is PCB245 btw.
 

Jovi Bon Kenobi

Well-known member
As it stands right now I resoldered in a smaller 1uf mlcc and there's nothing in R100. I used my multimeter to test R100's lower pad. *See photo on next page*

Still having the same issue. The pedal sounds perfect, it just that the red/green bi-color CA LED is always on, fading in and out of red... regardless if the pedal is active or bypassed. Honestly, I would prefer it it it was just solid on or off, not indicating the LFO. Is there a way to do this?
 
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