Problem with Phaser Pedal Kit (first pedal)

[Nnniiko]

Hi as the title states, this is my first pedal

I ordered the 45er phaser kit from das musikding:
https://www.musikding.de/The-45er-Phaser-kit
(I hope it's ok to post this link, I read the rules but I'm not sure about the etiquette yet)

Schematics are here:https://www.musikding.de/docs/musikding/45er/45erschalt.pdf

I soldered everything up and plugged it in. When the pedal is off the signal goes clean through but once I turn the pedal on I only get a rythmic pulsing sound and no guitar sound gets through (I have a video but I don't know how to add videos here but I uploaded it on reddit so here is the post with the video)
https://www.reddit.com/r/diypedals/comments/1c34cd2/comment/kzeze8u/?context=3

I have cleaned the pcb with alcohol and a soft brush and checked the connections but I can't find a bridge or anything. The instructions didn't fully explain how to wire up the switch pcb with this board so I had to do that part myself, that might be a problem but I believe I have done it correctly.

The images were taken before cleaning







(Btw they delivered the kit with the 2N5457 transistors, that's why they don't match with the silkscreens direction)

I am very excited to join this hobby and thanks in advance for any answers

[moid]

Hi there, welcome to the forum!

From looking at your second photo, there is no power going to the +9V connector on the stompswitch PCB. Does the LED in your circuit light up when the stompswitch is turned on? This shouldn't stop the circuit from working, but I'm wondering if the power is wired differently to ow it should be. Also the main PCB seems to be missing a resistor on the left side of the image labelled R27... or maybe that is for an LED?

I'm no expert by the way, so If someone points out something else to check then please take their advice!

The PCB has a trimmer pot on it; usually they are on a PCB because they need to be adjusted with a small screwdriver until the circuit starts to work. I don't know this circuit, but it might be worth you trying to slowly adjust that trimmer while playing sound through the pedal and it might just bring the circuit to life.

[bluebunny]

I think Niko is using a handy 9V pad at one end of the "missing" R27 to take power to the stompswitch board.  R27 (CLR, from what I can make out) and the LED are on that board.  Agree that adjusting the trimmer is gonna be necessary to get (the best) phasing.

[Nnniiko]

Yes, I wanted to use the switch pcb that was included so I had to put R27 on the switch pcb and I connected the switch pcbs 9V to the R27 hole on the main board. Just like bluebunny assumed. Is that ok?

I have tried fiddeling with the trim pod but sadly that doesn't change anything

[Nnniiko]

Also the LED doesn't turn on

Edit: Ok I was able to borrow a friends multimeter and measure the voltages and it fluctuates but stays below 1V, first I thought it was the power supply but I measured right on the supply while it wasn't plugged into the pedal and it is supplying 9V as intended.
When I measure right on the power jack inside the pedal I get the weird low voltage. Does that mean I've got a broken power jack or am I just measuring wrong?

[bluebunny]

If the power is somehow reduced to 1V by the time it gets to the board, then the LED won't light up, and nothing much else will work either.  You may have a short circuit somewhere ("fluctuates" sounds like the power supply is trying to protect itself by periodically shutting down).  With no power connected, can you test for continuity between "9V" and "GND"?  And take a careful look at your board and wiring.  A magnifying glass will be handy.

[Nnniiko]

I'm very new to this so I hope I did it right. I put my multimeter into continuity mode and held one probe to the power jacks 9V wire and the other to ground and it did not beep, so I guess not continuity?
I also tried to look for shorts but couldn't find any. I also tried to check if I could find any connections to ground that shouldn't be there, but again no luck.
What really surprised me was: The LED has continuity to ground on one side and continuity to 9V on the other but it does not light up

[Matthew Sanford]

Welcome!

Aside from the LED issue, do you have an audio probe? Basically something to touch to nodes going through a cap (to block DC) and to an amp to follow from the input and see where your signal stops. I've been told many times by the maestros here and it sure helps to find circuit/solder errors!

[Nnniiko]

No I sadly do not

[stallik]

What really surprised me was: The LED has continuity to ground on one side and continuity to 9V on the other but it does not light up

Diodes conduct electricity in one direction. LED's are Light Emitting Diodes so they produce light while passing that current BUT, too much current and they burn out - very quickly. There's a resistor in series with the led to limit the current.
So, either the LED is in backwards or it has burned. Use your meter set to continuity and measure in both directions. One way should show continuity, the other not. If neither direction works, it needs replacing

[Phend]

Connect wire from 9+ on stomp switch daughter board to "LED" on main circuit board.
That might get the led going. Probably not fix phase...but

[stallik]

No I sadly do not

Easy build
Audio Probe

[Nnniiko]

I checked the continuity of the LED and it lit up, so it's also not the LED :/

[Nnniiko]

Ok to see what would happen I added a battery clip. With only the battery as power supply I don't get the weird pulsing and instead just get silence when the pedal is turned on