Aion FX Andromeda pop issues

[Jzwolensky]

Apologies in advance if this is a basic question, but I'm a newbie at troubleshooting. I've built four pedals—three kits and one from scratch—and have been lucky so far!
I built the Aion Andromeda kit. It's basically the Nobels ODR-1. It is a great-sounding pedal, but it recently developed a pop when turning on or off. I've replaced the output cap, as I've read about cap leakage, but there was no improvement. Can someone help me figure out how to do other diagnostics and testing of components while they are on the PCB?

 

[andrewsrea]

I suggest you set your true bypass stomp switching up like the ones shown on PedalPCB type builds. Check their Nobelman build documentations, page 4. You'll need to use a 3PDT stomp switch.

For silent switching, R26 (150k) of the Andromedia schematic. has to be well connected between the output and ground.

Read pins of the 3DPT from top left, down then to the right like this:

1. Input from the PCB 4. LED actuation (SW) 7. Output frmo the PCB
2. From the input jack tip 5. Ground from the PCB 8. Lead to the output jack tip
3. Jumper to pin #9 6. Jumper from pin #1 9. Jumper from pin #1

How this works:
- Think of the 3DPT switch pins in rows and columns. Pins with make up row 2, 5 & 8 are common to the other rows, depending if the switch is to the north (Pins 1, 4 & 7) or south pole (pins 3, 6 & 9).
- When to the north pole the effect is 'engaged'. The input jack goes into the pedal, the cathode resistor of the LED ('on' light) goes to ground,
lighting the LED, and the output of the PCB goes to the amp.
- When the switch is stomped, it then goes to the south pole, which the input goes straight to output via pins 2, 3, 9 & 8. Additionally, the PCB
input goes to ground, which silences and stray noise or DC build-up which would get amplified by a dirt pedal.

99% of the time, this results in quiet switching. Occasionally, it doesn't and that is typically mitigated by adding a 1M resistor between pins 2 & 5.

Hope this helps!

 

[Jzwolensky]

@andrewsrea
Thank you for the comprehensive list! I will begin to troubleshoot/modify as suggested.

One question: In this sentence, "Think of the 3DPT switch pins in rows and columns. Pins that make up row 1, 5, and 8 are common to the other rows, " Did you mean 2, 5, and 8?

 

[andrewsrea]

@andrewsrea
Thank you for the comprehensive list! I will begin to troubleshoot/modify as suggested.

One question: In this sentence, "Think of the 3DPT switch pins in rows and columns. Pins that make up row 1, 5, and 8 are common to the other rows, " Did you mean 2, 5, and 8?

Yes. I edited my prior post to correct.

 

[Noodles]

Any sockets? The only time I had a pop was when I had socketed some components I wanted to swap, but they didn't seat well in the socket. Lesson learned.