SOLVED Awful Waffle Issue

[joelorigo]

I built this last year and it worked fine last time I used it months ago, I tired it today and there is only a very low signal coming though in bypass and no sound when the effect is on. I thought it might be the foot switch because this was from a batch I bought that has had problems in the past - but it does have continuity between lug 2 & 3, 5 & 6 and 8 & 9 one way and between 1 & 2, 4 & 5 and 7 & 8 the other way. So

 

[giovanni]

The build looks clean, did you trace the signal with an audio probe?

 

[Mcknib]

Not 100% but sounds like there may be a fault with the buffer connections seeing as it's both sides of the switch

As far as I can remember in bypass it lifts the ground connection from the drive, level pots and C4, 5 and R6 making it a unity buffer

I've no idea how the switching works but check those components are grounded in effects mode and lifted in bypass mode

Looking at the schematic R5 connects to the switch too

Maybe someone that knows how it works can confirm that's what it does

It could well be your switch did you check that the middle common row only connects with one throw

I've had sticking switches that connected to one throw and one lug on the other throw at the same time

I've also had solder joints that look nice and shiny on switches that created a problem later but looked good a quick reflow and all was sorted

 

[joelorigo]

The build looks clean, did you trace the signal with an audio probe?

I checked the signal flow and it seems good. However I did notice that the switch continuity is 2 & 3, 5 & 6 and 8 & 9 with the effect activated and 1 & 2, 4 & 5 and 7 & 8 in bypass. Isn't that backwards?

 

[joelorigo]

Not 100% but sounds like there may be a fault with the buffer connections seeing as it's both sides of the switch

As far as I can remember in bypass it lifts the ground connection from the drive, level pots and C4, 5 and R6 making it a unity buffer

I've no idea how the switching works but check those components are grounded in effects mode and lifted in bypass mode

Looking at the schematic R5 connects to the switch too

Maybe someone that knows how it works can confirm that's what it does

This is correct. In effects mode the drive and level pots, C5 and R6 are grounded and not in bypass (I can't get my multimeter's probes to touch the leads for C5 without taking it apart and I haven't done that yet) . I assume it is normal however to get continuity with only one of the leads of the resistor and capacitor, and only one lug of the pots?

 

[joelorigo]

It could well be your switch did you check that the middle common row only connects with one throw

I've had sticking switches that connected to one throw and one lug on the other throw at the same time

Ah ha! Something seems wrong here. Lug 5 sometimes has continuity with the lug above and below when in bypass. Sometimes. But the LED comes on every time.

 

[Mcknib]

I assume it is normal however to get continuity with only one of the leads of the resistor and capacitor, and only one lug of the pots?

That's correct lug 1 of the pots and one lead of the other components grounded in effects mode and floating in bypass mode

It sounds like your 3PDT is dodgy as you know the middle common row should only connect to either the top or bottom row and not both at the same time

*Edit lug 1 volume lug 3 drive

 

[joelorigo]

I'm not surprised. It would be the 4th or 5th time I've had a problem with this batch of switches. I'll try putting in a new one.

 

[BuddytheReow]

If you're having issues with 3pdt switches you may be heating them too much. I've fried one or two by accident. I've only had one switch come in the mail that didn't have continuity.

 

[joelorigo]

Yeah that could be it. But since I switched to the blue CIC ones from small bear I have not had any of them have a problem. I have also gotten better at soldering since this batch I keep having problems with so there's that too.

Question though: If I had messed the switch up with too much heat, wouldn't that be a problem right away? Not after working seemingly normal and then sitting to several months?

 

[Mcknib]

Question though: If I had messed the switch up with too much heat, wouldn't that be a problem right away? Not after working seemingly normal and then sitting to several months?

Could be they're poorly made and as you've used it it's gradually broken down

I've been lucky and never had a failure but I always buy alpha or gorva 3PDTs these days

I've never bought the blue ones from eBay only from reputable suppliers where I know it'll be hassle free to exchange faulty one's

You should contact them if you've had a few duff one's you never know they might refund

 

[joelorigo]

I replaced the switch and now there isn't any signal coming through in bypass or effect mode. The lugs have the same continuity as above minus the problem with lug 5. Signal trace seems good.

 

[PJS]

I'm going to take issue with your statement that signal trace seems good. When people talk about a signal trace they mean to build an audio probe, and use it to trace an audio signal through the circuit until you hear where the signal is degrading or being lost. If the signal trace is fine then the signal is making it all the way from the input to the output with no problems.

 

[BuddytheReow]

TUTORIAL - Troubleshooting 101

There comes a time for every builder to spend multiple hours soldering, wiring, and breadboarding a certain circuit just to have it work incorrectly, if at all. This could happen on your first build or any build after that. This write up is to help you in your quest to figure out why it isn't...

forum.pedalpcb.com

Audio probe instructions included here.

 

[Mcknib]

I'm taking it you've not used a switch from the dodgy batch? as @PJS says maybe time to audio probe it

I'd start at the pcb in pad to see if audio's getting into the circuit in both switch positions

Because this ain't yer standard bypass wiring I'd suspect it's either not getting in or there's a fault in circuit maybe you've loosened a wire messing with it or dislodged something

I'd check all your grounds again

As I said I don't know how it works from what I can make out it just connects and disconnects ground from the components that give you drive so audio would go through the circuit in both modes

 

[joelorigo]

I'm going to take issue with your statement that signal trace seems good. When people talk about a signal trace they mean to build an audio probe, and use it to trace an audio signal through the circuit until you hear where the signal is degrading or being lost. If the signal trace is fine then the signal is making it all the way from the input to the output with no problems.

You're right, I didn't do a complete circuit trace, just to & from the PCB.

 

[joelorigo]

TUTORIAL - Troubleshooting 101

There comes a time for every builder to spend multiple hours soldering, wiring, and breadboarding a certain circuit just to have it work incorrectly, if at all. This could happen on your first build or any build after that. This write up is to help you in your quest to figure out why it isn't...

forum.pedalpcb.com

Audio probe instructions included here.

Awesome, thank you.

 

[Mcknib]

Here's some info from mine forgot I had one!

 

[joelorigo]

Here's some info from mine forgot I had one!
View attachment 18667

Thank you!

 

[joelorigo]

Thanks for all the help. I took it apart and examined the soldering. There were a couple of places that looked to be not the most ideal. I wasn’t a beginner when I built this pedal but I wasn’t great either. I re-flowed the whole thing and it is working. So maybe that’s all it was. If it has the problem again I have this audio probe/tracing info to do, and for any future problems on other builds, so thanks again.

Also, this pedal sounds great.