Hey there I'm in need of some expertise, built a Rullywow Queen of Bone Pedal, two actually, and they both have a serious pop issue, more than that when engaged they cause other pedals in the chain to pop. There are 1M pull down resistors already I've tried an additional 100k and then 2.2m resistor from output to ground with no luck. Any help greatly appreciated, I'm stumped :P
Do the pedals work? Could be a bad ground connection on the switch. I've had that happen, sometimes the pedal would work, sometimes it would die out, always made a huge pop. Maybe try reflowing the switch. Do you have any pictures?
Hi yes they work fine just get a brutal pop, tried reflowing the switch unfortunately no improvement. Thanks for the reply.
Output to ground I don't think will work that would just make the pedal quieter. I think we need pictures of the inside.
Measure to see if there's DC voltage on the output and input.
dave
Quote from: davent on April 27, 2017, 01:01:40 AM
Measure to see if there's DC voltage on the output and input.
dave
Yeah, this.
Thanks everyone for you help, here's a pic
And yes it looks like I've got about .45 volts on the output, how do I fix that?
This may be wrong but the circuit uses a charge pump which looks like you are missing from your picture and just have a socket. I don't know what that would do. I would guess it wouldn't work. But maybe it does? I looked at the instructions and there isn't really a 9 volt option, which, from what I have seen would have a jumper to bypass the charge pump. Any reason why it's not there?
It's not there on this one, do have it on the other I built, without it the pedal just runs at 9v, the issue is def the .45 v on the output, just need to know how to remedy
Cool, only thing I could think is a solder bridge somewhere. But I'll bow out and leave it to the experts here. Good luck, I hope you figure it out. I built the older version and its tons of fun to play.
Thanks very much for your help, really appreciate it
You have the same problem on both pedals? If so, you may have used an incorrect value component on both. Or bad electro caps.
Did you use the same charge pump to test both pedals? If so, it could be a bad pump or incorrect part.
Hi, thanks for the reply, same issue on both pedals, double checked component values and all look correct, I get the pop with and without the charge pump, any other thoughts?
Replace the output cap with a film cap to rule out a leaking electrolytic. If you still have DC, start looking for a short. I can't think of another place in that pedal where you would have .45V so it's most likely capacitor leakage.
Thanks very much will give it a go
Ok tried the film cap and sure enough pop is gone, does that mean it was the output cap that was leaking so that's the one to replace, sorry might be a dumb question but I've built a bunch of pedals and never run into this, also really weird to have it on two separate builds of the same pedal. Thanks again for your help this was driving me nuts.
It is improbable for it to happen to both builds, but not impossible. Any chance you overheated them during installation?
Oh, and yes, you'll want to replace those output caps. If it were me, I'd test them or at least make sure they were not from the same batch. I doubt you'd have three leaky caps, but you've already had two, so...
Thanks very much, turns out I had a bunch of leaky caps, I'm wondering at 1uF with a cap that has max voltage of 50 or 100v if the tolerance allowed is just too much for this kind of circuit. Either that or I have some super cheap-ass caps.......