SOLVED Switch popping and noise galore with Bootleg and Glory Hole

[KR Sound]

Here’s what I’m building- dual Bootleg and Glory Hole with order switcher.



I tested them both prior to assembly without LEDs in the test platform and they both sounded great.

Now I put them all together and I’m getting switch pops on both and crazy noise from the BL

I took them both out, removed the LEDs and put them in the test platform with the footswitches attached.

BOOTLEG:
Bootleg still popped and buzzed at high gain and volume.

Removing the LED gets rid of the popping, but there’s still high gain buzz. I even swapped out all the ICs just cause.

https://docs.pedalpcb.com/project/BootlegOD.pdf

GLORY HOLE:
Changed the footswitch, changed LED, removed LED, and still have popping. The only thing different from the BOM is an 18k resistor for the LED.

https://docs.pedalpcb.com/project/GloryHole.pdf

There’s not much to this and I’ve built it before without any issues. I’m about to swap out the caps to see and then try the approaches on AMZfx perhaps.

AMZ - LED Popping

How to stop the pops in audio from LED current surges when switched.

www.muzique.com

What am I missing?

 

[chris.knudson]

There isn’t one- it’s a conduit between the INs and OUTs of the two pedals and the jacks.

3PDT Order Switch Wiring - PedalPCB Wiki

wiki.pedalpcb.com

Unless I hook something up to the case of the switch.

I’ll have to try it in the morning, everyone’s gone to bed for the night.

Yeah -- probably going to go to bed soon too. I'll keep reading for a little while -- maybe I'll find something useful.

 

[chris.knudson]

I've been doing a lot of reading and not coming up with a lot. You might be able to add an audio isolation transformer or an inductor, or you might try shielding and or twisting your leads, but honestly at this point I'm just guessing. Maybe @Robert or @Chuck D. Bones might have some ideas.

 

[KR Sound]

I grounded the toggle switch which eliminated popping when switching the order, however I’ve got some grounding issues still. Think I’m going to have to disassemble it and give it another good once-over.

So now everything is star grounded at the power jack- boards, jacks, and toggle.

 

[mzy12]

I highly recommend using isolated jacks (at least on the output) for a build like this. Tie the ground lug of the input jack to the chasis (as near as possible to the entry point, so something like a star washer around the jack would do). On the output side, tie the ground lug to chasis via a capacitor. That means you can connect the ground lug of the output to the rest of the circuit ground with out creating a new path for dc to go to. The goal is for ground to only be at one point. Connecting your toggle switch to ground via a wire like you have has the potential to create more ground loops. You've added another point for current to flow through to chasis.

 

[KR Sound]

I highly recommend using isolated jacks (at least on the output) for a build like this. Tie the ground lug of the input jack to the chasis (as near as possible to the entry point, so something like a star washer around the jack would do). On the output side, tie the ground lug to chasis via a capacitor. That means you can connect the ground lug of the output to the rest of the circuit ground with out creating a new path for dc to go to. The goal is for ground to only be at one point. Connecting your toggle switch to ground via a wire like you have has the potential to create more ground loops. You've added another point for current to flow through to chasis.

Thanks! I’ll definitely give this a shot.

 

[mzy12]

Popping is a genuine menace, even if you do everything, "properly." Here's an idea for solving , "L.E.D. popping," from amz. I put that in quotation marks because, honestly, I've never found LEDs to be a source of popping. Maybe it's an issue in this case. Here's an annoying article from Mr. Black Pedals that has some great points but is unfortunately not very clearly communicated and eschews a more direct technical explanation for his... particular writing style.

I'm pretty sure I've done everything correctly and I still get pops on my pedals. Even relays don't always work as intended. It's pretty damn frustrating. I'm going to stick some designs into one of my college's oscilloscopes one of these days and try to see what the hell can be done about this in a more reliable way. I will stick an isolation 1:1 transformer on the input/output to solve this if I have to that's not strictly a feasible solution, but what-the-hell-ever haha

 

[Giorfida]

Popping is a genuine menace, even if you do everything, "properly." Here's an idea for solving , "L.E.D. popping," from amz. I put that in quotation marks because, honestly, I've never found LEDs to be a source of popping. Maybe it's an issue in this case. Here's an annoying article from Mr. Black Pedals that has some great points but is unfortunately not very clearly communicated and eschews a more direct technical explanation for his... particular writing style.

I'm pretty sure I've done everything correctly and I still get pops on my pedals. Even relays don't always work as intended. It's pretty damn frustrating. I'm going to stick some designs into one of my college's oscilloscopes one of these days and try to see what the hell can be done about this in a more reliable way. I will stick an isolation 1:1 transformer on the input/output to solve this if I have to that's not strictly a feasible solution, but what-the-hell-ever haha

I believe (and this is dating me), besides being a way to get past the tone suck of the mechanical output only bypass (SPDT switch, old MxR, where input always tied to pedals PCB), and providing an indicator LED, one “advantage” touted with the buffered flip flop bypass that Ibanez and Boss used was that it was noiseless- no pops like mechanical switches.
I don’t care how well you design the circuit, I believe the mechanical action in some cases actually create enough of a static discharge that it can’t be avoided.

 

[KR Sound]

I put in some isolated jacks and wired up the output with a cap, and still the same thing. I did remove the toggle switch ground and that didn't make a diff either.

I'm going to tear it apart and verify again that each one is running relatively quiet to begin with and go from there.

 

[mzy12]

I believe (and this is dating me), besides being a way to get past the tone suck of the mechanical output only bypass (SPDT switch, old MxR, where input always tied to pedals PCB), and providing an indicator LED, one “advantage” touted with the buffered flip flop bypass that Ibanez and Boss used was that it was noiseless- no pops like mechanical switches.
I don’t care how well you design the circuit, I believe the mechanical action in some cases actually create enough of a static discharge that it can’t be avoided.

Switch bouncing and etc will probably contribute to that. Maybe boss's updated switch/buffer for the waza series isn't such a bad idea.

 

[KR Sound]

I had my friend check the Glory Hole I made for him last year, and it’s got a bit of switch pop as well.

 

[mzy12]

Mmmmaybe at a stretch the 2u2 coupling electrolytic is causing problems cos of ESR. Do you have any film caps to jam in there? Maybe in a tantalum. Barring that, put a 100k resistor to ground between the last volume pot and the output. Then a 1k to in series from the volume pot output to the output. (place it after the ground resistor to avoid creating a voltage divider.) See some boss pedal schematics to see how they do that.

I also realised you linked the AMZ led popping article in your earlier post, apologies for skipping over it and linking it again haha

 

[KR Sound]

I’ll give this a try for sure. Thanks!

 

[mzy12]

That's kind of the gist of Mr Black Pedals article... like I said, it's good, but not great. He suggests removing the pulldown resistor at the input (because the input of the pedal circuit will be switched with ground anyways, or at least it should be), and add those two resistors I mentioned in my last point. This gives the pedal output a dc path to ground, plus current limiting any excess pops caused by. Those by convention in other designs are 100k and 1k. You can also add a 1k resistor in series on the input before the coupling capacitor for the same reason. It's a good idea that I implement in any build I can.

 

[KR Sound]

That's kind of the gist of Mr Black Pedals article... like I said, it's good, but not great. He suggests removing the pulldown resistor at the input (because the input of the pedal circuit will be switched with ground anyways, or at least it should be), and add those two resistors I mentioned in my last point. This gives the pedal output a dc path to ground, plus current limiting any excess pops caused by. Those by convention in other designs are 100k and 1k. You can also add a 1k resistor in series on the input before the coupling capacitor for the same reason. It's a good idea that I implement in any build I can.

Adding a 100k from the volume pot ground to the output ground got rid of a lot of hum where it's acceptable with the gain all the way up, and most all of the pop on the MorningGlory. I'm kind of surprised.

Now on to the Bootleg side.

 

[t1redhands]

I've made a couple Moonshines on stripboard a while ago that both pop really badly. I'll have to revisit them with and see if Mr Black's tips help any.

 

[mzy12]

Adding a 100k from the volume pot ground to the output ground got rid of a lot of hum where it's acceptable with the gain all the way up, and most all of the pop on the MorningGlory. I'm kind of surprised.

I'm glad to hear that helped.

I've made a couple Moonshines on stripboard a while ago that both pop really badly. I'll have to revisit them with and see if Mr Black's tips help any.

You using an electrolytic or film cap on as the output cap? Schematics say film. I wonder if the relatively high output impedance of the NE5532 opamp would contribute to the issue (it being a bjt opamp). The pedalpcb schematics have the Boss/Mr Black style output resistors already, curiously, however, at 1/10th of Boss's usual values. Not sure why. There's nothing wrong with either value. Usually, anyways, hahah

 

[KR Sound]

I replaced all the caps on the Bootleg with Nichicons and it sounds so much better. And now it’s sounding great- there is obviously some noise at high gain, especially when one’s feeding into the other, but hardly any popping, so I’ll count this as a win.

 

[GizzWizzKing]

Been reading this thread regretting offering to do a combo build for a friend. And now I will go and make sure my tayda order is for quality caps across the board. Good thread to learn on.

 

[KR Sound]

Been reading this thread regretting offering to do a combo build for a friend. And now I will go and make sure my tayda order is for quality caps across the board. Good thread to learn on.

I’ve done several dual builds and this was the first to give me any issues. I think I ended up having a batch of shitty caps to add to whatever else was going on. No more cheapies for me either.

 

[KR Sound]

Got a nice message from the guy I built it for. This is my favorite part- making something that truly affects someone.

“This is the BEST dirt pedal I've ever had! And turning on the MG side with the fuzz was magical!

But seriously, Aslan's Revenge is amazing! You nailed it!

Be ready to build some more.....I have LOTS of guitar friends. And when they find out they can get their own design....watch out. Lol”