Need help with custom switching pedal please

[paintballnsk]

Hello,

I'd like to build this pedal. I'm aiming for a universal pedal that has:

Amp Channel Switch
Amp Effects Loop Switch
Guitar Pedal Loop - front of amp, always on when amp is on Dirty Channel.
Loop1 - Amp Effects Loop only on Dirty Channel
Loop2 - Amp Effects Loop only on Clean Channel

I was hoping you pedal experts could take a look at my crayon drawing and tell me if it would work.

Thanks

[iainpunk]

welcome to the forum

i guess you don't want a ton of HUM caused by ground loops? so i took out a bunch of detrimental ground connections, a also strongly suggest using either a plastic jacks or isolation tape to break the connection between the housing and the jack, since this too causes ground loops.

one of the switch functions was quite unnecessary since they are always connected anyways, and leaving them hanging like that causes hum and hiss.

the enclosure should be grounded through one single grounding point.

most of the diagram looks fine to me

cheers, Iain

[paintballnsk]

welcome to the forum

i guess you don't want a ton of HUM caused by ground loops? so i took out a bunch of detrimental ground connections, a also strongly suggest using either a plastic jacks or isolation tape to break the connection between the housing and the jack, since this too causes ground loops.

one of the switch functions was quite unnecessary since they are always connected anyways, and leaving them hanging like that causes hum and hiss.

the enclosure should be grounded through one single grounding point.

most of the diagram looks fine to me

cheers, Iain

Thank you for the reply.

Did you mean to upload an Image? I didn't see one.

Which connection is unnecessary? I guess I don't really understand how ground hum is introduced. This is my first try designing my own pedal, though I've built a few kits.

I bought regular switchcraft jacks, but I think their mounting ring grounds sleeve to chassis. Are you saying I should try to tape that off so it doesn't touch, or can I find jacks that are insulated from the chassis by design? Any suggestions?

Also, is this going to make "pop" noises when I change settings? How would I avoid that?

[iainpunk]

oops, it failed to upload i guess

[paintballnsk]

So I'm kind of new to all this. Why are the grounds open on some of them and the tip on the guitar amp send open? I thought the rings had to be grounded to each other and the tips sent the signal.

Can someone please point me to a reference that explains how this works?

[Marcos - Munky]

If you connect all grounds together, there's a huge chance on getting something called ground loops. That means basically some parts of your circuit will have more than one path connected to ground. This can result in hum noise.

Let's keep it simple and think of a very common example. A metal enclosure with two metal jacks (basically a usual stompbox setting). Let's say you have one ground wire A coming from the board and connecting to the input jack ground, another ground wire B from the board and going to the output jack and a wire C connecting both jacks' ground. In this scenario, you have:
- ground of the jacks connected by wire C.
- ground of the jacks connected by wires A and B.
- ground of the jacks connected by the enclosure because of the metal parts.
- circuit ground is connected to input jack by wire A, but it's also connected to the same jack because we have wire B connecting to output jack and the metal enclosure connecting everything together.
- the same above, but for output jack.

So, there are lots of paths for ground, and those are called ground loops. The best idea is to connect them together at one point only. For example, only one ground wire cames from the board and it's connected to input jack, and the output jack is grounded by the metal enclosure (some people also add a wire connecting the output jack ground to input jack ground).

[iainpunk]

So I'm kind of new to all this. Why are the grounds open on some of them and the tip on the guitar amp send open? I thought the rings had to be grounded to each other and the tips sent the signal.

Can someone please point me to a reference that explains how this works?

double deuce, i made a mistake in the edit. i confused the ground and tip on the guitar amp send... oops

the reason you don't ground both sides of a pedal loop is that it creates ground loops, basically a weird hum/noise antenna effect, cutting one side is preventing the loop from being completed.
https://hackaday.com/2017/03/09/wtf-are-ground-loops/

cheers and happy new year, Iain