Guitar/audio electrics people...


ajthemackem

Striker
Right.
I have three passive pickups (two piezos and a coil neck pickp). Each one runs into its own on/off switch.
The hot signal is running to these switches and the ground is looped. From the switches, they all run to the hot input of a preamp in the guitar.
The ground signal also runs to the preamp from all three.
All works fine but when all three switches are off you get the ground loop hum (plus a little bit from the piezos when they're on but they're not bad).
Do you knowwwwww....
Of a small circuit board or something I can put between the switches and the preamp to eliminate the hum?
Because I know enough to be dangerous. :lol:
@fyl2u
 
Right.
I have three passive pickups (two piezos and a coil neck pickp). Each one runs into its own on/off switch.
The hot signal is running to these switches and the ground is looped. From the switches, they all run to the hot input of a preamp in the guitar.
The ground signal also runs to the preamp from all three.
All works fine but when all three switches are off you get the ground loop hum (plus a little bit from the piezos when they're on but they're not bad).
Do you knowwwwww....
Of a small circuit board or something I can put between the switches and the preamp to eliminate the hum?
Because I know enough to be dangerous. :lol:
@fyl2u
Just buy an acoustic. Far too complicated that like.
 
Einstein couldn't work that shit out. Give the NASA guitar branch a bell. They might understand it.
:lol:
I mean I know the issue. When I had two pickups in before I had an on/on/on switch in it which had one, the other, or both on all the time, and that was fine.
Just this way you always need one switched on or the hum is godawful. The neck sounds great on but the piezos are a little iffy on their own... But I think that eBay thing might fix it. I'll see anway.
The only other way I can think of is to wire between the on/off switches in a way that one is always on until another is, which sounds like a right f***ing pig to work out.
 
Last edited:
Right.
I have three passive pickups (two piezos and a coil neck pickp). Each one runs into its own on/off switch.
The hot signal is running to these switches and the ground is looped. From the switches, they all run to the hot input of a preamp in the guitar.
The ground signal also runs to the preamp from all three.
All works fine but when all three switches are off you get the ground loop hum (plus a little bit from the piezos when they're on but they're not bad).
Do you knowwwwww....
Of a small circuit board or something I can put between the switches and the preamp to eliminate the hum?
Because I know enough to be dangerous. :lol:
@fyl2u

You could install an on-off toggle switch for the whole circuit just before the jack socket, I think. I don't think there's any way around the slight piezo hum, but the killswitch might get rid of the all-off hum from the preamp ground loop.
:lol:
I mean I know the issue. When I had two pickups in before I had an on/on/on switch in it which had one, the other, or both on all the time, and that was fine.
Just this way you always need one switched on or the hum is godawful. The neck sounds great on but the piezos are a little iffy on their own... But I think that eBay thing might fix it. I'll see anway.
The only other way I can think of is to wire between the on/off switches in a way that one is always on until another is, which sounds like a right f***ing pig to work out.

Could you not replace the three toggles with a 5-way?
 
You could install an on-off toggle switch for the whole circuit just before the jack socket, I think. I don't think there's any way around the slight piezo hum, but the killswitch might get rid of the all-off hum from the preamp ground loop.


Could you not replace the three toggles with a 5-way?
I was tempted by a five way like, that might be my last plan. :lol:
You actually might be right about the killswitch, I'll give that a bash tomorra.
 
I was tempted by a five way like, that might be my last plan. :lol:
You actually might be right about the killswitch, I'll give that a bash tomorra.

It might need a small capacitor across the terminals of the killswitch. It's been a while since I thought about this stuff. Can't remember exactly how I used to go about it.
 
You could install an on-off toggle switch for the whole circuit just before the jack socket, I think. I don't think there's any way around the slight piezo hum, but the killswitch might get rid of the all-off hum from the preamp ground loop.


Could you not replace the three toggles with a 5-way?
Actually thinking on, I'd need to do a Gilmour mod to get all 7 positions. :lol:
It might need a small capacitor across the terminals of the killswitch. It's been a while since I thought about this stuff. Can't remember exactly how I used to go about it.
I was thinking a capacitor like but then I could just do that across the open hot wire without the switch...

I'll see if this hum thing I bought is any good. :lol:
 
Actually thinking on, I'd need to do a Gilmour mod to get all 7 positions. :lol:

I was thinking a capacitor like but then I could just do that across the open hot wire without the switch...

I'll see if this hum thing I bought is any good. :lol:

Looking at the killswitch wiring diagrams on Google Images, it doesn't need the cap. Folks are just wiring it straight in.
 

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