Direct wiring problem

[StereoPlayer]

My main bass is wired direct to the output jack through swiches.
It’s a stereo J bass, tapped pu’s. It has tapped, single coil pu’s.
The hum is mainly from the neck pu…but I’m very sure it’s on the treble pu also. I just don’t use the treble pu very loudly.

It’s a very simple wiring…thru on/off/on switches to the output jack.
I also have another bass wired like this, but it isn’t so noticeable…since it’s a p/j.

When a pu is in the off position…there is an open circuit hum.
I read somewhere that this could be eliminated buy installing a diode or capacitor somewhere in the circuit.
But I can’t remember the details.

Also, is there a way to eliminate a popping noise when using the switches.


Any help here?
It’s really not that bad. I’ve used it this way for years. There is zero hum when the pu’s are on…so I can always do that.

 

[Crater]

Pickup switches can be wired in such a way that when both pickups are turned off, the output is grounded, eliminating the open circuit hum, but this won't work with on/off/on type switches, you need a regular DPDT switches. You'll either need to have separate switch(es) for the coil taps or use a different switching setup.

 

[StereoPlayer]

Pickup switches can be wired in such a way that when both pickups are turned off, the output is grounded, eliminating the open circuit hum, but this won't work with on/off/on type switches, you need a regular DPDT switches. You'll either need to have separate switch(es) for the coil taps or use a different switching setup.

Thanks for your reply.

 

[YRPALJG]

Tapped coils sometimes require extra care because the point beyond the initial tap can, under certain circumstances with an improper wind and wind tension, become a conductor.

Check the actual bridge ground connection. If that seems solid and is correct, examine the grounded connections at the back of the pots and make sure all is well and good there. Reflow the joint(s) if something looks funky and not right.

Tapped coils or not, you've got single coils so a certain amount of 50/60hz hum is to be expected. One can apply shielding tape to the underside of the covers, connected to a small strip of the same material that is connected to shielded coils. Float that ground wire individually for best results.

 

[StereoPlayer]

Tapped coils sometimes require extra care because the point beyond the initial tap can, under certain circumstances with an improper wind and wind tension, become a conductor.

Check the actual bridge ground connection. If that seems solid and is correct, examine the grounded connections at the back of the pots and make sure all is well and good there. Reflow the joint(s) if something looks funky and not right.

Tapped coils or not, you've got single coils so a certain amount of 50/60hz hum is to be expected. One can apply shielding tape to the underside of the covers, connected to a small strip of the same material that is connected to shielded coils. Float that ground wire individually for best results.

There are no pots. Hum is only when in the off position.

 

[YRPALJG]

There are no pots. Hum is only when in the off position.

The Ground connection is to the back of either pots or in your case, switches. Yes. Please do inspect and make sure. All must be linked together to the output jack ground.

 

[KidAmnesia]

Could you post pictures or a wiring diagram of your circuit?

 

[StereoPlayer]

Could you post pictures or a wiring diagram of your circuit?

It’s very simple.

The pu has three wires.
The ground wire is….well…grounded all the way to the output jack.
The half hot wind of the pick up goes to one side of the switch.
The full hot wind of the pick up goes to the other side of the switch.

The middle of the switch—hot… goes to the output jack.
On/off/on switch is used. Three position.

 

[YRPALJG]

Fender Jazz Bass circuit, V/V/T .. you can do it!

 

[StereoPlayer]

Fender Jazz Bass circuit, V/V/T .. you can do it!

No way! I'll take the hum...I just won't turn it off!

 

[YRPALJG]

No way! I'll take the hum...I just won't turn it off!

It has been said that silence in the secret extra member of any band, but hey: do it how you like it. Check your grounds please.

 

[StereoPlayer]

It has been said that silence in the secret extra member of any band, but hey: do it how you like it. Check your grounds please.

It's doesn't hum when the pu's are on...

 

[YRPALJG]

It's a grounding issue somehow then 100%. Or some bad electronics. That's it - it's one or the other. **Edit: are you sitting in front of a computer screen? how is the power/wiring in your home? Both of these can contribute and/or directly cause your issues.

Beyond that, examine your gear. Do other basses hum? If not, then it is specific to the bass in question and is some type of grounding or electronic issue. Without having your gear in front of me, plugged into a verifiable clean power source: how could I or anyone know more?

Dig deeper with your gear, Check grounds. Consider shielding. Check all cables. Check output jack. ♥

 

[StereoPlayer]

It's a grounding issue somehow then 100%. Or some bad electronics. That's it - it's one or the other.

Thanks for your help, I will investigate.

 

[Matt Liebenau]

How do you have the switches wired? When one of the pickups is shut off is the hot connected directly to ground? If not, it’s the equivalent of having your amp on and the cord unplugged from the bass.

 

[logdrum]

It might really help if you post pictures and I don't get it why you can't or won't post it. I don't think it is simple as you think (specially if you have a coil tap), otherwise, you would have no issues. Here's a couple that may help you from the German Bass Wiring Bible. This electronics bible... He has coil tap examples also but I can't find one without a volume knob. There is a dictionary at the end and it is pretty clear even to non German speakers or you can google translate

 

[StereoPlayer]

It might really help if you post pictures and I don't get it why you can't or won't post it. I don't think it is simple as you think (specially if you have a coil tap), otherwise, you would have no issues. Here's a couple that may help you from the German Bass Wiring Bible. This electronics bible... He has coil tap examples also but I can't find one without a volume knob. There is a dictionary at the end and it is pretty clear even to non German speakers or you can google translate

View attachment 4998638

View attachment 4998642

I'll try to put up a drawing tomorrow.

 

[micguy]

I'll try to put up a drawing tomorrow.

Good. An actual schematic is the starting point for discussing what you issues might arise. You say you have popping noises when you operate the switches - as you have no capacitors in the circuit, that doesn't make sense. You may get small ticks from switching if you've got a note going when you throw a switch, but if you're not playing anything, and you have no capacitors in your circuit, the switching should be silent. That it isn't makes me wonder what the actual circuit is that you have.

 

[micguy]

Fender Jazz Bass circuit, V/V/T .. you can do it!

If the OP likes the sound from direct wiring, then suggesting he go with a VVT setup is pretty bad advice - it definitely won't sound the same, and he'll have to deal with the interface and quirks of a VVT circuit, which are far from ideal.

 

[E2942]

The problem is that all the wiring becomes an antenna for inducing EMI noise when the switch isn't connecting the pickup through or to Ground.
It's about like plugging in an instrument cable to your amp & then not plugging in the instrument. If you wave that around you will hear the noise, if the amp is turned up.