passive+active pickup in the same guitar goes crazy!

[fatecasino]

Hello! I recently purchased a modified second hand mexican J5 telecaster with an active EMG (bridge) and a passive Twisted Tele (neck).

The Twisted Tele was disconnected, so I made an effort to reconnect it.

I connected it directly to the 3-way switch without any volume/tone potentiometer as shown in the image, as the positions for the potentiometers were taken by the EMG (active) volume and tone controls (25K) .

I know it's impossible to mix these two pickups, my only ambition was to play using them separately.

That's how it went, Twisted Tele pup played in the top position, the EMG in the lower switch position.
In the middle mix switch position I could only hear the EMG (quite reasonable and expected).

What happened then shows that things were not so simple!

If I only played with Twisted Tele everything was fine,

if I switched the switch to EMG it was fine too (+the pots were also working fine).

But after playing for a few seconds with the EMG returning the Twisted Tele switch position resulted having no sound from the Twisted Tele.

Instead, you could hear the EMG at extremely low volume (while the switch was in Twisted Tele!)

The only way to get back the sound from Twisted Tele was to pull and re-plug in the guitar's jack and re-start the EMG.

Apparently something is not going well

Is there a signal leak? via ground?

How do I hear the EMG while the switch is on Twisted Tele?

If I put a volume potentiometer on Twisted Tele will the problem be solved?


PS: The first thought is to find a passive bridge for a telecaster (any suggestions close to broadcaster but in humbucker size, I don't want to change bridge plate too), but until I find the money to do it, how could I change the wiring and listen to the two pickups separately?

 

[JB_From_Hell]

Re: passive+active pickup in the same guitar goes crazy!

I’ve used a Duncan Livewire single with Lace Sensors, no problem. The issue is not because of the active/passive mix.

 

[fatecasino]

Re: passive+active pickup in the same guitar goes crazy!

I’ve used a Duncan Livewire single with Lace Sensors, no problem. The issue is not because of the active/passive mix.

I suppose I should triple check soldering and the switch condition.

 

[Downrazor11]

Re: passive+active pickup in the same guitar goes crazy!

Personally, I'd swap those 25k pots for 250k pots, otherwise the single sees the equivalent of a turned-down volume all the time.. But yeah, check your wiring bc you shouldn't be getting any signal bleed..

 

[fatecasino]

Re: passive+active pickup in the same guitar goes crazy!

First to say is that I solved the problem, it was indeed a bad soldering at the switch

Personally, I'd swap those 25k pots for 250k pots, otherwise the single sees the equivalent of a turned-down volume all the time.. But yeah, check your wiring bc you shouldn't be getting any signal bleed..

Could you please explain this a bit further. Now I have fixed the problem I realized that the mix switch position is not so bad, I can hear a little bit the passive pup when I turn down a little bit the volume pot (both tone and volume control the active pup, whereas the passive pup is connected directly to the switch). However when I turn down completely down the volume I hear absolutely no sound, hence the signal from the passive pup somehow goes to the ground.

 

[Downrazor11]

Re: passive+active pickup in the same guitar goes crazy!

Could you please explain this a bit further. Now I have fixed the problem I realized that the mix switch position is not so bad, I can hear a little bit the passive pup when I turn down a little bit the volume pot (both tone and volume control the active pup, whereas the passive pup is connected directly to the switch). However when I turn down completely down the volume I hear absolutely no sound, hence the signal from the passive pup somehow goes to the ground.

Sure, without getting too technical, let's examine two scenarios:

-if you were to only connect the single coil to the 25k pot and then turn that pot all the way up ('10') it would be like having a 250k (audio taper) pot that you could only turn up to '4'.. And you'd be missing some high frequencies from having a low value pot. Let me know if you need more explanation than this about how pots work.

-if you were to connect only the active pickup to the 250k (audio taper) pot and have it at '10', you wouldn't notice any reduction in volume until about 4 or 5, and even then the change may be so abrupt as to make the pot function more like an on-off switch than a tapered volume.

I know there will be interactions between the pickups in terms of impedance and loading, but I haven't got the equipment to measure what this would actually do, so in my over-simplification of the two options I would choose {having more high-end and volume variability in the single coil (with the humbucker staying relatively constant) with 250k audio pots} over [having less high end in the single coil (but with more control over the humbucker) with 25k pots].

Again, I am sure someone on here knows more about the interactions between the outputs of pre-amped and purely passive signals meeting at the volume pot, so maybe another may chime in, but this is just why I would use 250k over 25k, YMMV.