1970 Fender Precision with new microphonic pickup issues

JetbassMiami

JetbassMiami

Mar 22, 2022
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#1
I have this all original 1970 Fender Precision Bass sunburst all original and last weekend for the first time, I had issues with what I think is a mirophonic pickup.
  • You could tap and hear a high pitch tone on the pickup cover (yes still in place) and also on the control knobs
  • The sound changed to something not normal
  • The volume control was fine but the tone control was acting like a second volume knob... all the way up the volume was diminished, all the way down the volume was exponentially higher and also the treble component in the tone.
  • I tried a different cable and same issue
  • I am playing through a Markbass combo amp.
I am afraid of doing something wrong that can affect the value of this vintage instrument.

Any advise please?
 

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#3
Yes I purchased the bass from Olivia's las November... I have contacted them and gave me Tom Brantley's email and I have contacted him too and I's waiting to hear from him. I was hoping to get some input from the members before I have to remove the pickup from the bass.
Tks for your help
 
#4
  • The volume control was fine but the tone control was acting like a second volume knob... all the way up the volume was diminished, all the way down the volume was exponentially higher and also the treble component in the tone.
you may have a bad solder on the tone cap/pot !!! , check all solder joints as well. could be a combo of issues , you have more going on then just potting
 
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#6
A poorly potted pickup (or one with no potting at all) will not cause the symptoms you're seeing with the tone pot. I really don't think this is a pickup issue.

Can you take the pickguard off and show us some close up photos of the wiring on the controls? My guess is you have a poor connection or a partial short. Probably a partial short of the hot side of the cap to ground. This is pretty easy to have accidentally happen if the wiring gets bumped, or one of the nuts on the pots comes loose and the pot gets spun in it's mounting hole.
 
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#7
dwizum said:
A poorly potted pickup (or one with no potting at all) will not cause the symptoms you're seeing with the tone pot. I really don't think this is a pickup issue.

Can you take the pickguard off and show us some close up photos of the wiring on the controls? My guess is you have a poor connection or a partial short. Probably a partial short of the hot side of the cap to ground. This is pretty easy to have accidentally happen if the wiring gets bumped, or one of the nuts on the pots comes loose and the pot gets spun in it's mounting hole.
Click to expand...

I agree, this does not sound like a traditional microphonic pickup. It wouldn't cause what the tone control is doing. I am very interested in discovering the wiring condition. This is a new problem to me and I have worked on hundreds of passive wiring harnesses. "Very interesting".
 
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#9
mike buzzetti said:
  • The volume control was fine but the tone control was acting like a second volume knob... all the way up the volume was diminished, all the way down the volume was exponentially higher and also the treble component in the tone.
you may have a bad solder on the tone cap/pot !!! , check all solder joints as well. could be a combo of issues , you have more going on then just potting
Click to expand...
Beat me to it.
 
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