Pickup impedance and pots

[picker]

Hey y'all, hope you are all surviving the Great Pandemic of 2020!

 

I bought a tri-cone resonator guitar a while back Well, the magnetic pickup in it sounds pretty lackluster by itself. So, I purchased a Schatten tricone pickup, and I need it installed. I think I want it to work with the existing pickup, but I'm not sure what would be the best way to incorporate it into the guitar. I think I'd like the two pickups on a blend pot, and from there fed into the volume pot and out to the the amplifier/PA/whatever. But, I wondered if the difference in impedance between the old magnetic pickup and the new piezo would cause problems using one pot, which might not be the correct value for both. So, maybe separate volume pots going into the output jack, like a bass guitar does, would work better.

 

Or would it?

 

Being only electronically savvy enough to get into deep do-do if I tried anything beyond my limited knowledge, I thought I ask if anybody could tell me what they think would be the best way to go about this.

 

WHaddaya say, folks?

[Larryz]

I would run your ideas by your tech since you are having the new pickup installed and take the tech's advice. If I were running ideas by my tech, I would not really be wanting to blend the piezo with the magnetic pickup. I would consider having a push/pull volume pot much like switching a humbucker to a single coil selection and run one at a time. Or, I might run two volume pots and maybe a couple of mini toggles to turn them on/off separately and have a master tone pot. Just a couple of thoughts...

 

Ps. if your magnetic pickup is a humbucker, ask about a 500k pot. If it's a single coil, ask about a 250k pot.

[KuruPrionz]

I searched for specs on the Schatten tricone pickup series. The following is quoted from installation instructions, regarding amplification.

The 1-2 megaohm figure quoted is in line with many pickups of this type. As Larryz says, most magnetic pickups will want a pot from 250k to 500k. Schatten clearly indicates preferred impedences and they are not compatible. So a double-ganged pot is more work but it will not be optimal for one, the other or both pickups.

 

"High impedance in these instances may indicate an allowable impedance in the 1 or 2 mega ohm range - which will allow passive pickups to be used. Or it may indicate a maximum input impedance allowed of 20,000 ohms or less - which will handle magnetic electric guitar pickups but not passive pickups. You should carefully read the technical specifications of your acoustic amp in order to see what it will do."

 

Seperate pots would be advised but make sure the installation tech understands how the circuit works. You want to pots to be hooked up with the hot lead from the pickup in the center, like a Fender Jazz Bass. That configuration varies the output by gradually grounding the pickup itself so turning one pickup all the way off does not turn the other pickup off.

 

The more common circuit is like a Gibson Les Paul, where the hot lead of the pickup is connected to one of the outside lugs and the center lug is the output from the pot. So attenuation is realized by shunting the output to ground. Since both pickups share ground, turning one pickup all the way down will turn the other all the way down too. That is NOT what you want so make sure the tech understands those two circuits.