Frankenstein guitar project stalled!!!

[donovanlopez]

Guitar Brothers in Arms, please help this noob!!!  I have an acoustic guitar that I am attempting to electrify.  Hardware involved:
1.  EMG 89-X humbucker w/ tone and volume pot (9v)
2.  Cherub G-Tone G6 piezo under saddle p'up w/ active preamp (9v)
3. 1 stereo output jack
4. 3 way toggle switch to swith between EMG and piezo p'up.

Can someone...ANYONE point me in the right direction for a wiring schematic that wires up two totally different types of p'ups, PLEASE??!!! I just can't figure it out!!!

 

[vetteman]

Seems like there were diagrams like that on the guitar electronics and/or guitarnuts sites.  Maybe 1728 or Seymour Duncan also.

 

[line6man]

The typical issue with mixing piezo and magnetic pickups is the fact that the output impedances do not match, and hence, buffering of the magnetic pickups is required. Since you have active pickups, however, the buffering may not be necessary.

Before you can make any decisions about wiring, you need to figure out whether or not the output impedances of your EMG pickups and the piezo buffer are similar enough to be summed together, without additional buffering.

 

[rgand]

After you have a pair of pickups matched up, here's a sheet from Seymour Duncan that shows some of the major manufacturer's wire colorings.

 

[Cagey]

What some folks do is wire both pickups to a stereo (TRS) output jack, one per hot line, then use a stereo cable to plug it into either a splitter box or a stereo input on an amp or mixer, so each line has a separate channel and can be treated appropriately. It eliminates any issues with buffering/impedance matching, at least at the guitar. If you have a volume control for each pickup on the guitar, you can do some nominal mixing there.

 

[line6man]

What some folks do is wire both pickups to a stereo (TRS) output jack, one per hot line, then use a stereo cable to plug it into either a splitter box or a stereo input on an amp or mixer, so each line has a separate channel and can be treated appropriately. It eliminates any issues with buffering/impedance matching, at least at the guitar. If you have a volume control for each pickup on the guitar, you can do some nominal mixing there.

A relevant note on the use of TRS jacks: For an active guitar, the signal goes out on the tip terminal, and the sleeve terminal is the ground, as usual, but the ring terminal is used to connect the negative from the battery to ground, when a standard "mono" guitar cable is inserted. If we want to repurpose the ring terminal to allow a second signal to be sent to a splitter box, via a stereo cable, then we will have to find some other way to switch the active stuff on and off. For this, we will need a specialized jack that has an isolated switching circuit. These jacks certainly exist, but they are not quite as easy to obtain, as they are not commonly sold through the usual vendors in the audio/guitar parts industry. You will have to get your jack from an electronics supplier.