#1
Hey!

I am thinking of the way to install a piezo element in my guitar, already equipped with EMGs 81&85.

After reading alot about the matter, I think I have a proto-sketch for the hole thing.

Main questions here are if the handmade "mint-box" buffer would match the impedance of my active wiring, and if I could blend sound coming from active w/ piezo.

I think that FIsherman Powerchip would solve the preamp and mixing issues, but Id like to hand-make it all.

Thanks!
Attachments:
wiringSMALL.jpg
Last edited by bazuriya at Nov 5, 2008,
#2
Here is another possible sketch.
It's showing the diagram of EMG81/85 wiring with 9/18V switch.

The deal with the 5 way lever pickup selector is the following:
-Bridge position: EMG81
-Second position: EMG81 + 85
-Middle position: EMG81 + 85
-Fourth position: EMG85 + piezo
-Neck position: EMG85

The way its wired in fourth position, its intended to drive the piezo signal directly from the piezo to the jack, while emg 85 signal still goes through volume/tone. So, volumepot is intended to blend signals.

Would all this stuff work?
Attachments:
YamahaRGX240sEMG_PIEZO3.JPG
Last edited by bazuriya at Nov 5, 2008,
#3
What I did on my guitar (granted I don't have EMGs) is put the pickups and piezo in series. I put a volume know on the piezo and thus I can just blend it in whenever I see fit. I can all the way on, all the way off, and anywhere in between. Also, I wouldn't imagine you'd have to match impedances my way.
I believe your way will work, and sound good. Keep it updated. I like the sound of the piezo on a guitar.
#4
Quote by end_citizen
What I did on my guitar (granted I don't have EMGs) is put the pickups and piezo in series. I put a volume know on the piezo and thus I can just blend it in whenever I see fit. I can all the way on, all the way off, and anywhere in between. Also, I wouldn't imagine you'd have to match impedances my way.
I believe your way will work, and sound good. Keep it updated. I like the sound of the piezo on a guitar.


I tried the "radio shack" elements this weekend. I stuck 2 piezo elements to the wood at the spring cavity behind them, and wired them in series, and then to a jack.

It sounded well, but with a very very low output level. I had to crank my pod volume up to 10, when I had only to set it to 2 when using EMGs. The sound is more or less balanced, but the lowest pitch string (which is B, baritone guitar ) sounds much softer than the rest.
There is also a lot of "string drag" sound, which sounds much louder than the normal ringing of the string.
In general, sounds pretty similar to my EMG81, but there are some details in tone that reminds of an acoustic guitar.

I could notice a strange reverb effect which I think comes from the FR springs, kinda spring reverb, which is great BTW.

As I didnt have grounded the negative terminals of the piezo elements, there was a loud hum that was quickly killed by touching the jack. When I installed the active circuit for my EMGs I removed a couple of screws which were stuck to the wood of my guitar as a ground. What can I do now to ground my piezos?

Im about to make a preamp and see if the output problems are fixed this way, because with such a tiny level its gonna be impossible to wire it to my regular circuit.

Im wondering which preamp design will suit better my problem, mint box preamp or the one by InvaderJim.