Example of Modification
On this portion of the web site I will demonstrate the application of various switch schemes mentioned previously on a standard Yamaha Pacifica guitar. You will be able to compare the original circuit to a complete modification that greatly improved the guitar's overall sound and versatility.
Pacifica’s Original Circuit Diagram.
This is the final modification done to the Pacifica. This particular guitar has
an X-Bridge pickup that is already build into the vintage style bridge. The X-Bridge
instructions urged not to have the piezo and the magnetic pickups to be hooked up
at the same time unless you use their active mixing circuit. The passive configuration
called for a stereo jack to be used. I experimented with the stereo option and found
that the X-bridge had somewhat sounded out of tune with the standard pickups. I
measured the X-Bridge by itself with a tuner and found that it did have a slight
intonation difference. The X-Bridge by itself sounds great for cleans and distortion,
so I incorporated a selector switch to bypass the magnetic pickups when the X-Bridge
was selected. It is nice to have one of these since it is like having two different
bridge pickups on one guitar.
The three magnetic pickups have series/parallel switching. I
found this to be very useful to take the "hot" pickups down a notch, or to have them
up at full power. The phase switch is hooked up to the neck pickup. This allows
the phase effect to be useful when the neck is hooked up to the middle pickup or
the bridge. There is also a high bypass capacitor hooked up to the volume pot. I
seldom use the volume control, but this allows the lows to be rolled off first with
slight movement of the knob, then all the way down like a typical volume control. I
also further experimented with different capacitor values for the tone pot, and found
adding a 0.022uF in parallel gave me more control over the guitar’s overall tone. I
found the Dimebucker, that I used in this guitar, was a very good pickup, but more
of a one-trick-pony that was only good with distortion.
The original guitar had gold hardware, which when the guitar was brand new, looked
great. After over ten years of use, the gold took on an ugly tone. When this modification
was done I also replaced all of the gold hardware with chrome. The overall look
of the guitar was improved by this modification as well. In the picture the "original"
Pacifica was actually already modified with a Screamin Demon pickup, and three switches
that just worked the bridge.
The improvement in this guitar was dramatic, but a
few problems did come to surface.
I had problems getting the action high enough to eliminate fret-buzz without being so high that it was difficult to play. This problem was remedied many times but kept coming back. I later found that the neck had become warped more and more over time. I tried putting a modern Pacifica neck in the guitar to replace it, but the neck pocket didn't match up very well. The neck didn't play as well as the original even after it had been sanded to fit in place. The lesson that I learned through all of this is that a guitar is a very finely tuned instrument. The length and height of the strings all play an important role to match up to the rest of the guitar with very small tolerance. It takes great deal of patience to hone your guitar to a good sounding state from the ground up as far as the hardware is concerned. Do not be discouraged or disappointed when the guitar sounds terrible after first being built. Set the string height (action), then set the intonation and the guitar comes into focus quickly. The book “How to Make Your Guitar Play Great” really takes this sting out of setting up your guitar.
After a lot of consideration I later decided to put all of the electronic parts into a Fender Stratocaster.
I felt that a well made guitar like that would be an all around better guitar and not subjected to some of the physical limitations I found with the Pacifica. When I looked into the prices of finished Fender guitars, I started to consider just to get the parts I needed, a really good neck and body. I found that I could have a custom made Stratocaster made by a company named Warmoth. With Warmoth I could have any type of wood and finish on a guitar. It was an interest of mine to use some woods that Fender never uses. Every detail of the guitar would be custom to my specifications, meanwhile still having the standard Fender shape and set up to work with. I would recommend doing any modifications you want on your guitar, but you can't always polish a turd.
There were some other modifications done to the guitar as well. I sanded the neck
pocket of the guitar down since it was very rough and still coated with finish. That
act alone greatly improved the tone transfer and the sustain of the guitar. You
never know unless you look, I suppose. There are also several small holes drilled
through the body from the inside of the pickup compartment. This was also an experiment,
but it worked out great for the tone and sustain of the guitar as well. This was
my first electric, so I was a little reluctant to start drilling.
Yamaha Pacifica before second modification.
The Yamaha Pacifica final modification
This diagram shows the Yamaha Pacifica’s original circuit. The photograph above shows the guitar after a few different phases of modification. This circuit has evolved several times due to refining and changing the circuit. The modification below is the final draft of all the modifications done to make the guitar as versatile and functional as possible.
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