MoSch Machine: Building a Bass from a modified EX-4 kit

[MoSch]

Sooo more than six years after I ordered a modified EX-4 kit and after a lot of help here in the forum, I think I should finally start a build diary (no, the bass still isn't finished at all...)

I never built an instrument before, and I am not a craftsman. So modifying a kit was not because I knew what I was doing at all...
My goal was to learn a little bit about the instrument I'm trying to play for many years - I was not (and am not) expecting the result to turn out competitve with professional built instruments. Therefore I decided to built at least something unique with features I cannot get anywhere else, even though it might end up looking like something a teenage heavy metal kid might design and grown up musicians might consider silly.
So please don't feel offended as a musician or luthier if in this thread "features" like bottle opener, mounts for pyrotechnics or lasers or similar stuff might appear (if I ever find the time and motivation...).

I do like explorer-derivatives, especially my Charvel Star Bass but also my Dean ML, Aria Pro II ZZB (and meanwhile a Solar E2.4 PN), so of course I wanted something explorerish.

I ordered the then available EX-4 kit in summer 2019 as it was the only shop I knew where I could get modifications on my kit. A good reason for me to order it on the other side of the globe (I live in northern Germany).

What PitBull Guitars offered back then:





And my very first sketch after finding out there are customizeable bass kits without any further research



sooo.... with these information and idea I started to plan what to order....

[MoSch]

After reading a lot online and considering my experiences with my bass guitars I ordered the kit with the following modifications:

Modification 1: Body routing and Pickups: P-P
Neck Pickup: P-Pickup
Bridge Pickup: P-Pickup

Modification 2: Body material: Ash

Modification 3 Fretboard material: Ebony

Modification 4: Inlays: Shark tooth

Modification 5: Headstock: “Extra Large Black Paddle”

Modification 6: Hardware: Chrome

Modification 7: If possible: controls /control cavities parallel to the lower edge of the body instead of the strings.

Back then, Pit Bull Guitars offered the posibilitie to customize a lot of the kits:

[MoSch]

While waiting for the kit to arrive I read about components. Being lazy I knew, it's unlikely I will change parts once it is done...
So I checked every component if I wanted something else...
long story short:

The pickups I ordered and intend to set up together are an EMG Geezer Buttler for the neck position and a DiMarzio DP146 (Billy Sheehan) for the bridge position. I listened to examples also of other pickups (EMGs, DiMarzio, Quarterpounder, Steve Harris,...) - those two seemed fitting.
EMG offered a PJ set inkluding all the cables, electronics, potis,... with a solderless system... so I went for that. (anyone needs a single Geezer Buttler J pick up...? )
I also found discussions online about mixing pickups that suggested this combination might work. also the few electronical information on impedance I was able to find suggested that it might work.

The bridge from the kit has a bad reputation, also in this forum, and of course I looked for somethig easily substituteable, so there is Babicz and Hipshot.
As I figured out later that the holes to mount the bridge were not well positioned* I could have gone for basically any bridge... but so I went for Babicz

Seeing Gotoh tuners need bigger holes than those in the kit... I knew I have to decide before painting and got those as well.

I also got other knobs to my taste.


* see full story about my issues with the bridge, including a lot of help and encouragement from the community here in the thread
EX-4: Bridge Position / Scale length problem

[MoSch]

in the end of November 2019 I could collect my kit from customs.

Here with the aforementioned parts:

[MoSch]

First thing the manual suggests is a mock build. So headstock needs to be shaped first!

I learned a lot about why headstocks loock like they look...
A nice summary I found here and here and also Wikipedia. Those sources explain why so many high end modern guitars have boring headstocks

Of course I want both. An exciting headstock and acceptable performance of the tuners/strings/....

So I started designing "my" headstock taking into accound all those constraints. At least I hope I knew all...

Design study:



First CAD-drawing of my preferred design:



Then I started practicing... I bought cutting boards ("Frühstücksbrettchen", something obvously not existing in the rest of the world.. dictionary suggests "the wooden boards Germans eat their breakfast from") from the same wood as the neck and practiced cutting, drilling, mounting the spikes,...



The spikes have a thread, the tip they are screwed on a threaded bolt. Getting them there was... challenging
This way they can be exchanged, removed to fit into my case, and potentially be abused to mount all other kind of funny stuff


I put one of those dummies in position for a first impression how it might look like:



I liked it, and wanted to go for it!
Then it took a looong time until I finally hat the guts to work on the real headstock..... (I think we are now already in 2023...)

[MoSch]

so... around Mai 2023 I summoned up the courage to finally work on the real headstock.

Work in progress... not tooo nice yet



getting better



highly professional mount to drill the holes for mounting the spikes...



(I also only drilled or cut into the table once. So far...)

Final result:



yes, the tuners fit that way. Glad I did the CAD-design to check.

[MoSch]

First time it makes noise



but... the bridge holes are at the wrong positions. Maybe due to my customizations with pickup-holes and tilted control cavity...

The whole story can be found in this thread.
Summary: The nice folks here in the community encouraged me to fill the holes and redrill...
So I practiced that on my breakfast boards again, learnt what a japanese saw is,...



and filled the holes.

Of course that took me another year, so spring 2024 saw the bass with no more wrong holes - but also no correct ones.

[MoSch]

the original bridge mount with press-fitted ferrules seemed rather archaic to me... also... with that approach I only had one chance... I dont like this idea...

encouraged - AGAIN - in this community as well as by the bridge manufacturer who responded nicely to my email, I decided to try a different concept.
So to say... a MoSch-mount

Of course, I neither had know-how nor tools to make it happen... I hunted for the neccessary parts, then I learned what a Forstnerbohrer (Forstner drill?) is, bought one, and got help from a friend with drill press access.
And figured out already now the bass doesn't fit any of my cases...

So... after adapting the Charvel Star Bass Case with a knife and violent force - I was able to carry it to a drill press in the end of 2025, get new holes in its body and finally mount the bridge









The grounding of the bridge is now done with hole between the control cavity and the closest huge bridge mount hole.




So the next step could be a new "Mock build"... but I have to wait for the suitable drill to be delivered first. Of course that one was missing in my collection.

So... lets see how many years it takes me this time to make a next step

[fender3x]

Good use of the breakfast boards! Where my daughters live in Germany they call those boards "Vesperbrettchen" (or "Vesperbrettle" because they are in Baden). Good use of them! Here I think they would just be called "small board" and you could get them at an arts and crafts shop.

Cool headstock! Looks like you were creative at both ends of the bass!

"Forstnerbohrer" translates to "Forstner bit"... It looks like you drilled those holes with a drill press. (If not you have an incredibly steady hand!) Curious what drill you need to complete the work?

At some point you'll get to the pickups and wiring...and since you speak German, you may want to take a look at my absolute favorite reference for bass wiring:

https://www.bassic.de/misc/E-Bass-Schaltungen.pdf

...as far as I know there is no more comprehensive reference, particularly for passive basses. It even gives you two versions of passive Gibson Explorer bass wiring plans ;-)

[fender3x]

Cadfaels has an almost endless set of custom diagrams for two pickups and three controls at the end of the list of historical diagrams. I could spend another 7 years just figuring out which one(s) I'd like to try ;-)