The Lab Rat -- A bass for pickup experimentation

[Jon Clegg]

I was originally planning on doing this as a $100 challenge entry, but life got in the way so I knew I wouldn't complete it in time.

As I started playing with low-impedance pickup designs in this thread, I found that I was pretty limited where I could mount my prototypes with just a surface mount.

My thought was to use the pine-prototype that I had built for this bass as the basis of an instrument just for experimentation:

As you can see, I used it a s a bit of a guinea-pig for routing, templates, etc. so I'll have a bit work to do. But hey, I love a challenge.

I'm also planning on this being my first time building my own neck; so as long as I'm building the neck, I figure I might as well build something hard to find commercially, so I'm going to build this as a 32" scale bass.

More to come...

 

[michaelwayneharwood]

Sub'd.

 

[josiah goldfish]

If this is for testing pickups, I would use a 34" scale length, as I wouldn't want to create extra variables. I love the idea, and that first bass you posted is very pretty!

 

[michaelwayneharwood]

If this is for testing pickups, I would use a 34" scale length, as I wouldn't want to create extra variables. I love the idea, and that first bass you posted is very pretty!

If it's a bolt on it's easy enough to build necks in any scale length you want to test.

 

[josiah goldfish]

If it's a bolt on it's easy enough to build necks in any scale length you want to test.

That's true, but the taper will be different in the pocket

EDIT: ...unless the 32" neck had a wider nut width. If you take a 34" neck, and measure two inches from the nut, that'll give you the nut width of the 32" that would have the right heel shape

 

[michaelwayneharwood]

That's true, but the taper will be different in the pocket

Agreed. As with everything you have to make compromises to enable versatility. I am super stoked to see how this turns out!

 

[josiah goldfish]

Agreed. As with everything you have to make compromises to enable versatility. I am super stoked to see how this turns out!

Me too!

 

[Robert Canfield]

Sub'd... The neck pocket can be oversized to fit any neck. Really don't see how it would matter in this bass.

 

[Jon Clegg]

Pickup position is more a matter of percentage of scale length as opposed to absolute position I think. The aperture size relative to the scale length may be a factor but I think it can be ignored. In any event, I'll plan for a 32" scale as it's a mid-point between my short scale EB-0 clone and my long-scale. I'm also looking at have the bolt-on neck tenon extend far down into the body, somewhat like Brian May's Red Special.

The neck is going to be maple with a maple fretboard. I found a nice 4' long maple 1x3 at home depot a while back and a 24" x 3" x 3/8" maple fretboard blank at woodcrafters. I'll be using one of two 2-way truss rods I scored off of amazon.

The pickups I'd be working with will be either of the flat designs that I played with on this thread. I'd be looking at routing a channel on the treble side to accommodate the transformer for the CSE-187L based pickups, I'm also looking at doing a multi-turn PCB coil with built-in preamp along the lines of the Fishman Fluence. Also I'll be using some sort of on-board pre-amp, so I'll have a spacious control cavity to house that.

Finish wise, I'm thinking that an tru-oil fiinish will be most forgiving if I need to do additional routing.

 

[Jon Clegg]

OK, Time to get started... First thing that I needed to do was to replace the much abused center section of the top, since the top and back are still just screwed together, this was just a matter of unscrewing the sandwich, cutting apart with the bandsaw, truing up and gluing in a piece of maple 1x4. Note that at this point I want to keep the sandwich where it can be taken apart for interior routing for wire channels, hence the wax paper between the layers.

And now clamped up and drying overnight.

 

[Jon Clegg]

So a bit more progress: Took the sandwich apart, did some interior routs and glued it back together:

The shot below shows where the 'well' for the transformer will be; I'll rout that out after I've done the neck pocket rout. Also plan on re-shaping the lower horn a bit.

And back in the clamps!

 

[SamanthaCay]

This looks nice!
I have only one suggestion and that is to incorporate a vice of some sort that will extend as wide as possible, ie one jaw up by the neck and the other down by the bridge or anywhere in between. You could also make those jaws pivot so you can throw pickups in there at an angle if desired.
Anyways that's what I want to do to mine when I get the time.

 

[Jon Clegg]

This looks nice!
I have only one suggestion and that is to incorporate a vice of some sort that will extend as wide as possible, ie one jaw up by the neck and the other down by the bridge or anywhere in between. You could also make those jaws pivot so you can throw pickups in there at an angle if desired.
Anyways that's what I want to do to mine when I get the time.

Thanks Sam. Currently, I plan to inlay steel strips in the top outside of the string area. I'll build pickup carriers that incorporate rare earth magnets to allow me to mount the pickups wherever I want.

 

[SamanthaCay]

Thanks Sam. Currently, I plan to inlay steel strips in the top outside of the string area. I'll build pickup carriers that incorporate rare earth magnets to allow me to mount the pickups wherever I want.

Hmm...
I actually kinda like that. I guess my only concerns there would be first getting the magnets far enough away to not effect the pickup which I think if ya use a not so super strong magnet and enough space that should be pretty do-able. Second to that is how to attach to the carrier.
I guess in large part the ease of attachment would also depend on how you're making your pickups. In other words if you're sticking to some specific sizes the carrier or a few of them would work great because they could be made to fit said sizes.

Anyways all this got me wondering what others are doing with shop/test basses in general. I wonder if we started a general thread on these things if anyone else might step up and show what they're using.
Is this a good idea, are we the only two on here or are there others?

Last this also reminded me of this,
About a minute in they talk about leo's test rig.

 

[michaelwayneharwood]

Anyways all this got me wondering what others are doing with shop/test basses in general. I wonder if we started a general thread on these things if anyone else might step up and show what they're using.
Is this a good idea, are we the only two on here or are there others?

There are others. I built a bass for a similar purpose: Sonum Experior | TalkBass.com

 

[Jon Clegg]

Brief update: I harvested the high mass bridge that some cretin had mounted on the old National, after some de-rusting in vinegar, it looks pretty good:

It should work out well on the lab rat.

I also found these 1/4" square steel rods at the local hardware store which should work perfectly for my magnetic mounting rails. Here's what I have in mind:

Once they've been shortened a bit, they'll suit the purpose.

​

 

[Jon Clegg]

OK time to build a neck, so here goes with my first scarf joint... I'm aiming for a 14 degree tilt back, with a headstock about the size of the one on my EB clone. Naturally since I've read many build threads there's a good chance that things will go awry with my first crack so I cut both pieces with room for error....

So far so good

And well.... good thing I have room to try again!

Well time to cut off the first attempt and try again.

Since I'm not @SamanthaCay, who can cut scarf joints with nothing but cold steel and nerves of steel, this time I'm building a jig to mill/sand the angles and match it up where I better see the joint.

 

[Jon Clegg]

So getting back to this... Decided to buy a 34" scale neck to mount on this sucker to un-stall this project. I have a specific use for a specific pickup in mind and want to try it out before the Winter build off.

 

[RBS_Johnson]

If you still wanted a 32" scale, and aren`t too picky, I think Rondo Music still has medium scale necks for sale for cheap.

Just throwing it out there.
-Jake

 

[Jon Clegg]

If you still wanted a 32" scale, and aren`t too picky, I think Rondo Music still has medium scale necks for sale for cheap.

Just throwing it out there.
-Jake

Thanks. I'm cool with using a 34" scale for a test mule. I'll just need to remember to translate the position for other scales.