Modding a P into a P-Tractor

[xray]

SUB!
Nice work and idea - I like the reverse tractor concept - from p to tractor. Always wanted to do something like this but haven't found a reasonable donor bass yet. Interested in how you cut the holes for the wire for the j pups. Always wondered how I'd get the bit in that tiny space.

[ronaldpdbrandt]

Originally Posted by xray

SUB!
Nice work and idea - I like the reverse tractor concept - from p to tractor. Always wanted to do something like this but haven't found a reasonable donor bass yet. Interested in how you cut the holes for the wire for the j pups. Always wondered how I'd get the bit in that tiny space.

I forgot to take pictures of that, but I'll take them later. I bought a really long drill bit, which helps. I was a bit worried, actually, but it came out perfect! I somehow was able to get both pathways to exit the same hole in the control cavity, which made me very happy for some reason.

[ronaldpdbrandt]

Here are pictures of the channels between the Js and the control cavity, for xray:




Note that the two channels meet where they exit into the control cavity. I thought that was cool, but in retrospect it probably would have been easier to fish the wires through if I had kept them separated. Anyway, your hardware store should have a long 1/4" drill bit (at least 12" long) that can do the job. That way you can get the drill's body out of the way, to make the angle of the channel very shallow.

[ronaldpdbrandt]

Here's where we are now:



So close! I wired it all up, but somethings not right. The "middle" J pup is not responding, and I'm getting some weird grounding buzzes when I touch the pickups. Something like this always seems to happen at this step. I think the bottom of the push/push pot and one side of the DS might be touching the copper sheilding I used. Anybody know what kind of tape I can use as a barrier?

Also, the DS is not completely in place yet, that's why it's not in line with the strings. I'll be fixing that.

[T-34]

I dig!

[thebassbuilder]

Just use electrical tape. The bass looks killer and please post a sound clip of it.

[ronaldpdbrandt]

Thanks, and I will!

[tomersg]

cool project! but the original tractor bass have separate controls for each set of pickups. you don't plan to do so?

[ronaldpdbrandt]

Thanks! And no, I wanted to keep the control area as simple-looking as possible.

[tomersg]

so how the wiring and controls goes?

[ronaldpdbrandt]

Originally Posted by tomersg

so how the wiring and controls goes?

The wiring schematic is shown in the first post of this thread.

[EduardoK]

A P-tractor is something I have thought about for a couple years...
subscribed!
Have you thought about matching the DS and J's outputs and hum-cancelling? the DSs are pretty hot...

[T-34]

J's are wired in series, this should do

[ronaldpdbrandt]

It's all done! I was able to get the grounding buzzes resolved, and I got the second J pup working. I was able to balance the outputs pretty well by lowering the poles of the DS just a hair (It seems these Js are decently hot as it is).

The only thing left to do is to get a couple more pickup screws for the Js and put my personal logo on the headstock!

I'll get some sound clips up as soon as I can. I will say that it is living up to what I was hoping for it!

[Splods]

I'm digging this!

Cannot wait to hear the beast.

[wraub]

Very cool.

wraub

[dkimbrobass]

Looks nice, what's that cab in the background? Thanks

[bassistjoe93]

Sub'd for sound clips! I'm thinking of doing something sort of similar, but I'm not quite sold on the idea yet. Looks great though!

[ronaldpdbrandt]

Originally Posted by dkimbrobass

Looks nice, what's that cab in the background? Thanks

Why, it's a self-built (no kits for me!) fEARful 12/6, of course!

[T-34]

my (quite similar) mod is at this stage now, waiting for the electronics.