4004 pickup mods?

[cjj]

I've seen a few references to modifying the 4004 HB1 pickups to work like a single coil but so far I haven't been able to find any info on how this is done (or whether it's worth the bother, sound-wise).

Does anyone have any info on this?

[weemac]

You just need to remove the heat shrink from the hook up end of the wire and the joined wires that you expose become the new earth for the pickup(the hot remains the same). This will tap it to a single coil.
When tapped the HB-1 will sound like a cross between a 70s Hi gain and a 60s toaster....
Eden.

[cjj]

So, what's happening here is that you are now just using one of the coils, right? Seems simple enough, easy to change back if I don't like it as well! Thanks!

[weemac]

So, what's happening here is that you are now just using one of the coils, right? Seems simple enough, easy to change back if I don't like it as well! Thanks!

Thats correct. Try it on the neck pickup first!
Eden.

[cjj]

This doesn't actually have anything to do with mods, just an observation...

I was poking around in my 4004 and noticed that the tone pot measures 330K instead of the 500k called out in the schematic on the RIC site. Has anyone else measured theirs? I'm what it'd do, perhaps a tad less high end.

[weemac]

A 330k pot will make it a bit darker... Is the volume pot 500k?

I recently rewired my 4001 that has an HB-1 in the neck position (with tone controlled coil tap) with 500k pots, and it opened it up by a whopping amount. It's very versatile....
Eden.

[cjj]

They are both 330k. I'm planning on doing the V/T V/T stacked knob mod to it and I'll be using 500k pots all around for that. I'll give the split coil mod a go as well. It would be nice to be able to switch it in or out, but adding switches would be a bit of a pain. How does the tone controlled coil tap get wired?

[nukebass]

I haven't measured mine, but I just looked at the schematic and it listed 330K pots for the 4004.

http://www.rickenbacker.com/pdfs/19516.pdf


I started looking at other diagrams and there are some interesting ones. The phase switch on the 481 interests me. I played my brothers Brian May guitar with the phase switches and that has some interesting sounds (and on/off for each pickup). The other one that looked intersting, but I have absolutely no idea what is going on, is the listing for the 420. A toggle switch with a single pickup? I couldn't follow the diagram, but I'm assuming it has something to do with extra capacitors. I need to learn some wiring

[jps]

I started wiring up the Lemmy tonight as VVVT!

The only problem is, the flux capacitor Brian got me to fit in the control cavity is a bit too large so I am going to carve out a bigger cavity. I think the upper half of the carvings on the front may have to get a pickguard put over it to hide the hole. It could make for an interesting sort of Light Show Lemmy Bass, however.

[johnallg]

I haven't measured mine, but I just looked at the schematic and it listed 330K pots for the 4004.

http://www.rickenbacker.com/pdfs/19516.pdf

Interesting - the schematic I saved off the RIC site on 11/16/2007 shows 500k pots. Looks like RIC has standardized to the 300k value.

[weemac]

They are both 330k. I'm planning on doing the V/T V/T stacked knob mod to it and I'll be using 500k pots all around for that. I'll give the split coil mod a go as well. It would be nice to be able to switch it in or out, but adding switches would be a bit of a pain. How does the tone controlled coil tap get wired?

To do a tone control tap, wire the link between the coils (the one under the heatshrink) to the unused tab on the tone pot (with the tabs facing down it's the one on the left) and thats it!
From 1-9 everything is as normal and on 10 one coil is shunted to ground tapping the pickup...

Eden.