Bill's first build - JBA-4

[WeirdBits]

Yep, the new shape looks great.

[billb]

Thanks all for the comments so far. As with everyone real life keeps getting in the damned way!

Anyway, I have made some progress. First coat of intensifier went on this morning, another one next weekend and then probably again the weekend after.

In the mean time I've started working on the neck. I've levelled (hopefully) the frets and am now in the process of crowning them. Hopefully I'm doing a passable job on this as it's the bit that most worries me about this build. Getting there slowly.

I also shaped the headstock this morning and I think it's come out fairly well. I'm using small body machine heads so I could take a fair amount of wood off.

The only thing worth taking a picture of from the progress so far is the head stock so here's some pics of that.

Before


During


After


There's also a completely different custom pickguard on the way from Pablopepper which I'm really looking forward to

[Chuck]

Really nice billb! I realised I hadn't checked in on this one for a while when I was reading about your next project - it's always a good thing to have one project in "finishing" phase and one in "woodworking" phase!!

[billb]

OK, an update!!
The last month or 2 has been 5 minutes to do a coat of stain, intensifier or finisher and then wait a week before doing another one, then repeat. Infuriating!
In the meantime I've also put Paua fret dots in, did a semi-decent (I hope) fret job and finished the fret board with lemon oil. the neck itself is a very light Feast Watson Old Baltic stain (thanks for the suggestion Chuck) and then tru-oil.
The machine heads are Gotoh and the barrel is slightly under a mm smaller than the bushes are so I put a layer of masking tape around the barrel then coated that with superglue to give it all a really solid fit.
Easter however has worked out well as this weekend was a fortnight after the last coat of Dingotone so I got stuck into it.
I polished the body with Meguiars and then put a coat of Gilly Stephensons gun wax on the body. The wax looks nice but I'm not sure if it's as tough as I'd like so I probably wouldn;t bother with it next time.
I've shielded and grounded the body cavities with copper and tested with my cheap little multimeter. Mine doesn;t have a continuity beeper but I set it to the lowest ohm measurement range and tested everything. It read 1.4 to 1.7 from everywhere to everywhere. I'm not sure what that actually means but it was the same reading as when I put the probes about 2mm apart on the copper tape so I assume it should all be grounded.
On the bridge I had to gouge out more of a channel to seat the ground wire in so the bridge would actually sit flat, hopefully that's all worked out - I'll find out when I get it ready to play, hopefully it will have minimal hiss.
& then this afternoon - I was able to attach the neck. And it looks like a bass!!
The neck, bridge, pickup locations, string paths, etc. all seem to be about right so when it goes together properly it might, hopefully, work.
From here I need to lower/shorten the DB bone nut slightly, install the electronics (EMG passives with no soldering required), install my PabloPepper custom pickguard and then set the whole thing up! So definitely getting there
Thanks all for the info on the forums - it really is very helpful.

Anyway, a couple of pics:

[Simon Barden]

Looking great.

The 1.4 to 1.7 reading should indicate 1.4 to 1.7 ohms (and it's probably lower than that), which is fine. Most of the hobby level multimeters aren't really designed to measure very low ohm values accurately)

However, looking at the lower photo, you've probably been a bit too tidy with the copper tape. It needs to be connected to ground to work. The metal control plate will be grounded through contact with the potentiometers. So for the main control cavity/neck pup rout, run some tape over the lip of the control cavity so that it can make contact with the underside of the control plate. Obviously do it within the outline of the control plate so that the copper doesn't show.

The bridge pup rout is on its own, so you'll probably need to solder a wire ground link between the main control cavity copper and the bridge pup rout copper. You should be able to do this easily. Alternatively you could simply run a non-insulated bare piece of thin wire between the two cavities and tape the ends down with some more copper tape.

I believe in making as big a ground plane as I can if I'm shielding a guitar, so if you put a layer of copper tape under the pickguard and run some tape over the edge of the neck pup rout, then that gives a much larger area of grounded copper to absorb RFI.

Apologies if you've taken care of the above after the photos were taken, but just in case, I though I'd raise it now. Nothing that can't be fixed at a later date, but if you hadn't done the above, then you may wonder why your 'shielded' bass was still noisy.

[billb]

Thanks Simon, belt and braces approach always works for me too!

That's good news on the reading. I assumed it was due to the cheap multimeter.

The control cavity cover and pick guard will each be grounded through a strip of copper tape from the cavity to one of the screw holes, I'll put that on once I've got the screw holes positioned and drilled, I'm planning on only grounding one of the screwholes for each cover to avoid any chance of multiple ground paths. The pickguard/control plate are both plastic so I'll back them with tape.

Also I lined the tunnel from the bridge p/up cavity to the control cavity with copper foil and flared it into the copper covering the wall on both cavities.

Thanks again

[Simon Barden]

I'm not sure that multiple ground paths really apply here. Whilst you certainly want to avoid them in wiring circuits, here you're trying to make the best Faraday cage you can and the best ones are solid metal containers boxes. It's not like the foil is acting as a return path and carrying any of the guitar signal. But as long as any gaps are as small as you can make them, then wavelengths short enough to penetrate the gaps will be in the microwave range rather than radio range, so are unlikely to make their presence heard (unless maybe you live by a radar station).

[billb]

OK, I ended up putting a lot more copper foil on the surface and folded in to cavities - and it worked. This thing works perectly with no hiss, hum or other carry on.

In other words, it's together and playing! Not finished yet as I'm waiting for the headstock decal but everything else is done and it's been played in anger. I' seriously happy with it!

& a big thanks to Pablopepper for the pickguard which I love





& to prove it works here's a couple of clips taken on an IPhone so fairly low quality sound with some of the bottom end missing. Go easy on the playing this is the first time i've ever video'd and shared - bum notes and all. (it was actually a good learning experience I do tend to race a bit amongst other issues so now I can work on that).
& let's be honest - it is so damned cool playing something that I built!!

[billb]

[billb]