First Build JZ-6

[JoelDee]

So after spending my evening wet sanding up to 3200 I had a very smooth surface front and back so got stuck into it with the cutting compound. I used Meguiars Polishing Compound and am pretty happy. There are still some visible swirls - I'm not sure if repeated goes with the compound will resolve or the waxing process might help fill/hide.

Regardless, after trying this process on another build with terrible results actually getting the beginnings of a mirror finish I'm very happy.

And I couldn't help myself and have attached the neck as I wanted to see how it was all going. I'm a week away from any further building as I have forgotten to order Baritone strings and my local guitar store doesn't stock them!

[JoelDee]

I've started to assemble so that I can test the pick ups etc. I am getting a huge amount of feedback/hum thru the amp and only when I turn the volume on the guitar up to 10 and am touching the string/bridge etc does the hum stop and the guitar sounds normal (quite good actually).

I've used my multi meter to check the grounding over the guitar and it all seems OK.

The only inconsistency I can find is that some of the pick ups screws are grounded and 2 are not. None of the pick ups are grounding. Is this correct?

Any trouble shooting advice would be appreciated!

[Simon Barden]

The usual reasons for that level of hum are either getting the output jack connections crossed over, or the third (right-hand) tab on the volume pot not being connected to ground/ the back of the pot.

Pictures of the wiring will help. It won't be the screws.

[JoelDee]

Thanks Simon, I checked the grounding on the jack and it looks correct and the third tab on the volume pot is grounded. I had to replace some of the wires that snapped (from being moved around so much) but didn't alter any of the wiring from the standard. I'd assume if i had the switch wired backwards it would just cause it to be out of whack, not any hum or feedback.

Wiring is below, hope it's clear enough.

[Simon Barden]

The wiring looks OK to me, though it would be easier to tell with it sat in front of me whilst using a multimeter.

Are you using a decent lead and not the POS lead that ships with the kit that has all the hum-reducing properties of poking a stick into a wasps nest?

[JoelDee]

Yeah I'm using my Fender lead and amp so no issues on that front. I rechecked the lead and amp on another guitar and it's all good.

BUT i think I solved it! As I moved the pick ups apart I had to reroute some of the cavity, when the pickguard is sitting in place and I play, there is no hum. As soon as I press down on it (like if I had screwed it in) near the jack it hums. The cavity under the jack is not deep enough so the tip is hitting the shielding tape I assume and causing all that drama.

I'm off to get myself a spade bit from the hardware store!

Thanks again as always Simon. It's always so handy to have someone double check your work!

[Simon Barden]

If the tip is hitting the shielding tape and not going silent, then that means there is no proper ground connection to the shielding tape, so the signal is connecting to the tape and the tape is acting as an aerial for noise.

It looks like there's a decent overlap of the body tape onto the top that should make contact with the tape under the pickguard. So check that the copper tape on the pickguard is making contact with the pots and so is being grounded. Also use a multimeter to make sure that you are then getting continuity between ground and all parts of the copper tape. Even with conductive adhesive, I found that I sometimes didn't get continuity across pieces run in parallel with a small overlap until I'd run another piece across them at right-angles.

[JoelDee]

Well, after some time off to move house and get some decals delivered from the UK (~7 weeks...) I have finally finished the JZ-6.

I left the majority of the hardware as standard, drove across Melbourne (when it was still legal) to find baritone strings and think it sounds really great. I still need to put in some research and practice and I will endeavour to record a sample of how it sounds in the near future.

Some of the key things I learnt with this build...
- I will avoid cutting/shaping custom pickguards whenever possible (caveat on this is of course practice and the right tools)
- Using primer filler still left a grain pattern under solid paint but lesson learnt, I am using it on another build and will try to leave a solid coat on (update this is so far going successfully)
- Truoil for the neck on this and my PB build has been really simple to work with. A few coats, sand back with 0000 steel wool and repeat and it's super smooth and fast
- I think it is worthwhile replacing wiring where you can, after moving pots etc between pickguards some wires broke at the solder. I replaced with higher quality 22AWG wire where i could. It's also nice to get a bit more practice soldering!

Anyway, some pics below (apologies for the quality, I just can't seem to get anything close to high def). It sure is something different for the collection!

Also, there must be a market for Jazzmaster custom guitar stands...it just never sits quite straight...

[dozymuppet]

Looks great \m/

[AlesanderPlo23]

'Well, as luck would have it the kit just arrived in time for the long weekend. 3 days of sanding!
Did a layout and everything is in the box, although I don't think I got the right strings included ha ha. They fall a bit short for checking the neck so I will have to raid the sewing kit.'

So, how is it going? I'm not sure what may help me to check the neck, because I always think it not looks straight, but in fact I believe it is.