Monday, January 07, 2013

The state of the Jazzmaster, January 2013 - shielding, witch hats and more!

It's no surprise to me that my most popular posts all deal with certain pretty specific themes - what's probably more surprising is that I know this yet keep writing about other stuff that only I seem to care about.  Anyway, over the years I've written a few posts about tinkering with my Japanese Fender Jazzmaster and they still get tons of hits (they're way up in the Google search results).  So I figured I'd post a little update on what I've been doing with it lately.

First, I have done one fairly major project that I hadn't yet written about (mostly because the results were a bit disappointing):

I shielded the entire pickup and control cavity using copper shielding tape. Why? Well, Japanese Jazzmasters ship with some pretty low output pickups - around the 4-5 ohm range. Because of that, they can get away with using black shielding paint rather than a real metal surface (vintage Jazzmasters shipped with solid brass tubs for shielding). This saves on both weight and cost.

But after upgrading to the Seymour Duncan Antiquity II's, which are closer to 8 ohms like a vintage JM pickup, I had definitely noticed an increase in hum. So I decided to shield it like a proper Jazzmaster. There shouldn't be any real difference in the effectiveness of shielding tape vs. the brass tubs, so I went with tape to add a minimum of extra weight. In case you're interested in doing this yourself, here's what you need:

The soldering iron is in case you need to do anything special with your grounding - I didn't, but some people like to specifically ground the shielding itself (you shouldn't really need to if you apply the tape correctly), or solder each piece of tape together. The sandpaper is similarly kind of optional - I used it both to sand down rough spots where the tape wasn't adhering, as well as on my pickup covers (more on that later). The pickup foam you need because you're going to throw out your old foam. The strings are because duh - you're removing your strings to get in there, may as well put on some new ones. And the multimeter's to check for connectivity all around - the tape needs to make a circuit, so the last step of the process is to check all over to make sure every part of it is electrically connected to every other, and it's all grounded.

You also need this - conductive copper tape from Stew Mac. The nice thing about this stuff is that the adhesive is conductive, so there's really no need to worry about soldering the tape itself together (as you need to with lesser copper tape).

Make sure you tape up over the lip around the edge - that's how you get a grounded circuit, because the shielding then is in contact with the pickguard foil. (Incidentally, I had to peel some of mine back after taking that photo, because the pickguard is right up against the edge of some of the body routings and the tape ended up sticking out in a few spots.)

So, does it work? Ehhhh. It's hard to say - it's still a single coil guitar, it's never going to be totally silent in the bridge or neck positions. (It's silent in the center position, where it acts like a humbucker.) I'm a little disappointed that there's about as much hum still as my Squier Strat, which has no shielding at all - not even paint. Then again, the Strat has much lower output pickups. The Jazzmaster's always been a hot guitar, output-wise.

So what was I doing on this night, with a screwdriver, multimeter, soldering stuff and more pickup foam?

Check out that weird reflection of the ceiling that makes it look like I've got some wild finish checking. (I don't.)

I reopened the thing up to check for "cold joints" in my pickup installation to make sure that wasn't the source of my hum. After resoldering one suspicious joint, I'm confident now that everything's tight.

That's a bad joint - the black wire's just kind of resting there, with some ugly looking solder holding it on and conducting all the current. Make sure you don't do this. I fixed this by desoldering it, then making a mechanical connection, then resoldering properly. Still have hum in single pickup config, though. Like I said, it's a single coil guitar. This is as good as it's gonna get!

I also wanted to raise my pickups a bit because one other quirk of Japanese Jazzmasters is that the pickup cavities are a little deeper than the American ones, so if you buy American pickups, the foam isn't going to push them out far enough.

By the way, check out that label. The official Fender Jazzmaster pickup foam is even listed as "weatherstrip" foam right on the label. If you're a purist about only using Fender foam, forget that - just go to the hardware store and buy some weatherstripping. It's what Leo would have done.

I actually didn't end up using this because I wanted to keep one package of foam sealed... for some reason. I'm kind of a hoarder. Instead, I carefully detached my old foam, cut a couple pieces of the stuff below in half lengthwise (so it's half this height) and then stuck it under the "official" pickup foam:

That's just high density rubber foam weatherstripping from Home Depot. At half height, when combined with the regular pickup foam, it ends up being perfect to push out the pickups to the required height.

Here's one other thing I did when I initially shielded the guitar:

Maybe a little hard to see but that's kind of the point - I fully sanded the finish off my pickup covers using that 600 grit sandpaper. They now have a totally smooth, matte feel to them that doesn't shine and is aging very quickly and very nicely. I said before that I don't like the look of the American reissue pickup covers - they're too dark and too shiny and just look weird, not like a real vintage cover. Well, unless you look right up close, these are already starting to.Without the protective finish, they're no longer a stark white but more of a cream color, and I just like the matte look of them too. Compare the color of the pickup covers to the real vintage knob next to it. Which brings me to...

Witch hats!

Witch hat knobs really should be on any "1966" reissue guitar - Fender Japan doesn't include them because they don't make them in general, and they obviously don't want to make them just for the Jazzmaster. Mine are real Fender new old stock from the 1960's - these are getting really hard to find and aren't that cheap considering they're freakin' KNOBS. You can see that mine are slightly mismatched - I may do something about that sometime, although this is certainly something that might have happened naturally to a real guitar from the 60's.  These knobs were just from different batches, and maybe even different years - one came to me still in the original sealed bag (oddly enough, the more discolored "tone" knob - that's real UV aging!), the other was obtained through a nice guy on the forums, and they've aged at slightly different rates.

The best way to quick-age old Fender plastic parts is to let them sit in some room temperature (not hot!) tea for a while - I may do that with my volume knob, or I may just leave it because it's not that noticeable, looks like plausible aging and it's just as likely I'd overshoot with the tea method and end up with mismatched knobs anyway.

btw, yes, they fit on CIJ/MIJ Jazzmasters, though they don't turn in a perfect circle (they're slightly off-axis) due to the smaller pot shafts. Again, not that noticeable, and you can always change the pots if you want.

At this point, I'm reaching diminishing returns with anything further I do to this Jazzmaster. About the last thing left is to just replace the remaining wiring and electronics, and I probably will do that sometime - although for me, it's mainly a vanity thing so my knobs turn in a perfect circle and I'll know in my own head that I have wiring "as good" as any American JM. But in terms of sound, playability and even look, I can't imagine how I'm going to improve this thing any further. It's a beautiful looking and sounding guitar (with literally the best neck I have ever seen) and I would 100% gig with it as it is.

Now on to fixing up my new Gretsch 5422T!

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About This Blog

This is increasingly not a blog about Alphabet City, New York. I used to live in the East Village and work on Avenue B, but I no longer do. Why don't I change the name if I'm writing about Japan and video games and guitars? Because New Yorkers are well-rounded people with varied interests, and mine have gone increasingly off the rails over the years. And I don't feel like changing the name. I do still write about New York City sometimes.


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