Jaguarillo gets new pickups and setup

This guitar is a friend of a friend’s. I worked on his acoustic before and I guess he was happy enough with it to come back. Sweet!

Jaguarillos are Jaguars but with two strat pickups and a humbucker in the bridge. The guy wanted to change the pickguard, and replace all the pickups – Novak lipsticks in the neck and middle position, and a Manlius Stud-Bucker in the bridge.

The pickguard needed some work because the humbucker wouldn’t fit. The radii of the corners were too big:


I already started working on it when I took this picture, see the bottom left corner.

I did the whole thing with files (Nicholson Handy File and a round file) and a razor blade turned scraper. It came out ok (forgot to take a picture), but not my best work. It would have been much easier to do with a router.

The rest of it was straightforward, except that when I put it all together I noticed that the tremolo clicks when actuated. This is a thing with the cheap, import tailpieces, and it can be avoided depending on how high or low the tremolo arm is set up. However, the owner of this guitar wanted me to set up the lock so the guitar can stay in tune if a string breaks, so I had to go in and start filing.

Mike & Mike Guitar Bar posted about this before, so that’s where I got the idea. You can read what else they wrote about import tailpieces here. Basically, I filed every surface so it is flat. I think that at the very least the molding marks should be knocked off, but if the plate is off the tailpiece and you’re filing, might as well go the extra mile.

There was one little problem that is worth mentioning – the Stud-bucker had only two leads – hot and shield. So the middle+bridge position were out of phase, and flipping the leads couldn’t fix it. The reason it couldn’t be fixed is because then the shield (and pickup casing) are hot, but the rest of the metal parts (and strings) of the guitar are ground. Then if the player touches both the pickup casing and the strings, or bridge, or any other metal parts, the signal will short. FWIW, Manlius offers these (and I assume all humbuckers) with coil taps, so the polarity of the pickup can be flipped. Here are a few pictures I took after it was finished:


J Mascis Jazzmaster rewire + goldfoil at the bridge!

This is my friend’s Jazzmaster. He asked me to install a Curtis Novak Goldfoil at the bridge, and rewire the guitar for two separate volumes and tones (using the rhythm circuit for the tones), and a kill switch.

I used this schematic, credit goes to Sigler Music Center in Arkansas:

JM two vol two tone kill sw

What I did differently is that I used linear pots for the volumes and log for the tones, and the kill switch is on (signal passing through) when it’s at the bottom. The switch being on when it’s at the bottom makes more sense because the player is more likely to hit it strumming down. Also, that’s what my friend asked for.

Without strings on, I thought there was too much of a hum in the middle position. I say too much because my setup here isn’t the quietest, being so close to the train and all. That made me think that the goldfoil’s magnet isn’t oriented so that its north faces the opposite direction than the neck pickup’s north. In other words, the neck pup and goldfoil aren’t RWRP.  However, the original bridge and neck pickups measure very close – 100 ohms different, with the bridge being the hotter one, of course. I told my friend about it and we decided to use the Mascis bridge pickup in the neck position. I put strings on it, and no hum.

I haven’t had a chance to really play through an amp and see how I like the volume pots being linear and the tones being logarithmic (it was too late when I was done), so I moved on to non-amplified setup. Basically, the low E string was slipping out of its saddle, and the radius of the bridge (TOM) didn’t fit the radius of the fretboard (9.5″), so I had to file the saddles a little bit.

This guitar is almost done, just need to hear it amplified.

Guild F-30 end block crack repair

This is an old repair that I never wrote about, but I learned a lot of important stuff from it, so I think it’s worth being documented.

My Guild F-30 was shipped with a cracked end block. I don’t know if it was cracked prior to shipping (bought it from Guitar Center’s used section, so not a lot of pictures), or if it cracked during shipping (the end pin wasn’t removed from the block). Anyway, it was cracked and I took my time figuring out how to fix it.

Frank Ford has a pretty good guide to fixing those cracks. I kept reading this one and going back to it. I think Frank Ford is the authority when it comes to guitar repair and I always try and follow what he does. I know his website looks rinky dink because it’s HTML, but the guy is a wealth of knowledge.

Now to the crack itself:

First a picture of the crack on the outside, taken right after getting the guitar.


Not the best picture, but it shows what was up.

And the crack from the inside:



Notice that there are these streaks along the crack? These baffled me. They looked like that could be glue, but the crack was still open. Also, They seemed to be “on the surface”, so I figured that if it’s glue it’s not epoxy, which coat the surface, and is probably CA glue. It didn’t make sense for it to be anything but glue, because why would anyone smear something on the end block?

Removing the previous glue is important, because it would prevent the glue I’d be using to adhere to the wood. So I took some acetone, and very carefully got it in and swabbed the crack. The streaks are gone:


Notice the wax paper inside the guitar. I don’t need any acetone accidentally dripping on the sticker inside and ruining it. Same thing on the outside, I wrapped the top with parchment paper in case any dripped.

Ok, cool, so it’s superglue. Now I needed to remove it from the inside of the crack. The obvious candidates to getting inside the crack were q-tip (not that great) and brushes. I tried different brushes that I had around, but none were long enough and thin enough to reach the entire crack. So I went and got a really thin fan brush. I need to take a picture of it, but it fit in the crack easily. Just dip it in acetone and get in the crack. Like Frank Ford, I used a long clamp to push the end block inward so the crack would open.


Checkout John Fahey’s How Bluegrass Music Ruined my Life, also parchment all over the top, and cork to prevent damage to the finish.


The crack is clean at this point, so it was time to figure out how I’d glue it. Like Frank Ford, I decided to use Titebond Original and reinforce the block from the inside.

I made a reinforcement patch with its dimensions matching the end block. The patch (as you can see in the picture) is beveled: on the top  the beveling starts 2.3cm from the edge, and on the sides it starts 1.6cm from the edge. Honestly, I don’t think the amount of beveling matters that much. The piece is 1/8″ thick in the middle.


I forgot what piece of mahogany it is, but I got it from a lumber yard, and it’s real mahogany as opposed to whatever tree that looks like mahogany but isn’t.

For what it’s worth, this was my first time making a patch like that. I wasted a lot of mahogany trying to thin it. Shaping it was easy with sandpaper.

I experimented with clamping a bit. One spool clamp through the end pin hole, and thick acrylic cauls on the inside and outside. That was given, and also what Frank Ford does. Clamping it top to back wasn’t so obvious to me. I tried spool clamps, but they didn’t provide enough clamping pressure. Someone suggested trying quick clamps, and those did it – the crack was closed shut.

One way one could get the glue in the crack is using  a filler gauge or palette knife, but what made most sense was get the whole bottle inside the guitar. I just aligned the glue bottle’s nozzle with the crack and squeezed. I got a lot of glue and got it all over the place. That was fine. It’s an easy cleanup.

Check out how much the crack was open when I pried it open with a clamp between the end block and neck block:


Whole lot of glue:


Spool clamp coming through:


Nice and clean before the mahogany patch goes on:


Patch is on  and clamped:



A word on getting the patch on: With a long threaded rod, the patch bumps against the braces and it’s impossible to get it on the block. What should be done is pull the rod back so it only sticks a little bit on the inside, then reach in with the patch, hold it against the block, and push the rest of the rod in. Then get the other end of the spool clamp on, and tighten the wingnut. Yeah, I bet if you read this now you wonder why is the wingnut end is on the inside. It’s not easy tightening it from the outside with the quick clamps on.

Here’s what it looked like from the outside:



And one more after it dried for about a day.



I think I did a good job!

Guild F-30 neck and headstock crack repair – finally done!

Finally glued up the F-30, but I also realized that I never posted pictures of the crack, and I’m no sure I wrote what happened. Basically, I put it on a stand, and it fell face down. It didn’t have any strings on so the crack was manageable. Here’s what that nightmare looked like:




The “nice” thing about this break is that it wants to close under string tension, so it should have very little incentive to reopen. Gluing it was a matter of opening the crack, getting glue inside (not so easy), and clamping it. I was worried about gluing the truss rod in place, but I talked to a friend who works with this guy who was the foreman at Guild in the 80s, and he said that even if the rod is glued in place it won’t matter since it’s on the first 3 frets and the rod doesn’t do much work there anyway.

Now there are three areas to clamp, as can be seen from the pictures: the neck, the nut slot, and the headstock’s face. For the nut and headstock I used 1/4″ thick acrylic, and for the neck I made some cauls which I’ve mentioned in previous posts. Here’s what they looked like after I glued leather strips (to protect the neck and fingerboard):


Unfortunately, I didn’t take any pictures of them before I glued the leather, but here’s one from when I was chiseling little grooves to fit over the frets:


As far as the gluing, the idea is to clamp the neck in a vise, use one hand to open the crack and the other to get glue in. I don’t have a proper bench, or a vise, so I improvised and used my neck rest and a clamp to hold the neck in place.

Sorry for the terrible back-lit photos.

Sorry for the terrible back-lit photos.

This wasn’t a bad idea, but the clamp was flexing as I was twisting the headstock, so you know, use a vise if you have one.

People recommended to get the glue in with a syringe, or a syringe with a surgical tube attached, but those are too thick. So I went with a little syringe (a mistake). What I did first was get some hot water in the crack to help the glue spread inside. Then I would open it, get glue in there directly from the bottle, then with a syringe, then blow some compressed air in there. Those syringes have very thin needles with really small openings, so there’s not a lot of glue coming out of them. Also, the needles would bend and I had to keep changing syringes. So I wouldn’t recommend those, or at least fill them all up with glue first. I didn’t think the compressed air was getting anything further in the slot either. I would have been better off using a palette knife, thin feeler gauge, or this wide and thin brush that I have. It’s glued alright, though, I think.

I didn’t practice clamping the thing enough. In fact, I never practice clamping all three areas together, which was a huge mistake. The problematic area was the nut slot. I tried a capo and I tried a pony clamp, but both were hard to fit there. I should have clamped the nut slot first, then the neck, then the headstock. Luckily, the nut slot is a straight and level as it were before.

Here it is clamped up:


That unopened compressed air bottle was my backup one.

Humidity in the room was at 58% when I glued it up. It’s a little higher than what I would have wanted, but I had no choice. The glue I used was Titebond Extend.

I waited a day and a half to take off the clamps, and immediately took pictures (because I always forget):

The headstock is glued perfectly. It's flat just as it were before the break.

The headstock is glued perfectly. It’s flat just as it were before the break.


The pictures aren’t pretty because there’s still glue there, but cleaned up it looks alright. The only problem is that there’s a ridge where the crack is. I don’t know if the wood swelled because of water/glue, or maybe it distorted when I clamped it? However, the neck doesn’t have a twist, so I’m happy with it and hope that the lacquer touch-up would diminish the ridge.

I cleaned up the glue and let the guitar rest for another couple of days before trying to flush in some CA glue. Wood glue has very different drying times when it’s not exposed to air. Think about it, the glue doesn’t dry when kept in the bottle. It needs to come in contact with air for it to dry. When you glue something and clamp it up, it can take the glue several days to fully dry. I know it sounds crazy, but I’ve put together a joint before, and then a couple of days later I took it apart and there was still “fresh” glue in there. I don’t know how the CA will interact with fresh wood glue, so I prefer to let the guitar sit for a little bit.

Here are a couple of pictures after I tried to get some CA glue in:

IMG_20151011_163540 IMG_20151011_163559

The glue was just sitting there and didn’t seep in, so I’m going to say the crack is glued tightly. I’m not too worried about the marks around the cracks because these will buff out once I touch up the finish.

Now to finish cutting the new nut. Hopefully the guitar won’t fall off a stand this time. After a couple of months under string tension I’ll fix the finish. Maybe around the holidays when I don’t get to play it as often.

Studer B67 recap: Part II, other studer work, some guitar work

I edited this post on September 22nd, 2015. If you’ve referenced it before that day, you might want to re-read it.

The next step after replacing the caps on the motor control boards was to check the voltages in the power supply. There are test points on the stabilizer’s PCB, so that’s easy enough to do. I did that and the -12V rail was reading 0. So I decided to take out the power supply and recap it. Removing it is a bit of a pain. There are two screws on the top, one horizontal screw that you need a 6″ T-Handle wrench to undo, a bunch of connectors that need to be removed, and the 50/60hz switch on the power supply.

The PCB is different than what the manual shows: The -12V regulator is a Motorola MC7912CK while the manual shows National LM320K-12. The manual shows some SAL caps next to the regulators while my PCB has all tantalums there. Turns out, my PCB is the same as what they used on the Mk I of the B67 (figured that one out after downloading the Mk I manual). The Motorola regulator is a variant of the LM320K-12, so no problems there, and the tantalums can be replaced with high grade electrolytics (which I’m going to do). They layout of my PCB seems to otherwise be identical to the Mk II manual, and the Mk I manual also shows a very similar layout. The only differences I could see are that D4 and D5 are interchanged (shouldn’t matter since they’re oriented the same way), and that the Mk I uses a 4.7mF cap for C3 where Mk II uses 10mF.

While waiting for high grade electrolytics to use instead of the tantalums, I replaced the axial lytics and a couple tantalum caps. I ordered a 1000uF filtering cap instead of 10000uF, so I’m waiting on the big caps until it’s all here.


See those blue tantalums? Those are the ones that should have been SALs.

I also recapped the little monitor board under the front panel. The one that drives the built in speaker. No pictures of that because it was late and I forgot.

I also cleaned the front panel of the machine real nice. Someone said that toothpaste is good for that, and holy cow – it is! It’s much better at removing years old grime than isopropyl alcohol. I also poked around the card cage and noticed that the stabilizer card has a blown capacitor. I’ve never seen anything like it! The is torched and got black sooth all around it. According to my french friend who’s a Studer expert, this is the result of it being really close to the heat sink. I’m going to replace those tantalums with electrolytics also.

As far as guitar work, I think I mentioned making cauls to fix my F30. Trying to shape a single piece of wood to have 12″ radius did not work. I did something similar when I built my neck rocker, and it came out somewhat ok, but required a lot of rasping, chiseling, and filing. I thought I’d have better luck here, but no dice. It was too hard to maintain the radius along that block of wood.

I was at the hacker space trying to figure out how to do this, and a guy suggested cutting the radius on a bunch of small pieces of wood and gluing them together. Then another dude suggested doing that with the laser printer/cutter. I complied, and the thing does cut a very accurate radius, but it can only cut slightly thicker than 1/8″ pieces of wood, and since I need a 5″ long caul, that meant having to cut (and glue) lots of pieces. I tried gluing all the pieces at once and it was a disaster. They kept slipping, then the glue was drying real fast on me (what the hell, it’s Titebond Extend which is supposed to have longer open time).

So I googled and found this page. I followed his advice and cut 7 pieces from pine on the bandsaw. Here’s what one piece looks like:


I’m gluing them up in pairs (to avoid what happened last time), and it’s working out well. Only one piece left to glue.

I hope this guitar will be fixed by the end of this week. I still get filled with sadness every time I think about it.

Guild S300-D finally done! Studer caps ordered!

This process took a while, partially because I’m lazy, but also because of other projects. Here’s a recap of what was done:

-The nut slot was cut too low. So I cut a piece of Mahogany with the grain oriented the same as the neck. Thickness-ed it and glued it to the nut slot with hot hide glue.

-Frets were removed, which was a little painful because I was getting a lot of chips. I glued the chips back in, and used some ebony dust where needed.

-Fretboad sanded and leveled. I could have really just waited to do that and then put superglue wherever the fingerboard was chipped.

-Frets installed, and I dripped superglue into all the slots to keep those little bastards in place. This was my first refret and not all the frets were seated wonderfully. The old frets’ crown was .106″, and I always felt like I my fingers couldn’t fit on the neck once I passed the 12th fret, so I went with smaller frets. I got StewMac’s Medium/Highest. The crown is 0.80″ and that makes a lot of a difference.

-Fret ends cut, filed, etc. Basically whatever is needed to be done so that they don’t poke you when you play.

-Leveled the frets. That came out really well. Maybe my best fret leveling job to date? Also dressed the corners of the frets, of course.

-New bone nut. I wrote all about it already.

-Pickups were potted by Fralin. Also talked about that already.

-Little bridge pickup mishap. These pickups are held in the rings with three screws – two on the bass side, one on the treble side. This way the angle of the pickup can also be adjusted. To do that, Guild (or Dimarzio) soldered a two-hole tab to the pickup’s single hole tab. Anyway, that two-hole tab broke and the pickup was jiggling around. Soldered the tab back on.

-Replaced the neck pickup with the a Guild S100 humbucker I bought for very little money from a friend.

Done. I’ll edit this later to add pictures.

I also ordered the caps I need to (partially) recap the B67. Going to do the suppression caps first, and see if it’s working alright. Then do all the electrolytics and tantalums in the PSU, Transport, and whatever else that has tantalum and isn’t in the audio path. Once the machine is working I’ll do the motor phase capacitors (big ones that are hanging from the chassis), and start working on the audio cards one by one. I’ll pose a list of the capacitors here for my own and others’ sake.

I have a few more things to post about the B67, but I’ll get to it later.

My Guild S300-D pickups are on the way back to me from Fralin’s. They potted them and added some tape (the wire was starting to show). However, I was told by the guy at Fralin that DiMarzio (the maker of the pups in this guitar) don’t pot their pickups. Gibson neither. I still went on with the waxing, not thinking about how I’m altering the original functionality of the pickups. On the other hand, the pickups were very microphonice to the point it was impossible to play the guitar with a loud amp. But hey, that’s a thing to keep in mind when potting pickups. I never realized not everyone dips their pickups in wax.