Showing posts with label electronics. Show all posts
Showing posts with label electronics. Show all posts

Monday, June 25, 2007

I'd Be Finished If I Didn't Screw Everything Up

Well--it's about time I start wrapping this up. I've had a good half dozen layers of poly finish on there for over a week and it seems to have been about as hard and dry as it can get for a good couple of days so it's time I start putting the thing together. At this point in the process, I'm so excited that every minor set back sends me off on screaming rampages throughout my apartment and the surrounding neighborhood. However, it is all working out slowly but surely despite various troubles.

The first thing I had to take care of was the strap buttons. It just slipped my mind entirely to drill them before I started finishing. It was an easy enough situation to rectify. I just put some green masking tape over where I wanted to be (to minimize chipping of the finish) and drilled the holes w/ my hand drill like so:


I did get a tiny amount of tear-out but it was easily covered by the strap buttons and hardly noticeable anyway. I also had to redrill some of the holes for mounting the bridge and mounting the neck as they'd gotten a little gunked up w/ finish--no big deal.

The controls in this were rather close together and it really caused me a hell of a lot of trouble trying to stuff it all into the control cavity. I had to resolder a couple things here in there to fit it all in. The end result works but it's ugly. I'm almost embarrassed to post a picture of it but I will because it's funny:


OK. Not that funny but you have to admit that's about as ugly as it gets as far as guitar wiring goes. Anyway, once I had that taken care of, it was a snap to put the rest of it put together, aside from a few things I noticed that I'll get to in a second.

She looks real nice though:


Once I finish fixing the problems I describe below, I will take her outside and take some pictures in the yard where the sunlight is nice. Then me an my homemade guitar will sit together drinking beer and grilling burgers all afternoon--heaven on earth if you ask me.

The first and most agrivating problem is I lost the screws to install the p90s. This is what made me have a fit. I know they're around somewhere but whether that's in my toolbox or some landfill I will never know. I gave up after an hour of looking and went to my local super depot of orange colored home tools and duct tape to buy something to stand in. Not to my surprise, they didn't have p90 mounting screws. The closed thing I could get were some number four screws but they were only an inch long and need to be more like an inch and a half. This left me w/ not much room for adjustment. Indeed, practically none. Here are the pickups at their maximum height:


There's also a nice shot of the goods for those who are interested what my crotch looks like. It's only a little bit too low but I really spend a lot of time adjusting pickup height and getting it just so (doing this makes a bigger difference in your overall tone than buying more expensive pickups, in my opinion) so it's a bummer not to be able to adjust them, especially since the volumes between the two aren't really well balanced at all. Plus, it just looks funny and I can't have that.

Worse than that but somehow less aggravating is I didn't get the bridge on there quite straight. If you'll notice, there's a lot more room between the edge of the fretboard and the string on the bass side of the fretboard (left in this picture) than the treble. It disgusts me to the very core of my being (you can also see the brass Phillips head screws I used instead of the p90 screws):


Actually, it plays just fine aside from the highest string feeling a little weird but it really irritates me to look at it so I'm going to remount the bridge so it's all straight. The setup right now is somewhat cursory but it really does sound pretty darn good--especially the neck pickup--and feels nice to play overall. In fact, I like it so much that I've changed my mind and decided to keep the baritone neck on this one and build a new body once I've finished my neck (or more likely right along side it).

Saturday, June 16, 2007

Harnessing Up - Part Two

The multimeter is more powerful than the very hand of God when it comes to trying to figure out what in the hell is wrong w/ the wiring harness for your baritone guitar. In all other things, the very hand of God is more powerful but in this one isolated case, the multimeter wins out. Here is mine in action (or right before or right after action, I forget):


Basically, all I use it for is a continuity tester to figure out what circuits are being formed when the switches are in various places and for this it works quite well (I also use it to double check that I haven't burned out any pots or switches by overheating them w/ the soldering iron). It turns out the mistakes I made were pretty minor and one mistake was actually the right thing to do in disguise. I temporarily soldered some the pickups on there so I could plug it into an amp and test it. Actually plugging the thing into an amp can be a big help. Sometimes, the multimeter will just pick it up as a break in the circuit but when you have it plugged in, you will hear the sound cutting in an out so you know it's just a cold solder joint or an otherwise weak connection. I ended up fixing some of the grounding and moving some stuff around to avoid short circuits and crossed wires. It is not the prettiest wiring job I've ever done but it works and it should be small enough to fit right in:


I think this is the first time I've ever wired up a guitar w/o getting at least one burn that blisters, which is pretty amazing as absent minded as I can be when I'm frustrated. The only thing that I'm not pleased w/ is that I couldn't get the solder to stick well to the back of the pot I'm grounding everything to so I ended up just grounding all the wires together and then grounding the back of the pot to that. The rest of the stuff will hopefully be grounded by the foil shielding in the control cavity. If not, I've got some more work to do later but I will worry about that when the time comes.

Tuesday, June 12, 2007

Harnessing Up - Part One

The wait in between coats gets me a good chance to wire up the harness for all the electronics in there. I'm not sure what everything does but I can tell you I've figured out one or two effective ways of directing small electrical pulses from the guitar pickup, through some controls and into a cable which I've hopefully managed to connect to an amplifier (not always the case though). Of course, this time I decided to do something strange to ensure I'd have a host of problems w/ this simple task. For starters, I'm making this a stereo guitar, which means that you can send each pickup to a separate amp. Some people do this using a stereo jack but I, being a crazy fellow, decided to put to go w/ two mono-jacks so I wouldn't have to worry about having stereo cables and a way to split the signal from them. Stereo mode is switchable so I can run it like a normal guitar and flip a switch to split the pickups between the two outputs. Also, instead of having an ordinary pickup selector, I'm making this so I can turn either pickup on or off w/ a switch. Each pickup has it's own volume and tone control and the switching is all done by push/pull pots, keeping the control layout clean and simple despite the advanced and amazing technology behind it all.

The first step of wiring all this stuff up is labeling all the pieces and laying it out in something like the order it's gonna be in when I'm done:


This is one of those things that people tell you to do and but you don't at first because you think it's a load of crap but it really does make things go a bit smoother. I label all the pots w/ a marker so I know what does what and put a little piece of tape on the back of the control cavity cover that tells me what color of wire is for what so I can remember if I ever have to open the guitar up to fix it or change the pickups (and I will). I also try to strip enough pieces of wire so I don't have to stop soldering every four seconds to strip another piece of wire. Of course, even if I spent several hours beforehand stripping wires, I'd still be about ten pieces short as the need for more wires tends to increase as you strip more of them. (This is actually explained by Heisenberg's uncertainty principle but I don't have time to be getting into Schroedinger's Cat and so forth and it doesn't make any sense anyway.) It's also a good idea to clean all contacts w/ some steel wool even though steel wool feels really weird on the fingers and you hate it.

While I was doing all this, I found time to make some pizza, which I then ate:


Fully delicious. There's nothing that gets me more in the soldering mindset than pizza so I got ready and had at it. Remember folks, hot solder can splatter and cause severe bodily harm, especially to the eyeballs so, as always, safety first!


W/o eye protection it would have been really stupid to be waving the soldering iron like this and there's no way I would have lost less than one eyeball. Instead, I survived to solder for a half hour or so before I realized I messed up my design big time. And I think the reason why is obvious from this picture:



OK. Well--I doubt you can tell a single thing from that mess. Basically, I wired it in such a way that if I had both pickups turned off, the amp would hum as if the cable's not plugged into anything, which is no good in high-volume situations. Anyway, I've had enough for now. I'm gonna have at this son of a bitch w/ a multi-meter and a keen sense of logic in the next couple days. Until then, I will just have to be satisfied w/ nothing since it doesn't work.