Geo

I don't think you can switch to a tune-o-matic bridge on that guitar without giving it a neck angle or else raising the neck pocket slightly. Or you could recess the TOM into the body. Make sure you plan it all out before you start.

[wouldnt a switch like this work http://www.banzaieffects.com/Miyama-3PDT-o...e-pr-16270.html ?

I guess. You need a switch that will let you ground the signal in the center position. I'm not sure what is meant by on-off-on. It might leave the signal wire "flapping in the wind", i.e. not connected to anything, which would buzz/hum.

Thanks. I understand about the hot wire. Just to make sure I don't misunderstand, the braided portion serves as the ground (earth), connected to the volume pot body at one end and the ground lug at the output jack? So if I'm using a shielded cable then, this is the only cable to the output and there is no other cable to it?

You can do it that way, yes. If you send the shield to the ground tab of the jack and the inner conductor to the hot tab and connect the shield at the other end to the volume pot casing, make sure all your other grounds go to the volume pot or to the ground tab of the jack.

Hm, I would test the pickup straight into an amp that you know works well. If the humbucker is super hot, I could imagine it overloading an input and seeming to lose volume, although you would hear nasty solid-state distortion with that.

"The AC input for the pedal is right next to the lead input on the back of the effects box and if they touch a loud crackle comes through the amp not dissimilar to the problem with the HB."

I'm not sure I understand.

It sounds like some of your connections are questionable. I would resolder all of them.

If you only got "good" sound when pressing one component, I would think that component was failing internally... but you have it with the switch and volume pot, so that's probably not the problem.

The other thing is maybe your pickup is shorting internally. You could test this by measuring its DC resistance with your multimeter. Plug a short 1/4" cable into the guitar; set all controls to full/10; set the switch for humbucker alone; and measure the DC resistance between the two contacts on the end of the cable. It would be helpful if you know the correct reading for this pickup (i.e. if you measured it when you first got it). But I would expect to see 8k-16k. If it's something like 2k or 0, or if you can consistently get different readings, then the pickup is probably shorted internally.

One other test... you could disconnect the pickup from its switches/volume/tone controls and solder the two leads directly to a 1/4" jack and see if it sounds normal "naked". If it does, then the problem is with the stuff between the pickup and the jack.

Thanks. I did notice that there was less buzz downstairs, so Samba is probably right.

As for JoeAArthur's hypothesis, I'm going to try that, too, though it doesn't make sense to me. I thought the signal coming from a guitar was an alternating current, and therefore it shouldn't matter which contact goes where. But, You undoubtedly know a lot more about this than I do, and it really isn't any trouble to try your solution, so I'll go for it. Thanks!

(Edited a spelling error)

The signal is AC, but you still have to pick one side to be ground. With the wires reversed, you've basically decided that the strings are no longer grounded but are now an antenna. It also makes all the shields in your shielded wires antennas.

So it's not so much that there is a real "correct" ground side, just that you've connected some things that must be grounded (shields, pot lugs, ground tab on jack) to one side.

Well, I'm not looking to build a tube amp now because I'm not that good at soldering nor guitar playing. But over time as that changes I'll head in that direction. But a small, solid state amp might be good because it's portable and cheap to build. Good learning project. And once my skills on the frets improves to the point I can actually play something I want to hear I should be far enough along to do a tuber. I'm just not there yet.

I know what you mean. I was kind of foolish and built an amp before I could really play guitar too well. But here's another angle... a better instrument (i.e. a good tube amp) will be more responsive and make you a better player.

If it's cheap, then go for it. If you're doing small solid state, perhaps you could build an effects pedal? I've never built anything like this, but I looked at the schematic for a fuzz face once and it's pretty simple.

Just offering some more thoughts... good luck.

Copy this layout, minus the tone controls.

http://www.guitarnuts.com/wiring/stockgibson.php

I can't think of a way to wire a Les Paul switch with the middle position as "off". Every solution I think of would ground the signal at all times, which would suck.

A little advice... personally, I wouldn't bother with two seperate volume controls, as I only use a volume control to turn the guitar off, which is what you want with the kill switch...

Well..... it goes like this:

If you don't bring things up slow, you really run the risk of few different problems, from "live" chassis (that whisker wire you didn't see), or a "boom" (that cap you had in backwards), all sorts of issues.

Bringing up a SS rectified amp, I like to check the voltages when the B+ is still quite low, say in the 50 volt range. Even on a tube rectified amp, I like to throw a SS rectifier plug in there, just to bring it up with. While I'm doing that, I'll give a chopstick test to make sure everything is ok. If it all holds up, then bring it down, put the tube recto back in and bring it back up again. This is just good practice to do.

I certainly agree that's safer... but I'm not a very safe guy.... and I'm a penny pincher. But then again, I would tend to stay away from complicated amps (the most complicated I've built is a cathode-biased Princeton Reverb w/out tremolo... woo, that amp is hot!), so there's less to screw up. I check everything several times, etc... I don't use stranded wire, so none of those invisible shorts from little strands...

"That's why I'm going to start on something simple like the Altoids can amp, then maybe a Rudy. If I still enjoy doing that perhaps a tube amp. But that's a year off at least."

Unless the supplies don't cost much, I PERSONALLY would not bother with those (I imagine they're solid state). A simple tube amp will sound a lot better. But I see your reasons for going that direction. Have fun whatever you do.

Would it be bad to layer 3 layers of poplar to get the correct thickness of the body? I would make 2 pieces of 3 layered poplar...then join the 2 pieces together with the joint in the center of the guitar. Would this be ok? Or would all the glueing and layering reduce the sound quality out of the body?

A good glue joint is stronger than wood (so I hear), so if anything perhaps it will improve "tone". I wouldn't sweat it... I built a guitar with a 5-piece poplar/spruce body, and I love it. The wood is ugly, though, so don't do a natural finish like I did.

And remember... every acoustic guitar has bookmatched top and back and two seperate pieces of wood for the sides.

But if MiKro is going to hook you up, go with that!

For tube amp work, you need not only a meter, but a Variac is essential.

Well, I've managed without a Variac. Just triple check the wiring esp in the power section.

Another great resource is the Hoffman forum:

http://www.el34world.com/Forum/yabb2/nph-YaBB.pl

"that gives you 21 tonal combinations "

Dang, brotha! My main guitar has 4 sounds, and I generally use two of them. But, to each his own.

There's still hope for this guy! No need to pay people to fix a wire. Perhaps you could put it back how it was (this may involve buying some shielded cable), take some pics, and we can tell you what to solder where.

For a "kill switch" I would use a single-pole, double-throw ("SPDT") switch (which takes a wire and directs it to one of two other contacts). You can cut any signal wire and install it at the break. Connect the signal "in" to the center lug. One outside lug is "live signal out" (i.e. the other end of the wire you cut), and the other lug should be connected to ground. I believe a LP switch is SPDT.

I believe you'd have to replace the output transformer with one that has multiple secondary taps. Unless the Blues Jr. OT already has them and Fender decided to just cap them off.

A headphone out could be tapped off the speaker output jack - a resistor feeding a potentiometer, wired to a jack.

Correct. You could probably get a replacement output transformer for $50 for that amp. FYI, most tube amps can handle a "wrong load" 100% in either direction--i.e., your amp should be okay with a 4ohm load or a 16ohm load (but not 2ohm or 32ohm). E.g., I have a 3w amp that should run 4ohm, but I use it with an 8ohm speaker. Also, I believe that impedance changes with frequency, so an exact match isn't important.

If you use a different load, you'll probably get slightly less power output and maybe slightly different tone (not sure).

With the headphone output, I don't think it's that simple. You want to wire in something that switches the speaker OFF and switches on a resistance in place of the speaker (something like a 10 ohm 20w resistor). The amp's power section needs to see some kind of load similar to what it's designed to see. With that set up, I think you could then do the pot and headphone jack.

Don't let the negativity bug ya... I think it looks great.

Whoa! Get some clothes on that guitar!

jnewman is right, you need to learn some basic things first. But I think once you have those down, you can get started on building an amp... though you should build something SIMPLE for a first project.

As to tube amp safety, you can probably search that on the web and learn everything in a few minutes--i.e., the amp is always UNPLUGGED (and the power section safely discharged) when you're working on it, or if it must be on while you're moving wires around, use something nonconductive to poke, and keep one hand behind your back, in your pocket, etc, and be aware of where the high voltage is in the circuit.

Yes, you've GOT to be able to solder correctly before you get started, or you'll have twenty cold joints on your circuit board and you'll wonder why your amp keeps crackling and farting out!

Alders in north america definitely have leaves like that, so I would vote alder.

green - 23Kohms.

Red/white - 11.5Kohms,

Black/open - earth.

Inductance is 8.23 Henries.

Wow, that's a really high DC resistance. Are you sure you're measuring it right?

I wouldn't place the pickups any lower than you normally would. The closer the pickups are to the strings, the more strongly the magnets magnetize the strings, and the louder the output (though you can't take this too far of course).

Maybe you could use super-hot pickups hidden under the pickguard and get a "normal" output level???

Hey man... my one piece of advice... DO IT!!!

I haven't built an 18watt, but here's a link to a photo of the guts of one of my amps. This is actually a good example of BAD lead dress (i.e. bad layout, wires criss-crossing, etc.) This happened because I built the amp originally as a Fender-style combo with tubes hanging down. I then rebuilt it as a head with tubes pointing up, ala Marshall. That's why the wires are a mess.

http://i134.photobucket.com/albums/q119/Georder/Me016.jpg

The finished product atop its cab (w/a Weber 12"):

http://i134.photobucket.com/albums/q119/Georder/Me018.jpg

For another project, I took a Plexi-style preamp (w/ bright and dark channels) and mated it to a 5w power section. This amp produces gnarly Marshall distortion at volumes that don't need earplugs. It's also great for old-school bass. I gutted my first amp (a SS practice amp) and built the Marshall in there. It cost me $50 and probably would have cost under $100 if I hadn't had any parts. I can email you a schematic if you're interested.

http://s134.photobucket.com/albums/q119/Ge.../5w%20marshall/

My final thought... this forum is where I learned tube electronics. People are friendly there (much more friendly than on this forum) and don't mind answering questions that get asked every week/month.

http://www.el34world.com/Forum/yabb2/nph-YaBB.pl

slowly building up to the idea of making a amp. might have a go at it during the summer holidays (im in australia, so its your winter). im not too big on electronics, might have a go at it with a friend or 2 who would be interested.

Cool.... warning, it's addictive.

surprisingly yes it is comfortable to play, the neck is thinner farther down, but thicker near the head but it suits how i hold the guitar so it works

Interesting. I've never seen a guitar with a neck fatter near the headstock... but that's the point of a custom guitar!

Wow, very cool--way better than my first attempts! I love the new twist on the violin-like waist. The neck looks kind of fat, especially where it meets the headstock. Is it comfortable to play?

We really are in the same boat! I'm a college student too.

I actually learned tube electronics pretty quickly. I find it easier to understand than solid-state. Building your own amp is almost as rewarding as building your own guitar. Also, you don't have to design your own... just copy a classic Fender, Marshall, etc.

Swedish Luthier, thanks for the info. I have some aluminum, so I may use that for a base-plate.