Texas Special strat help...please!

[kirtlpeterson]

Hey guys,

I actually used to post here back in the day. Did some kill switch mods and what not. Everyone was really helpful so I'll keep my fingers crossed for my latest prediciment:

Just did the QTB rewire...was quite excited about it until I plugged in and? No sound. Well. A slight, slight buzz at painfully high volume levels, but no sound from my string.

I'm thinking it could be the result of a couple things:

1) the seymour duncan Pearly Gates humbuckers. This had FIVE wires coming from it, one of which was completely bare. The bare wire was wrapped around the green wire and both soldered to the vol pot. I put both on the signal ground. Might be wrong? Not sure.

2) Fender blue Lace Sensor: Again, two wires were connected to the ground, I put both on the signal ground.

Another difference with the Texas Special is two capacitors on the tone pots. I desoldered these from the pot and resoldered to the signal ground. Wasn't completely sure I should do that, but I did!

And alas, it doesn't work. ...and it makes me sad.

Any help is much appreciated. Thanks guys,

Kirt

Edit: I removed the kill switch for the sake of no complications. Just so you guys no, that's not part of the problem.

[newey]

klp-

Hi, and welcome back!

It's difficult to do diagnostics over the web. At the very least, pictures of the wiring will be needed. You should also post a diagram of your wiring if you have one.

It is unlikely that the wiring from either of your pickups is the issue, since that would imply 2 independent problems. If the wiring from one was the only fault, you should still get output from the other.

No output whatsoever is more likely to be a bad connection in the common portions of the circuit, somewhere between the switch and the output jack. You will need a multimeter to do any troubleshooting.

I would start by checking the output jack connections, and work backwards through the circuit until you get a signal. Don't assume that the bad connection is necessarily one you rewired, it could also be that one of the existing connections worked loose while you were working on it.

It is also possible that a "hot" connection is contacting your shielding at some point. Since you'll have to remove the guard to troubleshoot it, check to see if you get signal with everything wired as is, but with the guard off the guitar- at least with it up far enough so no components can be touching the cavity shielding. If you get signal that way, then installing the guard is causing something to make contact. You can use electrical tape as an insulator over the portions of the shielding around the switch and pots if this is the case.

[kirtlpeterson]

Thanks for the reply and good tidings.

I'll take her apart again on Tues (driving a total of 15 hours round trip tomorrow. Ouch) and let you know how it looks.

A quick 'talk through' of the schematics:

JA's designs except-
1)no capacitor (just used a regular wire)
2)had two capacitors via stock wiring grounded on both tone pots which were desoldered then soldered to the signal ground
3)Neck and middle pickups both had two ground wires, both of which were brought to the signal ground.

In the meantime, if anyone else has any suggestions please let me know. Appreciate it fellas. Thanks again.

[ChrisK]

Ooooook

JA's designs except-

Which JA design (he's done more than one)?

1)no capacitor (just used a regular wire)

Which capacitor, what "regular" wire?

2)had two capacitors via stock wiring grounded on both tone pots which were desoldered then soldered to the signal ground

Was the stock wiring ground/signal ground isocapblock continuum violated by the "regular" wire?

3)Neck and middle pickups both had two ground wires, both of which were brought to the signal ground.

Both of both?
Continuuming along, was this violated therefore alsotosay?


May we have a clue in aisle 0, 1, 2, and 3?

[kirtlpeterson]

Alright! back from a long, long drive. Now back to work:

Newey, I double checked the solders, saw one ugly connection, resoldered, and now we've got some sound!

Problem is, I've got some loud buzz going. It's quiter when I touch the strings (or whammy....metal in general I suppose).

Last I saw my digital camera it was floating in my flooded apartment so I can't really provide pictures right now.

I'm guessing the type of buzz i'm hearing has something to do with a grounding issue. Oy!

[kirtlpeterson]

Jul 13, 2009 22:53:05 GMT -5 ChrisK said:

Ooooook

JA's designs except-

Which JA design (he's done more than one)?


Which capacitor, what "regular" wire?


Was the stock wiring ground/signal ground isocapblock continuum violated by the "regular" wire?

3)Neck and middle pickups both had two ground wires, both of which were brought to the signal ground.

Both of both?
Continuuming along, was this violated therefore alsotosay?


May we have a clue in aisle 0, 1, 2, and 3?

Your clues:

Johns original QTB design as found at

The .33uf 400 V capacitor was NOT used since I could not find one. Instead I used a 22 gauge wire from a large uninsulated ring terminal installed under my tone pot. the 22 gauge wire was crimped and soldered to a medium sized ring terminal.

I'm afraid I don't understand your question about the stock capacitors. (feel free to roll your eyes again.) Both my tone pots had capacitors originally installed- I removed the ground from the pot and put a 22 gauge wire in its place. The wire led to the signal ground. I made sure to insulate the connection with electrical tape so it would not have any contact with the foil on the body cavity.

The humbuckers two wires that were connected to the volume pot for grounding were moved to the signal ground. The two wires from my lace sensor that were connected to the volume pot for ground were moved to the signal ground.

I'm not sure if that clarifies for you...but I don't really follow "Continuuming along, was this violated therefore alsotosay?"

Edit: 22 or 20 gauge wire. I'm using excess wire that I cut from my fender lace sensor when I originally put it in.

[D2o]

Jul 14, 2009 13:53:31 GMT -5 kirtlpeterson said:

Problem is, I've got some loud buzz going. It's quiter when I touch the strings (or whammy....metal in general I suppose).

If it's a truly onoxious loud buzz, it could just be that you've reversed the wires on the jack.

If that doesn't help, I wonder if you can use Windows Paint and create a diagram of what you have done with the wiring. That could help to pinpoint the source of hum.

D2o

Oy!

Oy!

[kirtlpeterson]

D2o,

Well, it is an obnoxious hum, but when I reversed the wires on the jack, my definition of obnoxious changed. E-GADS was that a bad hum!

I'll get back to you with the wiring schematics. Thanks for the help.

[D2o]

Jul 14, 2009 15:46:27 GMT -5 kirtlpeterson said:

D2o,

Well, it is an obnoxious hum, but when I reversed the wires on the jack, my definition of obnoxious changed. E-GADS was that a bad hum!

I'll get back to you with the wiring schematics. Thanks for the help.

Good - we'll await the schematic.

I have a suspicion that you are missing a ground wire ... we'll see.

Do you have a wire from the bridge to the back of the volume pot?

If so, have you run a wire from the back of the volume pot(s) to the back of the tone pot(s).

D2o

[kirtlpeterson]

Schematic ahoy!

www.flickr.com/photos/40465960@N03/3723934453/



Thanks again for helping. I'm doing the music for an iphone app...or I'm SUPPOSED to do the music for the app, so why did I choose now to rewire my guitar? ...because I'm a fool. A FOOL!

Edit: The link works via copy and paste, not by clicking. Because the computer gods have it in for me today.

*calls therapist*

[D2o]

Nothin' doin' yet, Kirt - I cannot access it.

Keep trying, or upload to photobucket if you have to.

D2o

[D2o]

Dang! it's not just your account, Kirt ... (for those who eventually see a picture above this, at the time of posting it wasn't working)

[D2o]

BINGO! Thanks for sticking with it, Kirt.

[kirtlpeterson]

Oh, don't thank me. Thank my obsessive compulsive disorder.

I just hope we can get my poor wooden child back to work.

Edit: One (perhaps) important thing that I accidently left out of my drawing is that the neck pick up (the fender lace sensor) has a green wire that is soldered to a metal plate (that is shown on the picture). It came like this and I didn't think much of it until just now.

[D2o]

Assuming that your red that goes to the jack is actually going to the sleeve, and the gray is hot and going to the tip, everything looks fine.

the only thing I noticed is that I think you've missed one terminal on the switch (bottom left quadrant of the switch - the Fender schematic indicates that it continues the connection one more terminal towards the middle). I bet you've only missed it in the drawing, though - not in the wiring.

Proper grounding occurs of your shielding is working and continuous and actually making contact with your pots. If it is not, you may want to try soldering wires connecting the backs of the pots - it would be a (possibly) redundant ground, but may alleviate your hum. If it doesn't, a simple vasectomy of said wires reverses it.

That's all I see - it more or less looks like it should work.

D2o

(I am sure you have this link to Fender's Schematic )

EDIT - just noticed your note about the other wire. I have not thought about it, just so you know ... it has not been considered in these comments.

[kirtlpeterson]

I just double checked the switch- on the left side, and closest to the signal ground (ie the very bottom of the switch) there is a black wire running from the switch to the signal ground.

I'll head back to the computer and touch up the drawing.

Edit: And here we are!

farm4.static.flickr.com/3436/3725028342_ed387efeb2.jpg?v=0

Copy paste for the link to work. -added two wires, both appear larger than the others, one from the lace sensor and one from the bottom right of the far switch terminal-
EDIT:Link fixed by Newey.

[kirtlpeterson]

Jul 15, 2009 16:01:18 GMT -5 D2o said:

Assuming that your red that goes to the jack is actually going to the sleeve, and the gray is hot and going to the tip, everything looks fine.

the only thing I noticed is that I think you've missed one terminal on the switch (bottom left quadrant of the switch - the Fender schematic indicates that it continues the connection one more terminal towards the middle). I bet you've only missed it in the drawing, though - not in the wiring.

Proper grounding occurs of your shielding is working and continuous and actually making contact with your pots. If it is not, you may want to try soldering wires connecting the backs of the pots - it would be a (possibly) redundant ground, but may alleviate your hum. If it doesn't, a simple vasectomy of said wires reverses it.

That's all I see - it more or less looks like it should work.

D2o

(I am sure you have this link to Fender's Schematic )

EDIT - just noticed your note about the other wire. I have not thought about it, just so you know ... it has not been considered in these comments.

So just solder on 3 wires from the pot and leave them exposed to touch the foil?

That may be it, I don't think the pots are touching so maybe we're onto something here.

[newey]

Kirt-

I fixed your link. You just need to highlight the url and click on the little "world" icon, 3rd over from the left on the bottom row of buttons . This inserts the url tags at either end of the highlighted text.

So just solder on 3 wires from the pot and leave them exposed to touch the foil?

I think D2o means a more positive connection than that. You need to make a good connection to some grounding point, since, if you used aluminum foil for shielding, you can't solder to that. Even if you used copper, soldering to the shielding on the back of the pickguard is not a good idea- there's plastic underneath, after all.

[D2o]

Hi Kirt,

Since there doesn't seem to be anything really jumping out at me with the wiring, and you have indicated that you don't think the pots are touching (your shielding, I presume?), and you have hum ... I think that one possible solution may be that if you solder a wire to the back of tone pot 1 and run it to the back of tone pot 2 and solder it there, and do the same from the back of tone pot 2 to the back of the volume pot, you will eliminate your hum.

I don't know this will work, by any means ... but some of what you have described leads me to think that there is little to lose in trying it.

Are you willing to give it a go?

D2o

[kirtlpeterson]

But of course!

I'll give it a shot tomorrow and post right afterwards.

Thanks again for the time you're putting into this. Definately appreciated.

[kirtlpeterson]

Did some messing around this morning via adding some foil out towards the bottom tone pot to make sure a connection was being made. It was, and the hum is less noticable. It's still louder until I touch the string (which I wouldn't think is right, but beggars can't be choosers), but one thing still really stands out:

I'm wondering if I have bad volume and tone pots?

Get this: The hum is louder MID volume, and quieter when it's maxed out. Yep. You heard it right.

Also, the neck tone crackles quite a bit when adjusted. Maybe they got fried when I was desoldering wires? Not sure.

Sound familiar to anyone out there?

[D2o]

Kirt,

I guess at least a couple of things come to mind.

In order of responsible idea to possibly reprehensible idea:

1) Have we asked you to take some readings yet? That may reveal something.

If you can't get the readings:

2) Perhaps you could bypass the volume altogether - just run the signal and return directly to the jack? It's not too involved a chore, really, and if the hum is less than at mid-volume it may indicate that the pot is shot.

That's all that comes to mind for now.

D2o

P.S. One more thought: if your shielding chassis is not continuous, then do you really have a bridge / trem ground? I wonder if that wire attached to the shield may be attached to the star ground instead?

But don't do anything about that just yet ... better wait for some input from others.

[kirtlpeterson]

Jul 17, 2009 22:21:09 GMT -5 D2o said:

Kirt,

I guess at least a couple of things come to mind.

In order of responsible idea to possibly reprehensible idea:

1) Have we asked you to take some readings yet? That may reveal something.



If you can't get the readings:

2) Perhaps you could bypass the volume altogether - just run the signal and return directly to the jack? It's not too involved a chore, really, and if the hum is less than at mid-volume it may indicate that the pot is shot.

That's all that comes to mind for now.

D2o

P.S. One more thought: if your shielding chassis is not continuous, then do you really have a bridge / trem ground? I wonder if that wire attached to the shield may be attached to the star ground instead?

But don't do anything about that just yet ... better wait for some input from others.

Hello and thanks again-

The readings suggestion was mentioned but I didn't know what it meant (until now) and mistakingly thought it was just a wiring problem. I'll read up on that and, if i feel able, will give it a try.

As for the volume bypass, where do I connect the ground and hot wires if not to the volume pot?

And for your ps: The tremolo ground is screwed into the body on a separate ring terminal. It should be noted that the foil DOES touch this ring terminal (at the bottom) and has a piece of electrical tape over the top of it just because I didn't want it accidently touching anything else. It's the only wire connected to this particular ring terminal.

EDIT: Just checked out multimeters...and they're fairly expensive. Looks like it'll be about 35 to 40 dollars to do this test. I'm wondering if I shouldn't just buy new pots with the money that I have. (Things are tight since I'm moving to a new state in less than two weeks).

The hum really is bad...bad enough where recording simply doesn't make any sence. Definately a bummer.

[D2o]

Hi Kirt,

Do you have any electronics surplus stores in your area? They are a good source of cheap multimeters that are accurate enough for this purpose.

If not, and you still want to try the jack idea, all you would do is desolder the hot and ground wires that are coming from the switch from the volume

- WAIT! in case that is not clear, you desolder them from the volume pot, not the switch -

and then solder the hot to the tip of the jack and the ground to the sleeve of the jack. If there is less hum, then it's probably not a bad bet to replace the volume pot.

If there is no change in hum, you just desolder from the jack and solder to the volume pot as it was.

However, I continue to suspect that the shielding is not functioning as it should be ... I don't know why I think that, but I do. And you have no means of confirming that the shielding is continuous ... if it is not - and you do not have the chassis upon which to make the true QTB work, all of your efforts may be in vain (by the way, have you tried the wires between the pots yet, as I had suggested?)

Every once in a while a situation like this shows up that is impossible to diagnose over the internet.

But you have done something - from here, who knows what? - that is introducing hum.

So what can we do? I'll tell you something that may surprise you:

Most of the time, I just shield the guitar and don't bother with the star grounding.

Is that best practice? Nope.

Does it work just fine? Yup.

Basically, don't forget that you can always do away with the star grounding and rewire it back to bone stock (either the Fender Schematic I showed you before or something like this, whatever), but with shielding ... the point is it will still reduce hum, but won't be star grounded.

At least then you may have a functional guitar.

If you choose that route, when you solder everything back onto the backs of the pots, make sure you have good solder joints.

Don't use a soldering iron that is either too weak or too powerful. I would suggest a soldering iron of about 30 watts and I like to use the thinnest electronic rosin core solder that I can find.

Make sure that you allow your iron to properly heat up for at least 5 minutes, that you always keep the tip of your iron clean, and that you tin it (melt a thin layer of solder on the tip).

When I am soldering to something like the back of a pot, I lay the side of the tip of the iron on the surface to be soldered to for a good 30 seconds before placing the wires that are to be soldered to it on the surface and then laying the side of the tip of the iron on the wires that are on the surface for another good 30 seconds or so.

Then I press the point of the tip of the iron on the wires, and make sure I've got ample solder to make a huge honkin' glob of solder on a fairly hot surface, so that I have the best chance of getting a good and durable solder connection. I have never damaged a pot doing this - although that could happen with a much more powerful soldering iron, so best stick with about 30 - 40 watts.

Just some food for thought ... there's not much more I can do without readings.

D2o

[newey]

Earlier on, Kirt indicated that:

Problem is, I've got some loud buzz going. It's quiter when I touch the strings (or whammy....metal in general I suppose).

This would implicate the bridge ground as at least a part of the problem. I would move that wire to a point you know is grounded- your star ground point, or the back of the pot if you do as D2o is suggesting.

This doesn't explain the volume pot problem, but if it's quieter when you touch the strings or trem, that's because your body is doing what the ground wire isn't doing- grounding the strings/bridge/trem etc.

You may well have a good connection to the shielding, but if the shielding isn't electrically continuous, it could be that that portion of your shielding is floating from ground. And, without a meter, you have no way of checking the shielding for continuity.

I bought a perfectly good auto-ranging digital multimeter for about $13 at that big orange home improvement store. You need one that has at least 4 digits in the readout. Unless this is the only time you'll ever open up a guitar (or try to troubleshoot a pesky pedal, or any number of other non-guitar uses), you ought to have one.

[kirtlpeterson]

Hey guys,

Sorry for the delay- been working on the game music (using a keyboard) and not doing much else.

I'll check home depot for the multimeter today and update accordingly.

Thanks again,

Kirt

[ashcatlt]

Jul 18, 2009 19:23:37 GMT -5 newey said:

Earlier on, Kirt indicated that:

Problem is, I've got some loud buzz going. It's quiter when I touch the strings (or whammy....metal in general I suppose).

This would implicate the bridge ground as at least a part of the problem. I would move that wire to a point you know is grounded- your star ground point, or the back of the pot if you do as D2o is suggesting.

I'm afraid I have to disagree. This comes up so often around here. Maybe I can get a second (and/or third) on this, and it can be added to the "Read this first..." post.

AFAIK, the noise is supposed to be reduced when you touch the strings. The fact that it does means the string/bridge ground is at least partially functional.

I've explained the why of this statement in another thread.




(EDITed by sumgai to make ash's link go right to his explanation.)

[D2o]

Good point, Ash.

"I second that"

In fact, I recall the hum reducing when I touched anything metal on a non-shielded, used guitar that I had "newly acquired" about a year ago, and it ended up that there was a wire missing between the pot cases - not a bridge ground problem - and, once a wire was installed between the pot cases, the hum went away.

D2o

P.S. By the way Kirt, you should really use a 400 VDC blocking cap between star ground and the ring under the pot. Either that or get rid of that wire and ring ... it currently serves no purpose and may even be related to your hum.

[wolf]

kirtlpeterson
You mentioned about getting a test meter at Home Depot.
I had a feeling they wouldn't have exactly what you'd need - and after visiting their website, I found I was right.
(I don't know how Newey got his meter though).

I'd say the best (and probably the only) place to buy a multimeter right off the shelf would be Radio Shack.
Here's a link showing about 10 of their meters.
www.radioshack.com/family/index.jsp?categoryId=2032305
Maybe you've heard some bad things about Radio Shack but it's the only store that sells meters, capacitors, resistors, mini-switches and similar stuff off the shelf.
And just to reinforce the negative attitudes people have toward Radio Shack look at some of the reviews for their meters. A lot of customers are upset that one of the meters requires a hard to find 12 volt battery and they weren't told this fact when they bought it.
So, be alerted to that.
Also, I wouldn't ask the employees for any help in deciding which meter is the one you need.