Gibson Chet Atkins Tennessean pickup and wiring saga

[selloutrr]

I know it sounds frustrating but have you considered taking it a part and putting it back together? Once it's apart using alligator clips and testing before you resolder. This would allow you to swap pots if you do feel they are bad, but unless you over heated them or in the off chance you have a bunk one (i'd assume it would be scratchy, or have a dead spot in the taper) they should be ok. This would also allow you to experiment with altering the grounding scheme.
once it's quite you can solder it up and you should be good to go!

Just to make sure you do have continuity from the grounding bus to the bridge? I know you soldered the wire I'm just making sure it's not broken.

[Structo]

I hope you can fix it without taking it to the music store.

I know what they will charge and believe me, the odds are you know more than the guy working on guitars there.

Another tip I learned a few years ago was, determine if the pot will be turned to zero very often or dimed very often.
Rotate the shaft to the position seldom used and then solder up the back.
Not sure I have ever experienced it but supposedly you can burn the trace where the wiper is sitting and it can screw up the performance of the pot.

So I just do that before heating any pots, regardless if I am soldering to the back or not.

Good luck

[dehughes]

I know it sounds frustrating but have you considered taking it a part and putting it back together? Once it's apart using alligator clips and testing before you resolder. This would allow you to swap pots if you do feel they are bad, but unless you over heated them or in the off chance you have a bunk one (i'd assume it would be scratchy, or have a dead spot in the taper) they should be ok. This would also allow you to experiment with altering the grounding scheme.
once it's quite you can solder it up and you should be good to go!

Just to make sure you do have continuity from the grounding bus to the bridge? I know you soldered the wire I'm just making sure it's not broken.

Yeah, I may do that...I talk a big game about taking this into the shop, but I'd rather fix it myself. Like I said, though...would rather not hand myself another project. I wanna play this thing, not tinker with it!

But yes, your idea is good. I should do that, being as I have all the electronics hanging out of the F-Hole. Perhaps tomorrow or Tuesday afternoon... I think first I should take (someones...) advice and solder a pickup directly to the output jack and see if that cuts out the hum, then gradually add components back in.

[dehughes]

I hope you can fix it without taking it to the music store.

I know what they will charge and believe me, the odds are you know more than the guy working on guitars there.

Another tip I learned a few years ago was, determine if the pot will be turned to zero very often or dimed very often.
Rotate the shaft to the position seldom used and then solder up the back.
Not sure I have ever experienced it but supposedly you can burn the trace where the wiper is sitting and it can screw up the performance of the pot.

So I just do that before heating any pots, regardless if I am soldering to the back or not.

Good luck

Yeah, I too hope I can fix it...just a question of resolve, ultimately.

As for the local store...I'd take it to the 12th Fret on Belmont....if you're in Salem then it's worth your while to drive up to Portland and have these guys work on your guitar. Saul Koll worked there for a while until he got too busy with his custom builds, so that gives you an idea of the quality of their work. If they can't fix my guitar, then I don't know WHO'd be able to...

GREAT idea about the pot setting during soldering. I'd never have considered that. I'll do that for sure when I swap the pots on my SG (fingers crossed!). However, I don't think the trace is screwed up in a specific spot on these pots due to overheating, as things are equally as hummy regardless of the various permutations of pot settings. Still though, it's a good practice and I'm all for covering bases and not taking chances.

[dehughes]

I went to the 12th Fret and picked up two more 500k CTS split shaft pots and replaced the volume pots in my SG, as well as replacing the caps with .022uf Sozos...basically the same thing as what I did with my Tennessean. No issues whatsoever....my SG never sounded better...or quieter.

SO, I wager that rules out the pots, as they were most likely from the same batch. If the pots are good, and my ground scheme is good (r.e., identical to what was before), then something else must have changed when I replaced the pots. The question is what....

As well, I put the bridge ground (for the strings, etc...) on the tone pot instead of on the bridge pickup's pot in the hopes of making a more "true" star ground. This actually made the noise slightly worse...so I'll put that back. Looks like having the tone pot as the star ground point isn't such a great idea.

[dehughes]

I checked out my wiring schematic and saw I had the wires to the master volume (see PDF earlier in the thread...) reversed. I didn't think this would make a difference, but I swapped them anyway. At the same time, I moved the guitar bridge/strings ground wire from the tone pot to the volume pot...

So far, so quiet! Not sure why....doubt it was the ground wire, but hey, I'm not complaining. It's still a bit noisier than I'd like, but WAY quieter than before. I'm assuming once I get the pickups back in and get the harness back inside the guitar it'll be better. What an odd thing..two wires...essentially split by a master volume pot...and reversing the wires made all the difference. Perhaps I don't fully understand what that'd do, but it's better now, and that's what I'm happy about. I'll look over the wiring schematic again and try to make sense of the difference.

[dehughes]

On a side note:

If one removed the master volume pot from the circuit, would that "brighten up" the guitar, as then the circuit wouldn't see two 500k paths to ground (essentially 250k)? I'm contemplating leaving the master volume out of the circuit, as I don't foresee myself using it at all, and would prefer a simpler circuit with less wiring in between the pickups and the output jack.

What do you think?

[crbowman]

Deleted. (I should REALLY learn to read these in their entirety before I post)

[daydreamer]

electricity goes to the path of least resistance and one thing I've learnt about rewiring guitars is the tiny voltages you are dealing with mean that even though the path is there and intact and a second path is there and intact and both paths are meant to be there, it makes a difference which one is closer to the pickup. Sometimes there just isn't enough power from the pick up to get that far properly!! (the half wound pickup I'm assuming is half power?) We are talking minute voltages, what looks like it should work either way, won't. And you are right, If you don't need it, don't put it in, it will just ad resistance which kills treble tone first. Especially if you aren't a 'set and forget -1 tone at different volumes' player, i.e you are always switching tones, better to put a master kill switch than volume for me.

[Structo]

Having those wires reversed does make a difference as you found out.

As Daydreamer stated, you're dealing with millivolts in the guitar circuit so it is very sensitive to outside noise influences.

You can try a treble bleed circuit on that guitar.
I use those on just about all my guitars, it makes using the volume and tone controls on the guitar much more enjoy able when they don't get muddy when you turn down.

I like to use a 150K/ 1000pf Mallory 150 on my guitars.

[dehughes]

Good info guys. Thanks.

I installed the TV Jones Classic today (bridge position) and noticed it was out of phase with the Lollar low-wind Imperial in the neck. Odd. I reversed the wires on the TV Jones and all is well, phase-wise.

However, I noticed that with the leads to the master volume reversed from what is shown in the schematic (see attached PDF....), I actually PREFER the vibe/tone of the neck pickup. With the MV wired "correctly", the neck pickup is a bit weaker/more muffled/less output. With the MV wired "incorrectly" the neck pickup sounds beautiful...but there is annoying amounts of hum. See the attached PDF for a clearer explanation.

Odd. Tomorrow I'll try reversing the wires on the MV again and see if that does anything. I REALLY LIKE both pickups, but am not convinced they work well in conjunction with each other. However, I'm not going to write them off yet....not before I put the MV wiring back to it's stock position (leads reversed, as came from the factory) and see if that changes things now that both pickups are installed and working.

What an odd project this has turned out to be....

[Structo]

I've had problems before using two different pickups made by different companies.

In the end I believe it was phasing issues probably caused be the winding direction or magnet polarity. I dunno.

I do know on at least one occasion I picked which pickup I liked the most and bought the companion pickup from the same maker to avoid any conflicts.

[daydreamer]

without a doubt you are down the rabbit hole with Alice here.

The big boys (Gibson et al) spend alot of money getting pickup configurations balanced and working together and over many years of trial and error some combos become classics, but there are plenty of failures, it really has a fair amount of 'black art' because on paper things should work, but then they don't and no amount of head scratching fixes it, (Gibson would just rewind the pickup, redesign the pot, throw away the capacitor etc guys get paid good money to mess with this stuff all day long). I'd be inclined to go with Structo and choose the pickup you like best and find a matching pickup from that company. Follow their installation instructions (pots and caps included) to the T and all will be well in wonderland.

From what you are saying about the tones changing, you definitely need to put down the guitar and back away slowly...before your sanity suffers!.

[dehughes]

Dang. Okay. I'll play them both tomorrow and see what I prefer. I wanted a Filtertron in the bridge (for the sake of Malcolm Young) and a humbucker in the neck (because I really like humbuckers in the neck, and find Filtertrons too thin in that position), but if they ain't gonna work, then...well...ech. We'll see what tomorrow brings...I'll post back.

[daydreamer]

yeah, i know how you feel. I'm thinking of getting into electronics full time so your dilemma has got me thinking, but I have in the back of my head a recent announcement by Maton Guitars that they got their humbuckers adjusting to full volume when being split from hum-bucking mode to single coil. that cannot have been easy, and they have been around 50 something years!

I also keep thinking that without the shielding that a normal cavity can provide, your experiments will be at the mercy of what ever buzz it floating by, I bet the guys how designed the guitar had the same issue, and thought 'i hope no sucker tries to change this!'

not relevant i suppose, but this is the Maton product anyway;
thttp://www.maton.com.au/pdf/whats-new-20101007.pdf