Re-wiring emergency - HELP PLEASE!!!

[mesaray]

Hi everyone! I've been deciding whether or not to rewire my Classic Custom Goldtop with the 50's wiring. I decided against a true 50's style setup BUT I did decide to keep the modern layout and swap out the stock 250k Gibson volume pots for some 500k Gibson pots and I also swapped out the stock porcelain .022 pots for some mojo tone Vitamin T .022's. I took some pictures before hand so that I could retrace my steps with ease. I took all of the old stuff out and dropped all of the new stuff in VERBATIM - EXACTLY like it was before I started. I've never really done anything like this before so I was fairly please and very proud of myself. I fired up the Marshall to give it a try and I'm absolutely gutted now. I was under the impression that by upgrading the 250k's to 500k's that I would experience more of a wider dynamic range of volume. That statement couldn't be more opposite from what I'm experiencing now. I lose ALL volume at 6 on my neck pickup and at 5 on my bridge pickup. Even at 10 it doesn't seem all that loud, or what I would consider 'normal', I don't think anyway... I have no idea what the problem is or could be. I double, triple and quadruple checked the wiring with the pics that I took and I checked all solder joints and everything is correct and solid. I've included a few pics, just so you guys can go back over my work to make sure that everything is 100%. Can anyone provide any insight into what I've done wrong here? I'm about to pull my freaking hair out this evening over this.... HELP!!!

 

[Elkoki]

I'm not an expert when it come to these things, I know how to solder,and follow wiring diagrams, that's the only reason i've been able to do my own pickup installations... A while back I gutted all of the electronics on my Epiphone and installed everything..I plugged it in,and there was no sound... Everything looked fine, but after looking closely I found that the ground "sleeve"? was touching the input jack..so moving that out of the way made the guitar work..Look around and see if any of the grounds are making contact with something they shouldn't be touching...Another thing I messed up, was I didn't completely solder one of the wires too well, so sometimes the volume would be too low,or cut off completely if it moved around.. I found out which one it was and resoldered it.. all has been fine since..

 

[ARandall]

All I can think of is to dewire all the tabs and check the K rating on the pot.....see if its still ok and hasn't been cooked.

And 250k to 500k won't do anything for volume in the slightest. It will make the tone a bit brighter with the 500k pot there.
The taper can help with the speed of the Vol change, but there's certainly not 'more' volume at all.

 

[johnh]

If you chsnged from 250 or 300k linear, to 500k log, then the volume would drop off quicker, but max volume should be fine and clear.

 

[mesaray]

Thanks for the replies guys! When you say that a taper (vs. a linear) would drop off quicker, you don't mean 5 or 6 do you? I'm not sure if the old 250k was a linear or not, but I think stock pots are always taper, right? The new one that I put in is taper, and i'm 100% sure of that. Upon further playing and testing, it appears that max volume is fine. I think my ears were just playing tricks on me. BUT to address the volume difference between 250k and 500 or 500+k, I was under the understanding (from a few threads) that having a 250k volume pot in a humbucker les paul was the equivalent of only being able to turn up the volume to about 7 and that by giving the pickup the 500k you would gain that volume that you typically couldn't reach before. Regardless of whether that is true or not, it shouldn't be dropping out totally at 5 or 6 so I could care less about the true functionality of a 500k volume pot vs a 250k volume pot...I just want my guitar to be 100% again. Lol. I'm up and at em bright and early this morning so I guess I'm going to undo all connections to the pots, test them and then resolder it all again. I'm really not sure what else to do at this point. It sucks when you try to save a buck and a do job yourself and screw it up. Bad part is not knowing what is screwed up! Lol

 

[six pack]

you went liener to audio taper the roll off is not the same

 

[splatter]

according to this
Gibson.com: Gibson Les Paul Classic Custom

you had 300k linear pots from the factory .The ones you changed to may have a tighter tolerance and drop the volume quicker . the fact that you changed to 500k will have absolutely no effect on the output of your guitar with the volume on 10 .
500k will make the guitar sound brighter not louder .Gibson uses 300k on maple capped guitars to cut some of the brightness.

doesn't matter if its 300k or a 500k pot when its set on 10 (max volume) its gonna read 0 ohms.

if You read that 500k is louder you got some bad info .

as for audio vs linear

The easy version....

When you turn down linear taper pots, it's more abrupt. When you turn down an audio taper pot, it's more gradual.








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[mesaray]

according to this
Gibson.com: Gibson Les Paul Classic Custom

you had 300k linear pots from the factory .The ones you changed to may have a tighter tolerance and drop the volume quicker . the fact that you changed to 500k will have absolutely no effect on the output of your guitar with the volume on 10 .
500k will make the guitar sound brighter not louder .Gibson uses 300k on maple capped guitars to cut some of the brightness.

doesn't matter if its 300k or a 500k pot when its set on 10 (max volume) its gonna read 0 ohms.

if You read that 500k is louder you got some bad info .

as for audio vs linear

The easy version....

When you turn down linear taper pots, it's more abrupt. When you turn down an audio taper pot, it's more gradual.

Thanks for the info! Ok so now I understand that 500k would increase brightness and not the actual volume. But I'm still just as confused as to why mine doesn't give any audible output until they were on 5. Can this sometimes be normal for a 500k? All of it crammed in from 5-10??

 

[johnh]

On the log taper pots that you have, do you really mean absolutely no volume at 5 and below? (That would be unusual ), or is it just very quiet? If the latter, that could be normal and would allow a medium-high-gain crunch at 10 to be 'cleaned up' by 5.

If you are happy with the tone and volume at 10, but want some more volume at 5, there are useful tricks using a resistor and cap to fix this (parallel treble bleed, 150k and 1nF cap, in parallel from hot outer to centre vol pot lugs). I use this, but not commonly done, and not to fix an actual fault though.

 

[mesaray]

On the log taper pots that you have, do you really mean absolutely no volume at 5 and below? (That would be unusual ), or is it just very quiet? If the latter, that could be normal and would allow a medium-high-gain crunch at 10 to be 'cleaned up' by 5.

If you are happy with the tone and volume at 10, but want some more volume at 5, there are useful tricks using a resistor and cap to fix this (parallel treble bleed, 150k and 1nF cap, in parallel from hot outer to centre vol pot lugs). I use this, but not commonly done, and not to fix an actual fault though.

Correct, there is no volume at all - below 5. Nothing.

 

[David Collins]

Nothing? If every knob on your amp is cranked full up, ear against the speaker, there is absolutely zero audible signal whatsoever coming through once you are below 5? That would be a very odd problem.

 

[mesaray]

Nothing? If every knob on your amp is cranked full up, ear against the speaker, there is absolutely zero audible signal whatsoever coming through once you are below 5? That would be a very odd problem.

No audible sound at my normal playing level. I didn't dime the amp because if there is nothing audible at 5 on my normal playing level - something is wrong.

 

[David Collins]

Do you have a multi-meter? This is a rather odd problem to speculate on, and a meter would help. If you are entirely new to electronics, it may be a case worth taking in to a decent tech of you have one near by.

If it were one volume, I would say defective pot (although in the thousands of guitars I've worked on I've never seen this, and would require a very odd form of defect). Two volumes though? Very odd, and difficult to imagine what type of wiring error or defect may cause this.

Forgive me for being skeptical, but I'm just having a very difficult time figuring out what may explain no output whatsoever, not even the slightest amount below 5 or 6.

 

[David Collins]

Your original volumes were spec'd at 300k linear, which could have been as low as 250k measured given their loose tolerances. If you replaced them with 500k audio taper you should not expect any increase in loudness at 10, but just the tone being a little bit brighter, that's all.

The bigger effect comes from the taper, and with 500k audio when you are down in they 5-6 range they should delver approximately similar volume to where your original pots would have been at around 2. That's how they should work, and is why we're attempting to clarify whether you are getting no output at all below 5, truly absolutely zero output, or just much less than you are used to with the originals.

 

[mesaray]

Do you have a multi-meter? This is a rather odd problem to speculate on, and a meter would help. If you are entirely new to electronics, it may be a case worth taking in to a decent tech of you have one near by.

If it were one volume, I would say defective pot (although in the thousands of guitars I've worked on I've never seen this, and would require a very odd form of defect). Two volumes though? Very odd, and difficult to imagine what type of wiring error or defect may cause this.

Forgive me for being skeptical, but I'm just having a very difficult time figuring out what may explain no output whatsoever, not even the slightest amount below 5 or 6.

Yes I have a multimeter. I'm not entirely new to electronics but I am confident enough to have thought I would be able to swap out 2 pots and 2 caps without any issues. lol

 

[mesaray]

Your original volumes were spec'd at 300k linear, which could have been as low as 250k measured given their loose tolerances. If you replaced them with 500k audio taper you should not expect any increase in loudness at 10, but just the tone being a little bit brighter, that's all.

The bigger effect comes from the taper, and with 500k audio when you are down in they 5-6 range they should delver approximately similar volume to where your original pots would have been at around 2. That's how they should work, and is why we're attempting to clarify whether you are getting no output at all below 5, truly absolutely zero output, or just much less than you are used to with the originals.

OK yes we're now safely beyond the "increase of volume" stuff that I mentioned earlier in the thread. I realize that was an error on my part. My bad.

Again there is NO AUDIBLE NOISE AT ALL (originating from the guitar) coming from the amp (100w marshall tsl turned up almost 1.75 or 2 - which is normally more than sufficient) when the volume pots were turned to or below 5. At first everyone was saying that it was just the difference between linear and taper but upon watching videos of the differences of the two pots, that is not what I'm experiencing. I appreciate the help guys. Thanks~
Don

 

[David Collins]

Well that one's got me stumped. Perhaps some meter readings could shed some light on things, full up and full down just to confirm we have the normal pickup resistance and full 0, then I'd be interested to see where the output reads at 5, for either pickup. I'm at a bit of a loss though, as for now it's escaping me how you could get a reasonable pan from 10 down to 5 or 6, then a complete cut out all through at 5 to 0, especially on both volumes.

Maybe someone at CTS came to work drunk and stuck some MN pan wafers in your pots. Short of that very unlikely scenario, I'm out of ideas.

 

[moreles]

If you are "gutted" by a wiring snafu, you ought not to be working on your own guitars. Take it easy. We all make wiring mistakes, or find a cap or pot choice disappointing. It is impossible to predict everything in advance, which is why we work on our guitars -- so we can adjust, change, and correct. Many of the posters, and some of your own posts, seem to avoid the basics. As ARandall already said, your pot change should not result in diminished volume when turned all the way up. As someone else advised, if you're not getting a full signal, then undo your connections and redo them correctly. Then, once your wiring is right, you can fuss over pot taper if you want. Until you are getting full volume at 10, the rest is petty, because something major is incorrect -- either a broken pot (unlikely, but it happens) or a wiring error or unnoticed short.

 

[NYC LP player]

- redo you grounds and ground lugs (often the issue)
- run the guitar and amp and poke around and jiggle wires when your volume is below 5 and listen for sudden changes

 

[David Collins]

But can anyone conjecture any possible error in wiring which could explain this phenomenon as described?

I'm typically pretty good at identifying possible problem sources from description of symptoms. This situation, best as I can understand from the description however - output normal at 10, fading from there to about half way, then entirely shut off from around the half way point and downward - short of extremely unlikely flaws existing not only in one pot, but both, this situation seems impossible.

At this point I am mostly just fascinated with the riddle of this seemingly impossible problem. I do enjoy riddles and problem solving challenges, but my hunch is still that there is a glitch in how the symptoms have been communicated.