Upgrading LP guitar electronics

[andrius]

First of all, I am newbie to all these things.
I've got a Tokai LS98 (with SD Seth Lover in the bridge; unknown stock potentiometers, not CTS), and I'd like to improve its electronics. I don't know much about that part - what components are there? Potentiometers, capacitors, pickup switch, output jack? Anything else?

1) I understand that potentiometers do a lot in the signal chain, but why should I change the switch and output jack? I don't switch the pickups much. I mean, does the switch affect the clarity or is it only that a better switch will work with less noise?

2) What do the capacitors do?

3) Since my guitar is Japanese and I don't want to drill or do anything else to the body, what good parts would you suggest that would fit here? I read that RS potentiometers won't fit the Japanese guitar. How about CTS? Anything else?
By the way, I live in Europe, so I prefer to buy from Europe for the faster shipping (USA is cool too).

4) Second thing: I want the volume potentiometer to have absolutely no effect on the frequencies (I want it not to cut the treble). What works better in this case: "50s Wiring" or a so-called "Treble Bleed Wiring"? What is a simplier solution?

5) I don't ever use tone control, so maybe I could just disconnect it? What effect would that have?

6) Is it possible to make it work so that if I turn one volume knob all the way down, the other pickup is not turned off?

[Steve Conner]

Let's see.....

1) No reason to change them unless they're faulty or you don't like the way they look or feel. The Gibson style pickup switch often suffers from bad contacts causing it to crackle, but cleaning them is just as effective as replacing the switch.

2) They make the tone controls function (see 5) Russian paper-in-oil caps are a popular "upgrade", but we don't know if they really make much of a difference.

3) I like the Bourns guitar pots available from Farnell, but I don't know if they will fit the holes in your guitar.

4) The volume control will always have some effect on the frequencies, unless you go for full active electronics. The treble bleed wiring is more effective than the 50s wiring in retaining highs as the volume is turned down.

5) If you don't have any tone controls, you won't have to worry about the capacitors any more. The guitar will also sound slightly brighter, because the tone control drains off a small amount of highs even when set to "10".

6) Yes Wiring Diagrams - Wiring Library - Independent Volume Controls

[soundguruman]

First of all, I am newbie to all these things.
I've got a Tokai LS98 (with SD Seth Lover in the bridge; unknown stock potentiometers, not CTS), and I'd like to improve its electronics. I don't know much about that part - what components are there? Potentiometers, capacitors, pickup switch, output jack? Anything else?

Changing the electronics won't make any difference, unless they are broken.

1) I understand that potentiometers do a lot in the signal chain, but why should I change the switch and output jack? I don't switch the pickups much. I mean, does the switch affect the clarity or is it only that a better switch will work with less noise?

It won't improve anything.

2) What do the capacitors do?

The caps roll off the treble when you turn the tone control.

3) Since my guitar is Japanese and I don't want to drill or do anything else to the body, what good parts would you suggest that would fit here? I read that RS potentiometers won't fit the Japanese guitar. How about CTS? Anything else?
By the way, I live in Europe, so I prefer to buy from Europe for the faster shipping (USA is cool too).

Any aftermarket part will require some kind of modification. We don't know which parts are made to fit, because all guitars (especially Japanese) are different. There is no standard thickness and size for all guitars. You have to measure first, then order parts that seem like they match.

4) Second thing: I want the volume potentiometer to have absolutely no effect on the frequencies (I want it not to cut the treble). What works better in this case: "50s Wiring" or a so-called "Treble Bleed Wiring"? What is a simplier solution?

There is no such potentiometer.

5) I don't ever use tone control, so maybe I could just disconnect it? What effect would that have?

Disconnect it, it won't work anymore. No amazing change.

6) Is it possible to make it work so that if I turn one volume knob all the way down, the other pickup is not turned off?

No.

[andrius]

No.

Which question are you talking about exactly?

[andrius]

The potentiometer changes the resistance in the chain. But, for example, if it's a truly 500k potentiometer - is it always 500k at the highest (or lowest) position? If so, then what is the resistance at the lowest (or highest) position? I mean, what is its resistance at 10 and at 0?

If I get it right, the bigger the resistance is, the more signal is passed through the resistor, right? So 1000k potentiometer passes more signal, right? What is then the biggest possible resistance that passes all the signal and does not filter anything out? I mean, if I get it right, 0 resistance means no signal passes, right? Then was is the maximum value were everything comes through? I understand that it's impossible in reality, but I am talking about ideal case. And what is the maximum possible resistance?

[soundguruman]

Which question are you talking about exactly?

"Is it possible to make it work so that if I turn one volume knob all the way down, the other pickup is not turned off?"
No. Not with the switch in the middle position.
Normal guitar wiring is not that way. When both PUs are on, either volume will turn the guitar to 0.

[big_teee]

"Is it possible to make it work so that if I turn one volume knob all the way down, the other pickup is not turned off?"
No. Not with the switch in the middle position.
Normal guitar wiring is not that way. When both PUs are on, either volume will turn the guitar to 0.

Hi Andrius and the Gang:
If you do the independant wiring like in Steve Conners Link, it will be independant.
Here it is in a word file.
You can save it to disk.
If the output lead is in the center then the vol pot kills either pickup when turned off.
If the output is on the outside like the diagram then you have independant Vol. Roll off.
T
Les Paul 60s and 50s wiring Web Site.doc

[andrius]

Thank you, big teee!


Could someone please explain me what is the difference between good and bad potentiometers?

[soundguruman]

Thank you, big teee!


Could someone please explain me what is the difference between good and bad potentiometers?

Cheap junk is what you find in almost any guitar. The control is made from pot metal, and the internal resistor wears out quickly. Good quality controls, like Bournes, Precision Canada, Allen Bradley, etc, are almost never used-- because the manufacturer does not stock, and the price is sky high. They have to be ordered according to all configurations and measurements, and then you gotta wait for months to get delivery. Therefore, you don't see a lot of good controls being used in lower price guitars.
The good controls show up in the really high dollar guitars, like LP customs, etc...and the price to replace them is substantial. The metal is much higher quality, like stainless steel, other proprietary metal materials, custom length threaded bushings, and shaft end configurations. Gibson even has their own internal metal shielding can, that encloses the controls...which is made of a proprietary metal alloy. (aluminum foil stick on shielding is basically a joke). Another good example of better quality is the EMG set up...that comes with the EMG pickups, prewired. This is conductive plastic and is a high quality, completely sealed construction.
The good control is designed to endure tens of thousands of rotations, and often has a industrial, military or aerospace specification code. The internal insulation, lubrication, etc, etc, meets a much higher standard than consumer grade hardware. Yes consumer grade is garbage...designed for Harry Homeowner.
The TAPER of the control (curve as you turn it) is much more even and uniform on a professional grade control. It gives you control that is predictable, smooth, from "0" to "10"---not available on cheap controls.
My choice is Precision Canada, stainless steel body, sealed, BUT you may find that the bushing length, shaft style, etc...does not meet your design, won't fit the stock knobs, or will not fit easily inside the guitar. And that is why the world is ruled by $2-$5 potentiometers.

Another BIG problem is that people who sell high quality controls--don't give the measurements and specifications! You are left stranded and guessing which control will or will not fit into the guitar. It's a ROYAL PAIN. My supplier sells the controls, but gives me almost NO information about the size, shaft length, bushing length, etc, etc...and so I have to measure it myself---AFTER I buy it. The measurements given by the seller is never completely accurate, and frequently erroneous...

[andrius]

Thank you, soundguruman. And what about the sound quality: is there a difference between a good and not so good potentiometer in that respect?

[soundguruman]

There are inductive and non inductive resistor materials. Like for instance a wire wound pot is inductive, and will tend to pick up a lot more external 60 cycle hum. If you dig deep into the manufacturer specification sheets, you will see that some high end controls are intentionally made "non inductive." And therefore, probably have a lot less hum from external sources.
Of course most manufacturers and vendors don't want you to know this, because you will stop buying the cheapo products.
Let me tell ya, it's HARD to buy good controls, because the sellers are hiding the real information. You really gotta do your research!

[andrius]

And besides that hum? My potentiometers don't seem to induce any hum (at least I don't realize it's there, if it is).

I want to lose as little of the treble frequencies as it's possible. So I wonder whether I am actually losing anything with mine (and if better pots lose less).
Do pots normally suck more of the treble frequences when they are turned lower?

[soundguruman]

http://www.bourns.com/data/global/pd...ng_appnote.pdf

Yes, when you turn the control down the treble drops off, same with all potentiometers basically...
we put a silver mica cap between the wiper and the input of the control to bypass the resistance (100-500pf) this is the same as the bright switch on a fender amp...just no switch, same circuit.
There are also "step" volume controls that are intentionally made so that the treble does not roll off. These cost $$$ and are used in high end hi fi amps.
http://www.percyaudio.com/Catalog.pdf See page 13...just to get the idea.
That is probably the advantage to an active volume, that uses a feedback loop to control the gain instead of a conventional volume circuit.

[soundguruman]

Wiring Diagrams - Wiring Library - Treble Bleed - High Pass Filter

[andrius]

Yes, when you turn the control down the treble drops off, same with all potentiometers basically...

So even if I make a "50s wiring" or remove the tone potentiometer at all and just leave the volume pot, it will still be cutting the frequencies, right? Even those highly-regarded CTS do so, right?
So the only way for it not to cut frequencies is (and not buying the ultra expensive "step" volume controls) is to make a treble bleed mod, do I get it right?