Resistors in wiring mods, and other unconventional ideas

[sparkplug]

Hey friends,

I'm not particularly familiar with how wiring and electronic components really work.
I have a handful of different resistors and capacitors on hand... I'm not sure what they do (mainly the different kinds; I understand that resistors regulate/normalize current flow, right?).

Can anyone help me understand some of the capabilities of components like this? Like, what if I just introduce a resistor into a signal chain, in series? Does it compress the signal? What about in parallel?
Can I create some sort of wacky effect with little components and put it on its own pot so that I can swell it in?
How much is it reasonable to experiment before I'm essentially just building a pedal into the wiring cavity of the guitar (lol)?

I'd like to build some interesting wiring configurations in a project guitar.

 

[Jacew]

Re: Resistors in wiring mods, and other unconventional ideas

First I'd suggest you to read the basics of electronics to understand how it works and what it is, So you can understand the basics.

You can do simple wiring mods easily without it, but comparing guitar wiring to designing a pedal schematic is like comparing plans for a book shelf for a house blueprint...

To get you started:

The guitar pickups form and AC voltage in the wiring. It flows through it from one pickup lead to other. Components (and the amp on the other side of the lead) go parallel with the source (pickup). When you have two components in series in that line, they're both parallel with the source, but in series with each other.

Resistors resist the flow. They're used to direct the amount of flow in analog circuits. If you have two same sized resistors parallel, both sides gets half the flow. If other has twice the resistance, twice more of the signal flows through the other.

Capasitors essentially work like batteries. They store electricity. They also have reactance in AC circuits, which basically means the change their resistance depending on the frequency. High frequencies, like treble in guitar use, flows through it, low frequencies won't. So they are used to adjust tone of the signal.

That very simplified wrap up of the basic use of those components. There is so much about that you just need to delve in to it.

I can't say I know a lot about this, but enough for my hobbying. Wanted to introduce those basics to you, because from personal experience I know how frustrating it can be when learned people insist on using perfectly accurate and very complex terminology to explain everything.
Like it's more important to know factual difference between impedance and resistance rather than how they affect the voltage for instance.

 

[beezerboy]

Re: Resistors in wiring mods, and other unconventional ideas

a resistor in series is like dialing down the volume knob. the more the resistance, the lower output from the pickup to the amp. could be switched in/out for lead & rhythm.... (completely out for lead). a resistor in parallel with the pickup? not exactly sure what would happen there, and it would depend on value, but at least some of the signal would simply feed into the resistor & be converted to heat at all times, so a lower output.

as for caps, thats (a big part of) where your tone control gets its mojo. installing different cap values alters how much bass gets trimmed out. there has been guitars like the 355 with rotary switch & each position has a different value cap and each will produce a different tone.

thing to do is check diagrams of various guitars for different pickup configurations. then you can see whats been done and how. I would start in the "support" section above and pull up diagrams. to me, its more interesting to fool with different pickups... switching in/out of phase or coupling coils that normally don't belong together. I've been playing with P-Rails lately too..... very kool

 

[Jacew]

Re: Resistors in wiring mods, and other unconventional ideas

a resistor in series is like dialing down the volume knob. the more the resistance, the lower output from the pickup to the amp. could be switched in/out for lead & rhythm.... (completely out for lead). a resistor in parallel with the pickup? not exactly sure what would happen there, and it would depend on value, but at least some of the signal would simply feed into the resistor & be converted to heat at all times, so a lower output.

Not quite: Potentiometer works like two resistors side by side. Other between output and input, and other between input and ground. When you turn it down, resistance of one between input/output grows and other between input/ground drops. Hence the amount of signal to output drops as more of it is bleeding to ground. Cap works in a same way, except it only bleeds the high frequencies out.

If you just add resistor in other lead, you add capacitance, but it won't have the lower output effect of volume pot as you don't have the ground connection to bleed it out. If you add it between hot and ground, it will have that effect, but will vary wildly based on the amp, lead and other things connected to guitar, because resistance there is straightforwardly affecting the amount of signal bleeding to ground.

You need both resistors to control the amount of signal.