Here are some of my favorite wiring diagrams that I drew up over the years. Most people have expressed appreciation commenting about the nice easy to read and color coded format. It is my hope that some
people will get some use out of a few of these.
Based on countless customer requests, Rothstein Guitars offers high quality wiring kits for the majority of these diagrams. To purchase a kit, simply click on the red link indicating a wiring kit is available for purchase. Please check out our
here.
Purpose
Simply put, resistors restrict the flow of electric current.
Measurement
Resistance is measured in ohms, the symbol for ohm is an omega . Resistor values are often represented in
k and M, where 1 k = 1000 and
1 M = 1000000 .
Resistor
Color Codes
Color
Number
Black:
xxx
0
Brown:
xxx
1
Red:
2
Orange:
3
Yellow:
4
Green:
5
Blue:
6
Violet:
7
Grey:
8
White:
9
Resistor color code
Resistor values are normally indicated using colored bands.
Each color represents a number as shown in the table.
Most resistors have 4 bands:
The first band gives the first digit.
The second band gives the second digit.
The third band indicates the number of zeros.
The fourth band is used to indicate the tolerance (precision) of the resistor. A special colour code is used for the fourth band tolerance:
silver ±10%, gold ±5%, red ±2%, brown ±1%.
If no fourth band is shown the tolerance is ±20%.
Example: a 220k resistor with a tolerance of ±10% will have a value within 10% of
220k,
that is between 220 - 22 = 198k and 220 + 2 = 242k .
This resistor shown has red (2), red (2), yellow (4 zeros) and gold bands.
So its value is 220000 = 220k.
When resistors are connected in series their combined resistance is equal to the individual resistances added together. For example if resistors R1 and R2 are connected in series their combined resistance, R, is given by:
Combined resistance in series: R = R1 + R2
This can be extended for more resistors: R = R1 + R2 + R3 + R4 + ...
Resistors in Parallel
When resistors are connected in parallel their combined resistance is less than any of the individual resistances. Use the following equation for the combined resistance of two resistors R1 and R2:
Combined resistance of two resistors in parallel:
R =
R1 × R2
R1 + R2
For more than two resistors connected in parallel a more difficult equation must be used. This adds up the reciprocal of each resistance to give the reciprocal of the combined resistance, R:
1
=
1
+
1
+
1
+ ...
R
R1
R2
R3
Fixed Resistors in Guitar Circuits
Treble Bleed Circuit One of the most common applications of fixed resistors in guitar circuits is in treble bleed circuits (aka volume kits). A volume kit is a very simple mod that will prevent the loss of highs as you roll down your guitars volume control. Many pros will recommend slightly different methods on how to achieve this. After much research I have settled on a 150K resistor in parallel with a small capacitor in range of 680 pf - 1000 pf.
Reducing the Value of a Variable Resistor (Pot) Let's say you need a 500k pot for a guitar application but you only have a 1 meg pot available? You can change the 1 meg pot to be used as a 500k pot by placing 1 meg resistor in parallel with the pot (that is across both outside terminals of the pot).
Rothstein
Guitars • www.guitar-mod.com • Serious tone for the serious player
Custom Guitars & Basses • Finishing/Refinishing • Pre-wired
Harnesses • Unique Wiring Mods • Authorized Retrofitter
for Buzz Feiten Tuning System®
Authorized dealer of Lindy Fralin, Joe Barden, Curtis Novak, Stephens Design, Rio Grande, DiMarzio
and Nordstrand pickups Fender®, Strat®, Stratocaster®, Tele®, Telecaster®, P-Bass® and J-Bass ® are registered trademarks of FMIC.
All rights reserved. The author has no affiliation with FMIC.
. Resistor values are often represented in
k
