Unauthorized reproduction or use without expressed written permission prohibited
by Steve Guest Copyright 2002
Unauthorized reproduction or use without expressed written permission prohibited
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Section One: Grounds Defined Sound System Components
The Infamous "Ground Loop"Ground - Quick Definitions
Earth Ground / AC Ground
The Difference Between Neutral and Ground
The Case of Voltage Between Neutral and Ground
Three Phase AC Power
Chassis Ground
Audio Ground/Reference/Common / Circuit Ground / Signal Ground / Zero Volt Reference
Earth Ground Referencing of the Audio Ground / Zero Volt Bus
Different designs of internal equipment grounding (or not) and shield handling.Possible solutions to avoiding differences in reference potential between audio equipment.
Unbalanced Consumer Equip. Possible Solution #1 Possible Solution #2 Possible Solution #3
Possible Solution #4 Possible Solution #5 Possible Solution #6 Possible Solution #7
Implementing a system wide ground schemeEvaluating the internal ground status of equipment
Testing the Ground Status Of Audio Equipment
The Hummer Test - John Windt's test device to spot troublesome gear with Pin 1 problems
Internal Grounding Design Examples of Equipment
Design Example 1 The Lowest Common Denominator of Balanced I/O Pro Audio Gear
Design Example 2 Balanced I/O with input shield lift switch.
Design Example 3 Balanced I/O with input shield unterminated.
Design Example 4 Balanced I/O with output shield unterminated.
Design Example 5 Balanced I/O with chassis ground and circuit ground (0V) isolated.
Design Example 6 Balanced I/O with chassis ground to 0V via solation switch or barrier strip.
Design Example 7 Balanced I/O with chassis ground to 0V via resistive isolation.
Design Example 8 Balanced I/O with ungrounded chassis.
Design Example 9 Balanced I/O with shields terminated to chassis.
Design Example 10 Balanced I/O with internal "Star" grounding to common chassis point.
Design Example 11 Balanced Input / Unbalanced Output with no 0V bond and no AC ground.
Design Example 12 Ungrounded and Unbalanced ¼" TS I/O & Consumer Type Audio gear.
Design Example 13 Transformer Equipped Designs.
Shield Telescoped Systems - the typical and conventional cheapest solutionOther Reasons Why Sound Equipment Hum or Buzzes
Troubleshooting shield telescoped systems.
Essential Troubleshooting Tools
Some good "Rules of Thumb" for shield telescoped systems
Front of House to Monitors
Front of House to Stage Inputs
FOH Drive Rack to Amp Racks
Checking the Ground Current
Upgrades options and alternatives to shield telescoped systems
High quality transformer isolated microphone splitter
Balanced AC power
Bridging lifted shields with capacitor and or resistor networks
Custom rack panel interfaces
A fully upgraded ground scheme
Other Ground Schemes: What's Out There
"So where is that buzz coming from?"
Audio Reference problems;
The Infamous Ground Loop (reprise) See the "Solution Animation"
The Pin 1 Page
Lack of an audio reference
Balanced Audio Problems -Transformers & Differential Amplifiers Overview
Balanced Line Fault
Unbalanced Inputs
High Impedance - Low Impedance
Unbalanced Outputs
Problems from Unbalanced Adapters
EMI problems:
Induced hum from RFI/EMI fields
Shield Fault
AC related problems:
Neutral-Ground Reversal or Short
Open or No AC Ground
Low Supply Voltage
3ø Overvoltage Danger
Faulty equipment
Special Section: Microphone Splitters : Introduction
Passive Hardwired Splitters
Active Splitters
Transformer Isolated Splitters
Getting more than 4 Splitter Outputs
[Top] [Title Page]
[ Section 1 ] [ Section 2 ] [ Section 3 ] [ Section 4 ] [ Section 5 ] [ Splitters ] [ Adapter Page ] [ Closing ]
