Audio equipment design analysis

I really like those electronics manufacturers that have the schematics of their devices on their data-sheets or manuals down-loadable from their site. Those schematics can aid in deciding if the equipment is well built, help in repair, designing possible modification and can be aid when you need to make your own designs that have similar

Ground currents: Open neutral

I received this kind of mail some time ago (part of the mail posted here with the permission from the writer): “His cable stopped working so he called the cable company. The cable guy unhooked the coaxial from the main box. After he unhooked the coax he struck it on the side of the amplifier

Star-Quad Cables

Star-quad design is sometimes quite a bit of talked about cable type. When I saw Star-Quad Cables and Double-Blind Testing posting at Controlgeek blog I decided that it would be a good idea to write something about them. Several companies use a quad configuration in their balanced cables instead of a twisted pair; Canare calls

Grounding Complications

Grounding Complications is a very informative 28 slide set from PowerCET. It worth to read for everybody working with ground loops and electrical wiring. The slide set concentrates on following issues: Sensitive Equipment, Isolated grounding and Supplemental grounds. The slide set tells about wiring practices in use in USA, but there are also general information

Audio isolation transformers

Allen Avionics Audio Isolation Transformers page describes the typical ground loop problem situation with the following drawing: If you want to do the ground loop elimination in audio path, you have to cut the galvanic connection but pass the whole audio range. The simplest and most common way to do the isolation is use audio

Laptop to PA humming

A quite typical audio/visual presentation equipment nowdays in many setups includes PC, video projector, audio mixer, amplifier and speakers. Typically you run presentation software through our laptop to a projector and the audio from mics, pianos, guitars, etc to a mixer and then to power amps then to the speakers. The problem many people are

Neutral wire grounding

An ungrounded system is one in which there is no intentional connection between the system conductors and earth. When the neutral of the system is not grounded, it is possible for high voltages to appear from line to ground during normal switching of a circuit having a line to ground fault. These voltages may cause

Scope and ground loops

Differential Scope Primer is a good introduction to oscillospe measurement. This web posting is a shortened version of the information on that document related to ground loops. I have also added here some of my own comments. Most oscilloscopes are designed to measure voltages that are referenced to earth ground, which is connected to the

Power Quality and Utilisation Guide

Power Quality and Utilisation Guide is a free on-line reference source for power quality information. It provides both background theory and solutions from electrical power industry. The guide is prepared by specialist authors from industry and academia, and edited by Copper Development Association‘s David Chapman. The Guide is organized into 8 sections and presented in