AC Line sniffers...Better ones have adjustable sensitivity...
Yep.
Tried this one as well- great for checking all of the wiring and cables in your setup! But look for the adjustable version.
Ref:
http://www.psaudio.com/ps/tips/15-noise-sniffer
AC Line sniffers...Better ones have adjustable sensitivity...
gmphadte said:A crystal receiver, as audio tracer.
Comes handy to find which stage of the amp is faulty
An injection needle comes very handy to probe the pcb.
Gajanan Phadte
...an LED with 3 wires, one side is blue the other side is red LED and the center wire is a common cathode..with a couple of 1N4004's and a 33k 2W dropping resistor, and a pair of clip leads, I made one into an "offset sniffer".
I once made something similar but with two bright LEDs in inverse parallel and in series with a 5w, 15k resistor. Works nicely from 5v to 240v, AC or DC. Add another circuit with a neon bulb in series with a 150k resistor to indicate high voltage.unclejed613 said:where i work, we regularly get Klipsch powered subwoofer amp modules for replacement. along with the amp module comes an LED with 3 wires, one side is blue the other side is th red LED and the center wire is a common cathode. with a couple of 1N4004's and a 33k 2W dropping resistor, and a pair of clip leads, i made one into an "offset sniffer". regularly Pioneer, Yamaha and Denon amps come in with blown channels, and the protection mode only allows a couple of seconds before tripping the power relay off. so hooking up the sniffer to the output lead to each channel and cycling the power makes it easy to go through a 7.1 surround amp and find the blown channel without getting confused by the slow sampling rate of a DMM flashing nearly meaningless numbers (the chances of a DMM sampling exactly when you want it to is slim to none (and Slim is out of town)). a solid red or blue LED while the power is on is a quick indication of a bad channel. it's much more portable than a scope, and not all the techs where i work have one at their bench, especially the "triage" techs the 1N4004's are for "steering" the applied voltage. the device comes in handy for checking for the presence of DC voltages, as well as checking for output signal at the speaker terminals (it glows purple in time with the music). the LED's turn on at about 3V, so it can test for the presence of 3.3V rails, on up to the power supply for the amp.
A crystal earpiece is such a high impedance that you can trace audio...A cheap battery powered CD player makes a convenient source for all sorts of test signals...