Troubleshooting Guide - Cary Audio Design CAD 211 AE Owner's Manual

TROUBLESHOOTING GUIDE ____________________________

SYMPTOM
Hum or "Buzzing" in speakers Ground loop
"Popping" or "Spitting" noise
AC fuse blows
Tube fuse blows
CAUSE
300B tube with high plate current
too high
Intermittent or poor connection of
interconnect
Noisy tube
Check bias of output tubes
Line voltage surge
Shorted tube (300B &
845 have separate fuses.)
9
REMEDY
Install 2-pin adapter
on AC cord to float the ground
Check bias of 845's. If high,
readjust to proper bias setting of
100 mA
Replace bad interconnect cable
If noise is in one channel
through the speaker, swap one
section of tubes at a time until the
noise swaps channels. Replace the
noisy tube.
If high or fluctuating rapidly,
replace output tube
Replace fuse
Replace tube