Troubleshooting guide – Cary Audio Design CAD 211 AE User Manual
Page 10
CAUTION
Never remove or insert the AC plug when the unit is on or the AC power switch is in the “ON”
position. Obstruction of the top portion of the amplifier will result in the tubes overheating.
TROUBLESHOOTING GUIDE ________________________________________
SYMPTOM CAUSE
REMEDY
Hum or “Buzzing” in
speakers
Ground loop
300B tube with high plate
current too high
Intermittent or poor connection
of interconnect
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
“Popping” or “Spitting”
noise
Noisy tube
Check bias of output tubes
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
AC fuse blows
Line voltage surge
Replace fuse
Tube fuse blows
Shorted tube (300B &
845 have separate fuses.)
Replace tube
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