11
Tube life varies depending upon
playing style and application. Power
tubes have a much shorter life than
pre-amp tubes which can last for
years. For continued optimum
performance from your amplifier, the
tubes should ONLY be replaced with
the same type tubes as specified on the tube
illustration below.
A simple way to check if the tubes are worn is to
replace the set in your amp with your spare set. (You
do carry spare tubes and fuses, don't you?)
When changing the tubes, ALWAYS unplug the
amplifier and remember THE TUBES ARE HOT!
Either wait for the tubes to cool or use an insulated
oven mitt to remove them from your amplifier.
• First, replace the OUTPUT tubes in the amplifier,
re-bias and listen.
• Next, re-insert the original output tubes and re-
bias. Replace the PRE-AMP tubes and listen.
• Finally, try replacing both the OUTPUT (re-bias) and
PRE-AMP tubes and listen.
If there is a marked improvement in the tone of your
amp at any point in this procedure, leave the new
tubes in your amp and purchase another spare set.
Your 300T's tube compliment consists of:
• One 12AT7A Tube (part #023531),
(tube location V4)
• Three 12AX7WA Tubes (part #013341)
(tube locations V1 thru V3).
• Six 6550C Tubes (part #048489),
(tube locations V5 thru V10).
If the amp is set up but does not
function, check the following items:
• Is the power cord properly plugged into an
electrical outlet?
• Is there power at the outlet?
• Is the instrument properly plugged into the
amplifier?
• Are the control knobs turned above 1?
• Is the volume control on your bass guitar turned up?
• Is the TUNER ONLY button disengaged?
• Is the STANDBY switch in the ON position?
• Are any cords cut or frayed?
• If using the effects loop, is the effects unit(s) is
properly plugged into the amplifier?
• Is there power to your effects unit(s)?
• Is the amplifier properly plugged into your
speaker cabinet or enclosure?
Eliminate any effects pedals, disconnect any
effect devices from the effects loop and try
another guitar cord.
Check under all tube covers to see if the tube
filaments are glowing.
FYI: Attenuating low frequencies may cause the
preamp to distort and this may not cause the INPUT
LEVEL LED to flash red. if this is the case, simply turn
down the CH.1 VOLUME and / or CH.2 VOLUME
until the distorted sound diminishes.
If, after checking all of the above, your amplifier is not
performing correctly, consult your nearest authorized
Fender service center.
Your 300T is covered in genuine
Tolex
®
for long life and lasting good
looks. To clean the Tolex covering,
use a sponge and a light soapy water
solution. Avoid spilling liquids on the
operating surfaces, grille, volume and
tone controls and switches. ALWAYS
unplug your amplifier before cleaning or approaching
it with fluids.
COVERING CARE
TUBE REPLACEMENT TROUBLESHOOTER’S CHECKLIST
To Next Page
Loading...
