Fender Twin Amplifier Owner's Manual page 4

Fig. 1
Fig. 2
If a fuse blows, it should be replaced only with a fuse in accordance
with the listing at the fuse holder. If the amplifier repeatedly blows
fuses, it should be checked out by a qualified technician. UNDER
NO CIRCUMSTANCES should a fuse of a different type or higher
rating, or a fuse bypass be used, as this could damage the equip-
ment and present a serious safety hazard.
B. POWER SWITCH — This switch turns the AC power on and off.
When the switch is off (down), the amplifier is completely shut down.
C. STANDBY SWITCH — When in the STANDBY position, the ampli-
fier is off; however, the tube filaments are left on as to eliminate
warm-up time, provided that the POWER SWITCH (item B) is ON.
Use of this feature during short breaks versus using the POWER
SWITCH will increase tube life.
D. OUTPUT SWITCH — When in the OUTPUT HIGH position, the
maximum output power of the Twin is set to 100 watts RMS, when in
the OUTPUT LOW position, 25 watts RMS. The OUTPUT HIGH posi-
tion is normally used in most applications, and the OUTPUT LOW
position is useful for simulating a smaller amplifier, especially when
the power amp is overdriven.
E. EFFECTS LEVEL — This switch directly affects the signal level
appearing at the EFFECTS SEND JACK (item F) by boosting or atten-
uating the signal being sent to the effects. External rack effects usual-
ly require a setting of 3dBV. Use the highest setting possible that
does not produce distortion for the best low noise performance.
F. EFFECTS SEND JACK — Provides an unbalanced output signal
from the preamp, pre-reverb. It is used to patch into effects.
G. EFFECTS RETURN JACK — This jack provides a pre-reverb return
from effects gear. Plugging into this jack makes the MIX control on
the front panel active.
H. PRE-AMP OUT JACK — The PRE-AMP OUT JACK, in conjunction
with the POWER AMP IN JACK (item I), provides a post-reverb patch
point at the power amplifier input. This jack can be used to provide
an unbalanced, line-level signal (1.3dBV) for recording and sound
reinforcement consoles, and for driving external power amplifiers, or
another TWIN used as a slave amp. To use another TWIN as a
slave amp, simply run a guiter cord from the master TWIN'S PRE-
AMP OUT JACK to the slave TWIN'S POWER AMP IN JACK .
(Note: this output is best for driving tube type slave amps. See item
P, BALANCED LINE OUT, for driving solid-state slave amps.)
I. POWER AMP IN JACK — This jack connects directly to the input of
the power amplifier. It automatically disconnects the preamp signal
when used. This is useful for using the Twin as a slave amp.
J. OUTPUT BIAS ADJUST — This trim adjustment is used in conjunc-
tion with the OUTPUT BALANCE ADJUST (item L) and the BIAS TEST
POINTS (item K) to set the output tube bias. See Output Tube Bias
Adjustment Instructions below.
K. BIAS TEST POINTS — Used to measure output tube bias and balance
with a digital voltmeter. See Output Tube Bias Adjustment Instructions below.