w w w . a c o u s t i c a m p l i f i c a t i o n . c o m
POWER
STANDBY
25W PENTODE
12W TRIODE
MASTER
REVERB
CLEAN
PRESENCE
LEAD
VOLUME
INPUT
CLEAN
VOLUME
NORMAL
HIGH
GAIN
LOW
GAIN
GAIN
GT50H
BASS
MID
TREBLE
Tube Lead
Series
LEAD
50W PENTODE
25W TRIODE
AC IN
FUSE
FOOT
SWITCH
CHANNEL
HIGH/LOW GAIN
REVERB
BOOST
SEND
RETURN
FX LOOP
MIX
SPEAKERS
16 0HM
DESIGNED IN CALIFORNIA
MADE IN CHINA
Acoustic Amplification
P.O. Box 5111
Thousand Oaks, CA 91359-5111
www.acousticamplification.com
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BOOST
LEVEL
DRY WET
MODE
TRIODE / PENTODE
TRIODE
25W
12W
PENTODE
50W
25W
4 0HM
OR
8 0HM
8 0HM
&
8 0HM
OR
16 0HM
16 0HM
&
GT50H
HEATER
250V/T 5A
ANODE
250V/T 500mA
CAUTION:
ENSURE THE DEVICE IS DISCONNECTED
FROM THE MAINS BEFORE REPLACING
THE FUSE. ONLY USE FUSES OF THE
SAME TYPE AND RATING.
~120V AC 50/60Hz 150W
T3.15AL/250V FUSE
BRIGHT
3
1. GUITAR INPUT: 1/4” two-conductor jack.
2. CLEAN VOLUME: Adjusts the relative volume of the
clean channel.
3. BRIGHT/NORMAL SWITCH: Enhances the high
frequencies on both the Clear and Lead channels when
switched to the “Bright” position.
4. HIGH GAIN/LOW GAIN: This switch increases the
preamp gain level on both the Clean and Lead channels
when switched to the “High Gain” position.
5. GAIN: This control increases or decreases the gain level
on the Lead channel.
6. BASS: This control increases or decreases bass
frequencies for both channels.
7. MID: This control increases or decreases mid range
frequencies for both channels.
8. TREBLE: This control increases or decreases treble
frequencies for both channels.
9. LEAD VOLUME: This control adjusts the relative volume
of the Lead channel.
10. PRESENCE: This control adjusts the upper high
frequencies when the Lead Channel is selected.
11. LEAD/CLEAN: Switches between the Lead and
Clean Channels.
12. REVERB: This control adjusts the level of the spring
reverb effect.
13. MASTER: This control adjusts the overall volume of
the amplifier.
14. HALF POWER SWITCH: This switch reduces the power
transformer output level to half power without
changing the sound of the amplifier. Switch between
50 watts and 25 watts when in Pentode mode. Switch
between 25 watts and 12.5 watts when in Triode mode.
CAUTION: The amplifier should be switched to
“STANDBY” before changing the transformer power
switch setting.
15. STANDBY: The Standby switch is used in conjunction
with the Power switch on tube amplifiers. The Standby
switch should be left in the off position for 2-3 minutes
after turning the Power switch on. This allows the
tubes to come up to operating temperature and will
extend the life of the tubes. The Standby switch should
be turned to the off position before turning the Power
switch off. The Standby switch can be used to turn off
sound from the amplifier while keeping the tubes at
operating temperature. Finally, the Standby switch
should be turned to the off position when changing
the position of the Half Power switch or the Triode/
Pentode switch in order to protect the amplifier and
extend the life of the tubes.
16. POWER: Turns the power on and off.
GT50H FRONT PANEL
5
2
1
4
3
6
7
11
12
8
9
13
14
15
10
16
