TREX BigTone T25 Combo User manual

B I G T O N E T 2 5
COMBO
USER’S MANUAL

USERS GUIDE
Congratulations on the purchase of your new BigTone T25 Combo.
T.Rex grants a 2-year warranty against defective parts or workmanship.
In the event of a defect, please contact your nearest T-Rex dealer.
BIGTONE T25 COMBO
The BIGTONE T25 Combo has been developed in cooperation with professional guitarists who need a solid,
good-sounding amp in the studio as well as in live situations.
The people at T-Rex Engineering have worked intensely in the selection of high-grade components and spent a lot of
time rening the mechanical construction of the amp.
As a result we are proud to present an amp that is guaranteed to provide you with years of condent use and that
will inspire for many hours of musical satisfaction and lasting enjoyment.
The BIGTONE T25 is equipped with 2*12” ALNICO speakers that use magnet alloy of aluminium, nickel and cobalt
(8 ohms each - wired in series for 16 ohm load).
ALNICO-speakers have a unique retro-sound with a denition and response that smoothens the sound into glorious
creamy overtones - rich in quality and sustain.
The BIGTONE T25 uses three 12AX7 preamp tubes and four EL84 power tubes, -a classic 30-watt tube constellation
that breaks up very musically at relatively low volume - a big advantage when playing smaller venues where lower
volumes are required.
The BIGTONE T25 is equipped with a tube driven Accutronics Spring Reverb, -the best possible way to obtain
authentic reverb effects.
Thirteen-ply birch (from Finland) cabinet ensures sturdiness and excellent sonic characteristics.
Total weight is 29,7 kilos.
PRECAUTIONS
Do not expose the amplier to moisture, rain or water, direct sunlight
or extremely high temperatures.
Always unplug AC power cord before changing fuse or any tubes.
When replacing fuse, use only same type and rating.
Avoid direct contact with heated tubes.
Insure adequate air circulation behind the amplier.
To avoid damaging your speakers and other playback equipment, turn off all equipment before
making the connections.
Do not use excessive force in handling control buttons, switches and controls.

TOP PANEL FEATURES
POWER SWITCH: ON/OFF (outer positions): Turns the amplier ON/OFF.
STANDBY (middle position): Warms up amplier.
It’s always a good idea to leave the amp at least 30 seconds of warm-up time in
STANDBY-mode during start-up to minimize the shock on cold power tubes, thus
prolonging their life substantially.
CONTROL LAMP: Lights up when amp is on.
MASTER VOLUME: Controls the overall volume of the amp.
REVERB: Controls the overall reverb amount.
CUT: Variable tone control to lower the overall higher frequencies for a smoother
tone.
TREBLE, MID & BASS: These controls are carefully designed so they won’t deform but enhance your
tone and supply you with a wide range of tonal opportunities.
Treble control
Adjusts the higher frequencies in your tone, from soft and full at one extreme to
bright and cutting at the other.
Middle control
Adjusts the midrange frequencies in you tone from a softer “dipped” sound at
one extreme to a bold and barky at the other.
Bass control
Adjusts the lower frequencies in your tone, from warm and light at one
extreme to dark and heavy at the other
GAIN: This control not only determines the overall Gain amount, shape and sen-
sitivity of the amp…but it is also a powerful Tone control. Generally speaking,
whatever is dialled here ultimately determines the amps personality.
Set low, it allows cleaner, brighter sounds with enhanced dynamic response,
especially in the higher frequencies. Set high the entire personality of the
channel becomes darker, fatter and more overdriven.
NORMAL/BRIGHT: Bright mode boosts higher frequencies.
INPUT: Input socket for instrument.

BACK PANEL FEATURES
MAINS INPUT: The BIGTONE T25 is capable of operating at line voltages of 115 or 230 V AC,
50-60Hz.
VOLTAGE SWITCH: Use this switch to change one of two voltages, 115 or 230 V AC
MAINS FUSE: If the fuse should fail, it must be replaced with the same type and value in
order to avoid damage to the amp.
HT FUSE: This fuse protects the power supply in case of tube failure. If it blows,
check for a bad power tube. If tube-failure is not the cause, the BIGTONE T25
should be brought to a qualied service center for repair. If the fuse should fail, it
must be replaced with the same type and value to avoid damage to the amp.
SPEAKERS: The BIGTONE T25 provides a 16 ohm and a 8 ohm speaker output. The
internal speakers use the 16 ohm speaker output. The 8 ohm output is
for connection of speaker(s) or speaker cabinet(s) with a minimum total
impedance of 8 ohms.
WARNING: Never play the BIGTONE T25 without a speaker connected.
This may cause serious damage to either the power tubes and/or the
output transformer. Always use speaker cable for extension speaker(s) or
speaker cabinet(s).
REVERB IN/OUT: Sockets for connecting the the built-in Reverb tank
REVERB REMOTE
SWITCH: Socket for the connection of a REVERB switch for switching the signal
from the built-in Reverb tank ON or OFF.
Issued in Vejle September 14th 2003
Lars Dahl-Jørgensen
Managing Director
® T-Rex Engineering Aps · Ibaek Strandvej 3A · DK-7100 Vejle · Tel. [phone] · www.t-rex-eng.com
Sebastian Jensen
Managing Director