Kustom Defender V50 User manual

Owner’s Manual

Table of Contents
Introduction..........................................................................................1
Safety Information....................................................................................2
Amp Specifications...................................................................................6
Amp Signal Path........................................................................................7
The Defender™ Control Panel....................................................................8
The Defender™ Back Panel......................................................................10
The Defender™ Accessories....................................................................12
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©Kustom Amplification
All specifications are subject to change without prior notice.
Contents
Kustom Amplification
2395 Arbor Tech Drive
Hebron, KY U.S.A. 41048
www.kustom.com
1.888.4KUSTOM
1.888.458.7866
Defending Your Right To Great Tone!
Thank You for purchasing THE DEFENDER™, the 50-watt amplifier that reclaims the sound that
sparked a revolution. Tapping into the essence of classic tube amplifiers, THE DEFENDER gives play-
ers the essential ingredients for smokin’ tones, all the way down to its 1960s-era Pine cabinet. In this
Owner’s Manual, you’ll learn about the many cool features of THE DEFENDER. Be sure to experiment
and find the sounds that speak to you and your playing style. Ideally, use it with a band that will ap-
preciate your now awesome TONE. Just be sure to give some thanks to THE DEFENDER...

2
Safety Information

3
Safety Information

4
Safety Information

5
Safety Information

6
Amp Specifications
Model Defender 112 All-Tube Guitar Combo Amp with 12-inch speaker
Power Amp Tubes 2-EL34 power tubes using AUTOKRUISE™ biasing scheme
Preamp Tubes 3-12AX7 preamp tubes(2 preamp, 1 phase inverter)
Output Power 50 W RMS 16, 8, or 4 Ohms @ 5% THD
Speaker 1 X 12 inch KEI(Kustom-Eminence Integrated) EPIC-12, 16 Ohm
Input Impedance
Hum & Noise -63dBV Residual Noise, all level controls 0% (minimum), Bright Off, Presence @ 0
60 dB Nominal Gain, Volume @ 5
86 dB Maximum Gain, Volume @ 10
Gain = +10 dB Maximum gain of footswitchable volume boost
Gain = +3 dB Gain increase at 1 kHz when Bright is switched
Nominal Signal to Noise 60 dB Volume half and Master maximum, Boost on 10
Footswitchable Boost Master Volume Boost Adjustable from 0 to +10 dBV, nominal -6dBV
USA/Canada 120VAC/60Hz, 180W
Europe 230VAC/50Hz, 180W
UK 230VAC/50Hz, 180W
Australia 240VAC/50Hz, 180W
Japan 100VAC/50-60Hz, 180W
mm/kg 486 mm (Height) X 569 mm (Width) X 261 mm (Depth), 17.3 kg
inches/pounds 19.125" (Height) X 22.375" (Width) X 10.25" (Depth), 38 Lbs
1M Ohms
Tubes
Power Requirements
Footswitch
System Gain
Dimensions/Weight
Is compatible with single button Kustom Footswitch, part # KAC-FS100
Uses a standard mono shielded cable
The Defender Specifications

7
Amp Signal Path

The Defender 112 Combo Control Panel
1) Input: This is a 1/4” 2-conductor input jack for plugging in your instru-
ment. It is intended for guitar but will accept other instruments as well.
2) Bright: Flipping the Bright switch will increase the high frequencies
of the signal, while also reducing low frequencies for a chunkier, tighter
attack. This function is very useful for fine-tuning the amp’s tone and
feel for different guitars.
3) Volume: This control adjusts the gain in the input stages of the pre-
amp. Utilizing an exclusive new circuit called Duo-Mod™, it changes
gain in multiple stages to allow a more variable range from clean to
dirty than is typical of most tube guitar amps. This control is used in
conjunction with the Master to adjust the amount of distortion and vol-
ume. For cleaner sounds, adjust Volume to lower settings and the Mas-
ter to higher settings. For slight breakup, the controls should be set in
their middle ranges. For heavier distortion, set the Gain higher and the
Master lower.
4) Master: The Master sets the overall volume and simultaneously tai-
lors the tone controls to work better for that range. If the Master is set
higher, as it would be for cleaner sounds, then the tone is adjusted for
cleaner, “chimey” tone. If the Master is set lower, as it would be for
more distorted sounds, then the lows are increased for a fatter distor-
tion tone that’s still tight sounding. The resulting system makes it easy
to get a good tone without having to change the EQ settings.
5) Master Bypass: Non-master volume amps are something that vin-
tage amp experts have always touted as being an essential element to
great, “crank it up” tones. This switch will entirely disable the Master
Volume control from the circuit to give you the penetrating tone and
headroom of vintage, non-Master types of amplifiers.
6) Bass: This passive EQ adjusts the low frequency equalization of the
amplifier. It interacts with the Middle and Treble as described in the
Treble EQ section (8). For a tighter low end, use the Bass EQ set to lower
settings. This is particularly helpful when using the amp at very loud
settings.
7) Middle: This passive EQ adjusts the midrange equalization of the
amplifier. It interacts with the Bass and Treble EQ as described in the
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The Defender Control Panels

Treble EQ section (8). For a heavier, more distorted sound, set the Mid-
dle lower. For more of a vintage-style, cleaner sound, set the Middle
higher.
8) Treble: This passive EQ adjusts the high frequency equalization of
the amplifier, but also interacts with the Bass and Middle controls as
follows: As the Treble is increased, the Bass automatically decreases
and the Middle slides down in frequency. Conversely, if the Treble is
decreased, the Bass automatically increases and the Middle slides up in
frequency. This interaction is typical of vintage-style passive EQ, and is
responsible for the increased effectiveness of such a simple system.
9) Reverb: Reverb controls the amount of the reverberation effect in the
amplifier. This effect is created by an authentic spring reverb pan and
sounds essentially like playing the amp in a large room. The Reverb can
be defeated by turning the control fully counter-clockwise.
10) Presence: The Presence control operates in the power amp section
of the amp and adds high frequencies to the tone. Higher settings will
provide more bite and help you cut through the mix.
11) Boost: The Boost knob controls the amount of footswitchable boost
in the power amp, and is particularly useful for solos. It will provide up
to 10dB of “Master Volume” boost. The tone is optimized to increase
the volume without sacrificing too much headroom in the power amp,
so the resulting solo cuts through. (Note: Boost is active if the foot-
switch is unplugged.)
12) Jeweled Pilot Light: When lit, it indicates that the amplifier’s power
switch is in the ON position.
13) Standby: This allows the amplifier to be powered up, but with the
tubes in a non-operational mode. The Standby can be used instead of
the power switch between performance sets, since it allows the amp to
“shut down” while keeping the tubes warm and ready to go. It’s also
best to power the amp up with this switch set to the downward “Off”
position until the tubes have had a few minutes to warm up, although
modern tubes are more tolerant of this.
14) ON Power: Provides AC power to the amplifier when in the upward
“On” position.
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The Defender Control Panels

The Defender 112 Combo Back Panel
1) Power Cord Receptacle/Fuse Holder: Insert the AC cord (pro-
vided) firmly into the AC connector. NOTE: Replace the AC power
cord if protective jacket is damaged or ground pin is damaged or
removed. The fuse is located in a housing just below the receptacle.
Replace only with same type and size. To remove the fuse, remove
AC power cord and pull out on the tab above the fuse symbol locat-
ed on the fuse carriage. Place the new fuse in the carriage clip and
re-insert. NOTE: To prevent an electrical hazard, DO NOT replace
fuse without using the fuse carriage. Replace the fuse carriage if lost
or damaged before re-inserting the AC power cord.
2) Footswitch: The Footswitch jack on The Defender is a mono jack
that connects a footswitch to the amplifier. The footswitch switches
the Boost feature on and off.
3) Tube Chart
a. Bias Switch: The Defender ships from the factory with classic
EL34 output tubes. However, if you happen to prefer 6L6s or just
want to try something different, this amp has the ability. Under-
neath the tube cage is a switch that may be used to change the bias
to accommodate either EL34 or 6L6 power tubes. (Note: This switch
is not a user serviceable item. Be sure to take it to a qualified service
tech to make these changes.)
b. EL34 Output Tubes: These power tubes were selected to provide
the best combination of performance and tube life, and shouldn’t
require adjustment to their bias. The amp uses a mixed-bias sys-
tem, which is a combination of fixed and self-bias techniques to
give the user the best of both worlds. The result is that the amp will
control its own bias to a certain point, but without the typical reduc-
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The Defender Control Panels

tion in power associated with normal self-biased amp designs. The
Defender uses two EL34s in a “push-pull” amplifier configuration.
c. Phase Inverter Tube: The phase inverter tube uses a single 12AX7
in what’s called a long-tail pair configuration. This results in the
most signal swing possible for driving a power amp and the most
symmetrical drive capability, as well.
d. Preamp Tube 2: This 12AX7 is used in boosting the gain and driv-
ing the EQ. It has the biggest impact on higher gain sounds.
e. Preamp Tube 1: Half of this 12AX7 is the input tube, and as such, is
the most likely to cause microphonic problems. If tube feedback oc-
curs, it can usually be corrected by swapping this first tube with one
of the other tube locations, since they have less gain following them
and are less prone to feedback. The first tube also has the greatest
effect on the “cleaned up” tone of the amp, i.e. the tone when the
guitar is turned down. The other half of this tube is responsible for
providing the extra gain needed for the Boost control.
4 & 6) Speaker Outputs: These 1⁄4” jacks are provided to connect
the internal and/or external speakers to The Defender. The amplifier
should never be operated without a speaker plugged into a speaker
jack.
5) Impedance Selector: This switch is used to select the appropriate
impedance, and is important in achieving the desired results from
The Defender. The correct impedance should be selected using the
Impedance Selector Switch as follows:
a. Internal speaker only: 16 ohm setting
b. Internal speaker + external 16 ohm speaker: 8 ohm setting
c. Internal speaker + external 8 ohm speaker: 4 ohm setting, al-
though it’s not matched.
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The Defender Control Panels

12
Accessories
KACCC36D - Amp cover to defend The Defender
from dust and the elements. Features an em-
broidered classic Kustom logo, top quality vinyl
and piping.
FACFS100 - Footswitch for activating the adjust-
able volume boost function on The Defender™.
The Defender automatically will have the boost
enabled at all times if no footswitch is plugged
into the amp.
You can find these accessories through your local Kustom dealer!

Kustom Amplification • Hebron, KY, USA • WWW.KUSTOM.COM