1
E
N
G
L
IS
H
4
5
IMPORTANT: READ BEFORE POWERING UP
Before powering-up your Marshall amplifier you must ensure that an
appropriate speaker cabinet(s) or dummy load is connected to the
correct impedance Loudspeaker jack on the rear panel. Failure to do
this could result in serious damage being caused to your amplifier.
Always use an unshielded speaker cable to connect the amp to the
speaker cabinet, never use a screened (shielded) guitar lead.
When powering-up the amplifier always engage the Power Switch (1)
first to allow the power valves to warm-up, we would also recommend
setting all volume controls to zero. After about two minutes the power
valves will be at their correct operating temperature and the Standby
Switch (2) can be engaged. To prolong valve life, the Standby Switch
alone should be used to turn the amplifier on and off during breaks in a
performance. Also, upon full power down, always disengage the
Standby Switch prior to the main Power Switch. Always allow the amp
to cool down before moving.
1. POWER SWITCH
On/Off Switch for mains power to the amplifier. Please ensure the
amplifier is switched off and unplugged from the mains electricity
supply before being moved.
2. STANDBY SWITCH
The Standby Switch is used in conjunction with the Power Switch
(1) to ‘warm up’ the amplifier before use and to prolong the life of
the output valves.
3. INDICATOR
Indicates that power is being supplied to the amplifier.
4. FX LOOP SWITCH
Switches the AFD100’s FX loop on and off. This can also be
controlled from the included footswitch. The LED is on when the
FX loop is enabled.
5. POWER
This control provides access to the AFD100’s Electronic Power
Attenuation (EPA) feature. The internal attenuator allows you to
adjust the overall output volume of the
amplifier whilst retaining all of your tone.
This works by electronically reducing the
voltages to components within the
amplifier instead of placing resistive loads
in the circuitry. Output of between 100%
and 0.1% can be achieved, making the
AFD100 ideal for stadium, studio and
home use! The adjacent diagram shows
the amount of power shown as a
percentage in relation to the dial setting.
Equalisation
Note:
The tone network is highly interactive; altering one control
affects the behaviour of others. Experimentation is the best way to
achieve your desired sound, a good place to start is to set all EQ
dials to half way and adjust from there. If you are looking for a
particular tone it is important to bear in mind that your choice of
guitar plays an important role as well.
6. PRESENCE
This control adjusts the power amplifier’s high frequency response,
making your tone more cutting and ‘present’.
7. BASS CONTROL
Controls the amount of low frequencies or bottom-end in your tone.
8. MIDDLE CONTROL
Dictates the middle register of the amplifier. Turning up this control
will make your guitar sound fatter. Conversely, reducing the amount
of middle in your tone will result in a sharper and thinner guitar
sound for a more ‘scooped’ tone.
9. TREBLE CONTROL
Controls the high frequencies or top-end in your tone.
10. MASTER VOLUME
Controls the volume output from the AFD100’s pre-power amp
section. Used in conjunction with the POWER (5) function, it is
possible to overdrive the power amplifier even at reduced power
output.
11. GAIN
Governs the amount of signal passing through the pre-amp valves.
Turning up this control overdrives the pre-amp and creates a
desirable, harmonically rich distortion. Reducing the Gain level will
begin to clean up your tone.
12. #34/AFD
This switch toggles between the AFD100’s two distinct gain
structure modes. The #34 mode of the amplifier replicates the
modded Marshall JCM800 2203 that Slash has been using since
the late ’80s. Switching to AFD mode provides a thicker, more
driven, higher gain tone, based of course on Slash’s legendary
Appetite For Destruction
sound. The LED indicator will be lit when
in AFD mode.
Inputs
Note:
As with most vintage Marshall amplifiers, the AFD100 has
more than one guitar input. Input I is the high sensitivity input for the
amplifier, traditionally this was used for guitars with lower output
pickups. Many guitarists now take advantage of this input, which
allows them to drive the amplifier harder as it pr6dB more
than the low sensitivity input. Which input you choose is purely
down to personal taste and experimentation. It is also possible to
daisy-chain amps from the low input to the high input of the next
amplifier.
13. HIGH SENSITIVITY INPUT
Traditionally used for guitars with low output pickups.
14. LOW SENSITIVITY INPUT
Traditionally used for guitars with normal output pickups.
FRONT PANEL
(LEFT TO RIGHT FEATURE BY FEATURE)
1. LOUDSPEAKER OUTPUTS
WARNING!
Never use the amplifier without a load attached! There
are five speaker outputs available on the rear panel. They are
labelled according to the intended impedances:
4
Ω
:
Connect a single 4 ohm guitar cabinet or two 8 ohm guitar
cabinets.
8
Ω
:
Connect a single 8 ohm guitar cabinet or two 16 ohm guitar
cabinets.
16
Ω
:
Connect any 16 ohm guitar cabinet to this jack.
WARNING:
Although the AFD100 amplifier has five speaker
outputs, never attempt to connect more speakers than rated, the
safe combinations being 1x4 Ohm or 1x8 Ohm or 2x8 Ohm or 2x16
Ohm or 1x16 Ohm. Any other speaker configuration may stress the
power amplifier section and in extreme cases may lead to valve
and/or output transformer failure.
2. EFFECTS LOOP
The AFD100 provides a series Effects Loop where you can connect
any outboard FX equipment you might have. This feature can be
toggled on and off from either the front panel or the supplied
footswitch.
Connect your external FX gear input to the SEND jack and the FX
output to the RETURN jack.
Return Level
– This control allows you to adjust the level of the
return signal from your Effects Loop. Reducing the level to 0 will
mute the signal from your Effects Loop, whereas increasing it to 10
will allow the maximum signal volume to be used. The loop can also
be used as a second master volume for attenuating or boosting (up
to +10dB) the signal by leaving it unconnected and using the Return
Level as a solo boost/rhythm attenuation control.
3. BIAS FAULT
Like any high performance machine, parts such as valves wear out
over time. It is essential that these all-important components are
working properly and that’s where the valve fault indicator comes in
very useful. This system allows you to monitor the AFD100’s power
amp and clearly indicates any valve that has developed a fault while
performing the biasing procedure. If lit under normal use, it may
indicate that a valve is faulty or that some kind of temporary fault
was detected and the valve needs to be examined. If all four LEDs
are lit, this could signal that the HT fuse has blown and needs to be
replaced. Only use the same HT fuse type as indicated on the rear
panel.
NOTE:
It is possible to have different octal pentode or tetrode
power valves installed in your AFD100. Some popular options
include EL34s, 6L6s, 5881s, KT66s, KT77s and KT88s.
WARNING:
This work should only be carried out by a qualified
engineer, never attempt to remove and replace the power valves
yourself. Ask your local Marshall dealer for more information.
4. AUTO-BIAS AND BIAS CURRENT TRIMMER
The Bias setting of an amplifier ensures correct operation. In order
to adjust the bias level of your amplifier press and hold the FX Loop
switch on the front panel while powering the amplifier up until the
FX Loop and #34/AFD LEDs begin to flash. This procedure will take
about three minutes after which the amplifier is ready to be used.
Whilst setting the bias of an amplifier is not something that needs to
be done everyday, having the correct bias will prolong the life of
your valves and ensure your amplifier functions smoothly. We
recommend either engaging the auto-bias function every time the
amplifier is powered-up (like a warm-up procedure) or at least
performing the operation every time the amplifier is moved to a
different place. This will ensure that the amplifier is taking care of
possible mains voltage variations and adjusting itself to the different
conditions.
The desired biasing current can be selected by turning the trimmer
control located to the right of the valve fault indicator LEDs before
activating the bias procedure. Possible values range between 20mA
and 50mA with every mark representing 3mA. Since there is not a
‘perfect’ bias setting, we recommend values between 30mA and
40mA.
The chart on page 25 can be used as a guide for setting bias levels
for the AFD100
If you are unsure how to properly bias an amplifier, we suggest you
speak to your authorised Marshall Amplification dealer who will be
able to advise you.
5. FOOTSWITCH
Both the #34/AFD modes and Effects Loop can be accessed via the
included AFD100 Footswitch (PEDL-00053). LEDs contained in the
footswitch will illuminate when the AFD mode and Effects Loop are
engaged.
The default setting for the FX circuit is off.
The default setting for the amplifier is AFD mode.
NOTE:
When the footswitch is connected to the amplifier, the
relevant front panel switches will not function.
6. HT FUSE
This is the access point to replace the amplifier’s HT fuse. This
should only be done by a qualified engineer. The amplifier MUST be
switched off and disconnected from the mains before replacing the
HT fuse. If unsure, contact your local authorised Marshall dealer
who will be able to assist you. Use a T1AE250V fuse only.
7. MAINS INPUT
Your amplifier is provided with a detachable mains (power) lead,
which is connected here. The specific mains input voltage rating
that your amplifier has been built for is indicated on the rear panel.
Warning:
Before going any further, make sure your amplifier is
compatible with your electrical supply. If you have any doubt, please
seek help from a qualified technician – your Marshall dealer can
help you in this respect.
The correct value of mains fuse is specified on the rear panel of the
amplifier. NEVER attempt to bypass the fuse or fit one of incorrect
value.
PLEASE NOTE:
Extreme control settings may result in
compromised audio performance due to the extreme gain settings
available in this ADF100 all-valve amplifier.
BACK PANEL
(LEFT TO RIGHT FEATURE BY FEATURE)
2
3
4
5
6
7
8
9
10
11
12
14
1
2
3
4
5
6
7
13
0.1
0.3
0.5
0.8
1
2
3
5
6
9
12
15
20
25
30
35
45
55
70
85
100
