Marshall Amplification JCM-1H User manual

JCM-1H and JCM-1C
Limited Edition, 50th Anniversary, all-valve 1-Watt Head and Combo
commemorating the 1980s decade of Marshall
OWNER’S MANUAL

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The JCM-1H head and JCM1-C combo are
1-Watt valve amplifiers voiced to emulate the
Marshall tones that dominated the ’80s, but at a
controllable, home-friendly volume.
In 1981, Marshall introduced the now iconic
JCM800 range and once again redefined the rock
guitar sound. The aggressive, biting sound of the
2203/2204 amplifiers became the “must have”
sound of the NWOBHM (New Wave of British
Heavy Metal) and also the “hair metal” movement
that was exploding on LA’s infamous Sunset Strip.
That said, it was also adopted by many other
genres. The late ’80s saw the introduction of the
split-channel amplifiers and the revered Jubilee
Series. These upped the ante with clipping circuits
to increase the overdrive. Now those classic
Master Volume sounds have been captured in the
JCM-1 H and JCM-1C, with a little extra “split-
channel” gain available for good measure.
The 3-band EQ section of Bass, Middle and
Treble allow for both fine tonal tuning and extreme
sonic shaping – rich, full-bodied crunch and
scooped metal tones are just a few dial turns
away. The Boost switch adjusts
the pre-amp between classic
Master Volume and later Split Channel voicings.
Controls for both Master and Pre-Amp (Gain)
Volume govern the JCM-1’s overall output and
overdrive respectively.
Internally, the pre-amp is driven by two ECC83
(12AX7) valves with one ECC82 (12AU7) valve
in the power amp. The power-stage is configured
as a ‘push pull’ amplifier, just like the famous
JCM800 amplifiers of the period, delivering that
classic bark and growl with a surprising amount
of “thump” for an amp of the JCM-1’s diminutive
stature.
The JCM-1 combo is fitted with a 10" 16Ω
Celestion speaker, specially voiced to give the
best balance between a compact size and a full
sound. Both the combo and the head can drive
an external speaker cabinet of either 16Ωor 8Ωat
full power via the corresponding speaker output
sockets on the rear panel. Both amplifiers are very
happy driving a full 4x12" cabinet for the ultimate
in mini Marshall ’80s tone.
Overview
ENGLISH
Follow all instructions and heed all warnings.
KEEP THESE INSTRUCTIONS.
Warning:
Before going any further, make sure that 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.
Mains Input & Fuse:
Your amplifier is provided with either a detachable mains (power) lead which should be connected to the mains input socket on the rear panel
of the amplifier or a fixed mains (power) lead attached to the rear of the amplifier.
The specific mains input voltage rating that your amplifier has been manufactured for is indicated on the rear panel of the amplifier.
The correct value and type of mains fuse for valve amplifiers is specified on the rear panel of the amplifier.
NEVER attempt to bypass the fuse or fit one of the incorrect value or type.
Transporting your equipment:
Please ensure that your amplifier is switched off and unplugged from the mains electricity supply and that all removable cables have been
disconnected from your equipment before attempting to move it.
Important set up information:
1. Make sure that the cabinet(s)/speakers, where appropriate, are connected to the correct impedance LOUDSPEAKER jack(s) on the
rear panel of the amplifier. See the Speaker Output guides in this handbook, if applicable, for specific information regarding impedance
matching. When using an extension cabinet make sure that you are using a proper speaker cable. Never use a screened (shielded) guitar
cable for this purpose.
WARNING! Failure to do any of the above may damage your amplifier.
2. Ensure that the VOLUME controls on the front panel are set to zero.
3. For amplifiers provided with a detachable mains (power) lead, connect the supplied mains (power) lead into the MAINS INPUT on the rear
panel first and then into an electrical outlet
4. Plug your guitar into the INPUT jack socket on the front panel.
5. Turn the front panel POWER switch on and, if a valve amplifier, wait a couple of minutes before going to point 6.
6. Turn the volumes up to your preferred level and your amp is ready to play.
EUROPE ONLY – Note: This equipment has been tested and found to comply with the requirements of the EMC Directive
(Environments E1, E2, and E3 EN 55103-1/2) and the Low Voltage Directive in the E.U.
EUROPE ONLY – Note: The Peak Inrush current for the JCM-1H and the JCM-1C is 1.5A.
From “the Guv’nor” Jim Marshall
Congratulations on purchasing one of our Limited Edition series
of 1-Watt heads and combos that celebrate Marshall’s
50th Anniversary. Each one is made in England with pride and
commemorates the distinctive tonal character, features and
iconic appearance of a specific decade – ’60s, ’70s, ’80s,’90s
and present day. The JCM-1H head and JCM-1C combo are
the third pair in the series and pay tribute to the Marshall amps
that literally dominated the sound of hard rock and heavy metal
in the ‘80s...
The 1980s was a huge, game changing, decade for guitar
music. A more aggressive sound was being sought by the
emerging rock and metal bands of the era, with many finding
the tone of the newly released JCM800 Series, especially the
100-Watt, 2203 head, exactly what they were looking for. The
innovation of Marshall’s Master Volume technology also meant
that the overdriven sound of these new Marshalls could now be
played at any volume.
The 1-Watt amp you now own pays homage to both the tone
and look of that all-important third decade and does so at a
very “studio” or “home friendly” volume. The front panel of
your amp is very simple, but extremely effective, and I’m sure
that its touch responsive, easily-overdriven tones will give you
countless hours of playing pleasure.
Welcome to the Marshall family!
Yours Sincerely,
Jim Marshall
Jim Marshall

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Front panel*
*NOTE: The JCM-1H front panel is illustrated. The
JCM-1C panel is identical but runs in the opposite
direction.
IMPORTANT: Read before powering-up
Before powering-up your Marshall JCM-1
amplifier, you must ensure that an appropriate
speaker cabinet is connected to the
corresponding impedance matched loudspeaker
jack on the rear panel, (unless ‘low power’ mode
is selected). Failure to do so could result in
serious damage being caused to your amplifier.
Always use an unshielded loudspeaker cable to
connect an amplifier to a loudspeaker cabinet,
never use a screened (shielded) guitar cable.
After use, always allow the amp to cool down
before moving.
IMPORTANT NOTE: Please refer to the Warning
plate on either the underside, or the rear of the
product
1. Illuminated Power Switch
This is the On/Off switch for the mains electricity
supply to the amplifier which will light up
whenever the amp is plugged into the mains and
the Power Switch is on.
NOTE: Please allow a minute or so for the amp
to ‘warm-up’ after switching on. This is normal
with valve amplifiers as valves need to reach their
‘working temperature’ to operate properly.
2. Bass
This control adjusts the amount of low frequencies
(bottom-end) in your sound. Higher settings
increase the ‘fullness’ of your tone, while lower
settings make the sound clearer and more
distinct.
3. Middle
This controls the mid-range of your sound.
Turning this up will make your guitar sound fatter
and fuller. Turning this down will make the sound
more ‘scooped’.
4. Treble
This control determines the amount of high
frequency (top-end) that is present. Higher
settings increase the ‘brightness’ of your tone,
while lower settings make the sound softer and
less defined.
NOTE: The Treble, Middle and Bass controls
are highly interactive; adjusting one of them will
change the frequencies and range of the other
controls.
5. Boost Button
Pressing this button changes the pre-amp from
the classic ‘Master Volume’ voicing to the later
‘Split Channel’ boost sound. When active, the
sound is smoother and more distorted. With
the button out, the sound is more dynamic and
responsive to the guitar’s volume control. The
effect of this control is more apparent when the
Master Volume is at lower levels (less than 2
o’clock on the dial).
6. Master Volume
This control sets the overall output volume of the
amplifier; it also lets you balance pre-amp and
power amp overdrive and so is often adjusted at
the same time as the Pre-Amp Volume control
(7). As the level is increased, the volume of the
amplifier rises until the power amplifier starts to
overdrive at which point the sound will thicken up.
7. Pre-Amp Volume
Adjusting this control changes the amount of gain
in the pre-amp. Low settings will give a clean
pre-amp and it will act as a volume control. Higher
settings will cause the pre-amp to overdrive.
Front panel continued
*NOTE: The JCM-1H rear panel is illustrated. The
JCM-1C panel is identical but runs in the opposite
direction.
WARNING: Although your JCM-1 amplifier has
2 extension speaker outputs, never attempt to
connect cabinets to both extension speaker
outputs simultaneously. Only use one speaker
output at a time.
1. Extension Speaker 8Ω
This is the output that connects to an 8Ωextension
cabinet.
2. Extension Speaker 16Ω
This is the output that connects to a 16Ωextension
cabinet.
3. Low Power switch
This switch activates the Low Power mode. The
amplifier is connected to an internal dummy load
and a reduced level is fed to either internal speaker
(JCM-1C combo) or external load (both head and
combo). This level has been selected for personal
practice and is approximately 0.1-Watts.
NOTE: With this button pressed, the amplifier may
be operated without a speaker connected without
causing any damage.
4. 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 back panel. Before
connecting for the first time, please ensure that
your amplifier is compatible with your electricity
supply. If you have any doubt, please ask the
advice of a qualified technician. Your Marshall
dealer will help you in this respect.
The correct value of mains fuse located in the
small drawer at the bottom of the mains socket is
specified on the rear panel of the amplifier. The
drawer contains a space for a spare fuse.
NEVER attempt to bypass the fuse or fit one of the
incorrect value!
NOTE: It is wise to carry spare fuses at all times.
Rear panel*
8. Input Jack Socket
This is where you plug your guitar into the amp.
You must use a screened (shielded) guitar cable.
Never use an unscreened (unshielded) speaker
cable. The input to any guitar amplifier is a very
sensitive part of the signal path and is very
sensitive to electrical interference, hence the need
for a screened guitar cable.
Your screened cable should be
of good quality. If you are in any
doubt regarding this, your Marshall dealer will be
more than happy to help and advise you.
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ENGLISH
1&2 34
JCM-1H and JCM-1C Technical Specifications
JCM-1H JCM-1C
Power (RMS) 1W 1W
Valves 1 x ECC82 + 2 x ECC83 1 x ECC82 + 2 x ECC83
Dimensions (mm) H , W, D 180 x 380 x 195 360 x 380 x 220
Weight (kgs) 5.2 9.4

Denbigh Road, Bletchley, Milton Keynes MK1 1DQ England.
Tel : [phone] Fax : [phone]
www.marshallamps.com
Whilst the information contained herein is correct at the time of publication, due to our policy of constant improvement
and development, Marshall Amplification plc reserve the right to alter specifications without prior notice.
BOOK-00106-13 / 03 / 12-IS:4