Gallien-krueger MICRO LEAD User Manual
Operating
Instructions
Micro Lead Series
A Word from Bob Gallien
and Rich Krueger
We want to personally introduce you to our labor of love: The
Microamplifier Lead Series. They symbolize our continuing
effort to make the musician's life easier and more fulfilling.
Everything, from the input stage to the speaker outputs, has been
redesigned and refined for one purpose : the ultimate guitar
sound.
After getting accustomed to the fact that this little package puts
out an unbelievable amount of power, the first thing you'll notice
is how quiet the amp is.
That's due to a newly designed input stage that reduces noise at
it's most prominent source. And the hum that is normally
induced into your guitar pickups from a typical amplifier is gone,
thanks to our advanced power supply design.
All this quiet can be instantly transformed into a roar of metal
thunder or a smooth singing sustain at your whim. The Lead
Channel offers flexibility that surpasses anything we've ever produced
with all the balls you could ask for. And the Clean Channel gives
a sweet, shimmering clean sound with vintage warmth and character.
As you read through this manual, we hope you will gain an
understanding of the care that went into the design and manufacture of your new amplifier.
Each feature has been designed to give you as much control over
your sound as possible and with a little experimentation you
should easily obtain your ultimate sounds.
We are proud of these amplifiers and feel they have passed their
final test with your purchase. We hope you enjoy this great guitar
instrument and wish you the best in your musical endeavors.
Bob Gallien & Rich Krueger
Front Panel Features
(1) Input Jack
Accepts a 1/4'' phone plug and can be driven by a
variety of instruments; however, the internal
electronics have been optimized for use with an
electric guitar.
(2) Channel Select Switch
Allows you to switch between the Lead and Clean
channels. The RF2 Foot Controller (on the ML/S)
or the RFG4 Foot controller (on the ML/E) will
switch channels when this switch is in the "in" position
and the footswitch is plugged in.
(3) Boost Control
This unique feature works like a third footswitchable
channel. It controls the amount of gain before the
first overdrive stage. Turning clockwise increases
the gain level. It is footswitchable with the RF2
Foot Controller (on the ML/S) or the RFG4 Foot
Controller (on the ML/E). You can achieve two different, footswitchable lead sounds by setting the
Gain Level control first for your low overdrive
sound, then setting the Boost control for your
extreme overdrive sound. The Boost can then be
taken in and out of the circuit with the footswitch.
The Boost has no effect when the Gain Level(4) is
set all the way up (clockwise).
(4) Gain Level
Controls the gain of the first and second overdrive
stages using a dual potentiometer. Turning clockwise will increase the amount of "saturation" in the
gain stages, producing fuller harmonics and
increased sustain. The gain of the first overdrive
stage will be increased when the Boost control is
used.
(5) Lead Channel Indicator LED
When lit, the Lead channel is activated.
(6) Lead Master
Controls the volume of the lead channel. It affects
the Send (12), Headphones(17), and Balanced
Outputs(30).
(7) Shape Control
This is a passive midrange control (post overdrive).
It effectively varies the midrange frequencies in the
Lead channel, allowing a variety of lead voicings to
be attained easily. Rotating clockwise boosts the
midrange.
(8) Clean Channel Indicator LED
When lit, the Clean channel is activated.
(9) Clean Channel Volume Control
Controls the volume of the Clean channel. It affects
the Send(12), Headphones(17), and Balanced
Outputs(30).
(10) 4-Band Active Equalizer
Provides boost and cut over four different frequency
bands. Each band has a specially selected Q and
center point optimizing it for a particular guitar
spectrum.
(11) Output Level Control
Adjusts the level of the signal being sent to the
internal power amplifier(s) and headphones, affecting
the Speaker Outputs(19) and the Headphone
Output(17). The Balanced Outputs(30) are not
affected.
(12,13,13E) Effects Loop
Provides a means of adding in-line effects. The
Send(12) can drive most standard foot and rack
mountable effects. (see Sample Hookups)
The Return(13) on the ML/S is switchable, allowing
you to return a regular mono signal with a standard
1/4'' phone plug or a stereo signal using a stereo
1/4'' stereo phone plug. The Stereo/Mono
Switch(14) must be in the appropriate position to
take advantage of the return's mono/stereo capability.
If the send signal should overdrive the outboard
effects (causing unwanted distortion), keeping the
Output Level greater than the 1 o'clock position
will usually solve the problem.
The Effects Loop comes after the Channel (1-9,23)
and Equalization (10) stages and before Output
Level (11) and line outputs (15&18) on the ML/S
and ML/E. The internal effects (24-28) and
Balanced Outputs are also post effects Loop on the
ML/E (see Block Diagram).
(14) Return and Line Out Stereo/Mono Switch
(ML/S only)
Affects the Return(13) and Line Out (15). In the
"Mono" position, the Return and Line Out accept a
standard 1/4'' phone plug and accept (Return) or
provide(Line Out) a mono signal. In the "Stereo"
position, the Return and Line Out accept a stereo
1/4'' phone plug and accept (Return) or
provide(Line Out) a stereo signal when using outboard stereo effects through the Effects Loop.
If the Effects Loop and Line Out are not being used.
The position of this switch is not important.
(15) Line Out (stereo/mono) (ML/S only)
Provides a line level signal that is switchable
mono/stereo to take advantage of the stereo capability of the Effects Loop Return. When used in the
"Mono" mode, it accepts a standard 1/4'' phone
plug. When used in the "Stereo" mode, it accepts a
stereo 1/4'' phone plug. Unless you are using stereo
outboard effects through the Effects Loop and the
Stereo/Mono Switch(14) is in the "Stereo" position,
only a mono signal will be present.
(16,16E) RF2 and RFG4 Foot Controller Jacks
Provides a means to hook-up the optional
footswitch for your amplifier. The ML/S accepts
the RF2 two-button Foot Controller, allowing
remote Channel Switching(Lead/Clean) and Boost
On/Off. The RF2 requires any standard 1/4'' stereo
phone cord for operation (available from GK (Part
#304-2500-0). The ML/E accepts the RFG4 fourbutton Foot Controller, allowing remote Channel
Switching (Lead/Clean), Boost On/Off (when in the
Lead channel) or Compressor On/Off (when in the
Clean channel), Reverb On/Off, and Chorus
On/Off. The RFG4 requires any standard 5-pin
DIN(MIDI) cable for operation. Please make sure
that the 5-pin DIN cable has all five wires, not two
or three.
(17) Stereo Headphone Output
Accepts a stereo 1/4'' phone plug, delivering a
stereo signal for use with any standard headphones.
Headphone Output level is controlled by the Output
Level(11).
Rear Panel Features
(18) Right/Stereo Line Out
Provides a line level signal (post Output Level)for
interfacing with outboard power amplifiers: Right
Line Out for mono internal power units. Stereo Line
Out for stereo internal power units. (see Sample
Hookups)
….on Mono Power Units:
Plugging into the Right Line Out splits the preamp
signal; "left" going to the internal 130 watt power
amplifier and "right" going to the Right Line Out.
By connecting this line out signal to an external
power amplifier (in this case the GK ML/P), you
have created a 130 watt per channel stereo guitar
system. A standard 1/4'' phone plug is required for
hook up. A slight volume loss in the internal channel is
normal.
…on Stereo Power Units:
A stereo signal is provided for connecting to an
external stereo power amplifier or two external
mono power amplifiers (the GK 265ML/P or
130ML/P are recommended for these applications).
Any standard stereo 1/4'' plug is required for
hookup.
(19) External Speaker Outputs
Allows external speakers to be driven by the internal
power amplifier(s). For optimum performance and
to avoid damaging your amplifier, use the following
minimum external speaker impedance:
HEADS:
ML/S & ML/E Mono Heads :
4Ω Minimum impedance Total
(1x4Ω speaker, 2x8Ωspeakers. Or 4x16Ωspeakers)
ML/S & ML/E Stereo Heads:
8Ω Minimum Impedance Per Side
(1x8Ω speaker, or 2x16Ω speakers per side)
COMBOS:
206 & 208 Mono Power Combos:
• With Internal Speakers "on" : 8Ω Minimum Total
External Impedance
• With Internal Speakers "off" : 4ΩMinimum Total
External Impedance
206 & 208 Stereo Power Combos:
• With Internal Speakers "on" : 16Ω Minimum
External Impedance Per Side
• With Internal Speakers "off" : 8Ω Minimum
External Impedance Per Side
112 Mono Power Combos :
• With Internal Speaker "on" : 8Ω Minimum Total
External Impedance
• With Internal Speaker "off" : 4Ω Minimum Total
External Impedance
112 Stereo Power Combos :
• With Internal speaker "on" : 8Ω Minimum
Impedance plugged into "Right" Side Jack Only!!!
Note : DO NOT plug external speaker into the
"Left" Side Jack on the 112 Stereo Power Combos
when the internal speaker is "on"!!!
• With Internal speaker "off" : 8Ω Minimum
External Impedance Per Side
IMPORTANT :
Warning : Under no conditions should the two
speaker outputs of a stereo power unit be connected
together in any way!!! This will damage the amplifier and void your warranty, so please be careful in
setting up your speaker configurations!
· · · · · · ·
Auto Amplifier Shutdown : To protect against
failure, the ML/S and ML/E heads and combos are
equipped with an Auto Shutdown feature that is
enabled when the Speaker Outputs are overloaded
or when the temperature of the unit exceeds safe
operation. The power dissipation in the outputs is
actually computed to determine if it is within safe
operating conditions and automatically shutdown
when limits are exceeded. When shutdown occurs,
the unit will appear to be on and all functions and
LED's will work; however, there will be no power
output to speakers. To reset the amplifier, turn the
power switch off, wait 3 seconds, remove or lower
the input signal, and turn the amplifier back on. If
you experience more shutdowns, even after correcting the cause of the initial shutdown, check all
speakers and cables. If further action is necessary,
please call your local GK Service Center.
(continues on the next page)
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