Mesa/Boogie MARK II-B - Manual (Page 3)

The Slave Level control and Slave Output jack located on the rear panel of the amplifier give
you a direct output feed which faithfully captures the entire sound of the amp and preamp and
can be regulated to properly match anything from a mixing board to a power amp to another
Boogie for a linked up arrangement. Although a few mixing boards (mainly Yamaha) won't
properly accept the Slave Output signal and cause distortion, an absolutely noise free recording
can be made with most other mixers. Set the amp normally. Start with the Slave knob off. While
playing, turn it up to provide sufficient signal for your power amp or Line In on your mixer. Higher
Slave settings and lower Master settings will result in lower overall noise. Always run the Boogie
with a speaker or load resistor (8 to 20 ohms, 50 watts) if you are using the Slave Out. A Pre Amp
Out - Pwr Amp In jack is located on the bottom of the chassis and provides access to the junction
of the preamp and the output power amp. With it, another Boogie can be linked up (Slave Out of
the first amp to Pwr Amp In of the second), or it an allow you to use the Boogie as a preamp only.
A volume pedal can be plugged into this pre-amp/power amp junction jack using just one cable
and will operate like a pedal operated remote Master 1 control. For weaker incoming signals, the
Effects Return can be used as an input and then the Graphic would be functional. For Effects
Loop use the jacks mounted on the back panel. The Effects Return Jack will interrupt the signal
flow while the Effects Send can be used as an output without affecting signal flow. If your Boogie
should ever lose power or die out, always first run a cable between the two Effects Jacks before
proceeding to test tubes, etc., as such a problem could likely be caused by faulty switch contacts
in the Effects Return Jack.
Also on the back panel are the Reverb (optional) and Presence controls. The Presence control
used from 0 to 3 will cut highs resulting in a smooth, mellow tone at a lower overall volume. Used
from 4 to 10 it will boost both volume and highs. Three speaker jacks are provided: one 8 ohm
and two 4 ohm. With 60 watts models, plug the single 8 ohm speaker into the 8 ohm jack for the
most power and clarity. If two 8 ohm, speakers are used, plug each one into a 4 ohm jack for
proper balance. But you may also try other combinations if you want one speaker slightly louder
or happen to prefer the tone caused by a slight mismatch; it will do no harm to the amplifier. With
100/60 watt models we recommend that when you run a single 8 ohm speaker you use the 60
watt position and plug into a 4 ohm jack. This will give the strongest possible output without
damaging the speaker. You may get more clean power by switching to 100 watts, and still more
by also plugging into the 8 ohm jack but remember to avoid lead tone distortion as it increases
power dramatically (though not so much the apparent loudness) and may cause speaker
damage. With two 8 ohm speakers, one in each 4 ohm jack, the 100 RMS can be safely used.
A cabinet with four 8 ohm speakers can be wired in series-parallel to give a total load of 8 ohms,
or a 16 ohm Marshall™ box may be wired in parallel to obtain 4 ohms. Use a speaker jack for
headphones. Again, no harm can be done to the amplifier by mismatched speaker loads and we
encourage you to experiment, if you want, with various combinations.
Also located beneath the chassis is a stereo socket for the optional Dual Footswitch. This will be
wired to activate, when applicable, the Graphic EQ and Reverb. When an amplifier is built with
only Reverb or Graphic, a mono 1/4” guitar jack is mounted for use with our Single Footswitch
and Cable Set. If your amplifier is equipped with a cooling fan and you wish to turn it off for quiet
studio playing, then unplug the fan power cord where it plugs into the chassis on the extreme left
end.
Most of all, this amp was made for your enjoyment - so go for it!!
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