Mesa/Boogie 55 Stereo Amplifier User Manual


 
PAGE 17
REAR PANEL CONTROLS & CONNECTIONS: (Continued)
50 / 100 WATT : (Nomad 100 Only)
This is the “half power” switch found only on the 100 watt Nomad. The two inside power tubes
are put in a standby mode when the 50 watt position is selected reducing the RMS power to approximately 50 watts. This switch may be
operated at any time during performance.
For optimum performance it is recommended that you change the speaker or cabinet from the 8 ohm
to the 4 ohm jack when switching down to the 50 watt position. This ensures a proper impedance
match by keeping the relative load the same. By doing so a brighter, bouncier response will appear
and the full 50 watts of power will be available to you.
If you prefer the fatter, darker nature of the speaker in the 8 ohm jack when in the 50 watt position you
may feel free to use this scenario with no harm to the amplifier.
REVERB:
These three rotary controls are responsible for the dry/wet mix of the traditionally rich analog three spring reverb circuit.
Each Channel has a corresponding Reverb Mix Control so that the amount of wet signal can be matched to the style of sound dialed up
in that channel. The REVERB can be remotely bypassed globally ( all channels/modes ) with the Reverb switch on the Footcontroller.
They are placed “backwards” (3,2,1) on the Rear Panel so that when
playing the amplifier from the front, the REVERB Controls follow the
sequence of the channels...allowing you to reach over and use them
without having to look at them.
NOTE: When the Reverb Footswitch is used to disengage the Re-
verb, a small amount of wet signal can still be heard. To completely
remove the Reverb from the circuit, turn the REVERB Control ( of the
respective channel ) all the way off.
SPEAKERS:
Three speaker output jacks (1) 1 x 8 ohm and (2) 2 x 4 ohm are provided to interface your Nomad to a variety of speaker
/ cabinet configurations. Nomad self-contained combos use the 8 ohm jack for their output and while this is the proper load, you may
experiment with mismatching ( in the high direction ) with the inability
to produce full power being the only downside. Some players prefer
a mismatch, citing a scoop or softening effect they like better than the
attack and presence of a proper impedance match.
If you wish to add cabinets to your combo or head - you may use
either one ( only ) 4 ohm cabinet on the 4 ohm jack leaving the 8 ohm
jack empty or two 8 ohm cabinets each connected to the 4 ohm jacks
thus leaving the 8 ohm jack empty and be assured of a proper match as well as full power capabilities. You may also use a 16 ohm cabinet
on the 8 ohm jack - and a 8 ohm cabinet on a 4 ohm jack ( leaving one 4 ohm jack empty ). This combination would yield the proper
impedance match. See Speaker Impedance Section later in this manual for more information.
NOTE: Nomad 100 owners should put the 8 ohm speaker/cabinet in the 4 ohm jack when switching the 50/100 Power Switch down to
50 watts to ensure a proper impedance match.
SLAVE
TO POWER AMP
USE WITH TWO 8 OHM SPKR
COMBO SPKR
8 OHM 4 OHM
SPKR
SPKR
4 OHM
SLAVE
TO POWER AMP
USE WITH TWO 8 OHM SPKR
COMBO SPKR
100 WATTS
50 WATTS
CH3 CH2 CH1
REVERB
REVERB
8 OHM 4 OHM
SPKR
SPKR
4 OHM
100 WATTS
50 WATTS
CH3
REVERB