2-5
The MPX R1 as a Dedicated MPX 1 Controller
If you are using the MPX 1 between a guitar preamp and power amp, refer to the
following section on using a series effect loop.
If you are using the MPX 1 in a dry/wet (3-way) rig, refer to the following section
on using a parallel effects loop.
What kind of effects loop do
you have?
In a series effects loop, the entire
preamp signal passes through the
MPX 1. (If you turn down the MPX 1
Output Level control, no sound
comes out of the amplifier.)
In a parallel loop, the preamp signal
is routed directly to the power amp
and the MPX 1 output is mixed with
it. (If you turn down the MPX 1 Out-
put Level control, you still hear the
guitar at normal level.)
Some amps have a mix control for
the loop. This is sometimes a switch
labeled “50/50” or “mix,”or a mix pot
with a range of 0-100%. These con-
trols allow you to use the loop as
either series or parallel. With a
switch, the 50/50, or mix, position
corresponds to parallel, the other
position corresponds to series. In
the case of a mix pot, 100% corre-
sponds to series and all other posi-
tions are parallel. (Halfway or 50% is
a good starting place.)
Using the MPX 1 and
the MPX R1 in a
Preamp/Power Amp
Rig or a Dry/Wet
(3-Way) Rig
Using a Series Loop
On the MPX 1:
Press System and make the following adjustments.
•
Set Pgm Bypass to Bypass.
•
Set Audio Bypass Level to –3dB.
(These settings will ensure that audio will be smooth and uninterrupted during
program changes.)
•
Set Bypass Mode to Bypass. (You will hear dry guitar when bypass is on.)
•
Set Mix Mode to Program so that each program will load with its own
independent master wet/dry mix value. (The master mix value for each
preset is initially set to work with the MPX 1 in a series effect loop.)
Adjust Mix and Level Values as follows:
•
To adjust the overall mix of dry guitar to all effects in any program: press Mix,
select Mstr Mix, and change the value to suite your taste.
•
To adjust the mix or level or any of the effects in the program: press Mix,
select the Mix or Level parameter for the desired effect block and adjust. If
you want to make the changes permanent, be sure to store your changes
before loading a new program.
Set Input and Output Levels:
Before powering up the guitar amp, make your audio connections, turn the
MPX 1 Output Level all the way down, and turn your guitar amp master volume
all the way down.
This can be a little tricky, since you must set the MPX 1 output level to match the
level of the preamp with nothing connected in the loop. If the levels are too low,
the amp will not have its usual power and tone. If the levels are too high, you
may overload the power amp – causing unwanted distortion. If your amp has
a loop bypass (like a Mesa/Boogie Mk IV), it’s pretty easy to match the levels.
If not, it will take a little more work. The extra effort is worth it — when the levels
are properly matched, your amp’s tone will be unaffected and you will be able
to use phase shifter, tremolo, wah and other “in-line” effects to their fullest
potential.
•
Power up the amp.
•
Load MPX 1 Preset 100 Guitar Solo.
•
Press Bypass.
•
Set the preamp controls to the highest gain settings you’ll be using.
•
Turn up the MPX 1 Input Level control so that the 0 dB lights occasionally,
then back it off a bit.
