Using The Fx Return As A Power Amp Input - Mesa/Boogie Roadster Owner's Manual

REAR PANEL CONTROLS & FEATURES
PATCHING EFFECTS:
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cables are used and kept to a length of 3 feet or less, you will notice very little if any degradation in the sound of your Roadster.
NOTE: Because the FX LOOP is wired in series with the main signal, it is very important that you choose processing devices that are of
professional grade quality from reputable manufacturers. In a series configuration, your amplifiers sound will depend on the integrity of the
processor's input and output stages, because you have inserted something into the heart of the most sensitive place in your amplifier.

USING THE FX RETURN AS A POWER AMP INPUT:

for amplification of processing or as half of a larger stereo rig. Because of the channel and mode specific changes that take place
internally you will want to follow the suggestions below for the best results.
1.) The FX LOOP SELECT switch must be set to LOOP SYSTEM IN (Loop engaged).
2.) The FX LOOP RETURN jack is the INPUT to the power section. This jack bypasses the entire preamp including the GAIN and
all the Tone Controls.
3.) The OUTPUT is your level control.
4.) You may use the SOLO Control for a footswitchable volume boost (Footswitch must be connected).
5.) You may use the Channel Strip POWER SELECT switches to select a power rating that is appropriate for the venue or applica-
tion.
6.) The choice of rectifiers is still available when using the Roadster FX RETURN as a power input. Remember that this choice
is channel specific. The SILICON DIODE selection is more in line with what you would find in most all other stand alone power
amplifiers, but for guitar applications it is nice to have the choice of the saggy response of tube rectification.
NOTE: Keep in mind that cleaner sounds, although they appear to be the same volume as saturated sounds, send a more dynamic
signal to your processor and therefore will probably register a hotter signal on the processors' Input indicator. This is not a problem,
but it will be of interest when setting up your sounds in the channels. Set the Channels for their relative volume and don't pay too
much attention to the processors Input unless you experience clipping. If so, reduce all the Channel MASTER controls a bit and
compensate with the OUTPUT control.
NOTE: It is important to understand that the EFFECTS LOOP was designed to work best with a unity gain signal. By increas-
ing the gain on your processors' Input or Output beyond this point, you run the risk of experiencing a high pitched squeal
or feedback. This is a result of the SEND and RETURN jack being connected together by adding excessive gain at the processors
Input and Output stage, thus reducing the internal separation between these stages we have built into the Roadster's EFFECTS
LOOP. Why can't there be more separation at this point in the circuit? There could be if we -and you - didn't care about TONE. This is
an extremely sensitive part of any amplifier, and we have always chosen these most critical part values on the side of TONE, knowing
that if the loops are used properly - with high quality processors there will be no problems.
Please try to keep in mind that this is a high performance amplifier and should be used in conjunction with outboard gear of equal
quality. If you must use lesser processing, you will have to tolerate any degradation in sound quality and remember that turning up
the gain of such a processor much at all will only cause feedback problems.
NOTE: Remember that the LOOP BYPASS switch removes all LOOP circuitry from the signal path including, 2 x 12AX7s and
the OUTPUT and SOLO controls.
You will find the FX LOOP a welcome feature for all rack type processing and when good quality
You may, at times, wish to use the Roadster as a stand alone power amp
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