Mesa/Boogie D-180 - Manual (Page 3)

EFFECTS LOOP
Two pairs of Send and Return jacks are provided, one pair on the front and one pair on the
back of the D-180. So whether you use effects devices on the floor or built into a rack,
patching with your D-180 is convenient and precise. The sophisticated Effects Loop circuitry
of the D-180 works extremely well. A low impedance "send" amplifier assures high
intercompatibility plus low noise. A unique Blend control located on the upper rear amplifier
chassis (where it won't get-broken or damaged) enables you to mix "dry" and effected
signals. With the Blend knob set at 10, all signal will pass through the accessory effects; set
at 5, about half of the D-180 signal will pass through the effects and half will go direct. Set at
0, the effect patch points are fully bypassed. Zero is the recommended setting when no
effects devices are patched into the loop. The Effects Send level has been padded at the
rear panel jack to accommodate low-headroom effects devices. The front panel Send jack is
unpadded.
The Effects Return jack offers access directly into the D-180's power stage, and about .775
volts (or 0 dBv) is required to drive it to full power when the Master is set at ten. This exactly
matches the input sensitivity of the M-180 basic power amplifier (no preamp or control
sections) so, by driving the M-180(s) from the Effects Send of the D-180, automatic level
balancing will be maintained between all amplifiers. But if distortion from the D-180 is being
used, or if heavy effects processing is in the loop, the 600 ohm balanced out or the Slave
Output would be preferable. These features are described below.
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