Hughes & Kettner Red Box Classic Operating Instructions Manual page 12

• You are using an unbalanced plug adaptor. Its pin
assignments do not match the Balanced Out jack's.
Use a plug and cable corresponding to the diagram
above.
The amp's Line Out is connected to the Red
Box, but the signal at the Balanced Out jack is
too weak:
• Ensure the amp's Line Out signal is properly con-
nected to the Red Box's Line In jack.
The amp's Speaker Out is connected to the Red
Box but the signal at the Balanced Out jack is too
powerful and is overloading the mixer/recorder's
input:
• Ensure the amp's Speaker Out signal is properly
connected to the Red Box's Speaker In jack.
The Balanced Out signal hums:
• The Red Box is not receiving enough power. Check
the battery or AC adaptor.
• The amp and the mixer/recorder's earth circuits
have formed a ground loop. Activate your amp's
or the mixer/recorder's ground lift switch, or use a
transformer to galvanically separate the line circuit.
• The connecting cable is poorly positioned and is pi-
cking up interference from a nearby source (perhaps
a mains cord, transformer, etc.). Replace it with a
high-quality cable and move this cord away from
the noise source.
12