Installations
Matica 500/900 Reference Manual
11
Banana plugs are inserted in the ends of the plastic insulating nuts on each output
terminal. The terminals are spaced to accept standard 3/4Ó (19 mm) spaced dual
banana plugs. Alternately, the insulating nuts may be loosened so that stranded or
solid wire may be attached. The threaded posts under the nuts have holes in them
which can accept fairly heavy gauge wire, but if the wire does not fit through the
hole, it may be wrapped around the post. In either case, the nut should be snugly
tightened to secure the wire in place.
Caution: Be sure that no stray wire strands accidentally touch an adjacent wire or
terminal. Lightly tinning the end of a stranded wire with solder after the strands
are twisted together will help prevent it from fraying and will insure that all
strands are connected, but be careful when tightening or stressing the wireÑtinned
wires may be brittle.
If a crimp lug terminal is used on the speaker wire and the lug is too small to fit onto
the threaded post, one leg of the terminal may be inserted in the hole in the post.
As with wire connections, make certain that the terminal is snugly attached by
tightening the plastic insulator nut.
A positive voltage applied to the High (+) side of either input when the amplifier
is in Stereo mode will result in a positive voltage appearing on the Red (+)
terminal of the corresponding output channel.
When connecting the output of the amplifier in Bridged Mono mode (assuming that
the input has been connected to Channel A and the Stereo/Mono rear panel switch
has been set to Mono), the loudspeaker wires are connected to the two center
terminals only. Note that, unlike amplifiers from some other manufacturers,
Bridged Mono connections are to Red and Black terminals,
not
to two Red or two
Black terminals. Do not connect anything to either of the two outer terminals.
In Bridged Mono mode, applying a positive voltage to the High (+) side of the
Channel A input connection will result in a positive voltage on the Red output
terminal (Channel A +).
Note that Channel B of each Matica amplifier is internally inverting, which
assures the maximum possible low frequency output when both channels are driven.
Connecting the wiring as described above will keep the input to output signal
polarity consistent. However, the Black terminals of Channels A and B are not at
the same potential and must not be connected together. Some loudspeaker switching
systems and many headphones use common wiring for the low sides of both
channels; these systems cannot be used with Matica amplifiers unless the alternate
wiring instructions below are followed.
Operation with a common output wiring is possible by connecting the black output
binding post of the A channel to the red post of the B channel. This is now the
common speaker or headphone output lead and is at ground potential. The
remaining red and black posts are the Channel A and B "hot" connections
respectively.
Next, the audio input to the amplifier must be from a balanced source. Wire the A
Channel balanced input wiring with normal polarity but wire the B Channel's
input with the Polarity inverted.
