Martin Audio – MA900 Amplifier
E
NGLISH
11
7.1.2
Unbalanced inputs
T o use a n un b alan ce d sou rce , co n ne ct pin 3 (ring on
T RS jack) to th e sh ield o f th e con ne cto r. If you le ave
o ne p in disco nn ecte d , yo u w ill lose 6 d B.
A b ette r m eth od for usin g u nb ala nced so urce s is
sho wn b e lo w. Th is is sim ila r to th e con ne ction fo r
b alan ce d lin e s, b ut pin 3 is co n ne cte d to th e sh ield at
the sou rce . T he h um an d n oise re je ction for th e cab le
is eq uivalen t to th a t fo r a b ala nced line . T o min im ize
h um in the a u dio, u se ba lan ce d inp uts w he ne ver
p ossible .
Unbalanced line connection
Balanced line with unbalanced equipment
For two-channel (stereo) operation, use both channels A and B. For tandem stereo or bridged mono operation, use
only one of the inputs. See
operating modes
for more details.
7.2
Connecting speakers
S pe aker co nn e ctio ns are m ad e via the tw o N eu trik NL 4F C S pe akon co nn e ctors. Th e S pe akon co nn e ctor is d esign ed
for h ig h p ow e r lo ud spe ake r use a nd m e ets all w orldw id e safety req uirem en ts.
The Speakons are wired:
Channel A output
Pin +1, Pin -1 = Output A
Pin +2, Pin -2 = Output B
Channel B output
Pin +1, Pin -1 = Output B
The right Speakon, Channel A, has both channel A and B outputs available, and is useful for bridging and bi-amp
operation (see bridged mono operation on page
7
). The left Speakon, Channel B, carries only the channel B
output.
Channel A and B into two separate
Speakons.
Channel A and B into one Speakon
(Stereo and Bi-amp)
Bridged mono
Never connect either output terminal to ground or to some other output or input terminal.
For normal two-channel operation, connect each speaker load across the output’s positive and negative terminals.
Pay attention to loudspeaker polarity; loudspeakers connected out of polarity can degrade sound quality.
Keep the loudspeaker cable as short as possible and use a good quality stranded cable. Do not use shielded wire,
such as microphone or guitar cable. The loudspeaker cable reduces the power of the amplifiers in two ways:
It increases the load impedance and introduces resistive power losses.
All material © 2007. Martin Audio Ltd. Subject to change without notice.
