Connections; Input Connections; Balanced Inputs; Unbalanced Inputs - Martin Audio MA1400 Manual

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CONTENTS
7

CONNECTIONS

7.1

Input connections

7.1.1
T he inp u t co n ne ctors a re N eu trik ® co m bo jacks an d incorp orate a n XL R a nd _" (6.3 mm ) jack. T h ey a re active
b alan ce d a nd wire d a s be low :
P IN 1
P IN 2
P IN 3
Figure 4. XLR input connector
T IP
R IN G
S LE EV E
Unbalanced line connection
All material © 2007. Martin Audio Ltd. Subject to change without notice.
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Balanced inputs

G RO UN D/S HIEL D
H OT (+)
C OL D (-)
H OT
C OL D
S HIEL D/G RO UN D
Martin Audio – MA1400 Amplifier
Figure 5. XLR balanced
_" TRS plug
Th e inp ut im ped ance is hig h eno ugh (20 K o hm s b ala nced) to a llo w
"d aisy-cha in ing ", or mu ltiple p ara llel inp ut co nne ction s. Th e h ead ro om
of the inp ut circu its is a lso h igh e nou gh to accep t the ma ximum ou tp ut
le ve l from virtually an y low -le vel sign al so urce. Ba lan ced sign als a re
le ss se nsitive to AC hu m a nd RF in te rfe ren ce . T he so urce imp eda nce
sh ou ld be le ss tha n 1 Ko hm s to a vo id hig h fre que ncy losses in lo ng
ca bles.
To daisy chain amplifiers, use the screw -te rm ina l (Ph oen ix co nne cto r),
la be led Link, provided o n e ach chan nel. It is co nne cte d in parallel with
th e Ne utrik® C om bo jack on each inp ut.
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 ja ck) to th e
shield o f th e con ne cto r. If you le ave o ne p in disco nn ected , you w ill lose
6 d B's in level .
A b ette r m eth od o f con ne cting u n ba la n ce d so u rces is sho w n in be lo w.
T his is similar to the co nn ectio n fo r b alan ced line s, b u t pin 3 is
con ne cte d to th e sh ield a t th e sou rce . Th e h um a n d no ise reje ctio n for
the cab le is eq uiva len t to th at of a ba la nce d lin e. T o m in im ize h um in
the a ud io, u se ba la n ce d inp uts w he ne ver p ossib le .
10
GUIDES