User Guide

Issue฀3,฀November฀2016฀ Model฀74/75฀User฀Guide฀
Page฀12฀ Studio฀Technologies,฀Inc.฀
for Surround
฀ ฀ Signal฀ Signal฀
฀ Connections฀ High฀(+)฀ Low฀(–)฀ Shield฀
฀ MONITOR฀OUT฀A-L฀ 24฀ 12฀ 25
฀ MONITOR฀OUT฀A-R฀ 10฀ 23฀ 11
฀ MONITOR฀OUT฀A-C฀ 21฀ 9฀ 22
฀ MONITOR฀OUT฀A-SUB฀ 7฀ 20฀ 8
฀ MONITOR฀OUT฀A-LS฀ 18฀ 6฀ 19
฀ MONITOR฀OUT฀A-RS฀ 4฀ 17฀ 5
฀ CUE฀OUT-L฀ 15฀ 3฀ 16
฀ CUE฀OUT-R฀ 1฀ 14฀ 2
Notes:฀1)฀Connector฀type฀on฀Model฀74฀is฀25-pin฀female฀฀
฀ D-subminiature฀(DE-25F).฀Installer฀must฀provide฀male฀฀
฀ (DE-25M).฀Connector฀uses฀4-40฀threaded฀inserts฀for฀฀
฀ locking฀with฀mating฀plug.
฀ 2)฀Wiring฀scheme฀follows฀TASCAM฀DA-88฀convention.฀฀
฀ Standard฀DA-88-type฀wiring฀harnesses฀are฀directly฀฀
฀ compatible,฀with฀the฀exception฀of฀4-40฀screw฀threads฀฀
฀ being฀required.
Figure฀8.฀Connections฀for฀Monitor฀Output฀A฀and฀
Line-Level฀Cue฀Outputs
฀ ฀ Signal฀ Signal฀
฀ Connections฀ High฀(+)฀ Low฀(–)฀ Shield฀
฀ MONITOR฀OUT฀B-L฀ 24฀ 12฀ 25
฀ MONITOR฀OUT฀B-R฀ 10฀ 23฀ 11
฀ MONITOR฀OUT฀B-C฀ 21฀ 9฀ 22
฀ MONITOR฀OUT฀B-SUB฀ 7฀ 20฀ 8
฀ MONITOR฀OUT฀B-LS฀ 18฀ 6฀ 19
฀ MONITOR฀OUT฀B-RS฀ 4฀ 17฀ 5
฀ UNUSED฀ 15฀ 3฀ 16
฀ TALKBACK฀INPUT฀ 1฀ 14฀ 2
Notes:฀1)฀Connector฀type฀on฀Model฀74฀is฀25-pin฀female฀฀
฀ D-subminiature฀(DE-25F).฀Installer฀must฀provide฀male฀฀
฀ (DE-25M).฀Connector฀uses฀4-40฀threaded฀inserts฀for฀฀
฀ locking฀with฀mating฀plug.
฀ 2)฀Wiring฀scheme฀follows฀TASCAM฀DA-88฀convention.฀฀
฀ Standard฀DA-88-type฀wiring฀harnesses฀are฀directly฀฀
฀ compatible,฀with฀the฀exception฀of฀4-40฀screw฀threads฀฀
฀ being฀required.
Figure฀9.฀Connections฀for฀Monitor฀Output฀B฀and฀
Line-Level฀Talkback฀Inputs
Monitor฀Outputs
Two฀connectors฀are฀used฀to฀support฀the฀฀
two฀6-channel฀(5.1฀surround)฀monitor฀฀
outputs.฀Please฀refer฀to฀Figures฀8฀and฀9฀for฀
details฀on฀the฀exact฀“pin฀outs”฀of฀the฀D-sub฀
connectors.
The฀monitor฀output฀channels฀are฀intended฀
for฀connection฀to฀audio฀amplifiers฀associated฀
with฀monitor฀loudspeakers,฀or฀to฀the฀inputs฀฀
of฀loudspeakers฀that฀contain฀integrated฀am-
plifiers.฀The฀monitor฀outputs฀are฀electronical-
ly฀balanced฀and฀capable฀of฀driving฀balanced฀
or฀unbalanced฀loads฀of฀600฀ohms฀or฀greater.฀
While฀balanced฀operation฀is฀preferred,฀unbal-
anced฀operation฀does฀not฀pose฀a฀problem.฀฀
To฀connect฀to฀an฀unbalanced฀load฀connect฀
the฀+฀terminal฀as฀signal฀high,฀and฀both฀the฀
–฀and฀shield฀as฀the฀signal฀low/shield.฀For฀
optimal฀unbalanced฀operation,฀it฀is฀important฀
to฀connect฀both฀–฀and฀shield฀together฀directly฀
on฀the฀D-sub฀plug,฀not฀at฀the฀other฀end฀of฀the฀
harness.
Note฀that฀while฀the฀Model฀74’s฀electronically฀
balanced฀output฀circuits฀are฀capable฀of฀driv-
ing฀loads฀of฀600฀ohms฀or฀greater,฀the฀output฀
level฀will฀drop฀slightly฀as฀the฀load฀impedance฀
approaches฀600฀ohms.฀A฀0.5฀dB฀difference฀
in฀output฀level฀can฀be฀expected฀as฀the฀load฀
impedance฀changes฀from฀10฀k฀ohms฀to฀600฀
ohms.฀This฀drop฀is฀not฀insignificant฀and฀leads฀
to฀the฀recommendation฀that฀input฀loads฀be฀
10฀ohms฀or฀greater.
It’s฀important฀to฀note฀that฀the฀two฀6-channel฀
monitor฀outputs฀can฀be฀used฀to฀create฀a฀wide฀
variety฀of฀monitor฀system฀implementations.฀
Configuration฀choices฀allow฀the฀two฀outputs฀
to฀perform฀tasks฀more฀nuanced฀than฀just฀
serving฀as฀a฀6-channel฀A/B฀switching฀matrix.฀
Please฀carefully฀review฀the฀configuration฀
section฀of฀this฀user฀guide฀prior฀to฀connecting฀
to฀the฀monitor฀outputs;฀don’t฀let฀the฀system’s฀
unique฀flexibility฀go฀underutilized!