User Guide

Issue฀3,฀November฀2016฀ Model฀74/75฀User฀Guide฀
Page฀16฀ Studio฀Technologies,฀Inc.฀
for Surround
AC฀Mains฀Power
The฀Model฀74฀is฀internally฀configured฀to฀
operate฀from฀an฀AC฀mains฀power฀source฀of฀
nominal฀100,฀120,฀or฀220/240฀volts,฀50/60฀
hertz.฀Units฀shipped฀to฀North฀America฀are฀
factory฀selected฀for฀120฀volt฀operation.฀
Units฀bound฀for฀Japan฀must฀be฀selected฀for฀
100฀volts,฀while฀our฀friends฀“down฀under”฀
and฀in฀Europe฀receive฀units฀set฀for฀220/240฀
volts.฀Before฀connecting฀the฀Model฀74฀to฀
AC฀mains฀power,฀check฀that฀it฀is฀configured฀
to฀match฀the฀local฀mains฀voltage.฀Look฀on฀
the฀back฀panel฀(adjacent฀to฀the฀power฀entry฀
connector)฀for฀the฀factory-configured฀volt-
age.฀Note฀that฀an฀incorrect฀configuration฀
could฀prevent฀operation,฀or฀cause฀dam-
age฀to฀the฀unit.฀Should฀it฀be฀necessary฀to฀
change฀the฀unit’s฀operating฀voltage฀it฀must฀
be฀performed฀only฀at฀the฀factory฀or฀by฀a฀
competent฀service฀technician.
The฀Model฀74฀uses฀an฀IEC-320฀C14-
compatible฀connector฀to฀mate฀with฀the฀
AC฀mains฀cord.฀The฀wire฀colors฀in฀the฀AC฀
mains฀cord฀should฀conform฀to฀the฀interna-
tionally฀recognized฀CEE฀color฀code฀and฀
must฀be฀wired฀accordingly:
Connection฀ Wire฀Color฀
Neutral฀(N)฀ Light฀Blue฀
Line฀(L)฀ Brown฀
Protective฀Earth฀(E)฀ Green/Yellow
Safety฀Warning:฀The฀Model฀74฀does฀
not฀contain฀an฀AC฀mains฀disconnect฀
switch.฀As฀such,฀the฀AC฀mains฀cord฀
plug฀serves฀as฀the฀disconnection฀de-
vice.฀Safety฀considerations฀require฀that฀
the฀plug฀and฀associated฀outlet฀be฀eas-
ily฀accessible฀to฀allow฀rapid฀disconnec-
tion฀of฀AC฀mains฀power฀should฀it฀prove฀
necessary.
As฀soon฀as฀AC฀mains฀power฀is฀applied,฀the฀
Model฀74’s฀power฀present฀LED฀will฀flash฀for฀
a฀few฀seconds.฀After฀the฀completion฀of฀a฀
software฀startup฀interval฀the฀power฀present฀
LED฀will฀light฀steadily.฀The฀data฀active฀LED฀
on฀the฀Model฀74฀will฀flash฀once฀upon฀pow-
er฀up,฀then฀briefly฀light฀upon฀completion฀of฀
the฀Model฀75’s฀power-up฀sequence.฀The฀
Model฀75฀will฀go฀through฀its฀own฀power-up฀
sequence,฀lighting฀each฀LED฀in฀secession.฀
Configuration
After฀the฀physical฀installation฀has฀been฀
completed,฀several฀configuration฀issues฀
must฀be฀addressed.฀On฀the฀Model฀74฀the฀
surround฀and฀stereo฀inputs฀must฀be฀cali-
brated฀using฀the฀trim฀potentiometers.฀The฀
operating฀parameters฀of฀the฀system฀should฀
be฀set฀using฀the฀Model฀75฀Control฀Con-
sole’s฀configuration฀mode.
Level฀Calibration
Sixteen฀15-turn฀trim฀potentiometers฀are฀
located฀on฀the฀front฀panel฀of฀the฀Model฀74฀
Central฀Controller.฀Taking฀time฀to฀carefully฀
adjust฀the฀trim฀pots฀will฀ensure฀that฀accu-
rate฀monitoring฀can฀take฀place.฀Each฀trim฀
pot฀allows฀input฀signals฀with฀a฀nominal฀lev-
el฀of฀–12฀dBV฀to฀+6฀dBu฀to฀be฀utilized.฀With฀
care,฀it’s฀easy฀to฀calibrate฀the฀surround฀and฀
stereo฀inputs฀to฀within฀one-quarter฀of฀a฀dB฀
of฀the฀desired฀value.
The฀monitor฀outputs฀are฀used฀as฀the฀
measuring฀point฀when฀adjusting฀the฀trim฀
pots.฀A฀laboratory-grade฀audio฀level฀me-
ter฀or฀equivalent฀is฀required฀for฀accurate฀
calibration.฀In฀addition,฀the฀audio฀sources฀
connected฀to฀the฀inputs฀must฀be฀able฀to฀
generate฀continuous฀audio฀signals฀at฀their฀
nominal฀operating฀level.