Millennia LOC Analog Legacy Phonographic / Archiving Preamplifier - Manual (Page 5)


LOC
Millennia
Media & Music Systems

LOC Millennia
Media & Music Systems
LOC FRONT PANEL
(1) MONO SELECT SWITCH "MONO (L+R)"
Pushbutton switch (German ITT) which combines left and right inputs into a summed mono signal.
When this switch is depressed and illuminated, left and right input signals are combined into a single
mono signal on both left and right compensation and filter paths.
(2) POLARITY REVERSE SWITCH "POL REV"
Pushbutton switch (German ITT) which, when depressed and illuminated, reverses the polarity
(180 degree inversion) of the right channel input signal. Use with vertical groove recordings or stereo
sources which are in reversed polarity relative to each other.
(3) RCA Input Select Pushbutton Switches (L&R)
Push in to select the rear panel RCA input jacks.
(4) SIGNAL PRESENT & OVERLOAD INDICATORS "SP" & "OL"
Green and Yellow LEDs (light emitting diodes) which show signal activity (green) and high-level (yel-
low). The green Signal Present LED illuminates with an audio signal level of approximately -50 dBu,
and should illuminate with any normal phono input signal. The yellow high-level LED illuminates with
an audio signal level of approximately +20 dBu and should only illuminate on the very highest peak
levels.
(5) HIGH RESOLUTION PHONO GAIN CONTROL
Detented, 36-position gain control employing a Grayhill mil-spec gold plated rotary switch. Switch gain
is approximately 1.5 dB per step and is inter-channel matched to better than 0.08 dB at all settings.
After a brief warm-up period, adjustment of this switch is virtually silent. Two illuminating pushbutton
switches ("A" = Green and "B" = Amber) determine the gain "range" of the rotary switch. When the
pushbutton switches are not depressed and non-illuminated, the phono preamplifier gain is as printed
on the front panel (9.0 dB, 10.5 dB, 12.0 dB, etc..). When the green "A" pushbutton switch (only) is
depressed and illuminated, add 18 dB to the gain settings as printed on the front panel. When the
green "A" and amber "B" switches are both depressed and illuminated, add 36 dB to the gain settings
as printed on the front panel. For example, with both pushbutton switches depressed and the rotary
switch at 1:00 o'clock position, the preamp gain would be 55.5dB (19.5 + 36). Maximum gain can be
customized up to 90 dB if required. Contact factory for more information
(6) Pre Eq Output Trim
Variable output from the input to the filter and compensation circuits. A setting of '0' is unity gain. This
is post preamp/switching circuits, pre compensation/filter circuits.
(7) Post EQ Output Trim
Variable balanced output post compensation/filter circuits. A setting of '0' is unity gain.