Millennia Media HV-3C and HV-3D 041722js page 6 of 8
HV-3 Series Preamp Front Panel
1.HIGH RESOLUTION GAIN CONTROL
Detented, 36-position gain control employing a
superior quality 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 (Green and Amber) determine the gain
"range" of the rotary switch.
When the pushbutton switches are not depressed
(non-illuminated), the mic preamp gain provided is
as printed on the front panel (9.0 dB, 10.5 dB, 12.0
dB, etc..).
When the green pushbutton switch (only) is
depressed and illuminated, add 18 dB to the gain
settings as printed on the front panel.\When the
green and amber 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 12:00 o'clock position, the preamp gain would be
54 dB (18 + 36).
2.PHANTOM POWER SELECT SWITCH ("+48V")
Illuminating pushbutton switch which provides
phantom power (+48VDC) to the microphone
inserted into that channel. When this switch is
depressed (illuminated red), phantom power is
applied simultaneously through dual 6.81k ohm
resistors to pins 2 and 3 of the three pin female XLR
input.
Use phantom power with condenser and other
microphones requiring traditional phantom supply.
CAUTION: Applying phantom power to
ribbon microphones could damage them. Do
not use phantom with ribbons, moving coil,
and other microphones which do not require
phantom power. Use care, as well, to not
insert or extract mic cables from the HV-3
series preamp when phantom power is
active.
3.HIGH VOLTAGE SELECT SWITCH ("+130V")
Optional Illuminating pushbutton switch which
selects the four pin XLR input (+130VDC) for DPA
(B&K) high voltage microphones type 4003, 4004,
4009, and 4012.
When this switch is depressed (illuminated amber),
the HV-3 series preamp receives mic-level audio
from the four pin XLR input. If you are using a B&K
(DPA) high voltage microphone with four pin XLR
connectors, depress this switch so that it illuminates.
If a conventional microphone is used, do not depress
this switch. The HV-3 series preamp will not combine
("mix") both conventional and high voltage
microphones on one channel. NOTE: The HV-3 series
preamp is designed to provide uninterrupted DC
power to B&K (DPA) high voltage microphones,
regardless where this switch is set. Use care that
high voltage microphone
cables are not inserted or extracted from the unit
when power is on.
4.SIGNAL INDICATORS "OL" & "SP" LEDs
The green "signal present" (SP) LED indicates that a
nominal signal is present at the microphone input. It
is set to illuminate in the neighborhood of -35 dBu.
The red "overload" (OL) LED has been set to
illuminate when the balanced output reaches a level
of +25 dBu. However, the HV-3 series preamp can
produce unclipped, undistorted levels over twice this
voltage. Hence, the overload LED is not an indication
of preamp clipping. Rather, it is a general reference
showing a nominal "system" peak level.
If clipping is occurring in your recording path, check
all devices connected after the HV-3 series preamp
and reduce system gains accordingly. In the event
that B&K (DPA) 4004 or 4012 microphones are used
with hazardous sound pressures (over 130 dB, SPL),
an attenuator may be required between microphone
and preamp.
5.POWER SWITCH "POWER and PILOT
INDICATOR LIGHT LED - Rocker switch for
switching AC line power on and off. When LED is
illuminated, shows that the HV-3 series preamp unit
is powered up and active.
