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HV-3D
(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-
3D 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 occuring in your recording path, check all devices connected after the HV-3D
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) PILOT INDICATOR LIGHT
LED which, when illuminated, shows that the HV-3D unit is powered up and active.
(6) POWER SWITCH "POWER"
Rocker switch for switching AC line power on and off.
Summary of Contents for HV-3D
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