User guide

DMX-4 USB Mixer User Manual
5
General description:
The DMX-4 is a 4 channel microphone preamplifier with
4 analog to digital converters (A/D). The DMX-4
connects to a PC via a USB 2.0 connection so that audio
can be recorded onto the PC’s hard drive. There are 2
configurable monitor outputs, which can be
independently set to be a mix of any combination of the
4 input channels. The monitor outputs can be used to
connect to a PA system or for video/teleconferencing.
All level adjustments are solid state; there are no
mechanical knobs on the unit. Level adjustments are
made by moving virtual slider controls in the Antex
Mixer Program running on the PC. This allows for
settings to be stored and retrieved as a “scene”. Also, if
the PC connected to the DMX-4 is connected to a LAN,
adjustments can be made from a remote computer
somewhere on the LAN.
The microphone inputs are professional balanced XLR
connectors. The differential input impedance is 2K.
Phantom power of +14 volts can be turned on under
control of the Antex Mixer Program. Phantom power is
connected through a 1K resistor on each line. In
“microphone” setting, all 4 inputs have a gain range of
+10dB to +85dB. Note that 65dB of gain is done in the
analog circuitry, and the additional 20dB is done in the
digital domain. As you increase the gain on any input,
the level of this audio will get louder in the monitor
output and in the recording level. However, once you
exceed 65dB, the recording level will continue to
increase, but the audio in the monitor output will not
increase any further. Input channels 1 and 2 have a