CONTROLS AND CONNECTIONS
1.Output Volume Pots control the level at the corresponding rear panel output XLR. Each of the controls has a gain range of -60dB attenuation at full off to + 18dB of gain at full on.
2.Individual Clip LEDs on all 8 outputs and on each of the two inputs indicate signal overload conditions within the circuitry. The red clip lights illuminate at 3dB below actual clipping (the unit clips at ±28dB balanced, the LEDs illuminate at +25dB).
3.Signal Present LEDs on each of the input channels indicate that signal is being applied to the input. The green lights illuminate when the input signal is greater than -14dB balanced or -20dB unbalanced.
4.Combine Switch converts the DA-2 from a 2 by 4 configuration to a 1 by 8 distribution amp. In this mode the two inputs are actively mono -summed or either input may be used to feed the eight outputs. The mono-sum feature allows the DA-2 to properly combine left and right stereo signals into a mono feed.
5.Channel 1/2 Select Switch determines which channels input signal is fed to the headphone circuit for monitoring.
6.Headphone Circuit monitors the signals coming into the DA-2 inputs. It is a mono circuit which drives both earpieces in stereo headphon es that have an impedance greater than 20 Ohms. The volume control has a gain range of -60 to +18dB to accommodate a wide range of audio levels. The jack is a standard 1/4” TRS type.
7.Power Switch connects AC to the transformer primary and the LED indicates that the unit is working. Both sides of the AC line are switched and a mains fuse is located on the circuit board inside the unit.
8.Output XLR5 on the DA-2 are actively balanced with the audio ground lifted (pin 1 disconnected). If grounding pin 1 of the XLR is required, there is a spot for a jumper for each XLR output on the PC board. Each output is driven with its own individual driver circuit providing channel-to- channel isolation greater than 74d B. The outputs are wired pin-2 positive, pin-3 negative and are RF-bypassed with capacitors for rejection of RF signals on the output lines.
9.Input XLR Connectors feed actively balanced differential amplifiers providing over 90dB of common mode rejection. The input impedance is facto ry-set at 1Meg Ohms, allowing the inputs of many units to be paralleled together. If lower input impedance is desired it can be easily accomplished by an inter nal resistor change. In Combine mode inputs 1 and 2 are actively summed to mono. Pin-2 is positive, pin-3 negative and pin-1 is connected to audio ground.
10.Ground Lift Switch connects the audio circuit ground to AC ground and the chassis of the unit, if desired.
11.Power Cord - a standard 15 amp plug for l20VAC and has no plug on the DA-2X 230VAC model. Black is line, white is neutral and green is earth.
