NKI1480B DAX60 and DAX120 Amplifiers—Installation
Page 8 of 18 (Jul-98)
amplifier, the maximum speaker load should be approximately 50 watts; for a 120-
watt amplifier, the maximum speaker load should be approximately 100 watts.
For unbalanced operation, place a jumper between one of the speaker terminals
and “GND." Do not ground the center tap when you use unbalanced operation.
Grounding the Center Tap
If required by the installation, the center-tap terminals may be jumpered to the
"GND” terminal when the balanced speaker output is used. The "GND" terminal is
next to the negative "AUX POWER" terminal on the DAX6O; on the DAX12O,
the "GND" terminal is next to the "COM" input terminal. When the two center-tap
terminals are linked together, either one of them may be connected to the "GND"
terminal.
Important:
Do not install a jumper between "GROUND" and "CT" with the unbalanced
speaker connection: connecting both points to "GROUND" would create a short
circuit across the output transformer
Split-Center-Tap Operation
The amplifier output transformer can be configured for split-center-tap operation
with symmetrical output voltages on both sides of the center tap. This is intended
for special applications with Rauland systems such as the Telecenter
®
5000 and the
Responder
®
3000. When a DAX amplifier is used with the TC5OOO or the
NCS3OOO, (a) no more than 50 watts of power may be drawn through the system,
and (b) a TC5007 Transformer Module is required (see KI-1486).
If the installation requires an isolated, split-center-tapped output, remove the
supplied link from the two "CT" terminals; this will separate the two halves of the
output windings (see "OUTPUT CONNECTIONS," above, and the attached
KMO7BO).
Important:
There is a large capacitor inside the TC5OOO and the NCS3OOO that provides a
low AC impedance across the center taps. The split windings are not designed to
be used independently.
Auxiliary DC Power Supply
The 28-VDC terminals (on the right side of the DAX6O; below the output
transformer of the DAX12O) can provide up to 1.2 Amperes to preamplifiers,
Director Series control panels, and other auxiliary devices requiring DC power.
Since this supply is floating, it can also be used for devices requiring an isolated