4 CHANNEL POWER AMP TA 4D
OPERATING INSTRUCTIONS
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2.2.4 Protection Systems
As a KS Audio standard of operation, the input signal to the amplifier is effectively limited to
protect the drivers. On powering up the TA4D amplifier a 20 Amp switch-on relay circuit is engaged
to ON to protect the drivers. If the DC current changes by more than 0.5 V, a special detection
circuit disconnects the speakers from the amplifier for their protection. The same protection takes
place if electrical shortage or low impedance occurs. When the cause is remedied the circuits return
to their full operational status. If the internal heat increases above 85 C (185 F), protection is
engaged to deactivate the power amps for as long as it takes for the cooling fans to reduce the
temperature to 85 C (185 F) again. Overheat status will be indicated by a RED ERROR LED light and
the power READY light is dimmed. Also, during this protected time, information appears in the LCD
display pointing out the problem. The LCD display is only available when F MOD controller card is
inserted in the amplifier.
3. OPERATING
3.2 F MOD Digital Controller Card
Please check details in the F MOD controller card manual.
3.3 Audio Connectors
All audio input connections are a balanced electronic type conforming to the XLR international
standard, nominal 20 KOhms for matching to a typical 50 ohm line output (grounding is on pin #1).
For very long cable run installations, a transformer-balanced output is preferable to avoid ground
differentials and 60 Hz hum loops over mixed type cable runs. The impedance is 2 x 10kOhm and is
discreet (independent for pin 2 and 3). Multiple devices can share the same input signal by using
the male-female sockets as a daisychained audio link. A total of only 1 dB of signal loss on the input
signal is seen when up to 20 devices are sharing the same input signal. Digital AES/EBU lines should
be run with 110 Ohm cables. You can daisy chain as many products you wish, as the XLR male
outputs feature an active line transmitter.
3.4 Power Transformer
If you run very long power line feeds, especially when using different power circuits, a balancing
power transformer should be utilized to avoid ground hums. This will also help to avoid electro-
magnetic interference caused by generators or lighting fixtures and dimmer circuits. Please note,
on KS systems, the digital signals always have an input transformer and separate transformer
output built-in.
3.5 Outputs
There are 4 Neutrik Speakon speaker level output connectors. These 4 audio outputs are
configured automatically by the controller card selected for the system. The bi-amp mode is +1 /-1
for the lows/mids and +2 /-2 for the tweeter. In bridge mode for high-power-subwoofer
applications one amp is on +1/+2 while the other amplifiers runs as -1/-2. The selected
configuration is indicated through green LED’ s located next to each of the 4 outputs. KS
recommends the use of 4 conductor, 12 gauge cable for all speaker to amplifier connections for
