2 . 1
N A C S 1 A U D I O I N P U T S A N D C O N N E C T I O N S
The NAC S1 preamplifier provides five stereo analogue audio line inputs intended for the
connection of analogue output source components such as CD players, streamers, audio-visual
processors, DACs, phono preamplifiers or music servers. The inputs are accessed through
connection sockets located on the connection panel. This is illustrated in Diagram 2.2.
The connection sockets comprise three 5-pin DIN sockets, three left/right pairs of RCA phono
sockets, and two left/right pairs of balanced XLR sockets. Each of these eight physical inputs
can be “mapped” to one of the five internal preamplifier inputs.
The default NAC S1 input mapping is tabulated below:
I N P U T N A M E
I N P U T S O C K E T ( S )
C D
1 (5-pin DIN)
S T R E A M
2 (5-pin DIN)
A V
4 (RCA phono pair)
P H O N O
3 (5-pin DIN)
A U X
7 (balanced XLR pair)
Two pairs of RCA phono inputs sockets (inputs 5 and 6) and one pairs of balanced XLR input
sockets (input 8) are by default not mapped to any preamplifier input Modification of the default
input socket mapping is described in Section 4.1.
N O T E . Balanced inputs are different to conventional “single ended” inputs in that the earth and
signal negative conductor are separate. In a conventional “single ended” signal interconnect cable the
earth and negative conductors are common. In a balanced arrangement the negative and earth are
carried on individual conductors. Balanced connection between preamplifier and power amplifiers
significantly reduces the potential for noise and hum – especially over long cable lengths. The diagram
below illustrates balanced and unbalanced interconnects.
2 . 0 N A C S 1 P R E A M P L I F I E R
common earth
signal – left
signal – right
earth
signal – positive
signal – negative
Unbalanced stereo interconnect cable
Balanced mono interconnect cable (two required for stereo)
1 2
1 3
