General Application Guidelines
Load Impedance Range (input impedance of equipment the receiver drives) .. . . . . . . . . . . . . . . . . . . . . . . 22 kÙor more Note 1
Source Impedance Range (output impedance of equipment driving the transmitter) . . . . . . . . . . . . . . . . . . . . 2 kÙor less Note 1
Maximum Input Cable (equipment outputs to transmitter inputs) Length. . . . . . . . . . . . . . . 10 feet (3 m) of typical cable Note 2
Maximum Transmitter to Receiver Cable Length, !1 dB @ 20 kHz. . . . . . . . . . . . . . . . . . . . 50 feet (15 m) of typical cable Note 3
!1.3 dB @ 20 kHz.. . . . . . . . . . . . . . . . . . . . . . 100 feet (30 m) of typical cable
!2 dB @ 20 kHz. . . . . . . . . . . . . . . . . . . . . . . 250 feet (76 m) of typical cable
!3 dB @ 20 kHz. . . . . . . . . . . . . . . . . . . . . . 350 feet (107 m) of typical cable
Maximum Output Cable (receiver outputs to equipment inputs) Length .. . . . . . . . . . . . . . . . 3 feet (1 m) of typical cable Note 2
Notes: 1. Typical performance is with source impedance of 600 Ùand load impedance of 22 kÙ. Source impedances less
than 600 Ùwill substantially reduce the effects of transmitter-to-receiver cable capacitance (cable length).
2. Cable capacitance of 50 pF/ft (160 pF/m)
3. Cable capacitance of 15 pF/ft (50 pF/m), Belden 1583A or equivalent
System Hookup
Cables known as CAT-5, CAT-5e, CAT-6, etc. have become standards for use in Ethernet
and other digital applications. At audio frequencies, differences among the various
category numbers are negligible. The cables consist of four twisted-pairs and are most
commonly terminated with 8-position 8-contact (8P8C) “RJ-45" male connectors. The
cable assembly used must be a standard or “straight-through” type wired according to
TIA/EIA standard T-568A or T-568B. Pin numbering is shown at the right and pair color and audio channel assignments are
shown below:
RJ-45 Pin Wire Color Function
1 green/white Channel 1, Left +
2 green Channel 1, Left !
3 orange/white Channel 4, Right + (via “EXPAND” interconnect of 2 units)
4 blue Channel 3, Left + (via “EXPAND” interconnect of 2 units)
5 blue/white Channel 3, Left !(via “EXPAND” interconnect of 2 units)
6 orange Channel 4, Right !(via “EXPAND” interconnect of 2 units)
7 brown/white Channel 2, Right +
8 brown Channel 2, Right !
Note: Wire colors shown are for TIA/EIA standard T-568A. Standard T-568B simply swaps the green and orange pairs and
has no effect on input to output channel assignments.
CAT cables and RJ-45 connectors are widely-available in either unshielded “UTP” or shielded
“STP” varieties, either of which may be used with these ISO-MAX units. However, we
recommend STP cable and shielded RJ-45 connectors (example at right) for improved immunity
to both RF interference and channel-to-channel crosstalk. Because the STP cables use an overall
shield rather than individual shields per pair, some crosstalk must be expected at high audio
frequencies. Therefore, we also recommended that all channels carry related program content
(such as stereo or four of the 6 channels of “5.1 surround” systems).
For a two-channel system, plug the cables from the signal source into to the transmitter RCA “IN” jacks “L” and “R.” Plug the
CAT cable into the transmitter RJ-45 “OUT” connector. At the destination end, plug the CAT cable into the receiver RJ-45
“IN” connector. Plug the cables to the destination equipment into the receiver RCA “OUT” jacks “L” and “R.”
