S/PDIF Connections
Page 25
Peavey Electronics Corp
To drive an S/PDIF input from the CAB 16d’s out-
put, a similar circuit must be implemented. Again,
the impedance of the CAB 16d must be matched to
properly terminate to the S/PDIF input. This is
accomplished by using a 22 Ohm resistor across the
output of the CAB 16d. The level correction is
accomplished by placing a 75 Ohm and a 56 Ohm
resistor in series with the positive side of the CAB
16d’s output as shown. The negative side is carried
straight through to the shield conductor of the
S/PDIF device’s input. (Jumper is optional.)
In addition to adding the resistor circuits, it may also be necessary to configure the CAB 16d output
CHANNEL STATUS to
Consumer Mode
before the interface between the S/PDIF device and CAB 16d is completed.
The
Consumer Mode Select Switch
can be found in the CAB 16d CHANNEL STATUS BLOCK, located within the
CAB 16d’s software control panel. (See pages 14-15.)
Connecting an S/PDIF Source to a CAB 16d input
requires that the output level and impedance of the
S/PDIF source be matched to the CAB 16d’s input
circuit. The following circuit provides attenuation
from the source through one in-line 51 Ohm resistor
on the positive leg of the signal. The impedance
matching is accomplished by using a 150 Ohm resis-
tor across both legs of the S/PDIF source signal.
NOTE: A jumper is required between the negative
and SH terminals to complete the termination.
When making these interface connections, it is important to install the resistors at the CAB
™
16d’s output terminal, using the
removable Euro connector. The design of this connector, supplied with the CAB 16d, will provide a solid mechanical mount for
the resistors. The wiring from the consumer RCA coax cable should be soldered to the other side of the resistor network. All
interconnecting joints should be soldered as well. All resistors should be 1% or 5% tolerance, 5 W, typical.
RCA connector
To S/PDIF input
From S/PDIF output
Unbalanced Coax
Positive “Hot” wire
Negative/Shield
22 Ohm resistor
56 Ohm resistor
75 Ohm resistor
51 Ohm resistor
Jumper
150 Ohm resistor
Fig. 8, S/PDIF resistor network configurations
