Cloud Electronics Z4MK3 - Manual (Page 20)

Z4-8 MK3 Installation and User Guide 20
Music source
Music source for a zone may be controlled by applying various DC voltages of between 0 and +10 V to pin 3, the 0 V reference
being connected to pin 1. 0 V at pin 3 will select Line input 6 and between +7.5 and +9 V will select Line input 1. The other line
inputs will be selected with intermediate voltages. Taking pin 3 above +9 V will deselect all inputs, making the zone effectively
‘off’ for music.
The table below lists the DC voltages required at pin 3 to select each line input. The third column is the value of a resistor which
should be connected between pins 1 and 3 to permanently ‘force’ a zone to a particular line input.
INPUT DC VOLTAGE RESISTOR VALUE
OFF >+9.0 V
Line 1 +7.5 V 16k
Line 2 +6.0 V 11k
Line 3 +4.5 V 6k8
Line 4 +3.0 V 3k9
Line 5 +1.5 V 1k8
Line 6 0 V short-circuit
Note that there is an internal 15k “pull-up” resistor between pin 3 and the internal +15 V rail. If pin 3 is left “floating”, this pull-
up will cause ‘OFF’ to be selected. The output impedance of the control voltage source should be low enough to overcome the
effect of this resistor.
Fitting loudspeaker EQ cards
The Z4 MK3 and Z8 MK3 are compatible with various popular installed-sound loudspeakers; a single-channel loudspeaker
equalisation module may be fitted to as many zone outputs as necessary to optimise the frequency response of the channel to
the loudspeaker type being used.
Please check the cloud website (
www.cloud.co.uk ) for makes and models of loudspeakers for which EQ cards are available.
To install equalisation modules, first remove the top cover from the Z4 MK3 /Z8 MK3 (six screws). The modules plug into the white
12-pin connectors labelled CON2 on the vertically-mounted sub-cards; there is one sub-card for each zone output, and the
modules can be plugged in without removing the sub-boards. Note the header connectors on the PCB have two notches on one
side only; these engage with lugs on the equalisation module’s mating connector to ensure correct orientation.
See the Appendix section “PCB jumper locations and settings” page 22 for further details. Replace the top cover with the
original screws after fitting.