Cloud Electronics 46-50 - Manual (Page 13)

46-50 Installation and User Guide V1.0 13
INSTALLATION
Hardware considerations
The 46-50 Mixer Amplifier is built in a 2U-high 19” rack mount
enclosure. It is recommended that the 46-50 is installed in a
19” rack wherever possible. The units are approx. 320 mm
deep, but at least 400 mm of rack depth should be available to
allow for rear connectors and cabling.
The 46-50 uses thermostatically-controlled forced-air cooling,
using a two-speed fan. The enclosure has air intake slots in
the front panel; ensure that these are not obstructed once
the unit is installed. Warmed air is expelled at the rear of
the unit by the fan. It is recommended that 1U blank panels
are fitted in the rack above and below the 46-50; do not
fit slotted ventilation panels as these defeat the action of
forced-air cooling.
If the unit is to be used free-standing (i.e., not mounted in a
rack), the four feet supplied in the accessory pack should be
fitted to the bottom of the chassis. These should be inserted
into the four 5 mm dia. holes clearly identifiable in the corners
of the bottom panel.
The choice of location will be dictated by the specifics of the
system and building layout. It is recommended that wherever
possible, the 46-50 should be mounted adjacent to as many
of the music sources (CD players, music servers, TV receiver
boxes, etc.) as practical.
When deciding the Mixer Amplifier’s location, bear in mind
that access to it (particularly the rear panel) will probably be
required even if a full complement of remote controls is being
fitted as part of the system, as certain adjustments can only
be made on the unit itself.
Power Supply
The European version of the 46-50 operates on standard
230 V AC mains; an alternative version is available which
operates on 115 V AC. An IEC mains cable with a plug
appropriate for each country is supplied with the European
unit. The unit’s power consumption is 181 VA (measured using
8th-power pink noise driving 4 x 4 ohm loads).
Fuses and ratings
The only externally-accessible fuse is an AC mains fuse in the
IEC connector housing.
Only replace a fuse with one of
exactly the same type. The table below gives the correct
fuse types.
VERSION RATING FUSE TYPE
230 V
3.15 A 20 mm x 5 mm slo-blo T3.15AH
115 V 6.3 A 20 mm x 5 mm slo-blo T6.3AH
The fuseholder is of the “bayonet” type; press and twist the
holder anticlockwise to remove the fuse. If a replacement
fuse blows immediately, it indicates that the mixer amplifier
has developed a fault, which should be referred to competent
service personnel.
Internally, two 20mm x 5mm fast-blow F4.0A fuses protect
each amplifier channel (eight in total). These are service
components, and should not require attention. Failure of any
of these fuses indicates a fault condition, which should be
immediately referred to a competent technician or authorised
service centre.
System connections
Music sources
Connect the system’s various music sources to LINE 1 to
LINE 6. All line inputs offer unbalanced connection for stereo
sources on a pair of standard RCA jacks (phono sockets).
The sensitivity range available should allow most standard
items of audio equipment such as computers/tablets, music
servers and media receivers, etc., to operate at a satisfactory
level. Most equipment of this type will have stereo unbalanced
outputs, and as long as the source equipment is adjacent to
the Mixer Amplifier, normal phono-phono (or 3.5 mm jack-to-
phono) leads can be used. Always avoid using pre-made leads
of an unnecessary length.
Mono and stereo sources:
The mixing section of the 46-50 is mono; the stereo line inputs
are summed internally. Stereo sources should be connected
in a normal stereo configuration, using both L and R inputs.
If connecting a mono source with only a single output, it may
be connected to either the left or the right input.
Balanced sources:
If it is necessary to connect an item of source equipment with
a balanced output to the 46-50’s line inputs, ideally, a balancing
transformer should be inserted between the source and the
unbalanced input. Suitable audio transformers, which should
have a ratio of 1:1, are readily available from major audio
component suppliers. The transformer(s) should be mounted
as close to the 46-50 as practical, and housed in a screened
enclosure if they are not individually screened. The preferred
connection method is shown below.
LEFT
+
-
SCN
Unbalanced
inputs SCN
LEFT
+
-
SCN
Audio balancing transformers
RIGHT
+
-
SCN
Unbalanced
inputs SCN
RIGHT
+
-
SCN
pin 1 ground
pin 2 hot
pin 3 cold
Balanced outputs (XLRs):
1 2
3
1 2
3
If transformers are not available, a balanced source may feed
an unbalanced input directly as long as care is taken over how
the connections are made. A variety of design techniques are
in use to implement balanced outputs in audio equipment,