Cloud Electronics CX2300 - Manual (Page 9)

5.03 The Power Supply
The CX2300 has a standard bi-polar 15-0-15 volt power supply derived from the two
adjustable regulators. This enables a smooth power-on as the circuitry has a slow rise
characteristic thus reducing power supply derived thumps and other extraneous signals
which often find their way on to the audio signal.
5.04 Signal Connections and EMC
The CX2300 is fully compatible with the Electromagnetic Compatibility standards and if
you propose to use the unit where it may be exposed to high levels of disturbance such
as may be found close to a TV or radio transmitter we suggest that the screen of the
signal cables should be connected to the chassis connection on the XLR type connector.
To avoid any ground loops, the signal earth (pin 1) should only be connected at the
receiving end of the cable when the common mode rejection should reduce any
unwanted signals to a negligible level.
5.05 The benefits of balanced interconnections.
Most professional audio equipment utilise balanced inputs and outputs using the familiar
3 pin XLR type connector or perhaps a 3 pole 6.3mm phone jack. A balanced output
stage will normally have a very low output impedance and will happily drive a line with a
load as low as 600Ω. The interconnecting cable should have two twisted cores with an
overall screen and any interference that may penetrate the screen would be picked up by
the two inner cores and appear as a common mode signal. The balanced input stage is
sensitive to differential signals only and features a high rejection of the common mode
signal (Common Mode Rejection or CMR) which may be interference or ground loop
hums. We therefore strongly suggest that balanced interconnections are used by default.
5.06 Using the CX2300 with unbalanced equipment.
The CX2300 can be used with any equipment with unbalanced signal ports. Where the
signal source is unbalanced, connect the signal ground to pins 1 & 3 and use pin 2 as the
hot signal input. This will result in no signal loss and will operate normally but without the
benefits of noise and interference cancellation.
If the output of the CX2300 is driving an unbalanced load, connect the screen to pin 1 and
the hot signal output to pin 2. Do not make any connection to pin 3 whatsoever. The
system will operate with a gain loss of 6dB which can be recovered by rotating the front
panel gain controls clockwise.
5.07 40Hz - the minimum frequency.
The circuitry of the CX2300 is arranged so that the mother board is fitted with two low
pass filters and two high pass filters which operate at the low frequency of 40Hz with no
plug-in card fitted. The filter cards are fitted with resistors which connect in parallel to the
resistors on the mother board and increase the operating frequency of the filters. The
minimum crossover frequency is therefore determined by the fixed 40Hz with no card
fitted and the practical upper limit is 8kHz.