Ecler XPA SERIES - Manual (Page 5)

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3. INSTALLATION
3.1. Placement, mounting, cooling
All XPA amplifier models are presented in standard 19” rack format and are 2 units high.
It is important that the amplifier, as a heat source, is not placed next to other equipment nor exposed to
high temperatures. Therefore, the ventilation path should be kept free to allow fresh air entering the forced
ventilation tunnel. This system takes air from the unit's backside, bringing it directly to the power amp modules and
distributing it to the transformer and capacitors and then obliging it to pass trough the cooling tunnel to finally blow
out of the front panel. In case of rack mounting, this system avoids heat accumulation inside the unit and thus
increases lifetime of electrolytic capacitors. It is recommended to place power amplifiers on top of other equipment
and not underneath.
3.2. Mains connection
The XPA amplifiers are fed with alternate currents, depending on the country, of 110-120, 220-240V
47/63Hz. (see characteristics in the back of the unit).
The mains cables must not be near the shielded cables carrying the audio signal, as this could cause
humming.
In order to protect the power amplifier from eventual power consumption overloads it is protected by a set
of internal fuses. Should a fuse blow, it must be replaced immediately by one with identical rating. Should it blow
again please contact our Technical Service Department. NEVER REPLACE THE FUSE WITH ANOTHER ONE
WITH A HIGHER VALUE.
CAUTION: Fuse substitutions have to be performed by a qualified technician.
3.3. Input signal connections
The signal input connectors are of XLR-3 and 1/4’’ TRS Jack type (7,8) and electronically balanced. The
pin assignment is as follows:
XLR-3 JACK
Hot or direct signal > Pin 2 Tip
Cold or phase inverted signal > Pin 3 Ring
Ground > Pin 1 Sleeve
For an unbalanced connection, short pin 3 to ground (XLR) or the ring to ground (Jack).
The input impedance in balanced mode is 20k
 (10k non-balanced). This impedance makes possible to
parallel several amplifiers without losing audio quality. Input sensitivity can be selected via a switch placed on the
back panel (9) Selectable values are 0.775V / 1V / 1.4V
3.4. Subsonic filter
This filter cuts off inaudible frequency components which when amplified suppose a risk of damage to the
low frequency speakers as they generate excessive excursions of the woofer's diaphragm. The filter of the XPAs,
which has a Butterworth shaped response with 18 dB/oct slope, has a cut-off frequency of 30 Hz and can be
switched on or off via a switch on the rear panel (11).
Subsonic filters are very important when playing back vinyl records because the phono cartridges are
specially sensitive to feedback and acoustic coupling at very low frequencies.