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INTRODUCTION
The stereo processor module UCM 20 - Universal Crossover Module is a card that has been specially designed to
fit into ECLERs APA and DPA Series SPM Technology power amplifiers.
The UCM 20 card has been conceived for its use in bi-amplified applications. A 24dB/oct Linkwitz-Riley crossover
filter confers the system great precision and smooth operation, minimizing cancellations and other phase related
problems other configurations show. Cut off frequency can be pre-set from 100 to 200Hz. The UCM 20 can operate
as a high pass and a low pass filter, both for the amplifier into which it is installed, as for an external amplifier. The
action of the filter can be bypassed, so that the selected amplifier operates in full-range mode. These features make
an UCM 20 fitted amplifier an extremely versatile unit.
CONNECTION INSTRUCTIONS
The Cut off frequency and the input sensibility of the UCM 20 are factory preset at 100Hz and 0dBV respectively.
These settings can be easily modified (See paragraphs “SELECTING CUT OFF FREQUENCY” and “INPUT
SENSIBILITY”). No other adjustments are necessary before installing the card into the amplifier.
Keep in mind that the APA and DPA Series power amplifiers feature an efficient ANTICLIP system. Detailed
information about this protection system can be found in the instruction manual that came with your power
amplifier.
The attenuation potentiometers of the power amplifier should be left “open”, i.e. no attenuation should be applied.
However, these controls could be used to attenuate a problematic frequency range in acoustically poor rooms as a
first step for finer equalization.
IMPORTANT: In order to avoid damage to the loudspeakers, equipment should be turned on in sequence following
the same path as the audio signal flow. Last you should turn on the bass amplifier. Devices should be turned off
following the inverse sequence.
SELECTING CUT OFF FREQUENCY
Cut off frequency is selected using two four position switches found on the card. Separate switches are provided for
the L and R channels (8-9). The available cut off frequency steps are (from left to right): 100, 125, 150 and 200 Hz,
as depicted on the cards chassis. The blank space (10) on the front panel marked “FREQ-Hz” can be used to place
a provided sticker, onto which the selected cut off frequency can be written.
A set of FILER/FLAT switches (1-3) placed on the external panel of the card are used to bypass the action of the
filters, so the power amplifiers can be used both for bi-amplified applications and as full-range units. The HP/LP
switches (2-4) let you decide whether the amplifiers should operate on the low frequencies (LP) or high frequencies
(HP). This can be set independently both for the host amplifier with the UCM 20 card and the amplifier connected to
the unbalanced “EXT. AMPLIFIER OUT” (5-6)
INPUT SENSIBILITY
Input sensibility can be adjusted from 0dBV to +6dBV with a set of jumpers found on the card and following the
instructions printed on the card chassis. This setting affects both the host and the external amplifier and is always
active, regardless of the position of the “FILTER/FLAT” switches (1-3).
INSTALLATION
1. Disconnect the amplifier from mains supply
2. Unscrew the top cover and the blank panel on the rear of the unit
3. Remove the two jumpers of the connector found on the input stage of the amplifier. Save the jumpers and the
blank panel. You will need them in the future if you decide to use the power amplifier without the filter again.
4. Insert the filter into the slot of the rear panel and connect the filter cable (see diagram)
5. Screw the Filter and the top cover to the chassis.
CAUTION: The installation of the filter should be performed by a qualified technician.
