DC 243 Professional Series
DIGITAL ACTIVE STEREO CROSSOVER
GENERALITIES
The DC 243 is a two way crossover (BASS-TREBLE) plus
output SUB mono especially designed for professional
multiamplified systems.
The crossover frequency BASS-TREBLE is variable in 16
positions from 60 Hz to 3 kHz whether for the right channel
(CH R) or for the left one (CH L).
The filters adopted are Linkwitz-Riley type with gradient of
24dB/octave: this ensures an efficient protection of the
transducers employed, in particular of the trumpet driver
which could be stressed from too lower frequencies if the
tone is not correct.
The frequency of the tone of the sub is fixed at 100 Hz with
a gradient of 12 dB/oct.
The sections BASS, TREBLE and SUB of each channel
provided with independent level controls, makes the
LIMITER work and checks PHASE.
The input level can be internally selected by means of
JUMPER, between 0 dB and +6 dB (removing JP1 and JP2 it
becomes +6 dBm, see Fig.4).
It is also possible to add an internal equalisation card with
4i parametric equalisers.
The unit can be supplied complete with back closure panel
to prevent undesired manipulation.
POWER SUPPLY
This machine has been made for use with a power supply
of 230 Vac 50/60 Hz.
The auto-reset protection fuse is situated inside.
INPUT AND OUTPUT
On the back panel there is the input of the LEFT channel
and the RIGHT channel for the amplification system
connection. The connectors used are Cannon XLR with
three poles.
The line output BASS, TREBLE and SUB, provided for the
respective connection to the all low and high sections,
adopt the connectors Cannon XLR with three poles. Both
the input and output are electronically balanced.
CONTROLS AND FUNCTION
On the back panel of the equipment there are the
following controls (Fig.1):
1) POWER INDICATOR
A light signals that the unit is on.
2) OUTPUT LEVEL CONTROLS
Independent level controls for the BASS, TREBLE and SUB
sections.
3) LIMITER
When the output level exceeds the value set by the level
check by 6 dB, the limiter device intervenes limiting this
going over the threshold.
When the LIMIT light is on it signals the threshold has been
exceeded, with consequent limiter intervention.
When the SIGNAL light is on it indicates, however, the
presence of an output signal.
4) PHASE REVERSER
The unit is provided with a PHASE-REVERSE for the signal
phase inversion of the TREBLE section.
5) FREQUENCY SELECTOR CROSSOVER
By means of the digital commutator visible on the front
panel, the crossover frequency is selectable in 16 positions
from 60 Hz to 3000 Hz.
6) PHASE CHECKS
The unit is provided with a potentiometer for the phase
regulation with continuity from 0°to –180°in the BASS.
7) PHASE ALIGNMENT
For the sub output you have the insertion of the phase
alignment with the bass and relative led.
TECHNICAL FEATURES
Crossover frequencies 60, 80, 100, 125, 150, 200, 250,
300, 600, 800, 1K, 1.2K,1.5K,
2K, 2.5K, 3K
Input sensitivity......................0dBm (0,775 V)
Input impedance...................44Kohm (bal)
Max input signal...................+20dBm (7,75 V)
Nom. Output level ................0dBm (0,775 V)
Max output level ...................+20dBm (7,75 V)
Output impedance................270 Ohm
Ratio S/N ............................... >90dB (lin.)
Distortion................................0.03%
Frequency response ............20Hz÷30kHz ±0,5dB
Dimensions (LxHxP)...............483x44x125 mm (1 unity rack)
Weight....................................3 kg
Table: Crossover Frequencies
Posit. Crossover frequency
0 3 KHz
1 2.5 KHz
2 2 KHz
3 1.5 KHz
4 1.2 KHz
5 1 KHz
6 800 Hz
7 600 Hz
8 300 Hz
9 250 Hz
A 200 Hz
B 150 Hz
C 125 Hz
D 100 Hz
E 80 Hz
F 60 Hz
