Proel HPD2004 - Manuale (Pagina 13)

13
8. INPUT
This is a female combo connector, which accepts a XLR or a JACK plug from almost any type of equipment with a
balanced or unbalanced outputs. The XLR input is wired as follows:
Pin 1 = shield or ground
Pin 2 = + posi ve or "hot"
Pin 3 = - nega ve or "cold"
The JACK input is wired as follows:
Tip = + posi ve or "hot"
Ring = - nega ve or "cold"
Sleeve = shield or ground
When connec ng an unbalanced signal, wire them as follows:
Pin2 / Tip = + posi ve or "hot"
Pin 1-3 / Sleeve = shield or ground
NOTE: whenever possible, use always balanced cables. Unbalanced lines may also be used but may result in noise over
long cable runs. In any case, avoid using a balanced cable for one channel and an unbalanced one for the other.
9. LINK
This is a male XLR connector, it is connected in parallel with the respec ve INPUT, so the LINK is wired at the same
way.
10. GND LIFT
This switch li the ground of the balanced audio inputs from the earth-ground of the amplifi er. If you have HUM noise
problem on one or more loudspeaker try to change the posi on of these switches.
11. GAIN
Allows the selec on of the amplifi er gain.
For HPD2004: when se ng a sensi vity of 0dBu (0.775Vrms) the gain is 35dB (56x), when se ng a gain of 32dB (40x)
the sensi vity is +3dBu (1.09Vrms).
For HPD4004: when se ng a sensi vity of 0dBu (0.775Vrms) the gain is 38dB (80x), when se ng a gain of 32dB (40x)
the sensi vity is +5dBu (1.38Vrms).
NOTE: The fi xed GAIN of 32dB is a useful feature to set a complex loudspeaker system using a loudspeaker processor:
in fact having a fi xed gain the calcula on of limiters is simplifi ed. See the manual of your loudspeaker processor for
details.
12. STEREO / BRIDGE / PARALLEL
Allows the selec on of STEREO, PARALLEL or BRIDGE mode opera ons.
• In STEREO mode each amplifi er channel pair runs independently driven by respec ve input (see EXAMPLE A).
• In BRIDGE mode the amplifi er channels pair runs together but with channel 1 or 3 in phase and channel 2 or 4 out
of phase. The channels pairs are driven by Channel 1 or 3 input and the output must be taken from "BRIDGE" speakon
output (see EXAMPLE C, D).
• In PARALLEL mode both amplifi er channels pair run together driven by Channel 1 or 3 input (see EXAMPLE A, B, E).
NOTE: use this se ng if your inten on are to use the BI-AMP feature also.
13. HPF / BI-AMP / FLAT
This useful switch allows the selec on of one of the following features:
• In HPF enables a 100Hz LR-24dB/Oct. High Pass Filter for both channels 1-2 or 3-4: this a useful feature for SAT-TOP
SPEAKERS or STAGE-MONITORS (see EXAMPLE C).
• In BI-AMP enables a Linkwitz-Riley crossover 24dB/Oct. at 100Hz between channel 1/3 and channel 2/4, then allows
a single amplifi er without a dedicated processor to drive a SUB-WOOFER with channel 1/3 and a SAT-TOP SPEAKER with
channel 2/4 (see EXAMPLE B, D, E).
• In FLAT no fi lters are inserted in the signal path (see EXAMPLE A).
14. Channel 1 or 3 SPEAKON output
Accepts a male Neutrik Speakon NL4FX connector wired in this way:
• PIN 1+ connected to POSITIVE output of Channel 1/3;
• PIN 1- connected to NEGATIVE output of Channel 1/3;
• PIN 2+ connected to POSITIVE output of Channel 2/4,
• PIN 2- connected to NEGATIVE output of Channel 2/4,