Справочное Руководство для Crown studio reference i

Page 14

Studio Reference 

IIIII & II

  Professional Studio Amplifiers

3.3.4 Input Connection
The balanced inputs have a nominal impedance of
10 K ohms (5 K ohms unbalanced) and will accept the
line-level output of most devices. Phone jacks are pro-
vided on the back panel, while the factory-installed
P.I.P.-FX provides female XLR input connectors (see
Figure 2.2). Optional 

P.I.P. modules like the P.I.P.-BB

and the P.I.P.-FPX can provide barrier block and
phono (RCA) connectors. Various 

P.I.P.s are also avail-

able which provide a wide range of input signal pro-
cessing features (see Section 8).

Correct input wiring depends on two factors:
(1) whether the input signal is balanced or unbal-
anced, and (2) whether the signal floats or has a
ground reference. Figures 3.8 and 3.9 show the recom-
mended connection techniques for each combination
of source signal characteristics.

2-wire line cord

(or battery power)

Note: If two or more channels with

the same input ground reference

are driven from the same

floating source, connect

only one shield to the

source chassis.

3-wire grounded line cord

(or other ground connection)

Shield not connected
at this end

Output

Output

Fig. 3.9  Balanced Input Wiring

The amplifier’s built-in 

1

¦

4

-inch input phone jacks can

be wired similarly for balanced or unbalanced, floating
or ground-referenced sources. They have a standard
tip-ring-sleeve (TRS) configuration: the tip is positive
(+), the ring is negative (–) and the sleeve is ground
(see Figure 3.10). Wiring for various sources follows
the XLR wiring examples in Figures 3.8 and 3.9.

If you install a 

P.I.P. module other than the P.I.P.-FX,

P.I.P.-BB, P.I.P.-FMX or P.I.P.-FPX, do not connect in-
put signals to the phone jacks. The phone jacks are in
parallel with the output of the 

P.I.P. module, so the

source connected to the phone jacks can feed into the
P.I.P. and generate a distortion in the output. The
phone jacks can still be used as “daisy chain” outputs
to feed the post-processed signal from the 

P.I.P. to the

input of other amplifiers.

If the amplifier will be used in Bridge-Mono or Parallel-
Mono mode, be sure to follow the instructions provided
in Sections 3.3.2 and 3.3.3. Do not use the channel 2
input in either mono mode.

Fig. 3.10  Balanced and Unbalanced Phone Plugs

Fig. 3.8  Unbalanced Input Wiring

2-wire line cord

(or battery power)

Shield connected
to ground terminal

3-wire grounded line cord

(or other ground connection)

Shield is not
connected
at this end

3-wire grounded line cord

(or other ground connection)

Input ground
terminal not used

2-wire line cord

(or battery power)

Shield connected to both
negative (–) and ground
input terminals

Output

Output

Output

Output