Greg Hanks Design BA-660, Руководство по эксплуатации и обслуживанию

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BA660.doc 01/01/97 7 of 25
NOTE-
The circuitry associated with the
insert send and return is
bypassed when not in use,
(the bypass circuitry senses
either the presence of a
jack in the insert return
connector or the position of
the front panel switch.
When active, this circuitry is
the limiting factor in the
system headroom
.
•
Insert Return
Nominal signal level of +4. Located
at the input of the gain cell, this is the
input of the limiter, bypassing the
mic preamp and associated circuitry.
Input is balanced. See above note
regarding headroom. This signal is
normalled to the side chain input
•
Side chain input
Nominal signal level of +4, balanced
input, normalled source from the
insert return circuitry. Provides access
to the control circuitry for use in De-
essing or Ducking.
•
Side Chain Couple
Provision for coupling multiple units.
Both source and input are carried via
this port, and the signal at this port is
the active DC control line. The
signal(s) are summed on this port and
it should only be used with other
BA-660 limiters. The protocol for
direct operation of the gain cell is
available upon request from the
manufacturer.
•
Line Output
The line output is a balanced and
floating solid state class A type power
stage that can have either leg taken to
ground without degradation of either
headroom, gain, distortion or noise.
Care must be take however to select the
correct polarity to be grounded with
the Un-Balance switch on the rear. The
ground will be taken at the output of
the unit, and should not be take at the
input to a single ended device. Rather,
wire as balanced and have the single
ended input pick up it's reference from
the output of the BA-660. The shield
is source’d at pin 1 of the XLR. Pin 2 is
wired as plus (+) and Pin 3 is wired as
minus (-)Chassis
•
Chassis Gnd (Green)
The chassis ground connection
provides the ohmic contact to the
enclosure of the BA-660. This signal is
also the conductor present at pin 1 of
both the line in and the line out.
Inside, this line is tied directly to the
3rd pin of the IEC Power entry
connector. When the unit is operated
with the 3rd pin of the AC cord
connected, The link that is supplied
should be used to connect the signal
ground and the chassis ground
together. In this configuration, no
other studio grounds should be used.
•
Signal Gnd (Black)
This is the ohmic contact to the
technical earth of the BA-660 and ties
via a #12 cable to this point. If any
studio grounds, aside from the 3rd pin
of the power cord are supplied, they
should be referenced to this binding
post. The link should be removed
when the 3rd pin is attached as well as
the studio ground wire. If the 3rd pin is
not attached, and the link is lifted,
severe hum is likely. There is a small
degree of safety provided by 2 cross
shunting diodes and a .047
µ
cap that
internally ties these two points together.