Drawmer SL22 Sound Level Limiter - Manual (Page 6)

6
AUDIO CONNECTIONS
The inputs and outputs are electronically balanced on conventionally wired XLRs (pin 1 screen, pin 2 hot, pin 3 cold
and XLR shell is connected to chassis). Balanced use is recommended.
• Interference:
If the unit is to be used where it maybe exposed to
high levels of disturbance such as found close to a
TV or radio transmitter, we advise that the unit is
operated in a balanced configuration. The screens of
the signal cables should be connected to the chassis
connection on the XLR connector as opposed to
connecting to pin1. The 4X4 conforms to the EMC
standards.
• Ground Loops:
If ground loop problems are encountered, nev er
disconnect t he mains earth, but inst ead, try
disconnecting the signal screen on one end of each
of the cables connecting the outputs of the 4X4 to the
patchbay. If such measures are necessary, balanced
operation is recommended.
The front panel has a plate on the front under-which the
two calibration controls sit. This is secured using M3
TORX tamperproof screws. A screwdriver is supplied to
remove this plate, as well as a tamper-proof label that
further secures the SL22’s settings. Once the front panel
security plate has been replaced, after the calibration
process has finished, the label can be placed across so
that it adheres to both the plate and the front panel. If
the security plate is tampered with and the label touched
it will leave a ‘void’ identification, showing that the settings
have potentially been altered and that calibration must
be performed again.
SECURITY PLATE & LABEL
Drawmer have gone to great lengths to make the SL22
tamper-proof by incorporating the locking plate with
tamper-proof screws on the front. However, if the rear of
the unit, along with the power amplifier, were reconnected
then the protection system would effectively be bypassed.
For this reason Drawmer have designed the Tamper-
proof Bracket - trapping the XLR’s in place and making
it extremely difficult to disconnect them without removing
the bracket. This bracket could be specified in order to
conform to Local Authority noise abatement regulations.
Installation of the Tamper-proof bracket could not be
simpler: After setting up the SL22 as described in this manual, with the XLR’s in place, simply slide the Tamper-
proof Bracket over the rear of the unit, making sure that
the XLR cables locate through the gaps on the bracket.
Next, screw in to place at the four locating points (arrowed
below) using the M3 screws provided. Further protection
can be gained by fitting M3 TORX tamperproof screws,
to a maximum length of 6mm, the same as used on the
front, and utilizing the same tamperproof screwdriver.
In addition, for extra protection, both the SL22 and the
power amp should be locked in a rack, where access to
the rear is very difficult.
TAMPER-PROOF BRACKET