Hafler SR2300, Owner'S Manual

Page: 17 / 40

– 15 –
FLOATED EQUIPMENT
Units with a 2-pin mains power cord have no means to connect the audio output ground to earth ground, so usually the
audio output ground is floated from earth ground. However, this does not insure that when installed in a system, the audio
output ground will remain floated from earth ground. The input cable to this equipment may already be connected to earth
ground earlier in the audio chain, and it will typically be carried straight through to the output. It is also possible that the
audio output ground connects to the earth ground through the chassis to an earth-grounded rack. The only way to know for
sure is to test the installed system. Use an ohmmeter to check for continuity between the earth ground socket of the mains
power receptacle and the audio output ground. If the audio output ground is not connected to earth ground, it is floated
equipment.
Consult the following diagrams for examples of recommended wiring techniques:
The output XLR jack accepts a female XLR plug and provides a hard-wired pass-through of all 3 pins of the input jack.
LEVEL CONTROLS
The gain for each channel can be controlled individually using the front panel level control. The controls have 32 detented
positions that are calibrated in dB. The maximum gain position is marked as the "0 dB" position, and the lower gain posi-
tions indicate the amount of attenuation relative to the maximum gain position in dB. Minimum gain position is marked as
“Off” and represents over 100dB of attenuation relative to the maximum gain position.
The CH B level control is used for all Bridged Mono configurations, and 100V and 70V modes (Except for SR2600 Dual
Shield
Chassis
Audio
Ground
XLR, 1/4" Mono Amplifier
1/4" Mono: sleeve shorts
— input to Audio Ground;
XLR: short pins 1 & 3 together
COAX OR TWISTED PAIR
FLOATED,
UNBALANCED
SOURCE
2
3
1
Shield
Chassis
Audio
Ground
XLR, 1/4" TRS Amplifier
SHIELDED TWISTED PAIR
FLOATED,
UNBALANCED
SOURCE
shield connected at both ends
1
3
2
Shield
Chassis
Audio
Ground
XLR, 1/4" TRS Amplifier
SHIELDED TWISTED PAIR
FLOATED,
BALANCED
SOURCE
shield connected at both ends
1
3
2
Shield
Float
Audio
Ground
XLR, 1/4" Mono Amplifier
1/4" Mono: sleeve shorts
— input to Audio Ground;
XLR: short pins 1 & 3 together
COAX OR TWISTED PAIR
GROUNDED,
UNBALANCED
SOURCE
2
3
1