Williams Sound
®
Helping People Hear
9
I
NPUT
The input can be configured to accept three types of signal sources: Balanced or Unbalanced
Microphone, Balanced or Unbalanced Line, and 70 V speaker line. The input is configured to
accept various combinations of these inputs by means of the Audio Select switch. (See
Figure 3, page 8.)
PROFESSIONAL MICROPHONE
Most dynamic, ribbon, or condenser microphones equipped with a balanced output and a
3-pin XLR connector can be used. Power can be supplied for condenser microphones
according to DIN 45596. It can be turned off for dynamic and ribbon mics, though this is not
usually required. Microphones are connected in the normal industry standard pin
arrangement. The “in phase” signal conductor is connected to pin 2, the “out of phase” signal
conductor is connected to pin 3, and the shield is connected to pin 1 of the XLR connector.
Optimum performance is attained with 200
Ω
microphones.
LOW COST MICROPHONE
Most low cost dynamic or condenser (with an internal battery) microphones equipped with a
two conductor 1/4" plug can be connected if an appropriate adapter is used. A suitable
adapter is Radio Shack
®
part number 274-017.
BALANCED LINE
Any balanced line level source can be connected to the 1/4" jack or the 3-pin XLR input. The
Audio Select switch must be set properly. The “in phase” signal conductor is connected to
the Tip of the 1/4" jack or to pin 2 of the XLR connector. The “out of phase” signal
conductor is connected to the Ring of the 1/4" jack or to pin 3 of the XLR connector. The
shield is connected to the sleeve of the 1/4" jack or to pin 1 of the XLR connector. The input
impedance is approximately 20 K
Ω
and performance is improved with a low source
impedance. With most professional audio equipment, connecting the input directly to a line
level output is best.
UNBALANCED LINE
Any unbalanced line level source can be connected to the 1/4" jack or the 3-pin XLR input.
The Audio Select switch must be set properly. The “hot” conductor is connected to the Tip of
the 1/4" jack or to pin 2 of the XLR connector. The shield is connected to the sleeve of the
1/4" jack or to pins 1 and 3 of the XLR connector. If a Tip-Ring-Sleeve 1/4" jack is used, the
Ring must be connected to the Sleeve. Input impedance is approximately 20 K
Ω
.
Performance is improved with a low source impedance. With most professional audio
equipment, connecting the input directly to a line level output is best.
2
TO
16
Ω
OR
70 V S
PEAKER
L
INE
The T4 input can also be connected directly to 2 to 16
Ω
or 70 Volt speaker lines.
IMPORTANT: If you choose to connect to 70 Volt Speaker line, be certain to set the
Audio Select switch correctly. Transmitter damage will occur if you do not.
When making such connections, it’s very important to avoid creating ground loops. Pin 1 of
the 3-pin connector and the sleeve of the 1/4" jack are connected directly to the chassis.
Normally, one of these would be connected to the common output terminal of the power
amplifier connected to the speaker line. But in most installations, there cannot be an external
connection from the common terminal of a power amplifier to ground. To avoid this
Summary of Contents for PERSONAL PA Pro Wide-band System 275
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