User manual

Operating Basics
2-32
AM700 Audio Measurement Set User Manual
single-ended loads. The generator output level driving an unbalanced load will be
half of the indicated value (6 dB less), and the source resistance will be half the
selected output impedance value. For example, if the selected output impedance of
the generator is 10 Ω, the single-ended output source impedance is 5 Ω nominal.
The proper output connections for driving an unbalanced load are made using pin 2
(the + output) as the hot lead and pin 1 (shield) as the common lead as shown in
Figure 2-23. No connections should be made to Pin 3 (the – output).
NOTE. If pin 3 of the XLR analog generator output connector is connected to
common, internal circuitry will current limit, but no damage will result. If pin 2 is
connected to common, the – signal at pin 3 will be reduced or muted, especially if
the 10 Ω source resistance is selected. There is no need to connect pin 3 when
driving an unbalanced load with the AM700.
Pin 3 (NC)
Pin 2 (+)
Pin 1 (shield)
Unbalanced
load
Hot
Shield tied to
common at the load
Figure 2-23: Driving an unbalanced load with the AM700 generator