User guide
821667: VAMP2 Series User Guide
© 2012 Wohler Technologies, Inc. All rights reserved.
20
VAMP2 Series User Guide
Rear Panel Connectors
Figure 1–5 Balanced AES In with Loop Out
DB-25 Connector Pin-Out
• RS-232 #1 (DB-9): This connector provides an interface for 
downloading the user interface, unit functionality, AES 
programming, setup, and diagnostic information into and out of the 
unit.
• AES Input Termination (DIP Switch): Termination for both pairs 
(AUX 1 and AUX 2) of the AES inputs (AES IN, 1 or 2) is adjustable 
through the four-position DIP switches located between each pair of 
input connectors. The switch section nearest the associated 
connector sets the termination for that connector. Move the switch 
down (75 , balanced; 110  unbalanced) to terminate the 
connector, or up (HI Z) to unterminate. See Figure 1–6 below and 
Figure 1–7 on page 21 for switch ID settings. 
Figure 1–6 AUX 1 - AES Input Termination
AES1 AES2 AES1 AES2 AES1 AES2 AES1 AES2
AUX 1
AUX 2
AUX 1
AUX 2
AES Input
Loop-Through 
Output
1234
Up: Unterminated
Down: Terminated
AUX 1, AES 1 Balanced
AUX 1, AES 1 Unbalanced
AUX 1, AES 2 Balanced
AUX 1, AES 2 Unbalanced










