2001 Wohler Technologies, Inc. ALL rights reserved
2
II.
OPERATING
INSTRUCTIONS
Connect the AM-2B power cord into a grounded 3-pin AC mains power source. If there is
any doubt as to which mains voltage the AM-2B is wired to accept, please refer to the power
transformer wiring details on the AM-2B "Chassis Wiring" schematic and verify that the
power transformer is wired correctly for the local mains voltage standard.
Audio left should be cabled to the rear panel connector labeled CH-1 and audio right to CH-
2.
Proper connection can be verified by supplying a continuous tone of known correct left/right
phase and amplitude to the AM-2B. This will produce a stationary line on the scope along
the "IN PHASE" vector. The phase vector angle displayed is a result of phase and
amplitude. So only a test tone, which has correct phase and equal amplitude left to right will
produce an "IN PHASE" display vector. If in doubt about the phase accuracy of the test
signal, it is best to fabricate a "Y" cable and drive both AM-2B input channels with the same
test tone signal source momentarily to verify proper AM-2B phase display.
The test signal of known amplitude can also be used to verify that the AM-2B is still
calibrated to studio standards on the VU and LED meters.
The AM-2B is useful to inspect the phase integrity of all studio equipment. Not only tape
machines, but also other devices such as audio mixing boards introduce sometimes-
surprising phase errors, for example.
