VT-I/F Vacuum Tube Instrument Interface
D.W. FEARN
16
The OUTPUT connectors (4) are XLR-3 male wired according to AES standard:
pin 1 is ground (shield), pin 2 is “high” or “+,” and pin 3 is “low” or “-.” The out-
put is transformer-balanced. The output level is a nominal -30 dBm. This is some-
what higher in level than a typical microphone.
Grounding and Shields
A full discussion of proper studio wiring schemes is beyond the scope of this
manual, but, in general, the shield should be connected to pin 1 of the output con-
nector. The shield should be connected to ground at only one end; however,
although not recommended, the shields can often be connected at both ends with-
out a problem.
