Transformer isolated 4?, 8?, 16?, 25V and 70V taps
Rear panel auxiliary receptacle
One dedicated MIC 1 input — Lo-Z balanced
One switchable MIC 2/Aux 1 input
Contact muting of Aux input
Transformer-isolated 600? telephone paging input
Separate rear panel-mounted TEL volume con- trol
Voice activated muting of Aux input by Tel input
Variable trigger threshold for voice activation