An electronic record/play switch with low noise low input impedance preamplifier

摘要

An electronic preamplifier assembly is specifically configured so that it can be directly interchanged with existing mechanical relay/preamplifier assemblies such as those presently in use in recorder/reproducer apparatus having dual function record/playback heads, without disturbing the associated operating parameters of the record or playback channels. The electronic preamplifier assembly includes a balun transformer (40) and solid state switch means (42) coupled from a record amplifier to the record/playback head(12) via a rotary transformer (14) to define the record channel. The playback channel includes diode bridge switch means (46) and a preamplifier circuit (50) also coupled to the rotary transformer (14) and the head (12). The playback channel is electrically isolated from the record channel, and vice versa, by the solid state switch (42) and diode bridge switch means (46) in response to a select play/record mode signal (44) applied thereto.