Fisher's first integrated stereo amplifier. Earliest version with ganged tone controls. This one actually follows the Sam's schematic for it (for the most part), where as later versions deviated significantly from it, with Sam's never providing an updated schematic for the later versions . Lots of early stereo standards hadn't been sorted out at the time of manufacture, so there's no Tape Monitor switch, but provisions to monitor one channel were made through the use of a special monitor interconnect cable that could be plugged (or not) into the single, special Monitor jack offered. The monitor cable was special in that it had a long pin RCA plug on one end, so that when inserted into the special monitor jack on The Fisher, the internal signal path was automatically broken, and the monitor signal inserted in its place. Surely a cumbersome way to monitor a 3 head mono recording deck, but it must be remembered that stereo recording decks didn't even exist at that time, and 3 Head mono decks were so rare as to be virtually non-existent at the time as well. So even in this primitive state, the monitoring feature of the X-101ST was ahead of its time. LP and 78 EQ only appears as a single input in the left channel, with RIAA 1 and RIAA 2 having different input impedances to accommodate the wide variety of non-standardized magnetic cartridges of the day. No doubt it's a great sounding unit. But besides its restoration (and depending on your use plans), you'll have to familiarize yourself with its early stereo features to gain maximum enjoyment from it.
Good luck with it!
Dave