After the gain in size and multiple functions of its preamps throughout the 1980s (CX-1000, CX-10000), Yamaha went slim-line again with two versions of the same preamp :
strictly audio (CX-1) and conveniently audio-video (CX-2).
Both were part of the ToP-ART series : Total Purity Audio Reproduction Technology.
The CX-1 uses a very beefy trafo, select parts (Elna Duorex and Great Supply), all-ALPS pots, of which the motorized volume is a 4-gang, a model used in manymany components of the time.
However, there is only one single PCB holding everything from phono to power-supply... ToP-ART had its limits.
But the pre-out is a low 47 Ohm - good.
Anyway - pretty rare, perhaps due to a fairly uninviting design, but the CX-1 is Yamaha's last strictly 2-channel preamplifier and still worthwhile.