Beautiful and bestselling preamplifier with a ten-year production run.
Since transistors are current-amplifying devices, at the center of the P-L10 were Gm Processors : transforming voltage into current to amplify it and converting it into voltage again.
This engineering slant should sound familiar to Sony heads : Sony at about the same time put ACT (Audio Current Transfer) in the TA-F555ES, TA-F777ES and the ST-S555ES tuner.
This vanished after 1985 for Sony but JVC kept it throughout its top lineups until the late 1980s...
Gm Processors were here used where it counts most : the volume attenuator.
To avoid limiting frequency response or adding noise and distortion, the attenuator isn't in the signal path : the pot merely sets the voltage-to-current conversion ratio so that the amplifier itself adjusts the gain.
Gm Processors were also used where it counted most then : in the phono stage. The system there has the same structure as that of the attenuator, sans attenuator - see image #5.
Phono inputs are two, with a vast array of load and resistance settings for the Phono 1 (load only for the phono 2) allowing the use of ultra-low output MC cartridges.
Componentry was (as time has proven) refined but reliable : high-stability metal-film resistors, low-noise Zeners, silver-foil clad contacts and unetched capacitors.
The hidden controls aren't plethoric but nevertheless allow dubbing and monitoring, changing some of the tone balance and recording a source while listening to another.
The display of the secondary functions used is equivalent to the A-X9 : a semi-reflective shiny strip partly hides the scripting of the unused functions but those used actually shine through in green.
Actually very pretty (and clear) in the dark, not so much during the day as the unused functions' scripting remain darker than the others - and therefore more immediately visible :)
At a time when Kenwood (L-08M) or Pioneer (C-Z1a) were trying sci-fi designs, Victor crafted magnificent enclosures made of real rosewood trims and 21 lacquering steps. And sold much more than the others put together.
Wise hi-fi of the discrete kind - Victor !