Luxman's big push toward modern high-fidelity of the fairly affordable kind.
Probably Luxman's most coherent lineup, too, technically as well as visually.
All based on DC cicuitry with select temp-stabilized componentry, Super Class A (a variant of Class A/B to minimize notch distortion) and Real Time Processed to minimize transient distortion.
Souvenirs that would soon be integrated (and already were elsewhere) : separate peak level meter and parametric tone control units...
Souvenirs that would disappear everywhere : Dolby FM compatibility for the 5T50 tuner.
This wide 1976 lineup at first consisted of :
5C50 : preamplifier 160k¥
5M21 : power amp 240k¥
5T50 : fm tuner 220k¥
5F70 : tone control unit 86k¥
5G12 : equalizer 145k¥
5E24 : peak level unit 80k¥
...to which were added in '77 and '78 :
LK5000 : rack 79,5k¥
5L15 : integrated amp 168k¥
5M20 : power amp 210k¥
5T10 : fm tuner 108k¥.
5K50 : k7 recorder 280k¥
There also was a 5G11 in '78 (briefly), and a 5B21 Mos-Fet monoblock prototyped and shown at the JAF of october 1978 but finally not produced.
The four round spots on each LRS are to allow stacking the units without fear of imbalance or mechanical damage : feet and spots are linked by metal stoppers inside the enclosures.
Some wood enclosures were made, mainly for the USA and japanese markets - very rare.
Optionally and with luck aplenty, one could (try to) buy the dedicated (but unfindable) LK5000 rack and/or LB5000 blank black fronts in 1U, 2U and 3U heights.
However, at 79,500¥, that rack previsibly didn't find many buyers ; the closest you'll get to it is by looking at the november 1977 color ad below. The small rack shown here in b/w wasn't produced at all.
Luxman would produce many other lineups bearing the Laboratory or Reference tags (or both, or anything in between) but this was the original, still under sole Luxman ownership.
Depending on country, most of these components remained available well into the 1980s and sold very well - except the eq, meter and tone units, previsibly.
None of these saw equivalents in the Luxkit lineup : Luxman, for once, made it almost simple.
The original LRS components were however also planned to be released in black-is-black style but I have never seen any...