An extra-rare item outside Japan but a very common hothouse flower in Tokyo, Yokohama and Matsuyama. Just like the hothouse it followed the tracks of - L-570.
Part of the true peak of the Alpine period, the M-06 and M-06a sold like hotcakes. And they are magnificent. And they are excellent.
From afar looking like a beefed-up M-03, inside is a very different landscape : pure hot Class A produced by a large toroidal trafo, a dual Heat-Pipe and two pairs of... unknown transistors.
Unknown because 1987 is the beginning of the "blank" Luxman era : large poetic landscape, tiny detail images and not much beyond that.
The M-06 and M-06a have "ultra" parts : nitrogen gas-filled relays, a second transformer just for the digital display and circuits, PC-OCC wiring throughout (including bus bars !), fixed-resistor attenuators with a real off position ("direct"), two monster 18,000µF / 50V / 85° Hitachi main caps, complete stability down to 2 Ohm, really balanced inputs and a front machined with Luxman's own custom CNC deck.
The dimmer function allows three brightness levels plus off (entirely off : the dedicated transformer is shut).
When on, it shows the output power per channel, with selectable 1 /3 /5s peak hold and 4 /6 /8 Ohm impedance.
Visually, the 06 still bears the codes of the 1980s Alpine with two front side-stoppers while the 06a has rounded top corners. The inputs pots are on the 06 round and protruding knobs (reused later for the entire L-570 series), identical to the other three for the 06a, as shown here (but the nudie is a 06).
Otherwise, as for the L-570X's and L-570Z's, real differences between 06 and 06a ("a" for "alpha") reside in parts upgrade : polystyrene-copper caps, customed wiring and abundant copper shielding etc. A 50,000¥ custom / hand-made upgrade !
Both versions can become monoblocks but the 06a sold better ; the M-05 replacement was the M-07.
The M-06 only saw an Alpine T-Tag ; the M-06a's last batch had an Azden T-Tag.
A real M-06 here ; a real M-06a here.
M-06a nudies amillion at the indispensable amp8.com.