Supreme build-quality and... 8 tuning gangs !
The original Supreme 700T used only five but was built very differently - a little bit like Sony's ST-A7B and ST-A6B : the small one has more gangs but is (fairly) conventional, the big one has less gangs but is technically more original.
Original being the appearance of the Pulse Count Detector system :
"This new detector consists of a crystal oscillator, a mixer, a low-pass filter and a pulse counter. It has a perfectly linear bandwidth of over 3.92 MHz, compared with the near-linear 2 MHz, bandwidth typically found in competitive FM tuner designs.
Distortion components developed in this detector are so low that even if modulation levels were to exceed a full Megahertz in bandwidth (some ten times greater than the modulation actually used in FM broadcasting), total harmonic distortion would still be less than 0.05%.".
Read the TECH description for all about the 600T's inner mystique.
The Supreme series having been quite not too successful in Japan, the export Supreme 600T had a near-equivalent there : the KT-9700.
More precisely, the 600T is the export version of the 9700, with one differing function and adjusted looks to remain coherent with the (mainly export) Supreme series.
Instead of having the normal / 25us deemphasis switch and a push-type power-on button, the KT-9700 has an antenna A / antenna B switch and a switch-type power-on.
See the KT-9700 at the indispensable amp8.com.
The specifications are however fairly different, and the tuning range, too : Japan tunes in between 76MHz and 90MHz !
The official name, outside Japan, is Kenwood Model 600T, but Supreme is the sub-tag, as once carved into the front plates of the first production batch... in Japan !
See the large two-page schematiic of the Model 600T here.
And be sure to read FM Tuner website's info on both the 600T !