While the 7000 had a similar face plate and chassis as the Eight, it is not a model in the "Single Digit Series" (Eight, Seven, Six, and Eight Deluxe). The 7000 is a cap-coupled receiver in the X000 series, whereas the single digits are direct-coupled. The 7000 is the highest powered cap-coupled receiver Sansui produced.
I am wondering if there is anything under those covers on the side and what material the covers are made of? On the Eight and Eight deluxe they cover the OTs and are machined aluminum.
Some say this, others say that. The 7000 has been created - that's what old experts say - to save costs. Because Eight and Eight deluxe have been very cost intensive. Too much costs, to less profit. For me, regarding the models in detail, this is conclusive.
This is what I know, as just a simple collector of receivers: In 1970, Sansui launched two new receivers, among others: the Model 7000 and the Eight. While they look very similar, they are quite distinct. None of the circuit boards used (all designated F-XXXX by Sansui) are identical, and it quickly becomes apparent that the Eight is the older design, as all the board numbers are lower than those of the 7000. They also differ in their technical specifications: the Eight weighs 2 kg more than the 7000, which was rated at 2 x 100 watts RMS into 4 ohms, while the Eight was rated at "only" 2 x 80 watts. The input sensitivities of the FM sections also differ significantly: 1.8 µV for the 7000, but even 1.25 µV for the Eight. The price difference between those two receivers was only 200 DM in Germany (exchange rate: German Mark DM3,70 has been 1$) with the Eight being the more expensive model. It cost a hefty 2,840 DM (around $768). Furthermore, the 7000 offers a microphone input that can be mixed into all programs via the front panel. The Eight doesn't have this feature, but it does have a volume control for speaker group C and level controls for radio playback on the rear panel to match other sources. What prompted Sansui to offer two such similar devices on the market simultaneously will likely remain a mystery. It's certainly interesting, though.
The side covers of the 7000 are made of aniodized, extruded black aluminum. The Eight has the same, only another color. The covers of the TO3's are made of plastic. Bottom, seide panels, front, cabinet are interchangeable. Beside the fact, that there had been three different versions of the cabinet. The unique, two part, dial-mechanism is the same.
I didn't compare it yet with the Eight Deluxe - as this unit still is waiting to be revitalized.