For me, it was a totally sensual - not sexual - experience. It wasn't just utilitarian, it *invited you* to touch it, become part of it if only just for a moment.
That experience was cheapened quickly in the late 80's / 90's, with cheap-a** membrane buttons and gawdy led's and so forth. It was simply too costly to do it like they did in the 70's. The invitation to play was lost.
You took it new out of the box, preferably after you had fondled it with a live demo, and the senses go nuts. You didn't even have to play music through it.
So it looks good, but more importantly to me FELT good - silky smooth tuning or perhaps well lubed detents, the push of brushed aluminum buttons, made even more sensual if you could feel the ridges in the brushed aluminum when toggled. (stop laughing!)
After you fire it up comes that gorgeus perfume of new electronics (and perhaps the wood surrounds) wafting from the vents to you across the room.
So yeah, I've relived that with my beloved Sansui days. Then it came time to recap, send it to a pro for alignment, yadda yadda.
It's different now. I don't *need* that kind of sensual involvement with my gear, but I sure do remember how it made me feel. I miss it truth be told.