It was a stereo-sized block of well-polished ebony. There were no plugs, speakers or displays, and there was only a single control: a dial labelled "Silence" which scaled from zero to eleven.
"The latest revolution in home sound systems," he said proudly, "Is noise-free high fidelity. The 433SX Elite guarantees no static, no feedback, no interference - perfect sound fidelity."
"But isn't it just a -"
"Too expensive? Maybe, if you're not serious about your silence. But if you want the best - if you're really someone who appreciates peace and quiet - then this is the stereo for you."
"Couldn't I just use a different stereo, and turn it off?" I asked.
He looked shifty and nervous. "Uh..." He fumbled with something in his jacket for a second or two. "Well, uh. No. No, you couldn't."
So I bought it.