> Many digital audio devices are now using a class D amplifier for power
Oh, in that case, one should seek out an old Boombox, before Class D amplifiers existed. For example, my computer speakers use an old "CD Receiver" from TEAC connected to passive speakers, and that's not a problem at all for me. And my living room stereo uses a Class A amplifier from Creek, also no problem.
Right now I just have the computer and it's not really very loud speaker to even hear the music -the speakers do not work and I have headphones hooked up that are about the same as the speakers from a about 7 feet off any white noise or doing something and can't hear it. I have an RCA AA battery discman just so I can have some music. The last boom box I had a few years back was so cheaply made and junk the buttons quit and it got shipped to square trade after not much use. I had originally planned to get an old Kenwood car CD deck and have it modified w/ a DC plug and speaker hook ups to plug in the Bose cubes, but I just do not have the power or $$ for such a thing. So much is bluetooth now it's harder to find options. I do not have power to spare either if I did get better computer speakers to leave it playing music when I am not on it.
I have had some nice little shelf units in the past, but they run on 120v. The CD player was always the first to go and I would be back at the luxury stereo showroom for another. The guy at the desk would always come out and try to sell me a disman to plug into the RCA jack-he did this at home w/ his Bangs and Ofson and after the 2nd pricey shelf unit I gave into his idea. Powered through the shelf unit sounded as good as the original player. I wonder if maybe an old boom box that has RCA jacks for an AUX item and plug in the discman. My plugs are DC so will not take a shelf unit. A thought.
PS again: in 2010 all wahers and dryers came w/ smart chips. Smart meters are rolled out just everywhere. So all electronics and anything that plugs into the wall will eventually be "smart". I am not sure that is the case w/ DC stuff that is not made to be used w/ the grid. I can well imagine that a new boombox from the store would have a transmitting RF chip blasting away. Something to check.