First system when I was around 13:
-Panasonic AM/FM/TAPE/RECORD combo unit with a pair of matching speakers. The speaker wires connected to the head unit via phono RCA and there was no auxilary input so I connected a Sony boombox to a tape adaptor. I thought it sounded good at the time.
When I reached 15 I got to rework my entire system:
-Denon PMA-300v Pre-Main Amplifier (yes, it actually said that on it). Denon has used the acronymn PMA at the begining of most of their integrated amplifiers. Nice little amp when it worked, rated 55 watts per channel.
-Jensen C-JR bookshelf speakers, purchased brand new from Circuit City with my puny allowance. Thought they sounded so awesome compared to the Panasonic speakers in the simulated wood cabinets.
-Sony D-E301 Portable CD player. It had a line out on the back of the unit as well as an included AC adaptor. I received this as a brand new gift, so you could guess my age within the range of a year or so (should have lied and said my first CD player was a Magnavox CD-560 so I could conceal my true age).
All pictures above are examples, not my actual equipment. Odly enough I got another Sony D-E301 for nostalgia and I got my Jensen C-JR bookshelf speakers back.