Congrats! This is the top 'black pastic' panny, also the best one from the Panasonic Platinum collection (based on what other people say, I have not heard the CT-990). Better than cobras, but mainly more durable. I had it for a few weeks and enjoyed it, although my preference is for single-piece black plastics, especially the RX DT8 (Japanese domestic model) because the bass is tighter and the volume is even more massive. But the DT680 is great too, indoors of course as there is no open back here. CD output is awesome and very loud. It is very nice in design too.
It has a CD but does not have a Line-in. But there is a mod that can be done fairly easily to create your own Line in. I have the instructions somewhere if you are interested - it takes very simple soldering and you can hijack the tape line. Otherwise, if you don't want to modify, you can also work around it as it is and play Line-In signal through the Line Out Aux connections for the CD, by playing a Data CD (not a music CD) - you need to try a few different CDs to see if it works; I think for me what worked was one of those half-size CDs with software on them.
Another mod I was going to do but didn't manage to was some acoustic dampening inside the plastic speaker cabinets - some acoustic foam or even bubble wrap to try to reign in the booming bass.
As for maintenance, the main thing is to clean and relube the mechanisms and belt change if needed (my Panasonics have very durable belts) - but also one yellow brittle gear in the tape mechanism which gets old and starts losing teeth. Mariyan from fixyouraudio has replacement gears. I think all Panasonic boomboxes of those years use a similar tape mechanism with this brittle gear. You will hear it click if a tooth is broken; sometimes is clicks only in reverse. Luckily, it is only one gear wheel per deck.
Enjoy the sound, this one is rated as approaching hifi area and it's a very nice design for a black plastic. It was also one of Reno's favourite boxes - it rivals the JVC m90 indoors; different sound signature but good quality loud sound.
