Trash Day Curbside Find - Panasonic RX-DT770 Boombox - Page 1
Forum section: electronics / general

author: edy
author_rank: Super Contributor
timestamp: May 04, 2023, 02:41:17 pm
content: I found this Panasonic boombox next to the curb on trash day. It belonged to a neighbor down the street, mixed in with their other items (they are moving and probably cleaning out their old stuff). I figured if it wasn't working it would be fun to teardown and try and repair, but I've plugged it in and other than some cosmetic nicks and scratches, dust and need to clean up, it sounds great!Both tape decks work, there is a CD with 3-disc changer. Only issue I found is it will switch to CD1 and CD2, but when I press CD3 it keeps shuffling as if it can't detect the 3rd CD and won't stop the tray automatically. I have to press STOP or some other buttons until it finally "catches" that 3rd CD. However, once it loads all CD positions play totally fine. I'll have to look into the mechanism for how it detects the CD's in each tray and see why it keeps ignoring the 3rd tray. Radio works great as well, picks up FM tuning fairly well in my area, haven't tried any other bands yet. The 3-band equalizer and XBS "bass boost" also is loud and works, no static. The darn thing is heavy, and it's not the speakers (which are detachable)... it's the main unit itself (and that's without any batteries inside).There's not a lot of info online. I've downloaded both user manual and schematics. I believe it is from the 90's. I've looked at Panasonic audio catalogues on hifi-archiv, internet archive, and so on... but can't pinpoint an exact date. I see a bunch of models in the mid to late 90's with RX-DT designation... but not RX-DT770. I've seen in a 1995 catalog the RX-DT610, DT600, DT690. One from 1992 shows RX-DT680. But for the life of me I can't find this model in any advertisement, catalog, just to see what year it was active and the cost at the time.There is no mp3 capability as far as I'm aware, and these typically didn't come with line-in (this is a major complaint regarding Panasonic of the era). The tape decks are mechanical, no auto-reverse and no Dolby of any kind. With respect to using line-in or Bluetooth, I thought of using a cassette adapter (I have a few from when I had a tape deck in the car). They have cassette adapters with a 1/8" audio jack that I can plug in, or some now come with bluetooth built in to the cassette. I believe that would be the easiest way around it, not ideal but if I want to stream something to the box that may be a way.If anyone has an idea about the CD tray mechanism glitch, or some more info on what year and any links to a catalog or advertisement of that time showing it, I would appreciate it. This is my only "boombox" as I had ridded myself years ago of my previous one (a Lloyds WW004 I had growing up in the mid-late 80's that I recorded tons of early hiphop from the radio on... and never quite needed one again). I've still got some of those tapes. I've attached an image of that as well. Nostalgia!

author: wilfred
author_rank: Super Contributor
timestamp: May 04, 2023, 03:05:48 pm
content: The CD mechanism sounds like it needs a bit of a clean up of the old lubricant. Based on my one experience with a unit of similar vintage I found on the roadside. Or shopping at "la Strada"

author: edy
author_rank: Super Contributor
timestamp: May 04, 2023, 04:00:02 pm
content: Quote from: wilfred on May 04, 2023, 03:05:48 pm"La Strada"That's a good one! Thanks for the advice on cleaning up the CD mechanism. I downloaded the service manual and it is copyright 1996 so I am going to assume it's from that year, but I have not been able to track down a Panasonic 1996 audio catalog or any advertisements, I'll keep looking. By the looks of the manual, it's a pretty low-end unit... Only supports Type I cassettes, no auto-reverse, manual mechanism (no soft touch), no Dolby. The sleep timer only available through remote, there is no clock. Volume and tuning through buttons, unlike other Panasonic boomboxes from the same era with a nice knob. Almost seems like this was one of the last units they built (and at a cheap price) seeing that cassettes were on their way out.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 04, 2023, 10:14:35 pm
content: Mod it so that the headphone jack is turned into a line in, that makes it a lot more useful in modern times. Probably the easiest is to have it intercept the signal from the radio part, just plug in a cable to switch from radio to aux in.

author: edy
author_rank: Super Contributor
timestamp: May 08, 2023, 05:18:10 pm
content: Thanks for the suggestion... I'm going to have to look at the schematics and see what feeds into the main amplifier circuit (from either the radio or cassette) and just piggy-back an input source on that. I guess I need to make sure the levels are ok as I don't want to overload the circuit with a line-in that is potentially too amplified. Alternatively, I have seen these and I'm pretty sure I have a wired one somewhere that I used to use in my car a while back:https://www.amazon.ca/Universal-Bluetooth-Audio-Cassette-Receiver/dp/B06XDDHXRN... and this one I have, will give it a try ...https://www.amazon.ca/RCA-AH600N-Car-Cassette-Adapter/dp/B000BUN79KI also have a BlueTooth receiver that I could technically connect to the wired cassette adapter, making it accept BlueTooth although it won't look as clean as the all-in-one BlueTooth cassette adapter:https://www.amazon.ca/Bluetooth-Receiver-WOCBUY-Streaming-Handsfree/dp/B09ZX23NTQ