This week I welcomed another neat vintage piece of gear to the collection, the Panasonic RA-6600. Featuring an 8-track recorder. 8-track, kids! It’s like cassette but bigger! I bought this puppy for $20 from an oddball fellow with a loud-mouthed pet bird way out in the Texas countryside. His girlfriend, who had been sunbathing in the back yard, walked through the living room in a bikini and said sorry. Dude responed “ain’t like this feller’s never been to a beach before!” I tell you I felt right at home.
Anyway at the time I bought it he said he thought it wasn’t working due to blown fuses on the back. Well, I replaced the fuses, still no dice. I noticed that the speaker cones would move all the way out to their max position when I hooked everything up and turned her on. That means DC voltage was going out the speaker terminals, thereby a blown transistor on the power amp section. Fortunately, this receiver uses a modular power amp design, so I just got on eBay and found a replacement STK-040, which clocks in at a devastating 10 watts RMS.
Opened it up and removed the old power amp with the help of me mate Vincente and discovered that the solder pads fall right off the 1970s PCB. Hmmm. Can’t solder anything into a circuit without solder pads. I put up a thread about it on a forum, and the helpful folks at all about circuits said hey no problem, just add some extra wires that follow the traces and connect to the next component lead. DUH! So I added the wires and bam, the right channel started working! The taste of sweet half-success!
I was feeling happy, having replaced the modular power amp and fixed the right channel, but also feeling a little daunted by the prospect of trying to troubleshoot the left channel which was still out. If it wasn’t the power amp, it could be something much trickier to locate. Hmmm. The Panasonic, along with a whole mess of tools and other junk, cluttered up my dining room table for a few weeks. My buddy who helped me install the modular power amp came back for another visit last weekend and we had sat down to chow on some tasty salmon burger action.
I had turned on the radio because it was there, and there was a blues station on. My buddy, a guitarist, decided he wanted to hear this better, so he turned up the volume a bit. A ferocious crackle came from the dead channel… followed by music! Apparently Vince has got the magic touch?!
I had previously tried working the volume control around, wondering if the potentiometer might be dirty, but I didn’t get any crackles at that time. Guess I just didn’t try long enough. Or maybe that inital round of deox-it had a delayed effect? Sweeeet. While the unit was apart I gave the volume pot a good blast of deox-it, and the crackles seem to have gone away. Also replaced the burnt out bulb and the dials light up now too. So it’s seemingly 100% now! I don’t have any 8-tracks to test out the player, but maybe I might get on eBay and pick some up soon. It’d be pretty neat to make some 8-track tapes…..
Tags: analog fetishism, DIY, retro
I have the same unit and need a build replaced but do not have the old one. When I opened up the case it was not their. Would be be help and send the build number that you use to replace yours. Thanks
Can you clarify what you mean? I’m not sure I understand what you were asking.