Awhile back I found a receiver in a dumpster while up in Chicago. It was a Pioneer sx 1980. Well, I hauled it back home with a suitcase strap; putting the 100 lb amp in the overhead on a 727 flite to Daytona. That was a BIG job. No security back then. You know, people saw me carrying that thing and they understood why. I repaired amps before for a living, so I will hence repair this one. Power supply blown output b-plus 65v rail =0. Well this was a tricky one because many of the small components(xistors)are matched and some are not available except as substitutions; specs are not exactly the same as oem. Also all voltages have to come up together or the power supply just blows everything. This happened many times. Drawings and service manual only available in microfich and maybe unavailable. Pioneer in Atlanta (or a serv.ctr.) there can repair these units. Mine works ok even the fm works (capacitave afc cool tuning)Generally, the unit is awesome but circuit boards are old phenolics not glass, alignment is tough-you got to set bias rite or a channel will run hot and you blow speakers-not funny when they are your favorite ones. Toroid xfmr good!
Old Classic Receivers: A Mistake to Buy?
I was contemplating purchasing a 70's receiver, as I used to love the construction and appearance of the Sansui, Kenwood, Pioneer, Marantz. However, when I ran this by an audio friend, he said, "Forget it."
He says: They sound terrible. The caps & resistors used before the early 90s' were dreadful. The electrolytics are drying up and will start crackling and substantially degrade the sonics. The switches and controls used were almost never sealed, so they deteriorate and make noise and can't be fixed even by taking them apart and cleaning them.
Tuners: He says that nearly all non-digital tuners used varactors, which go out of alignment and cause problems, so no old tuners, with the exception of the Mac MR-78 and possibly a few others, are worth dealing with.
I am tempted to believe all that he is saying is true, but I see a market for these items, and also know that people claim they are still using these pieces for 25 years.
What's the truth here? Can some of the techies enlighten me?
He says: They sound terrible. The caps & resistors used before the early 90s' were dreadful. The electrolytics are drying up and will start crackling and substantially degrade the sonics. The switches and controls used were almost never sealed, so they deteriorate and make noise and can't be fixed even by taking them apart and cleaning them.
Tuners: He says that nearly all non-digital tuners used varactors, which go out of alignment and cause problems, so no old tuners, with the exception of the Mac MR-78 and possibly a few others, are worth dealing with.
I am tempted to believe all that he is saying is true, but I see a market for these items, and also know that people claim they are still using these pieces for 25 years.
What's the truth here? Can some of the techies enlighten me?