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?
Where my daughter takes music lessons the guy has an old Kendwood receiver and some advents out and the sound is really great. I don't know if it was restored or not but it sure made me wonder about grabbing that for a second system.
I'm running a kenwood l-02a w l-02t tuner these pieces are not only beautiful to look at but the performance...I love my vintage gear. nuff said
I found a Fisher 400C receiver down the street at a garage sale for $10.00. Not only did it work, it replaced an Onkyo receiver because my wife liked the sound of it much better, as did I. It's all about the sound.
I bought a Sansui 90-90 in Japan back in the late 60s and loved it 'til I was seduced by the newer stuff with remote controls and surround sound. I wouldn't junk the Sansui so put it away where it has rested for a few decades while I played with a great Yamaha R9, eventually set aside for newer hi tech receivers with more flexible switching and more modern interface connections. A few weeks ago with nothing better to do I retrieved the Sansui 90-90 from the closet, hooked it up to my other toys (Definitive Technology BP10Bs; Klipsch KG 5,5S, KG 4s And KLF 10s; Boston Acoustic VR 965s and my old AR3as and AR 98LSs.) Not all at the same time of course. I alternated the Sansui 90-90 with my most recent receiver, Pioneer Elite VSX 91 TXH and an older Onkyo 702 and also switched to the amp in the old Yamaha R9 and also to a pair of old Carver M-500s.

It was all unscientific subjective listening, but for two channel stereo, CDs and AM/FM radio, the Sansui 90-90 with the AR3as sounded the most natural to me. A pair of old ADS 500s sounded as good as the ARs except for the weakness in the bass which the small ADS drops off about 45 hz while the ARs are down only about 10 db at 20hz according to my SPL meter.

True, the old Sansui doesn't have the hi tech switching and connecting flexibility, doesn't have remote control, weighs 52 lbs so it's harder to move around than the lighterweight hi tech things made today, but for 2 channel music to my ears, it doesn't take a back seat to the new stuff of the class described above. I've never heard receivers or amps that sell in the multi thousand $ range so don't know how it would stack up with them.

Is the Sansui and the AR3A really that good, or am I living with totally ignorant ears?
I have Accuphase E-202 integrated SS and love it.
Scott 299b is another integrated which is in my possession (tube).

Both represent the sentimental value rather then SOTA components.
But they do fine job considering there age.

Accuphase is very special because it is a SS design which I usually stay away from but this one is really fun and I might decide to do some mods on it in the future to bring it up to speed with the rest of my gear. Sweet and flexible.

Just my 2c.