Vintage Solid-State Audio Reliability

My everyday amp for the past seven years has been the forty-year old  Sumo Andromeda. Designed by the late James Bongiorno. It too has been in use 24/7 without issues. With any secondhand purchase you take your chances.

My dad used to be a rep for pioneer in the 70s. When he moved a couple years ago he gave me a spec 4 and a preamp that were not working. I took them to a local vintage hifi repair guy near Syracuse, NY and he fixed them up. Like any pieces of gear, service is required, but with proper service they sound excellent and have been working flawlessly since 

I had this period where I was rebuilding Acoustic Control corporation guitar/bass amps (271/371) sets (the whole thing, recapping, matching output transistors, paint, tolex, reconing speakers, refinishing to near-new specs) about 25 years ago. those amps where already 30 years old and older. Last I heard  from several of the buyers, they’re STILL going strong.

No, NOT “HiFi” but the principles are the same.

My FM tuner Technics ST1038/SH1038 is still going strong nearly 40 years later, I use - daily - REVOX RtR decks (B77-II and PR99-III) of similar vintage. Of course, I own the service manuals and do the upgrade work myself as a hobby although there are folks out there who can do more than I should I reach an impasse.

I have owned new receivers (ONKYO, JVC) that crapped out, dead as the proverbial steel fastener after the warranty ran out and the cost of repair was more than a new unit. Have owned, twice burned, exponentially shy, won’t get fooled again.

Of course, YMMV.

As with any older product the capacitors dry out after say 15 years if used daily

especially in loudspeakers

Electronics from the late 1960s to 1980s from major manufacturers like Mitsubishi, Marantz, Sansui, Pioneer, etc. are not only very reliable because of build and parts quality, but also because of the state of the art in design which I will explain further below.  That said, tuners and tape decks are not as reliable as amplification product due to their mechanical nature of operation.  The only real issue with vintage electronics is the power amplifier.  If it becomes defective, finding a replacement may be difficult requiring someone with experience and expertise in servicing vintage electronics to either find a new replacement that matches specifications or a used part.  Also, with vintage equipment, bulbs or CAPS may need replacement and the tuner may need alignment.  

The state of the art for circuit board design and manufacturing back then was manual surface mount through hole technology where components are hard wired and soldered.   Components were larger.  Today, printed circuit boards use surface mount technology (solder directly to the board surface) with much smaller components.  Most components are machine mounted, and only a minority are manually mounted.  Repair becomes difficult often requiring mounting new components under a microscope and by someone with keen expertise.   If direct replacement components are not available, matching alternatives becomes more difficult since today’s equipment has software that may be affected.  Often, the whole board may need replacement even if one component is the root cause.  If that model is no longer supported or the manufacturer is out of business, it may be impossible to repair.  Therefore, vintage equipment is easier repair IMHO.   It will be interesting to see, and at my age I will not see it, if today’s designs will be making music 50+ years from now   
 

I have my farther’s Pioneer SX 828 still making music since the 1970s.  Completely original including bulbs   Just occasional contact cleaning.   
 

If you proceed, find a good vintage repair service and have the tuner alignment checked and a general check and cleaning.  It’s worth the effort and cost.