Month: May 2024

The Yamaha amplifier I acquired last year sounds amazing. I fall in love with it all over again every time I power it on and put on some music.

But it has a secret. It's a ticking time bomb. It's not the age; it's generally accepted that Yamaha equipment will outlive all of us if it's properly maintained. The dirty secret is that after being soldered to the main circuit board, several critical components in the power amplifier stage were glued to the board with adhesive that over the years has broken down and become quite corrosive and is known to eat through metal. If left unaddressed this will eventually cause an expensive, catastrophic failure of the unit.

I only learned about this a few months ago, and sadly, the A700 I bought last year is showing this same dreaded corrosion.

That black goo at the base of those two big capacitors is the corrosive glue. As you can see it's already eaten away at several of the resistors immediately below. And who knows what it's done to the underside of those caps? Might explain why the left channel was occasionally dropping out. The joys of owning vintage HiFi gear, right?

When I first noticed this, I contacted my repair guy up north as well as the local tech I took my Kenwood to last summer, and they both quoted an estimate "in the neighborhood" of $200-300 to clear away the glue, replace all the affected components, and do the general maintenance this unit undoubtedly requires after being in service for the last 40 years.

Shortly after getting this news (and at least in the case of my guy up north, facing the possibility of being without the amp for the better part of a year), I was perusing eBay and ran across an auction for an identical unit that already had this servicing done.

Since I'm on a self-imposed budget I did not immediately smash the "Buy It Now" button. Amazing self-restrait, huh?

Actually, the seller was asking more than I was willing to pay, but I still filed the posting away on my watchlist. Just in case things changed.

About a month ago I got an in-app email from the seller offering a significant discount, bringing the price down into the $200-300 range I'd been quoted for the repair of my unit.

Damn.

But hey, Mercury was retrograde and already chewing me up into a million pieces, and I didn't want to tempt the astrological gods, so once again I fought the urge to hit that button.

Over the past few days, the left channel on the amp has been dropping out with increasing regularity, requiring a bit of volume-knob jiggling to bring it back to life.

Tick tock. Tick Tock. Tick tock.

By now I figured the seller had either sold the unit or removed it from the site, but I went to my watchlist today and amazingly it was still available. Mercury's finally out of retrograde, timing blessed me with an "extra" paycheck this month, so fuck the budget. It's gonna cost the same whether I buy an already-repaired unit or send mine out to get fixed. And I can justify the expense by telling myself I can sell my original unit and probably recoup most of the money spent on the new one.

Happy Early Birthday to Me! I did say it was a sickness…

Cosmetically, it's not quite as nice as my existing unit, but those parts can easily be swapped. The important thing—the guts—are what's important.

What's sad is that this repair isn't that difficult; if I had a modicum of electronics knowledge and didn't have the soldering skills of a six-year-old, it would be something I could easily do myself. But I know that as it stands right now I'd end up making a bigger mess of things than what exists now, so…nope. Leave it to the experts who know what the fuck they're doing.