Everything for Electronics
Posted in: Developing Perspectives (April 2016)

Indestructibles: The Lure of Tube Audio Equipment

By Bryan Bergeron

Well, that amp is still sitting behind my workbench. Someday, I’ll find an identical amp on eBay, buy it for parts, and cobble together something that works. In the meantime, I decided to rebuild a McIntosh 240: a hot, bulky, but virtually indestructible tube amplifier. I spent a weekend replacing the electrolytic capacitors and swapping out the dozen vacuum tubes, one at a time.

The McIntosh 240 — like many other amps from the ‘60s and ‘70s — is unimpressive on paper. A mere 40 watts per channel, total harmonic distortion a whopping 0.5%, and a stripped down weight of 56 lbs. Plus, no remote.

Output is via massive potted output transformers through old-fashioned terminal strips. For less than the price of the vacuum tubes, I could have bought an NAD 3020D or similar solid-state stereo amplifier with superior specifications, the form factor of a paperback, and the all-important remote.

Although I’ll concede on the specifications front, I’ll counter that I prefer the warm coloration that vacuum tubes provide. Most of all, I know that I can repair the amp — regardless of what happens. The transformers are a bit scarce, but can be found on eBay and other online sources.

Otherwise, everything is ordinary electronics stock — capacitors, resistors, diodes, and vacuum tubes. Schematics and manuals are freely available on the Web, and there are numerous third parties that cater to vacuum tube amp owners.

Do I miss a remote? I can live without one. Am I concerned that vacuum tubes are about as far from “green” as an electric toaster? Not really, because I use the amp maybe 30 to 40 minutes a day.

Besides, I’m saving one more device from the landfills. And lightning strikes? Bring them on!

In this era of disposable unrepairable electronics, I suspect that there’s a growing demand for the simpler but workable electronics of the past.

If you’ve recently turned to vintage repairable electronics, I’d like to hear about it.  NV