Category Archives: Collections

The Speaker Spotter — October 2, 2026

Posted on October 2, 2026 by retrovoltage

A recurring feature curating interesting speakers for sale on Craigslist from around the Pacific Northwest. Links to Craigslist postings might go down at any time if they’re sold or pulled from sale. 1977 Klipsch La Scala $3,500 · Portland Someone’s … Continue reading →

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Everything to Know about Bose 901 Series I and Series II Active Equalizer Repair & Speaker Systems (and the 800, too!)

Posted on June 12, 2026 by retrovoltage

A deep dive into the history and repair of Bose 901 Series I and II, plus the Bose 800, sourced from direct experience repairing more than 500 Active Equalizers. Includes vintage ad copy, photos, tips and tricks, schematics, and parts lists. Continue reading →

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The Speaker Spotter – March 3rd, 2016

Posted on March 3, 2016 by retrovoltage

Some interesting stuff on Craigslist in this week’s The Speaker Spotter, a curated selection of Seattle’s local speakers for sale online. As always, Retrovoltage is not affiliated with any of these sellers and you should click through the link to the … Continue reading →

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555 timer teardown (and a Retrovoltage drum trigger project)

Posted on February 23, 2016 by retrovoltage

Ken Shirriff’s blog has a fantastic and detailed teardown of a 555 timer, the ubiquitous decades-old timer circuit that turns up in so many places: If you’ve played around with electronic circuits, you probably know the 555 timer integrated circuit, … Continue reading →

Posted in Collections, Commentary, DIY, Gadgets | Tagged , , , , , , | 1 Comment

Antique Radio Shop near Kunming, Yunan, China

Posted on February 22, 2016 by retrovoltage

My friends over at Crimson Lotus Tea sent me this photo of an antique radio shop near Kunming, Yunan in China they ran into during a recent trip. They’re stacked to the ceiling in the shadows. Looks like a fun … Continue reading →

Posted in Collections, Photos | Tagged , , , , | 2 Comments

Building a Better Voltage Regulator

Posted on February 17, 2016 by retrovoltage

Glancing through my feeds, I stumbled across a note on The Paleotechnologist describing a new replacement for the venerable LM7805 linear regulator IC. It turns up in a ton of devices, pretty much anything with a medium-current 5V rail including … Continue reading →

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The Speaker Spotter – February 14th, 2016

Posted on February 14, 2016 by retrovoltage

Another installment of the occasional series “The Speaker Spotter”, showcasing interesting speakers for sale right now on the local Seattle Craigslist. As always, I am not affiliated with any of these postings. If the linked ad doesn’t load, it’s likely … Continue reading →

Posted in Audio, Collections, Speakers | Tagged , , , | 3 Comments

Merry Christmas from Retrovoltage!

Posted on December 25, 2015 by retrovoltage

Radio & Television News, December 1954

Posted in Collections, Commentary, Vintage | Tagged , , , , , , , | 4 Comments

What’s On Your Workbench? 2015 Edition

Posted on December 20, 2015 by retrovoltage

This post was from 2015! I’ll have a new one at some point. People ask me what kind of gear I use at Retrovoltage for projects. So, here we go: While it’s by no means the best-equipped workbench out there, it … Continue reading →

Posted in Collections, Commentary, Test Equipment | Tagged , , , , , , , , , , | 6 Comments

It’s Beginning To Look A Lot Like Christmas

Posted on December 16, 2015 by retrovoltage

Bring the Sound of Christmas Into Your Home with RCA Victor Radio

Posted in Collections, Commentary, Vintage | Tagged , , , | 4 Comments