Category Archives: Electronics

New Bench Gear: September 2026

Posted on September 4, 2026 by retrovoltage

A few new pieces of gear join the bench in September 2026: an HP 53181A frequency counter, and a Tektronix 434 Storage Oscilloscope. Continue reading →

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The Speaker Spotter — August 14, 2026

Posted on August 14, 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. Some really interesting, highly unusual things in today’s … Continue reading →

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Everything to Know about the Bose 901 Series IV Speakers & Active Equalizer Repair

Posted on August 10, 2026 by retrovoltage

A detailed look at the Bose 901 Series IV speaker system and Active Equalizer, with a brief history and explanation, plus repair tips and tricks, schematics, a discussion of the 5 different Active Equalizer versions for this generation, and a parts list with direct links to buy. Continue reading →

Posted in Audio, Bose, DIY, Electronics, Hi-Fi, Stereo, Vintage | Tagged , , , , , , , , , , , | 3 Comments

The Speaker Spotter — August 7, 2026

Posted on August 7, 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. Slightly fewer in today’s roundup than usual, but … Continue reading →

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Everything to Know about the Bose 901 Series III Speakers & Active Equalizer Repair

Posted on July 31, 2026 by retrovoltage

A look at the Bose 901 Series III speaker system and Active Equalizer, with a brief history and explanation, plus repair tips and tricks, schematics, and parts list with direct links to buy. Continue reading →

Posted in Bose, Electronics, Hi-Fi, Stereo, Vintage | Tagged , , , , , , , , , , , , , | 4 Comments

The Speaker Spotter — July 31, 2026

Posted on July 31, 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. klipsch la scala industrial split $2,300 · Eugene … Continue reading →

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The Speaker Spotter — July 10, 2026

Posted on July 10, 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. There’s a few interesting things in here today, … Continue reading →

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The Speaker Spotter — July 3, 2026

Posted on July 3, 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. Today’s roundup features several listings from Olson’s Hifi … Continue reading →

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HH Scott HHS-20 “Scotsman” Receiver Overhaul

Posted on January 27, 2017 by retrovoltage

A local repeat customer recently brought in his old HH Scott HHS-20 receiver for an overhaul. It worked a few years ago when he put it away, although not without a few issues of its own, and when he dug … Continue reading →

Posted in Audio, Electronics, Projects, Stereo, Vintage | 3 Comments

A Surprise in a Re-Stuffed Capacitor

Posted on October 18, 2016 by retrovoltage

I was recently re-stuffing some capacitors for a radio. It’s not something I do often, but I’ve accumulated a pile of pulled vintage caps over the years so I have some on hand if a customer requests the most detailed … Continue reading →

Posted in DIY, Electronics, Radios and Tubes, Vintage | Tagged , , | 3 Comments