Tag Archives: repair

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 →

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How to Buy Capacitors on Mouser.com

Posted on June 29, 2026 by retrovoltage

Learn about searching for electrolytic, film, and ceramic capacitors on popular parts house Mouser.com, with examples to help you get started selecting the right parts. Don’t risk counterfeit parts from 3rd-party suppliers – go right to the source! Continue reading →

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1937 Zenith 5-S-126 Tune-Up

Posted on October 30, 2015 by retrovoltage

This very nice Zenith 5-S-126 came through the shop a little while ago. It was originally purchased by a local collector from eBay already restored and playing, and served well for a couple of years, until it started having some … Continue reading →

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Creek 4140 S2 Overhaul and Voltage Conversion

Posted on August 23, 2015 by retrovoltage

This Creek 4140 S2 amplifier is a bit newer than most through the shop, although it’s getting up there. This particular one was constructed in 1989, and came via eBay from the UK configured for 220V power. The owner wanted … Continue reading →

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Sony ST-J75 Recap and Alignment

Posted on July 31, 2015 by retrovoltage

The Sony ST-J75 is a pretty well regarded, great sounding stereo FM tuner from the early ’80s. It’s one of the first forrays into digital tuning, with a frequency read-out, programmable memory, and seek/scan functionality and variable muting driven by … Continue reading →

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Philco 39-45 Retrofit to 40-201 Cabinet Vintage Radio Repair

Posted on January 16, 2015 by retrovoltage

A neighbor approached me with his family’s Philco 40-201 vintage radio to be restored back to working condition. It had sat for several decades, very well preserved, but ultimately needed some service after the years. Very unfortunately, however, the original … Continue reading →

Posted in Electronics, Radios and Tubes, Vintage | Tagged , , , , , , | 2 Comments

EICO Stereophonic Integrated Amplifier HF-81 Repair

Posted on November 7, 2014 by retrovoltage

From the late ’50s, I had this nice example of an EICO HF-81 amplifier come through my shop. These are nice little stereo amplifiers with a built-in phono pre-amp and RIAA equalization and feature about 14W of power output per … Continue reading →

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Harmony H500 Solid State Guitar Amplifier Repair

Posted on October 10, 2014 by retrovoltage

And now for something a little different, this time it’s a vintage guitar amplifier: the Harmony H500. The owner sent it to the shop out of the cabinet to be serviced since it quit putting out any sound. It’s a … Continue reading →

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Marantz 2245 Stereophonic Receiver Rebuild

Posted on September 19, 2014 by retrovoltage

An iconic piece of kit from the golden age of hi fi just came through my shop: the Marantz 2245 Stereophonic Receiver. This fantastic receiver is in pretty good cosmetic shape, but its owner reported that it started acting up – it’d take … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Projects, Stereo, Vintage | Tagged , , , , , , , , , , , | 7 Comments

1931 Westinghouse WR-8 Columaire Antique Radio Repair

Posted on April 14, 2014 by retrovoltage

I recently got to work on another beautifully reconditioned Westinghouse WR-8 Columaire radio all the way from Bellingham. It was originally in for service with the SPARK Museum, but the repair technician reportedly suffered some health complications and was unable to … Continue reading →

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