Category Archives: Projects

1974 Sony STR-6200F Receiver Overhaul and Alignment

Posted on June 19, 2015 by retrovoltage

I recently got to work on a pretty big, fairly rare Sony receiver from 1973-74: the STR-6200F. It’s a powerful receiver featuring 60W per channel of power available, with quite a few inputs and outputs, and a strong FM tuner … Continue reading →

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Marantz 2270 Stereophonic Receiver Overhaul and Adjustment

Posted on May 26, 2015 by retrovoltage

I recently got to work on another iconic piece of hi-fi history, the Marantz 2270 stereo receiver. I’ve had this model through my shop before, as well as a couple of other 22xx receivers and they’re well built and generally … Continue reading →

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Yamaha B-2X Check-Up and Adjustment

Posted on May 13, 2015 by retrovoltage

I recently had this Yamaha B-2X through the shop. It’s a massive beast of a power amplifier from the late ’80s, delivering up  to 170W per channel with 0.002% THD. Being somewhat more recent, this one just needed a quick … Continue reading →

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Accuphase C-200 Professional Pre-Amp Full Overhaul

Posted on April 16, 2015 by retrovoltage

When Kenwood’s engineers left to form Kensonic, they really brought their A-game, and this Accuphase C-200 pre-amp is no exception. It’s a mammoth device, built with exceptional attention to detail and top of the line components throughout. The owner reported … Continue reading →

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Telefunken Bajazzo Sport 201 Transistor Radio

Posted on March 30, 2015 by retrovoltage

I don’t typically service portable transistor radios, but I make an occasional exception for something especially unique or interesting. The Telefunken Bajazzo Sport 201 is no exception – it’s a high end piece of German engineering, a great performer with … Continue reading →

Posted in Electronics, Projects, Radio, Vintage | Tagged , , , , , | 8 Comments

Sony TA-5650 Full Re-Cap and Adjustment

Posted on March 4, 2015 by retrovoltage

I recently got to work on another of the Sony VFET line of integrated amplifiers, the Sony TA-5650. I’ve had one through the shop previously, and this one came in for the same service. It came in running fine – … Continue reading →

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1960 Grundig SO191 Stereo Hi-Fi Console Repair

Posted on February 27, 2015 by retrovoltage

Updated July 2026 with some additional photos from the archive, and schematics at the bottom. This was a pretty early repair from back in the shop days so there’s a few things I’d do more cleanly for a customer today, … Continue reading →

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Bose® 901 Series VI Active Equalizer #199732 Repaired

Posted on February 20, 2015 by retrovoltage

A first for my shop, I recently worked on a Bose® 901 Series VI Active Equalizer! These are considerably newer than the Series I-IV that typically come through the shop, although they’re still getting to be 25+ years old at … Continue reading →

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Harman-Kardon Citation 12 Deluxe Professional Power Amplifier Refurbishment

Posted on January 12, 2015 by retrovoltage

Matching the Harman-Kardon Citation 17S professional pre-amplifier shown previously, this Citation 12 Deluxe power amplifier is its 120W per channel companion. It came to the shop for a preventive rebuild after serving for quite a few years. The owner had the … Continue reading →

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Harman-Kardon Citation 17S Pre-Amplifier Refurbishing

Posted on January 2, 2015 by retrovoltage

I recently got to work on a Harman-Kardon Citation 17S pre-amplifier. Vintage HK gear is some of my favorite to work on: it’s robust, reliable, and built to be easy to service. The Citation 17 pre-amplifier is the companion for … Continue reading →

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