Category Archives: Hi-Fi

1950s Motorola Modded Standalone Tube Amplifier Measurements

Posted on July 6, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: Rain City Audio had an unusual project through the shop recently. It’s a Magnavox tube amp from the late 1950s. The owner brought it in reporting he’d purchased the amplifier, pulled from … Continue reading →

Posted in Audio, DIY, Electronics, Hi-Fi, Projects, Radios and Tubes, Vintage | Tagged , , | 3 Comments

1974 Sony STR-6200F Receiver Overhaul and Alignment

Posted on June 19, 2015 by jwk

From the Rain City Audio Repair Blog: 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 … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Projects | Tagged , , , , , , , , | 4 Comments

Bose® 901 Series IV Active Equalizer #244305 Repaired

Posted on May 30, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: Even the later series Bose® Active Equalizers are getting older, and the Series IV is coming up more and more. I just had another one through the shop, this one sent to … Continue reading →

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Marantz 2270 Stereophonic Receiver Overhaul and Adjustment

Posted on May 26, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: 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 … Continue reading →

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

Bose® 901 Active Equalizer Series I #37582 Overhaul

Posted on May 22, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: Another Bose® 901 Series I Active Equalizer came through the shop just recently for a full overhaul. These Series I equalizers were made from 1968-1972 and most are beginning to experience component … Continue reading →

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Bose 901® Series II Active Equalizer #114150 Overhaul

Posted on May 18, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: This Bose® 901 Active Equalizer came through my shop recently for a full overhaul. After so many years, the electrolytic capacitors in these units leak and go open, and the resistors drift … Continue reading →

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Yamaha B-2X Check-Up and Adjustment

Posted on May 13, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: 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 … Continue reading →

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Bose® 901 Series IV Active Equalizer #246341 Repaired

Posted on April 23, 2015 by jwk

Cross-Posted from the Rain City Audio Repair Blog: This Bose® 901 Series IV Active Equalizer came through the shop recently with a variety of intermittent issues impacting its performance. These later series equalizers are still getting to be quite old, … Continue reading →

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Bose® 901 Series I Active Equalizer #41065 Repair

Posted on April 20, 2015 by jwk

Cross-Posted from the Rain City Audio Repair Blog: This Bose® 901 Series I Active Equalizer came through the shop recently for an overhaul. It’s nearly 50 years old and the owner reported it had one channel beginning to drop out … Continue reading →

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Accuphase C-200 Professional Pre-Amp Full Overhaul

Posted on April 16, 2015 by jwk

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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