Category Archives: Hi-Fi

Boxed Kit Amps’ Gobo Stereo Amplifier Build and Review

Posted on November 26, 2014 by jwk

If you’re a subscriber to Nuts and Volts Magazine, check out my article in the December 2014 issue where I build, test and review the Boxed Kit Amps Gobo Stereo Amplifier, a great little desktop reference amp for any skill … Continue reading →

Posted in Audio, Commentary, DIY, Electronics, Gadgets, Hi-Fi, Projects, Stereo | Tagged , , , | 2 Comments

Harman/Kardon Control Amplifier A-401 Restoration

Posted on November 19, 2014 by jwk

This little Harman/Kardon Control Amplifier, model A-401, just came through the shop for a full overhaul. It was in a pretty sorry state to begin with – one channel distorted, one barely gasping for air, and a world of scratchy … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Projects, Stereo, Vintage | Tagged , , , , , , , , , , , , , | 8 Comments

Sony TA-4650 VFET Stereo Amplifier Inspection and Upgrade

Posted on November 11, 2014 by jwk

This Sony TA-4650 was shipped to me from Canada for a shop visit on its way to its ultimate owner in California, who just bought it on eBay. He had it sent to my shop for an inspection and a … Continue reading →

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EICO Stereophonic Integrated Amplifier HF-81 Repair

Posted on November 7, 2014 by jwk

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 →

Posted in Audio, Hi-Fi, Projects, Stereo, Vintage | Tagged , , , , , , , , , , , , | 1 Comment

Boes 901 Series IV Active Equalizer #241792 Refurbishment

Posted on November 3, 2014 by jwk

Bose® 901 Series IV Active Equalizers are getting up there in years now, too, so more and more are coming up for repair. This one came in with a flickering power supply in need of an overhaul. Series IV was … Continue reading →

Posted in Audio, Bose, Hi-Fi, Projects, Stereo, Vintage | Tagged , , , , | 1 Comment

Esteemed Bose® Model 901 Active Equalizer – Serial #230 Repair

Posted on October 17, 2014 by jwk

Cross-posted from Rain City Audio: I had the distinct pleasure of working on one of the earliest  Bose® Model 901 Active Equalizers from Series I’s first production run. Serial #230, in fact! It’s made entirely by hand and shows traces … Continue reading →

Posted in Audio, Bose, Hi-Fi, Radios and Tubes, Stereo, Vintage | Tagged , , , , , , | 2 Comments

Phase Linear 2000 Pre-Amp Overhaul

Posted on October 6, 2014 by jwk

Cross-posted from Rain City Audio: I had a Phase Linear 2000 through my shop lately. It was running okay, but had some pops and clicks and the controls weren’t all that smooth. Time for an overhaul before anything worse cropped … Continue reading →

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1956 Grundig 8080 German Hi-Fi Console Repair

Posted on October 3, 2014 by jwk

Cross-posted from Rain City Audio: German radios like this one are a lot more difficult to work on than most American and Canadian radios, and they’re a lot less common, but they do turn up once in a while. This … Continue reading →

Posted in Hi-Fi, Projects, Radios and Tubes, Vintage | Tagged , , , , , , , , | 2 Comments

Sony TA-4650 VFET Stereo Integrated Amplifier Check-Up

Posted on September 24, 2014 by jwk

This repair cross-posted from Rain City Audio: I recently had this Sony TA-4650 in the shop for a check-up. It was reportedly giving static in one channel. That’s trouble on an amp like this – Sony used an ambitious new technology, the VFET, a … Continue reading →

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Marantz 2245 Stereophonic Receiver Rebuild

Posted on September 19, 2014 by jwk

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