Author Archives: jwk

1967 Sony TFM-116L Transistor Radio Repair

From Rain City Audio: This cute little Sony 11-transistor portable AM/FM radio, the TFM-116L, recently came through the shop. It’s owner purchased it new back in 1967 while he was stationed overseas with the armed forces, and had been listening … Continue reading

Posted in Audio, Electronics, Radios and Tubes, Vintage | Tagged , , , | 1 Comment

1937 Admiral 488 Radio Dial Belt Repair

From Rain City Audio: Most tube radio repairs at Rain City Audio are full overhauls, but occasionally there’s something that’s just in for minor maintenance, like this Admiral AM 488 from 1937. This radio was fully restored in exacting detail … Continue reading

Posted in Radios and Tubes, Vintage | Tagged , | 1 Comment

Bose® 901 Series IV Active Equalizer #509052

From Rain City Audio: This Bose® 901 Series IV Active Equalizer, #509052, was just purchased and sent to Rain City Audio for an overhaul. This unit was originally a 220V model but had already been converted to 110V on a … Continue reading

Posted in Audio, Bose, Electronics | Tagged , , , | 2 Comments

Mercury Switch Find

Digging through a seldom-used parts bin, I made a cool discovery: a set of four mercury switches, still intact: These are used as tilt and vibration sensors in mechanical systems. They’re heavy from the mercury inside, and it sloshes around … Continue reading

Posted in DIY, Gadgets | Tagged | 3 Comments

Phase Linear 2000 Upgrade and Overhaul

From the Rain City Audio Repair Blog: I recently got to work on another Phase Linear 2000 pre-amp. These well regarded components are a fantastic part of any stereo system with their high output rating, multitude of inputs and outputs, … Continue reading

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

AUX in Volvo Stock Head Unit Radios

Dangerous Prototypes shares an article detailing how Karl Hagström hacked an aux input to his 2007 Volvo V70 stock stereo. Why, why, why isn’t there an AUX input on my car stereo from 2007? Yes 2007 was before the big … Continue reading

Posted in Commentary, DIY, Electronics, Gadgets | 1 Comment

DBX SFX-10

I saw this interesting set of speakers on Craigslist, but they sold quickly before I could investigate. They’re the DBX SFX-10s. There’s a very interesting article about their design in the May 1990 issue of The BAS Speaker, the publication … Continue reading

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Bose® 901 Series II Active Equalizer #66380 Repair

From Rain City Audio: This Bose® 901 Series II Active Equalizer #66380 came through for an overhaul just recently. The owner in California reported that he got these from his father, and the equalizer was sending only the right channel … Continue reading

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Dynaco ST-70 Stereo High Fidelity Tube Amplifier

From Rain City Audio: I recently got to work on another vintage stereo kit, the Dynaco ST-70 amplifier. These were powerful, 35W per channel stereo amps typically using a pair of 6L6GC, EL34, or similar power tubes. This turned out … Continue reading

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Bose® 901 Series IV Active Equalizer #265335 Overhaul

From Rain City Audio: This Bose® 901 Series IV Active Equalizer, #265335, just came through the shop for an overhaul. It’s owner bought this equalizer as a part of getting his Bose® system back up and running and sent it … Continue reading

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