Tag Archives: Bose

Bose 901 Series II Active Equalizer #103549

Posted on July 10, 2014 by jwk

This Bose® 901 Series II Active Equalizer is a part of Rain City Audio’s parts stock and got a full rebuild with upgraded parts and complete and comprehensive testing. All transistors, resistors, film and electrolytic capacitors were replaced, a new neon bulb added, and the controls cleaned and lubricated. This very detailed repair walkthrough has photos showing the drifted carbon composition resistors which can throw off the equalizer’s curve even if all the capacitors have been replaced. Click through for many more photos!

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Bose 901 Series II Active Equalizer #114743 Repair

Posted on June 26, 2014 by jwk

This Bose 901 Series II Active Equalizer got a full overhaul in the shop with all new capacitors, resistors, transistors and silicon diodes. After a thorough control cleaning, it sounds absolutely fantastic once again and should last for a long time to come.

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Bose 901 Series I Active Equalizer #41550 Repair

Posted on June 18, 2014 by jwk

This Bose 901 Series I Active Equalizer, serial #41550, came into my shop in need of an overhaul after being stored somewhere sticky for many years. After a rebuild and thorough control cleaning with high powered solvents, this equalizer performs good as new! All new capacitors, resistors, transistors and neon bulb will last for a long time to come.

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Bose 901 Series II Equalizer #58189 Repair

Posted on June 16, 2014 by jwk

This Bose 901 Series II equalizer came into my shop recently. It had one good channel, but the second channel was experiencing a large amount of distortion. No wonder why, the unit was mostly original, although it had some evidence of being serviced before.

Inside, about half the capacitors…

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Bose 901 Series II Active Equalizer Repair #126500

Posted on June 4, 2014 by jwk

This Bose 901 Series II Active Equalizer came into the shop for a complete overhaul after it suddenly stopped working entirely. While in the shop it also got upgrades to the output capacitors and added 4%-silver solder for the lowest joint resistance possible. After a full rebuild and live listening test it’s ready to go back home and serve faithfully for many years to come.

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Bose 901 Series I Early Production Equalizer #00570 Repair

Posted on May 27, 2014 by jwk

I just finished a new project over at Rain City Audio – Bose 901 Series I Early Production Equalizer #00570 Repair

This Bose® Active Equalizer is the earliest I’ve ever seen through the shop, serial #570. It’s very hand made and got a complete overhaul, including some upgrades to maximize performance. With all new parts to replace the worn out and failed originals after 46 years, it’s going to sound great for a long time to come.



Check it out at http://www.raincityaudio.us/blog/bose-901-series-i-early-production-equalizer-00570-repair! Continue reading →

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Bose Active Equalizer Model 800 #003833 Repair

Posted on May 15, 2014 by jwk

I just finished a new project over at Rain City Audio – Bose Active Equalizer Model 800 #003833 Repair

Those Bose Active Equalizer model 800 is from the early run of the Bose 800 PA system, which is very similar to the Bose 901 direct/reflecting speaker system. The equalizer had bad noise and distortion in both channels when I got it, but after a repair works and sounds perfect and will last for a long time to come.

Check it out at http://www.raincityaudio.us/blog/bose-active-equalizer-model-800-003833-repair! Continue reading →

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The Speaker Spotter – Speakers of Craigslist – April 18th, 2014

Posted on April 18, 2014 by jwk

There’s always something interesting for sale on Craigslist, especially in Seattle. Do click the titles to see the original postings with more photos and additional information if you’re interested – otherwise, enjoy the virtual window shopping! Rain City Audio is not … Continue reading →

Posted in Audio, Collections, Photos, Speakers, Stereo, Vintage | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 2 Comments

Bose 901 Series II Active Equalizer #111058 Repair and Upgrade

Posted on April 16, 2014 by jwk

This Bose 901 Series II equalizer just came through the shop for an overhaul and upgrade. It’s in pretty good shape except for a small piece of delaminating contact paper on the side, but isn’t showing any signs of having … Continue reading →

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The Speaker Spotter – Speakers of Craigslist – April 11th, 2014

Posted on April 11, 2014 by jwk

There’s always something interesting for sale on Craigslist, especially in Seattle. Do click the titles to see the original postings with more photos and additional information if you’re interested – otherwise, enjoy the virtual window shopping! Rain City Audio is not … Continue reading →

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