Tag Archives: series II

Bose® 901 Series II #101043 Repaired

Posted on August 4, 2015 by jwk

Cross-posted from the Rain City Audio repair blog: Another Bose® 901 Series II Active Equalizer came into the shop recently for a full overhaul. These equalizers are getting pretty old and even if they power up and pass some sound, … Continue reading →

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Bose® 901 Series II Active Equalizer #117185 Overhaul

Posted on June 15, 2015 by jwk

From the Rain City Audio Repair Blog: Another Bose® 901 Series II Active Equalizer came through for an overhaul and some upgrades. These equalizers are necessary to provide the curve shaping needed to get the great sound the 901 Direct/Reflecting … Continue reading →

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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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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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Check it out at Rain City Audio Continue reading →

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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 – March 14th, 2014

Posted on March 14, 2014 by jwk

There’s always something interesting for sale on Craigslist, especially in Seattle. Here’s a selection of especially notable vintage speakers and other audio products for sale on the local Craigslist. I’m not affiliated with any of these sales, but if you’re interested, you … Continue reading →

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Bose 901 Series II Active Equalizer #120325 Repaired

Posted on March 13, 2014 by jwk

I recently had the opportunity to work on another Bose 901 Active Equalizer, Series II. This particular model had been in service for a long time in active use and was showing its age. It was sent back to Bose … Continue reading →

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