Tag Archives: Active Equalizer

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 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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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 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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Bose 901 Series III Equalizer #181986 Repaired

Posted on April 8, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: Bose 901 Series III Active Equalizers are uncommon compared with the other series, but I did have one through the shop just recently. The Series III design – while a great performer … Continue reading →

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Bose® 901 Series VI Active Equalizer #199732 Repaired

Posted on February 20, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: A first for my shop, I recently worked on a Bose® 901 Series VI Active Equalizer! These are considerably newer than the Series I-IV that typically come through the shop, although they’re … Continue reading →

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Bose® 901 Series I Active Equalizer #55382 Refurbished [Repair Blog]

Posted on February 17, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: Another Bose® 901 Series I Active Equalizer came through the shop recently for a full rebuild. These are all nearly 50 years old and are definitely showing their age, and this one … Continue reading →

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Bose® 901 Series I #38949 Repaired [Repair Blog]

Posted on February 13, 2015 by jwk

Cross-posted from the Rain City Audio Repair Blog: Another Bose® 901 Series I Active Equalizer came through the shop. These equalizers were manufactured between 1968 and 1973 and are really showing their age: most have degraded in one way or … Continue reading →

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