Tag Archives: series II

Bose® 901 Series II #65097 Overhaul

Posted on August 8, 2016 by jwk

This Bose® 901 Series II Active Equalizer, #65097, just came through the shop for an overhaul. It worked briefly, but failed quickly on its original components. Nothing that an overhaul can’t take care of! This particular unit had its three … Continue reading →

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Bose® 901 Series II #114658 Repair

Posted on July 26, 2016 by jwk

From Rain City Audio: This Bose® 901 Series II Active Equalizer, #114658, just came through the shop for repair. It had stopped performing the proper equalizer functions, and so was time for an overhaul. Inside, it looks like the smaller … Continue reading →

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Bose® 901 Series II #71033 Overhaul

Posted on July 18, 2016 by jwk

From Rain City Audio: This Bose® 901 Series II Active Equalizer, #71033, came into the shop for an overhaul recently. It was showing some signs of age, in this case, a bad left channel. Nothing Rain City Audio can’t fix! This … Continue reading →

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Bose® 901 Series II Active Equalizer #66380 Repair

Posted on May 2, 2016 by jwk

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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Bose® 901 Series II Active Equalizer #81471 Repair

Posted on April 16, 2016 by jwk

From Rain City Audio: This Bose® 901 Active Equalizer, Series II #81471, just came through the shop for a repair. It’s owner sent this one all the way from Ontario, Canada for expert repair from Rain City Audio. This one … Continue reading →

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Bose® 901 Series II Active Equalizer #46234 Repair

Posted on March 21, 2016 by jwk

This Bose® 901 Series II Active Equalizer, serial number 46234, came in for a repair just recently. As is happening with nearly all of these early ’70s equalizers by now, this one had developed poor sound quality and distortion and … Continue reading →

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Bose® 901 Series II Active Equalizer #68953 Repair

Posted on February 28, 2016 by jwk

This Bose® 901 Series II Active Equalizer was originally a European unit, designed for a 240V mains supply. Most if not all 240V equalizers with U.S. style plugs were sold on military bases in Germany and elsewhere, and returned with their … Continue reading →

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Bose® 901 Series II Active Equalizer #64364 Overhaul

Posted on February 27, 2016 by jwk

This Series II Bose® Active Equalizer came through the shop. It had suffered age-related failures in its electrolytic capacitors, and the resistors had drifted with age and moisture to produce the wrong curves. Fortunately, it’s nothing some maintenance can’t solve! … Continue reading →

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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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