Tag Archives: series IV

Bose® 901 Series IV Active Equalizer #501554 Overhaul and Upgrade

Posted on January 20, 2016 by jwk

From the Rain City Audio Repair Blog: This Bose® 901 Series IV Active Equalizer, serial #501554, came into the shop with the owner reporting that it loses output on one channel and the sound degrades the longer it is powered … Continue reading →

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Bose® 901 Series IV Active Equalizer #219533 Overhaul

Posted on January 2, 2016 by jwk

From the Rain City Audio Repair Blog: This Bose® 901 Series IV Active Equalizer, serial #219533, came through the shop for an overhaul. The owner was reporting the left channel went out, so it’s clearly time for an overhaul! A … Continue reading →

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Bose® 901 Series IV Active Equalizer #269557 Repaired

Posted on December 10, 2015 by jwk

From the Rain City Audio Repair Blog: Another Bose® 901 Series IV Active Equalizer came in through the shop for an overhaul recently. This one was a bit unusual, and represents a fairly significant deviation from the published service manual. … Continue reading →

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Bose® 901 Series IV Active Equalizer #221114 Repaired

Posted on December 3, 2015 by jwk

From the Rain City Audio Repair Blog: Another Bose® 901 Series IV Active Equalizer came through the shop, this one serial #221114. It’s owner reported that it had lost one channel, so it was clearly due for an overhaul. It … 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 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 IV Active Equalizer #116907 Overhaul

Posted on December 12, 2014 by jwk

Cross-posted from the Rain City Audio Repair Blog: Another Bose® 901 Series IV Active Equalizer came through the shop recently. It’s owner shipped it in without the wooden cover for security. This is a bad idea on the Series I/II, … Continue reading →

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Bose 901 Series IV #244005 Repair by Rain City Audio

Posted on December 4, 2014 by jwk

Cross-posted from the Rain City Audio Repair Blog: Bose® 901 Series IV equalizers are coming through the shop more regularly in the past year. It’s expected as these are definitely getting up there in years. This one was sounding muddy … Continue reading →

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Bose 901 Series IV Equalizer #202245

Posted on August 29, 2014 by jwk

A bit different from the run of Series I and Series II that I usually see, I got to fix up this Bose 901 Series IV Active Equalizer which was sent to me from Austin, TX. The Series IV was sold from 1978-1983 and its construction reflects this.

The PCB on this model is single-ended, so can be completely removed from the chassis.

<img class="alignnone" src="https://lh4.googleusercontent.com/-yTJ3z3swIO4/U_wH-zjcj3I/AAAAAAAAkEA/YBDKfs9GTSs/s640/IMG_1459.JPG&quot; alt="" width="640" height="480 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 →

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