Tag Archives: bose equalizer repair

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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Bose 901 Series II Active Equalizer #67402 Repair

Posted on August 25, 2014 by jwk

This equalizer got a full overhaul with new 1% precision resistors, electrolytic capacitors, audiophile-grade output capacitors, transistors, gold-plated RCA jacks, 4% silver solder for all connections, a thorough switch cleaning, and computerized frequency response testing and a listening burn-in to verify proper operation. It sounds just fantastic with a very dynamic and life-like presence that really draws you into the experience of the source material, just like the Bose 901 should.

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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 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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Bose 901 Series II Equalizer #95007 Repair

Posted on October 14, 2013 by jwk

I got this Bose 901 Series II equalizer in for repair recently and have finally had a chance to send it back out! It’s going back to its home on the East Coast to be the centerpiece of a Bose … Continue reading →

Posted in Bose, Electronics, Speakers, Vintage | Tagged , , , , , , , , , , , , , , , , | 4 Comments