Tag Archives: Active Equalizer

Bose® 901 Series II #102678 Restoration

Cross-posted from the Rain City Audio Repair Blog: Another Bose® Active Equalizer came through the shop, this one’s a Series II. The owner reported that one channel had failed and the switches were badly gummed up. Time for a rebuild! … Continue reading

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Bose® 901 Series VI Active Equalizer #179043 Repair

Cross-posted from the Rain City Audio Repair Blog: Series VI Active Equalizers are the newest of the set and is on it’s second revision of production even today. Even still, the earliest ones are from the 1990s, and that’s getting … Continue reading

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Bose® 901 Series V Active Equalizer #130806 Repaired

Cross-posted from the Rain City Audio Repair Blog: More and more, even the newer generation Bose® Active Equalizers are showing signs of age. Series V and VI have been making appearances here and there, but seem to have picked up quite … Continue reading

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Bose® 901 Series II Active Equalizer #117185 Overhaul

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

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

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

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

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

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

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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