Bose 901 eq update#

Note that I didn’t replace everything on the board. Ordering Parts: Using the schematic (PDF) and the actual board as a cross reference, I made a list (CSV) of all the components I would need to order.I was slightly concerned about by ability to execute, but I was reminded that the EQ didn’t work anyway–no matter what I did, it wasn’t going be any worse. Based on KF7LZE’s blog post, I was confident that, if executed properly, this repair would work. The before and after pictures appear below and there is a parts list in the resources section at the end. I’m happy to report that the repair was a success and, while I haven’t heard for myself yet, I’ve been told that it sounds “awesome” it sounds pretty awesome. He found this post on KF7LZE’s Blog about replacing the old resistors and capacitors to bring the old equalizer back to life and suggested that I give it a go. One of his EQs worked well, but the other, not so much. These speakers were designed to be used with an active equalizer without it, the sound quality is quite poor. BackgroundĪ friend got sort of a two-for-one deal on some vintage Bose 901 speakers. In this project, a non-functional Bose 901 Equalizer is repaired by replacing the old resistors and capacitors with modern parts. Over the years, vintage audio components can begin to fail due to the age of their electronics. I’m flattered, but I’m not an electronics pro, so I can’t repair other people’s gear.

Bose 901 eq update#

Update : Several people have contacted me asking if I could repair their equalizers or other equipment.