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 failures which rob them of their performance. In addition to an overhaul, this one came in with requests to upgrade the output capacitors and install new gold-plated jacks with all silver-bearing solder.

Inside, it looks like it’s all original.

All new parts installed:

Testing before replacing the jacks:

New panel jacks in the rear, for the main input and output connections:

Quite a few replaced parts!

If your Active Equalizer isn’t working well, Rain City Audio can help.