This Bose® 901 Series II Active Equalizer, #71033, came into the shop for an overhaul recently. It was showing some signs of age, in this case, a bad left channel. Nothing Rain City Audio can’t fix!
This unit was mostly original, although some of the electrolytic capacitors may have been serviced previously. No matter, though: all old parts were replaced with new.
The owner also requested some upgrades, including output capacitors, new transistors, and the addition of a switch to the power cord since his receiver did not come with switched outlets.
An inline power switch, since the owner’s receiver doesn’t have switched outlets and the Series II is always-on.
Testing showed all was good!
After a full overhaul and control cleaning, it works and sounds great on all functions and settings!
RETROVOLTAGE 