Here’s quick photo to help explain how to modify your Yamaha YST-MSW10 subwoofer to disable that annoying auto shut off feature – When the music volume is too low the subwoofer will shut off like it’s not getting a signal. The cut off threshold on this set is too high.
This can be solved by increasing the gain going to the sub, but isn’t always possible. I used a 22k (in arms reach) resistor between pins one and two on IC6. This essentially pulls the signal low and keeps it on. It’s also very easy to reverse.
I cleaned it up a bit more after taking this picture.
If you want to make this modification toggleable, wire a button switch on the outside casing and wire the resistor to it.
Rock on, at reasonable volumes!