On Sunday, June 13, 2021 at 6:23:58 AM UTC-7, W Pulaska wrote:
Pretty simple set up. I have my phono output from my desktop Audiofile
2496 sound card driving an Altec Lansing speaker set. Works fine when
everything is on, but when the desktop is turned off I am getting a
buzz/ hum from the speakers...

Buzz means harmonics from a sawtooth, typically. That indicates that the
speaker power source (a wall-wart power brick??) has a capacitor that has
gone high-impedance (high ESR, for instance). Speaker amplifiers aren't
critically dependent on exact-match power bricks, you can find another
(if necessary splice the cord from the old one to fit the socket) that'll work.

Sometimes, you can open and repair a power brick. Not often.