Outlet is "Open Ground" - Is There Still a Safe Way to Connect to My Audio Gear?

All I know is when the amp was plugged directly to the mains, it's metal front cover conveyed some minor current flow and when plugged into the Panamax, it was resolved.

I am not in a position to rewire my entire home either DIY or via a paid professional. I also don't own equipment anywhere near true audiophile or reference level cost or performance.

@motown-l  I understand money is a concern, but this sounds bad.  Not saying you need to rewire your home, but it sounds like a lifted neutral which can cause all sorts of electrical and life safety issues. 

Strongly suggest you get the cheap-o tester I recommended and see what it t4ells you, then consult with an electrician.  It's quite possible this is a small fix, and if it's a major fix it may well save your home. 

Thank you for the helpful additional insights, thoughts and recommendations.

Good news!  The home's current main panel was put in about 5 - 10 years ago. The home's prior owner is a builder.  He lived here 22 years and was renovating all over, up to a few months before he sold in 2023.  

Today I'll get a Husky GFCI plug-in adapter for the Open Ground outlet, to add some safety, if not protection against surges...Next I'll look in to an electrician installing a dedicated power circuit for the audio equipment and/or doing a full home re-wiring as needed...thank you. 

@vinylfun +1 for the dedicated line. I ran one to my listening room and noticed the system sounded quieter.