[Oldie Goldie]

Strange, I took a dinky 12v 2.5A wall wart and now it runs happy as a clam off it. I think the distortion was the original way I wired the speaker with front right -/+

Used a 5A brick as I could cut up a power cable and put it in.

Soldered everything, heatsink tubing on the power lines. Stuffed the power brick unceremoniously in the side. Might cut and bend a metal bracket or might not.
I left the wires long for future servicing like a real Philco.