[Ronin61]

When I turn the volume control I hear a high pitched screeching sound. All capacitors have been replaced so what did I do wrong?

[Steve Davis]

Are all the tube shields in place?

Steve

[morzh]

You may have a positive feedback. As Steve just pointed out, this may be due to the coupling because of the missing shields. Or because of some other coupling. Messed up wiring will also get you that.

[Ronin61]

The single tube shield is in place I'll check the wiring. By the way this is a philco tropic 3214.

[codefox1]

Hope you took a few "before" pictures, and did not deviate with lead dress and component locations. Double check your values and connections one more time.

[morzh]

Check how you dressed the wires. If you decided to bundle some of them - unbundle them and try in general to avoid running wires in parallel for long distance.
If any were run next to the chassis before, keep them this way.

an idea: while having the screeching sound, try to move wires by touching them with an insulated rod of some sort, see if at some point when you touch some wires it disappears. This will give you and idea if there are some proxymities between some wires that should be avoided.