Mcintosh C220 issues.

Presuming you've done the isolation drill by switching left to right with the cartridge and table leads, you want to see if you can test the preamp with another table rig as a final check. The C220 may be revealing a flaw in the cart you didn't notice before, and that might be the only way to find it if the isolation process doesn't reveal it. If the noise is still on the left channel after all that, you probably have some kind of issue in the C220's phono section that requires service attention.

It sounds like you have a bad tube..this preamp should be dead solid quiet!

When you say white noise, do you mean actual white noise, or something similar like hissing?

If the unit has the original McIntosh tubes in it you are probably hearing tube rush. Replace original tubes with Gold Lion reissues.