WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
This morning, I replaced the old 6BQ5 tubes with brand new Sovtek EL84M tubes. The noise is still there but much more quiet. I'll record the noise later today and post it.
Components look good. could be some kind of interference like others have said. I would certainly check the solder joints and connections. from this angle some look not too well.
