[Boatanchors] Here's a vintage stumper..

[StephenTetorka at cs.com]

Hi Don:

The noise is only with the one specific lead/cap....makes no difference which 
tube.

The other lead/cap...no noise either tube...while the suspicious one is not 
connected.

Please see my 'supplementary' note...the noise goes away...generally...after 
using the modulator...which makes me think about heat + time.

Regards,
Steve