Sure sounds like noisy tubes to me. Was this 'static' present when you used the Tong sols? Do you still have them. If yes and yes simply changes back to the tong sols. If they are quiet then you know that your problem is related to the tubes you are now using.
The solution then is to get tubes that are tested for low noise (new, NOS, or used). Age has little bearing. New tubes can be noisy. Noisy tubes can last a long time. In my experience this is is not a typical sign of aging. Forget the pillow case unless you think cleanliness will make a difference. My tubes/amps get dusty as hell with out negative effect (I do dust them once in a while :-).
The solution then is to get tubes that are tested for low noise (new, NOS, or used). Age has little bearing. New tubes can be noisy. Noisy tubes can last a long time. In my experience this is is not a typical sign of aging. Forget the pillow case unless you think cleanliness will make a difference. My tubes/amps get dusty as hell with out negative effect (I do dust them once in a while :-).