Sorry for my slow response. I personally have not had John modify a PH-3, but because it is a very simple circuit it is very easy to modify. John is well up to the task. The best modification that I know is the new Sovtek 6922 pi tube which will be available soon be looking for it. My preference is the standard PH-3 versus the SE model. most upgrades to the PH-3 can obtained with simple part refinements. It is a wonderful unit. My best to you as well.