I have owned a jp80 for 16 years,it is tube regulated and has ahigh volts b plus transformed winded in a similar fashion but with hmusical sounding pre amp to a fast detail retaining musicality and opennesseavier gauge magnet wire done by myself,i did replaced allresistors and audio caps usingMIT on phone and copper fiol papere in oil by Jensen I even aded a choke to filter the Hv . The Mc circuit was lousy sounding to my ears,dismantled and replaced by 2 Hashimoto step up trannies..All said it turned from a bit dark slow a bit oscure musical pre to amore detailed fast, retaining the wide sondstage and musicality.No way to replace it ....never will.Long happy mariage.