I'm converting my EL 84 to tube rec at the moment. And trying to re-design the PS on my Eico amp. The can caps are no longer made in those values so I got to replace them with new values. I thought maybe to just toss the cans and build outboard cap strips. Whats the rule for the first cap in an input cap PS? If the cap is 20uf can we go to 47uf? I would model this in PSUD but many of the values are impossible to find.