for adding 470ohm screen resistors...add between pins 1 and 4 on ptube sockets? Also, while this has probably been rehashed a million times...thoughts on these plans to change first three coupling caps to 0.022, leave PI couplers at 0.1, make 1st filter cap 30uf and second 2 caps 20 uf. And of course want to add screen resistors. First 5e3. Have built a 5f8a and 5f6a but somehow this feels more intimidating, probably because its a citcuit and amp im not familiar with.