You are most welcome signet02.
Yes, you are correct. J1 and J2 open for EF95 tube family (20v heaters). K1 and K2 jumpers connectting the L/H two pins, marked '408A' on the board. J3 & 4 open (3x gain) or closed (7x gain) depending on whether you need high or low gain (high or low impedance headphones).
Thanks... Just to clarify: My LD1+ manual says J3/J4 [closed] is for 3.5 gain, and J3/J4 [open] is for 7.0 gain... ?...