Be careful: the Jolida "loop" is exactly that - a tap off of the passive selector's outputs. I have a heavily modified "second system" 502 with the tape loop and found it can degrade sound quality with long tape line runs due to signal losses. BTW, do yourself a big favor and upgrade the stock input jacks which are, quite frankly, garbage. Upgrading the paltry OEM input wires will bring some further improvements as well. Toss the crummy Chinese small signal tubes while you're at it. Nice amp that goes a long way with a few judicious upgrades.