Try the second modification where the front board is bypassed.
Hook the three wires on the main amp plug all the way to the right direct to the rear RCA jacks.
Locate the input wires on the main board. (on the front of the board, towards the right side while looking at the amp from the front) They should be L G R. They are on the right side of the group of wires.
Yellow to white
Black to green
Red to blue
POOF! No more front board and about 35% cleaner amp! The difference is VERY noticeable.
You can drive it just fine from a computer (even though you will not reach really high volume, it is plenty) and this mod is easily reversible. Try it, my bet is...you will like it!