integrated amp - jumper between preamp and amp

Waste of money! As the French Chef says "No diffawrance!"

I had a pair of speakers with only one jumper. I put a nail in as another jumper. Worked fine. Speakers were Audio Note E's. Special jumpers? I think not.

[sarcasm]There will be a HUGE difference, but only if you also replace all the fuses with some of those "audiophile" ones.[/sarcasm]

In all seriousness, there is no objective difference in the sound by changing those jumpers. None.

@mofimadness +1      Emphatically, it always makes a difference AND improvement.  From the beginning, replacing horseshoe shaped steel bridging pins on an NAD 3120 dramatically improved everything.  Do it, report back.  Smile.

This was a while back, but I found it to be a fairly significant upgrade on my NAD 375BEE. It is a cheap tweak, give it a try.