01-07-13: Kijanki
"... My brother has NAD that originally had factory jumpers made of "U" shape steel rods. Replacing them with short Audioquest jumpers (basically short IC) opened treble..."
AMEN Kijanki!!
I replaced the rummy factory metal jumpers in a NAD C370 integrated amp used in a prior "B" system, with two aternatives:
(i) inserted the Audioquest jumpers; and then
(ii) quality VDH 6 inch length ICs
Result: in both cases, a large progressive improvement ....(i) just by going to to the Audioquest cheapos; and then
(ii) a more subtle but appreciable further improvement when I upgraded to the VDHs (still have 'em kicking around in a drawer - guess it's time to sell them cuz I don'y use them anymore)
In any case, the factory stock metal jumpers are noticeably inferior.
In fairness, I also professionally modded/upgraded the stock power cord configuration to a quality female connector that permitted a use of quality external Power Cord instead of the crap hard-wired-in power cord that came with the unit. That also made a huge improvement.