NAD 216 THX - Make it sound better?

Hi there,
I own a NAD216 amp, it's been playing in my stereo system for almost 13 years now.
about 5 years ago it start making some problems - taking it for service resulted in two things:
1. amp was fixed
2. service guy removed several components / changed several components - making the amp sound way better than stock

three months ago the amp went off again, this time it was due to electrical problem from the AC network.

took it again to service -
this time the service guy (a different one) used the amp original electrical schemes and just went over them and made sure all working properly.

now the situation is simple - i had an improved amp (i do not know exactly by what measuers), i sent it to service and now i got a stock amp again.

i need assistance in reviewing the amp electrical schemes and noting there what places can be "Improved" by manners of:
1. remove / bypass redundant / unnecessary protections
2. remove / bypass circuits that are in no use (bridge channels part / soft clipping)
3. remove filters applied in the amp which are not necessary

i found the schematics of the amp here:
Index of /~jga/nad216thx

link is taken from a thread located here:
http://www.diyaudio.com/forums/solid...nad-216-a.html

i could not locate and electrical schemes for any Silverline amps from NAD for comparison, so if any1 has some assistance about that as well, this may also help


would appreciate any kind of help

BR


Ron.