NAD 3020A Integrated Amp


So I have a series of questions re: a NAD 3020A I just bought on Ebay. I'm just getting started on trying to build a good system so please excuse my lack of knowledge.

1. NAD 3020A Amp hooked to JBL 4312A Control Monitors and new REGA RP-1 Turntable. NAD is replacing a early 90's Sansui RZ-1000. I would have thought there would have been an appreciable difference in sound quality but I'm not sure that there is. Can't tell if it better, worse or just different.

2. NAD delivers a electrical snap sound to the speaker which Sansui did not. Is this cause for concern? Should I have this unit tested / looked over?

3. As this is an older amp it has limited inputs. Is it ok to run IPOD or DVD into the AUX input? Also no CD input, any ideas?
Nate
iamnate
Nmmusicman's suggestion about replacing the jumpers with the IC is surely a great tweak for the Nad, yes it does improve the sound. I remember I used a Cable Talk Monitor 2 interconnect and there was a huge improvement. The cable which has low impedance as well as low capacitance will do the trick, I used Cable talk for this very reason.
I did replace the stock jumpers a few weeks ago w/ some regular old interconnects that I had laying around and I do think there was improvement. As my ear is not so finely attuned I always wonder if its a placebo though!.

I'm mainly interested in adding a power amp and using the 3020A as a preamp because it does somehow feel like its straining a bit to power the speakers. I know nothing about the whole impedance/ wattage thing w/ regard to matching amp to speakers, but something tells me these speakers need more heft.

HiFiHvn: I'll chk out the McIntosh. I've got a friend whose got an old McIntosh setup he got from his Dad that I'm eager to check out.

Thanks all f/ the suggestions...
Again, please excuse my neophyte-ness in advance. I thought I would just keep this thread rather than start a new one. I currently have:
NAD 3020A Amp
JBL 4312A Control Monitors
REGA RP-1 Turntable (1 year old)
NAD 4220 Tuner
NAD blu-ray player don't have it in front of me.
I'm trying to figure out how I can improve the performance incrementally w/out huge cost. I have cheap Radio Shack interconnects & speaker wire so that's one thing.
I know there are also upgrades available for the Rega in terms of cartridge etc. Any recommendations on improving the overall quality of sound would be appreciated. With my limited knowledge of stereos its hard for me to understand what is the weakest link in the chain.