If you want to retain your resale value, replacing jumpers and installing a IEC plug are reasonable options which will bring a slight improvement. The real drawback to this and other int. amps which have an A/B speaker selector switch and headphone jack, IMO. The reasons are two fold, one the signal has to go through more circuit boards and switches. (The less the signal is altered/routed the better.) The second reason which may apply to this amp (and others) is that the power lines and speaker lead wires are oftened tie wrapped together! Just seperating these wires lead to a hugh improvement in sound. I did this to my little Nad 302. Internally jumped the pre-in/pre-out w/ultra pure wire, replaced the stock power cord w/a fixed SJOOW 16 ga. Carol Cable. Lastly, I completely bypassed the phono jack and rerouted the spk. wires to the spk. binding posts using Kester solder. The sound improvement was dramatically better. Now, I bought my little NAD for a song and never plan to sell. Pure musical enjoyment. Perfect w/the PSB 300i's and a little Def. Tech sub. Not sure how far you're willing to go w/your NAD, but you may never know the potential of the amp. Just my 2 cents. Bill