I have a PT1 with an RB300 arm, in need of a rewire. I would suggest that your NAD amplifier is in need of an upgrade. The NAD 3020 was popular with the Dual 505 and also the NAD turntable, which to be honest are no where near as good as your LPT. I use a Naim Stageline, 112X/Flatcap and 150 for amplification. Probably a little too much for the LPT, take your LPT to a shop for some demonstrations. Prior to my Naim purchase I used a Mission Cyrus one for amplification, excellent phono stage but lousy for CD/digital playback. This is not my Cyrus One, but there is a beautiful early model on eBay. http://www.ebay.co.uk/itm/142128737573?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
The Cambridge Audio phono stage is ok, not as good as the Cyrus One, if you are near a Richer sounds branch you could always purchase one, try it, and take it back for a refund if you are not happy? I found the CA as good as the Rega Phono.http://www.richersounds.com/product/turntable-accessories/cambridge-audio/cp2/camb-cp2-blk
Don't forget you need a good quality phono lead to connect your NAD to the phono stage, also do not use the NAD phono input!! I would not recommend putting coins on your tonearm, you have to be careful placing centrally, also your arm need rebalancing and tracking weight adjusted or you will ruin your stylus.
If you are in the Midlands, then I would suggest booking an appointment with Cymbiosis to have your turntable checked/serviced. Peter has a reputation for servicing LP12's, however, his first turntable was a Pink Triangle, until he learn't to like the Linn sound https://www.cymbiosis.com/