I have have tried more then 1 preamp but I am curious about sound through the 1280. The 1280 didn't resolve as well on most things vs the denon pre + any amp. Not that it was bad.
I'm in no hurry on the cart exchange/return, AT would certainly look at it. The main concern is where and when it's an issue, and for listening purposes, through speakers, it's not -usually.
When I tried some recording trials, the old AT70 had some hum, although lower. I think this is Likely due to being less sensitive. This is why I suspect the table/arm/wires. Frustrating as I want to get the tape going but I might end up doing mostly CD-> tape anyway...