I would say a dedicated phono stage is only a must if you establish a budget and listen to dedicated phono stages within that budget vs your existing internal phono stage and hear a noticeable difference.
Don't upgrade willy nilly.
Also, under no circumstances do you float the ground by using a cheater plug. That defeats a very important safety feature. Do not do this!!!!!
People that used cheater plugs typically had ground loops that they didn't want to fix by determining what exactly caused the ground loop and fixing (or replacing) it.
I noticed four things that helped substantially.
1). Power conditioner. All low level equipment (pre-amp, tuner (yes, I still have a tuner), CD Transport, DAC, Music Server, Phono Stage, Turntable, electronic Crossover) are plugged into the power conditioner and that in turn is plugged into its own dedicated line to the panel.
2). dedicated lines. I installed four. One for each amp and another for the power conditioner. My noise floor is zero now. Dead Quiet. Also, i have virtually eliminated any possible ground loops.
3). Bass traps in the corners behind the speakers really calmed the bass output. It really did. I've had people over where I played music without the traps and then with the traps and they all heard a marked improvement with the traps.
4). large rug on the floor in front of the speakers. This also mas a marked improvement that eliminated a reflection point.
If you have a raised foundation house, then adding the dedicated lines is really inexpensive. Even with a concrete floor (non raised foundation) it isn't that expensive. Relatively speaking.
enjoy
