your speakers dip below 4 ohm and might be straining your amp at moderate volume levels- for example the impedance dips below 4 ohms in the bass frequencies between 100 to 200 Hz which means those frequencies take twice as much amplifier power to produce the same volume level.
With a 5K budget I would recommend a better, more robust amplifier as well as a better more dynamic phono preamp than the Mani which is an underwhelming sounding unit.
The Parasound Hint 6 is a very smooth, dynamic amplifier capable of very high sound quality and has enough grunt (240 watts at 4-ohms, your speaker's demanding frequencies).
For the phono preamp you usually get more up beat, dynamic sound when you have a more robust power supply. The Lehmann Audio Black Cube SEII is a very dynamic robust phono preamp that has a separate outboard linear power supply and is a giant killing value at it's price.
A new robust amp and new dynamic phono preamp will give you a huge upgrade and be suitable for your speakers which are more than capable with the right supporting system.