Hello everybody My system consists of a pair of Elac B5.2 loudspeakers + a Fosi Audio T20 Bluetooth tube amplifier 2-channel class D mini power amplifier + a Jvc XL-Z132 CD player, Audiophonics U-Sabre Lte Dac I would like to change ` amplifier, what do you recommend, budget 400 euros, I also look used. Thank you for your kind advice, have a good day.