Much will depend on the synergy of a replacement amplifier with your speakers, so whilst not making a recommendation, I can share the following experience:
I set up a small second system in our bedroom consisting of a second squeezebox touch, Bantam Gold and Rega RS1 speakers and lived with this system for a couple of years.
(I ran the amp from a linear PSU).
I saw a Quad 306 for sale on the forum and fancied trying it. (Being a power amp, I also got a Tisbury passive pre). The improvement in all areas of sound quality was amazing and the Bantam Gold went on ebay the next day!
Don't just limit your choice of amp to one from the same stable. See if you can loan a few for evaluation.
Sony PS-6750 Turntable, Sony CDP-X555ES CD Player, Sansui TU-717 Tuner, Vortexbox Music Server, Caiman SEG DAC with LDA Linear PSU, Squeezebox Touch with LDA Linear PSU, Accuphase E-302 Integrated Amplifier, PMC GB1i Speakers, MG G2000HD & G1500HD Interconnects, Van Damme 6mm Hi-Fi Speaker Cables.
Bedroom system: Squeezebox Touch with LDA Linear PSU, Quad FM4 Tuner, DCB-1 Turbo with Acoustic Dimensions switched attenuator, Quad 306 Amplifier, Rega RS1 Speakers. TV & DVD, Caiman MKII DAC with Baldwin Audio Linear PSU. MG G1500HD Interconnects, Fisual S-Flex 4mm Speaker Cables.
Back Bedroom Work Bench: Denon TU-260L Mk2 Tuner, Denon PMA-355UK Amplifier, Mission 780SE Speakers.