Those speakers need much better amplification than that. Stick to some good budget boxes like the Warfedale Diamond 9.1s (which work great with Teac kit) OR expand the budget and look to a minimum of Marantz 6002 series components or NAD C325BEE/C515BEE.
No it doesn't lack much in power and the TEAC Reference amps are excellent, but need to be partnered with cost equivalent speakers that will play to its strengths rather than highlight weaknesses.