Accuphase E-470

Hi I am looking at a Accuphase e-470 for sale ,but it is a Japanese model so will need a transformer to power it to our AC, is there any problem with using a transformer.Any opinions on the amp would be helpful. I am using a Prima Luna Hp integrated amp with KT 150 tubes,& Focal 1028 BE speakers, I find that at lower volume it does not have much punch. I have to turn it up to sound good, I am thinking a good SS amp give me more at lower volume, Any other suggestions on integrated amps new or used under 5k ? Thanks Lloyd.