I have a pair of Wharfedale 435 stereo speakers- 8ohms, 100watts. I am seekign views on the ideal amplifier to match. I currently hae a Technics SA-GX170 amp, but this is clearly the wrong one becuse at high volumes the amp switches off with a message 'overload'. I understand I might need a more powerful amp to drive the Wharfedale speakers I have. Any views ?