Anybody had problems with Bel Canto Evo Gen 2i

I have a Bel Canto Evo Gen 2i which stops playing through my speakers,but still plays through my headphone amp via the tape out . The amp would sometimes come back on if swithched on and off a number of times, sometimes generating loud pops and bangs through the speakers. I have changed both amp boards via Bel Canto Design, but the problem is still the same. I live in the UK. Can anybody offer any advice please?