Dealer has given me an Arcam A39 as a replacement. Has taken some running in but after a month nice sound but not quite as good as M6i (when it was working) although a better bass I think. It seems no fault was found with m6i but a part was replaced as a precaution(couldnt tell me which one) Arcam have told me to only connect a subwoofer via pre out as any other connection could damage the equipment, so it seems the problem all along may have been the subwoofer connections - even though I took pictures and sent them to dealer the first time it happened. I suppose the good news is I dont need the sub with the Arcam due to better bass. I still have a niggling feeling that the M6i was better sound though*help* Thanks for all your input to this post